Wednesday 2 August 2017

Monthly Summaries

I will now be posting a monthly summary at the end of every month on my record books website. The link is below:

http://privaterecords.weebly.com/monthly-summaries

Please feel free to leave comments and suggestions in the comments section here or in the record books website.

Enjoy!

206 comments:

  1. Thank you JJ. I like the new summary section. So how many July's in history were colder and warmer than this one?

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    1. The average mean temperature was at the 36th percentile, which means that 36% of the years were as cold or colder than this one... Which is about 53 years because there are 145 years in the dataset. So this July was the 53rd coldest. If this is confusing, I could always revert to just saying ''53nd coldest'' instead of percentiles. The percentiles are just really good at showing how extreme the value was in the dataset.

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    2. Hi JJ. Personally I would prefer saying " 53rd coldest " it's your choice obviously but I just find is easier to understand that way. For a while it was looking like it would end up in the top 30 coldest until the late month heat wave.

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    3. Ok I will either have both or that simpler version. Thanks for the input.

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  2. Also, what is the outlook for August? I've been hearing talk of generally below normal temperatures into mid month. Summer is running below average so far correct?

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    1. At a quick glance, it appears the first half of the month will be colder than normal. There are hints of warming up in the second half but I want to wait and see before coming to any conclusions.

      The summer is finishing near to slightly below normal so far. June-July averaged 17.9°C, while the normal is 18.3°C.

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    2. Yeah it looks like below normal for the first half. I wonder if we will see an extended heat wave again in the second half. Hard to believe Fall will be setting in in a month from now. The tree across the street is already starting to drop a few leaves.

      I am curious about this, why have septembers warmed so much? I see they used to average around 11.5C and now they average 13.5C. Especially in the last 25 years they've been incredibly warm. Is there a reason this is happening? Is September going to become a summer month soon? Yet we rarely ever get a nice warm May anymore, except for 2016 which was a warm one. Mays usually are near to below normal. Is there any reason for this? It's almost like summers are shifting later into the year.

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    3. I don't know why Septembers have been warming so much. It seems summers have been extending later into the year like you say. It appears to be a widespread change, not just localized here.

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    4. Yes I see what you mean. Do you also agree they seem to be starting later too? Because we never get hot May's anymore either. Except for 2016, the trend has been towards colder mays in the last 2 decades or so.

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  3. US CPC outlooks continue to call for a warm fall, what is your take on this?

    I think it would be highly unlikely to get a fall and winter like 2015-16 and 2016-17. Both falls and winters were extremely warm. Statistically this shouldn't repeat itself for a third year. I'm hoping for a colder fall and winter. It seems falls are trending warmer this decade.

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    1. Yeah you're right, it would be unlikely to get a very warm fall for the third year in a row statistically. We certainly are due for a cold September as well, but the trend of late has been for warm Septembers. I personally lean toward a colder fall simply based on these stats. Other than that, I can't say what fall will bring. Seasonal forecasts are difficult.

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    2. Yes I understand the difficulty with seasonal forecasts. The weather network said last winter was going to be very cold but instead it finished 14th warmest. The trend does seem to be towards warmer falls but I honestly can't see this upcoming fall being as warm as the last two. I would like to see a cold September too.

      This summer has been interesting so far. June started off with record heat which progressed to record cold ( low maximum record ) in the second half of the month. We've had some pretty chilly nights this summer too. Yesterday dipped to 6C. This morning to 8C.

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  4. The interesting thing is that the extreme September warming didn't really start until around 2000. As that's when the black line on your graph starts going up. So in 17 years they've warmed an entire degree. Interesting. They were on a slow cooling trend until then.

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  5. JJ. Do you think we have the potential to reach a top 30 coldest summer? It would have been very likely if we didn't have the late July heat wave that brought the mean up quite a bit. But depending on the rest of August could we be looking at a top 30 coldest? The nights have been quite chilly so far this summer with a definite lack of humidity.

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    1. Yeah, the nights this August especially have been very chilly compared to normal. Only 3 of 13 days have seen lows above 10C. In fact, lows so far have averaged 9.1C up to today which would be in the top 10 coldest for August. I'll have to check this week about comparing to other first halves of August, because climatologically we usually don't get chilly like this until the second half of the month. At least afternoons have been warmer and this is expressed by the fact that the average mean for August so far is about 17.1C or so, which wouldn't even be in the top 30 coldest Augusts. As you mention, humidity has been low.

      The summer so far has averaged about 17.6C using the August mean up to today. This would not make it to the top 30 coldest summers, but would be the coldest summer since 2009. We'll have to wait and see how the second half of August changes the means...

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    2. I do enjoy the chilly nights. It looks like some much warmer nights are on the way though. I would like to see the summer place in the top 30 coldest though. I am surprised how cold the nights have been even though the days have been warm. Highs of 28/29 degrees during the afternoon. It feels like a nice early preview of fall though.

      The highlight of this summer has been the chilly nights. Daytime highs have been pretty average except for a very chilly second half of June.

      If it wasn't for the warm first half of June we'd be talking about a top 30 coldest guaranteed.

      What is the average summer mean temperature for a normal summer? I do suspect this summer will finish below normal unless we get really hot for the second half of August.

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    3. 30-year normal is 18.4°C.

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    4. Thanks!
      Does it look like we will be heading into a warmer pattern? It looks like the days of single digit nights are over for a while now. Very warm lows in the forecast. In fact a high of 32C on Saturday with a low of 20C

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    5. I haven't seen anything too strong to believe that we're heading into an extended period of heat but it does look like a warmer second half than the first half overall. That 20C low seems too high under current guidance. I wouldn't expect warm nights like that unless we had some strong winds overnight or some higher dewpoints creeping north.

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    6. Is that why they get warm nights south of the border is because they get higher dewpoints?

      Although I don't think a high dew point is necessary for a warm night. On the night of July 11/12 1936, during Winnipeg's worst heat wave ever, the minimum was an unbelievable 28.3C with the temperature at or above 30C for most of the night. It has been said that it was very dry to allow temperatures to reach the 40s like they did. So how would a night stay that warm without high dewpoints?

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    7. Cloud cover and gusty winds at night can also keep temperatures warmer at the surface. A thorough explanation can be seen here if you want to know more https://courseware.e-education.psu.edu/courses/meteo101/Section4p05.html. Also, we don't have access to dewpoint observations from 1936 so we can't say for sure that it wasn't humid on some days. There was a 44 mm rainfall the day after that 28C low, which was likely thunderstorm-related, so there was definitely some humidity to play with. But in general, it was probably a very dry month, because it is extremely difficult to get to 37-42C with high humidity.

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    8. Thanks!

      Why did they not start taking dewpoint, hourly temp observations, humidex and windchill values, or thunderstorm data until the 1950's? Is there a specific reason they didn't take this starting in 1872?

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    9. Some measurements, like wind (and therefore humidex and wind chill) (I'm not sure about others like dewpoint etc.), were taken as early as the 1920s. However, they have not been digitized (only available in hard-copy format) and are sitting somewhere (might be Western University in Ontario or somewhere else, I'm not entirely sure).

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    10. (and therefore humidex and wind chill)... shouldn't have included humidex there because it requires dewpoint.

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    11. I'm surprised they haven't put the measurements in the online databases then. It would be interesting to see those wind chills.

      Did they not have the technology to measure dewpoint back then?

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  6. JJ how is our outlook into early September looking?

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    1. Looks like a near normal to warmer than normal end to August then likely increasingly variable in September as is typical with fall. If August finishes below normal, it will be the 4th consecutive below normal month. Appears we have entered into a drier and cooler weather pattern and at this point it doesn't appear it should change much in the near future. However, we haven't had a truly colder than normal September since the 1990s, so I hope this trend continues into this year.

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    2. Thank you. I am hoping for a cool September. Septembers have warmed significantly as we were discussing previously but I wonder if this is going to change this year. It looks like after September 5th or so highs will be descending below the 20C mark. What's are your hopes for September?

      May June and July have been slightly below normal and I hope August continues this trend.

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    3. It is too early to say what September will bring. I am leaning towards near or below normal simply based on the trend of the last 4 months and the fact we are due for a below normal September.

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    4. Thank you JJ. I've been hearing talk of frost risk tonight. Winnipeg is down to 9C as of 11PM but I think they will get colder than that forecasted low of 6C. It really is amazing how cold the nights have been. I'm on vacation north of the pas and it's way warmer here at night than it is in Winnipeg! How cold could winnipeg get tonight? Record will be hard to reach, -0.6C in 1885. How did they get a frost so early in the season back then?

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    5. Got down to 2.1°C which is the coldest low since 2004... Yet another sign that this is a cold summer similar to 2004 and 2009 and somewhat 2013 (which warmed up in late August however). Certainly feels like fall has arrived prematurely this year.

      Records in late August are hard to reach nowadays because we haven't had frost in August in 117 years. We were simply in a much colder climate back then with summers ending earlier than they do today.

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    6. Yet this summer won't even place in the top 30 coldest probably. So it hasn't been that cold. The days have been nice, it's just that the nights have been cold.

      I am hoping for a cold September. But you are right back in the late 1800s we were in a colder climate. I really do wonder if it's human caused climate change that has warmed us up or if it's just natural variability. And I wonder what the climate was like before 1872. They say there was a period hundreds of years back called the " medieval warm period " where climate was warmer than it is now.

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    7. Yeah, if it wasn't for the dry conditions and low humidity, I'm sure the days would have been cooler. It felt like a warmer summer than it really was thanks to lots of sun and lack of rain.

      I'm personally hoping for a warm September to make up for a cooler summer.

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    8. I'm actually hoping to break the trend of warm septembers and get a colder one!
      Summer wasn't that far below average. It's only running about 0.7C below average so far and it won't place in the top 30 coldest. However, an I correct in saying that it will be the first below normal season since spring 2014?

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    9. This summer will actually be the first colder than normal season since fall 2014. Last summer (2016) was close, finishing bang on normal.

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  7. It looks like sprague dropped to 0.4C according to the hourly readings. Did anywhere in Manitoba get below freezing?

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    1. In northern Manitoba, Thompson and Kelsey Dam dipped below -1°C and Long Point dipped slightly below 0. August frosts aren't terribly uncommon in the Thompson area. In fact, Thompson dipped to -2.5°C on Tuesday.

      Sprague actually had a low of 0.2°C this morning. The only freeze I could find in southern Manitoba was Hadashville at -0.1°C.

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    2. Thanks JJ! Winnipeg came close to a freeze but unfortunately it didn't happen. I would have liked to see an August frost! It looks like lows will be back up in to the mid teens tonight with a heat wave to start next week. Looks like a warm start to September cooling to average values by the second week of the month. August will likely finish below average.

      Are there any indications for the upcoming winter ( DJF period ) last year they were calling for a cold one but it ended up very warm again. Are there any signals that are pointing one way or another?

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    3. A frost this early in the season would be devastating to agriculture, especially since it hasn't been a warm summer so some crops that require longer growing seasons are possibly a little delayed.

      I haven't looked that far out and seasonal forecasts aren't my expertise (I tend to focus more on the statistics side, like for example, we are due to a cold winter after having 3 consecutive warm winters so I'd say there's a higher chance of a colder winter than in the past few winters).

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  8. Thanks JJ. The winter of 2013/14 was our last brutal winter. It was the coldest December to March period in 115 years and 11th coldest winter overall. The winter of 2014/15 was 33rd warmest overall, 2015/16 was 9th warmest and 2016/17 was 14th warmest. So yeah I agree we are due for a cold winter. I am personally hoping for a cold winter because I love cold weather!

    That said, are we looking at either an El Niño or a La Niña this year? Or are conditions neutral?

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    1. We are currently in neutral-ENSO conditions and the forecast is for this to continue through the winter. http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

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  9. Hi JJ! Although August is not in the top 30 coldest for mean temperature, am I correct in saying it will likely place in the top 30 coldest for daily minimum temperatures?

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    1. Hi Matt,
      Lows have averaged 9.9C so far this month which would tie for 16th coldest in August.

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    2. Thanks JJ! So it will likely place in the 30 coldest for lows by the end of the month?
      It's looking like it will also be a top 30 driest August.

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    3. Yes to both. Watch for the final stats on my record books website on Friday.

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    4. Thanks JJ I appreciate you taking the time to reply to my questions. Are you still a part of a weather moment? I miss the regular updates on your blog here.

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    5. I am still apart yes. I mostly do the top 10 weather events summary at the end of the year now. I haven't updated the blogs much lately because life became busy. I try to respond to all your comments, I apologize if I miss any! It's refreshing seeing someone with so much interest in climate stats!

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    6. Thanks JJ. Yes weather is one of my interests/passions
      I love all the statistics and I thank you for putting together the records website as it's so easy to use and it has so much data in it. It's really interesting to see the trends in our climate. For example, although the winters are getting warmer snowfall has generally remained the same ( and 3 of the last 4 winters have been extremely snowy ). In fact last winter turned out to be 8th snowiest despite being 14th warmest, mainly because of the 2 big December blizzards we had.

      I am looking forward to fall. It looks like the first half of September is going to be above normal, which is not a surprise considering how septembers have been trending. However I am hoping we will see our first shot of fall weather soon to get the colours on the trees changing!

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    7. The increasing snowfall in the last 15 years is at least partly an artifact of station changes. I switched over to Charleswood (measurements taken by an EC meteorologist) in 2002. Being in a residential neighbourhood, snowfall amounts tend to appear higher than over the Airport's fields. Nonetheless, the past decade appears to have been more snowy than the 1970's and 1980's at minimum which were quite dry with respect to snow.

      I'm hoping we stay away from big cool downs for a few more weeks to allow crops that require longer growing seasons to reach they peak and be harvested. An early frost can be devastating. A large part of southwestern Manitoba normally gets its first frost in early September, particular north of Brandon. The Red River Valley normally doesn't have frost until mid September and in some locations not until late September.

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    8. Hi JJ. Yes we do seem to be having snowier winters again. The 1970s and 80s were a very dry decade in terms of snowfall. Winters 13/14 15/16 and 16/17 were all extremely snowy winters. 13/14 was the only winter of the three that was cold, the other two were very warm.

      Last year we didn't get our first frost until october 8th, but I am guessing that is more of an anomaly instead of a trend right? Probably a product of the extremely warm fall last year.

      Why do they get their first frost in the southwest earlier? Winnipeg airport usually gets its first frost in late September and the forks not until October.

      I am going to predict September will be above normal and break the string of colder than normal months, which is not a surprise given the trend of septembers. I am ready for fall weather to arrive, but it makes sense that some farmers need a longer growing season.

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    9. Yeah, the date of first frost hasn't been changing much in recent decades.

      The Forks has the benefit of the urban heat island and so can have their first frost as much as 1 month later in some years. The Red River Valley has the benefits of lower elevation, local warming from the still-warm lakes and a slightly more humid climate.

      Yeah, September forecast has trended a little warmer lately overall. Unfortunately, the next couple weeks at minimum look quite dry. This is probably actually good news for farmers though who need dry conditions to harvest. Although I am hoping for a good rain soon.

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    10. I would like some rain too. The forecast is actually very warm for the next 2 weeks and that means it will probably finish above normal. I wouldn't be surprised if we get a top 30 warmest September as well.

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    11. What do you think of those AccuWeather long range forecasts? They have data for the weather every day into mid November. Is there any accuracy to this or is it all guesswork?

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    12. I would not trust daily forecasts like that beyond 14 days in my opinion. They are forced more by climatology because it's just too far out for models to resolve that accurately. That far out, you're better off looking at seasonal forecasts to get a better idea of what the general weather will be like because that far out, we aren't yet capable of accurately forecasting weather for individual days (i.e. which specific days will be warm and which specific days will be cool).

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  10. Also, summer will finish below normal. When is the last time we had a below normal season?

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    1. Fall 2014 was the last below normal season

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    2. Wow so it has been almost three years. Yes we certainly were due for a colder than normal season and here we have it. Summer 2017 will finish below normal. Will the summer stats be on your record books this weekend too?

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    3. That's just because of the cold nights because the days have been warmer than the last 3 summers.

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    4. Highs this summer (Jun to Aug) averaged 24.8°C. In the past three years, highs averaged:

      2014: 24.3°C
      2015: 25.2°C
      2016: 24.6°C

      So highs were't warmer than in 2015. Lows averaged 10.9°C which was the coldest since 2009 and were what caused this summer to be the coldest summer since 2009.

      Yes Matt, I'll find some room for the summer summary as well.

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    5. Thanks JJ! What is the average summer maximum temperature? Was this year above or below for the average high?

      Yes the nights were quite chilly this summer, with August lows placing in the top 30 coldest as well. Summer lows just missed being in the top 30 coldest though.

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    6. 1981-2010 normal is 24.7°C.

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    7. Thanks! So that is interesting, highs have actually been above normal but lows were much colder than normal. I am guessing this is due to the lack of humidity this summer!

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  11. JJ. Environment Canada is insisting on a warm fall and yet another mild winter, at least according to David Phillips. What are your thoughts? It does look like September will be warmer than normal and the CPC outlooks call for a warm fall, but I highly doubt it will be as warm as the last 2 falls have been. How can they predict that far ahead as well when there are ENSO neutral conditions? I don't see how they can make any calls on winter at this point either since it is just the first day of meteorological Fall today. With ENSO neutral conditions expected to remain through the winter, And the fact that we've had three consecutive warm winters, with two of them being very warm, I would imagine we are in for something colder this year.

    My best guesses are we could see a medium winter such as the winter of 2012/13 or possible a colder and more variable solution such as the winter of 2008/09. what are your thoughts?

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    1. Skill with those seasonal forecasts is quite low. People who have to do seasonal forecasts will look at such things like sea surface temperatures, what the overall weather pattern is expected to be, ENSO... etc. Sometimes the signals are not particularly strong and so these forecasts must be taken with a grain of salt. For example, a strong El Nino will more often than not indicate a warm winter here (but sometimes other signals will overpower other signals and result in the opposite).

      I certainly can't say that I'm an expert at seasonal forecasting. All I can say is, like what you said, we've had 2 very warm falls and 3 warm winters in a row, so the chance of another warm fall and winter would appear to be lower than usual to me. However, there is an incredible amount of warmth still in place over western North America, and if this pattern were ever to shift a little to the east, it wouldn't have to shift very far east for us to get into a warm pattern.

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    2. Thank you for the complete explanation JJ. What is going on in the west? I heard Calgary recorded their hottest summer EVER this year? That's pretty impressive especially considering we just had our coldest summer in 8 years. Is there a reason the west has been so hot all summer? As the days are shortening I would imagine that pattern is going to burn out sooner or later. I think with the upcoming forecast it's safe to say September will be warmer than normal though.

      I hope we don't get a repeat of last years november. 20C in Nov is not normal! I would love to get an earlier winter this year.

      Regarding the 1981-2010 normals, is it likely our next set of normals is going to be even warmer despite the current ones being the warmest ones on record so far? Are there any months that are likely to cool in the next set of normals?

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    3. Calgary actually had its second hottest summer on record. There was a lot of missing and ''estimated'' data during the summer which just happened to mainly occur on the cooler days. Those who say it was the hottest summer likely did not fill in the missing data, resulting in a false record.

      General pattern over the summer has been massive ridge over the west and trough over the east, with Manitoba in between.

      Currently the 30-year yearly average temperature is 0.1°C warmer than the 1981-2010 normal. The 2010's actually haven't experienced much warming overall, contrary to the general feeling. February, March, April, May and July have all seen a cool down this decade with February and April cooling the most. September has warmed the most, followed by November and December.

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    4. Thanks you for the info JJ! I am surprised February has cooled down because the last 2 Februaries have been in the 30 warmest. It is not a surprise that September has warmed the most. How has March warmed when we had our warmest march in 2012 and marches 2015 and 2016 were quite warm.

      But most of the cool downs have been quite small I would assume. Mays really are getting colder though. May 2016 was the first real warm may in 20 years.

      So it seems the rate of warming is slowing? And what happens in the next set of normals will depend on the next few years.

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    5. Yeah it is strange how March has cooled even with the warmest March on record in 2012. It is likely influenced by the two very cold March's of 2013 and 2014. We didn't have a March anywhere near as cold in the 1980's which had warm March's overall. So essentially we lost some warm March's in the 1980's and gained two very cold March's.

      As for February, we had a lot warm ones in the 1980's, which we are losing. 2014 and 2015 also had very cold Februarys. This explains the big cool down this decade in the 30-year average for February.

      The 30-year average for May has slowed down the cooling with only 0.1°C of cooling since the 1981-2010 normals. Most of the cooling occurred in the 2000's.

      Yes, the next few years could change the trends a bit for the 1991-2020 normals. The warming has slowed a bit this decade here but this certainly isn't the case in other parts of Canada and the world. Also have to wait and see how the next couple years impact the 2010's trend. The yearly average rose 0.3°C from the 1971-2000 to 1981-2010 normals, explaining what I meant by a small slow down in warming this decade so far.

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    6. Thanks for the info JJ!

      March has warmed about 6 degrees since the 1800's. I find that very interesting and it's probably a sign that's spring's are coming earlier now. We've had a couple of very early springs this decade. And yes although the warning is slowing here that is not the trend for most of the planet, with the last few years being the hottest ever. I would suspect that may will warm in the future once we lose the cold mays of the 2000s.

      What has been going on with April though? April's appear to have cooled a full half degree since 2010. Is that because of the cold aprils of 2013/2014?

      November is no surprise. With several warm novemvers this decade and last years freakishly warmest November on record, the November average is sitting around -4C now. Which is ties for the warmest it's ever been. I'm pretty sure they were as warm in the 1940s or so.

      The 1940s were a warm decade weren't they? They had multiple warm winters during that time and falls and novembers were quite warm then too. The trend I find interesting is how quickly temperatures rose at the end of the 1800s, seemed to peak in the 1940s and then cooled down through the 70s again, and have been warming ever since. I am interested to see how this trend will go in the future.

      Do you suspect winters will be warmer in the next set of normals? Could any seasons potentially see an overall cooldown?

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    7. Currently, falls are warming, summers are warming very slightly, springs are cooling and winters are in a neutral pattern. The warming of winters has slowed down thanks to cooling Februarys essentially cancelling out the warming Decembers.

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    8. Thanks for the information JJ! It is interesting that springs are cooling especially since we've had a couple of very early springs this decade.

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  12. I just took a look at the graphs for April and it seems that aprils have cooled by half a degree since 2010. That is quite significant and likely a result of the cold aprils of 2013, 2014, and 2016. Three of the last five aprils have been colder than normal with 2 of them being well below normal. April 2013 was actually on track to be our coldest April on record until a warm up in the last few days of the month knocked it down to last place. The 2 aprils in the last five years that have been warmer than normal have only been slightly so and not significantly above normal.

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  13. Hi JJ! I saw you updated your record books with the summer summaries, very good explanation of our weather this summer! I think you may have forgotten to update the summer 30C day graphs though!

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    1. Thanks. They should be updated because I updated them this morning. We only had 6 30C days this summer.

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    2. Thanks! Yes 6 30C days is only half the normal, a hallmark of a cooler summer.

      As for September it is looking very warm now and I think we may have to wait until late month for the first frost of the season. Highs rising back close to 30C next week again. I hope we will see a turn around to some cooler weather by October.

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  14. As for rain and snow, how are we doing this decade? Taking a look at December it seems they are averaging the snowiest they ever have, while februaries are the driest they ever have?

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    1. Of all the months that receive snow, only September and October are in a decreasing pattern. Other months are increasing with December and January seeing the largest increases. This is partly the result of switching over from the Airport to Charleswood, but I do believe snowfall has been increasing at least slightly in the winter. September is now the 4th month to not average any snowfall.

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    2. As for rain, rain is decreasing in most months. Only January, March, April and May have seen increasing rainfall this decade, with May seeing the most significant increase. June, July and August have seen the largest decrease. The increase in January is only 0.1 mm, but we don't normally receive much in January anyway.

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    3. Thanks JJ! I am curious, why do we never get snow in September anymore? Looking at the records the snowiest September on record had over 18cm all the way back in 1872! We haven't had any September snowfall since the 1980's now. What has changed?

      We haven't had any snow for the last 3 octobers I'm pretty sure. I miss the days of October snow, probably a result of the last few falls being extremely warm. I hope we'll see snow this October. And yes I would agree that snowfall is increasing in the winter.

      January's rain increase was likely due to that rainy night we had this past January, march and April as a result of earlier springs, and who knows about may.

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    4. We don't get September snowfalls anymore probably because they have warmed so much that they are now at a point where it is difficult for snow to occur (climate ''too warm''). This certainly doesn't mean it can't snow in September because it has many times in the distant past.

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    5. Thanks JJ. That definitely makes sense. Who knows what the future will bring though!

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  15. JJ. Are we looking at the potential for frost on Wednesday morning? I've heard talk of the possibility that YWG could tank towards 0C

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    1. Within city limits and downwind of the lakes it will likely remain above freezing. Elsewhere, there is the potential for some isolated locations to fall below freezing unfortunately. Can't rule out the Airport falling below freezing, given its notoriously cold temperatures in northwest flow under clear skies. It would be the earliest date to do so since 1946 if it were to happen.

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    2. Thanks JJ! The predicted low last night was 9C and instead the airport got to 3.4C in the hourly readings!! So considering EC is predicting a low of 3C tonight I have a feeling it's going to get lower. Interesting how we are talking frost potential right now and by the weekend lows will be in the mid teens again.

      Is there any sign of any more cool weather in the future? I know we are getting a summer like warm up late this week but what about after that? I suspect September will finish above normal.

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    3. I suspect a more variable September than anticipated, which makes more sense. Warm then cool then warm then cool.

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    4. Yes the makes sense. Overall do you think it will finish above normal?

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  16. JJ how is the forecast looking now? Is it looking more and more likely that Winnipeg will see frost tonight?

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  17. Down to 6C at 10PM. Tonight is definitely looking like a record breaker unless that cloud moves in.

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  18. Low of 2.9C at the airport, no record. Now we turn our attention to mid summer like heat returning this weekend

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    1. Low was 1.7°C at the Airport. Somewhat widespread freeze east of the city with temperatures falling below freezing in Sprague, Steinbach, Beausejour, Zhoda, Vivian, Woodridge, Hadashville and also north of Winnipeg in Narcisse.

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    2. I was hoping for a freeze in Winnipeg! Oh well. That's already hadashville's second freeze of the season as well ( they had one in August )

      I don't see us having another frost potential for a couple of weeks now, what do you think?

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    3. Yeah looks like we should get lucky and escape an abnormally early frost.

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    4. It was looking like an early frost was going to happen but probably not now. What is your prediction for the next few weeks and potentially into early October? We have this heat wave coming up this week but what do you see after that?

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  19. JJ. After this upcoming heat wave do you see any return to fall like conditions after?

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  20. JJ we broke the record high today!! 34.8C is incredible for this time of year! Is the record books going to be updated with it?

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    Replies
    1. I'll update it now.

      By the way, if you have Twitter, you can follow me (@jjcwpg). I regularly post weather statistics whenever there is extreme weather around here. I wish I had more time to update the blog too but I find Twitter more convenient and I can reach more people. Feel free to keep commenting on here though because I'm glad to answer any of your questions.

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    2. Thanks JJ! I have a twitter account but don't use it often, I'll search your blog up on there though.

      So about the upcoming pattern change, how is this gonna play out? I hear that highs will be struggling in the low to mid teens this weekend and that highs will remain in the teens through the end of the month. What are your thoughts on this? Is summer pretty much over now and what about frost potential?

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    3. Looks like a cold and rainy day Friday with highs struggling in the low teens. There is very good consensus among models that 15-30 mm of rain could fall.

      In general, we are entering into an unsettled pattern with troughing to our west, allowing for the possibly of a series of systems riding up from the states in the next 10 days. This could bring some much needed moisture. I don't believe we are done with warmth yet because some of these systems could bring some brief warm air ahead of them. We can also still get 20°C weather in October. I don't see any major chances for frost yet, but this depends on clearing overnight under colder air masses behind these systems. Also, with the more unsettled pattern, moisture and humidity will be higher which may help to reduce frost risk. Too early to say when our first frost will be.

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    4. Hi JJ. I'm pretty sure we are done with summer like heat though. Yeah we could see 20C in October but I think it's not likely we'll see any 25C+ weather any more.

      How long does this below normal pattern look to persist for? Could we be trending colder from now on?

      Regarding this September, it's currently in place for 2nd warmest ever!! That will drop with the cold spell, but do you suspect September is going to finish in the top 30 warmest?

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    5. Matt,
      If every day in the remainder of the month average at normal, this September would just miss the top 30 warmest. The second half of the month would have to average above normal to be in the top 30 warmest as a result. Tough to say what will be the case because the second half looks quite variable and unsettled at this point.

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    6. Thanks for the info!

      Just how warm has the first half been compared to other first halfs of September? The second half looks like it should generally average out near normal. It'll be quite interesting to see what happens. Is it pretty much certain that this month is going to finish above normal though?

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    7. The first half of September will have been somewhere around 19th to 25th warmest depending on today's high and low. There's a good chance the month will finish above normal yes... Unless the second half finishes way below normal.

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    8. Thank you JJ. I thought it was actually much warmer considering we had that heat wave but I guess not. Do you happen to know what the warmest and coldest first halfs of September were?

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    9. Warmest - 1927 (20.5°C), Coldest - 1890 (9.0°C).

      Similar to the summer, cooler lows continued to bring down the average this year.

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    10. Thanks JJ! Septembers lows have not been cold though, they've actually been quite a bit above average. Remember how warm the September of 2009 was? And that was after a very cold summer. If this September does make the top 30 warmest it likely won't be anything close to septembers of 2009 or 2015.

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    11. You're right lows have been warmer than normal. What I meant by that is lows have not been as much above normal as the highs have been. As a result, the lows have brought down the mean compared to what it could have been if lows were just as much above normal as the highs.

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    12. that makes sense thank you JJ. What I find interesting about the upcoming cool spell is that the highs will be cooler than normal but the lows may be warmer than normal. Normal lows are now 6C.

      So is it true we could be returning to summer like temperatures in the mid 20s this upcoming week, before another fall like cooldown for next weekend?

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    13. Could see 20°C weather Monday and Tuesday, then cooling with rain mid week.

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  21. JJ just how cold is this weekend going to be? I've heard that temps will be struggling in the 10-12C range?

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    Replies
    1. Highs will depend largely on how much cloud and rain there is. Highs should be in the teens from Friday to Monday, then warming up some on Tuesday ahead of another system (possibly in the 20's if we can get enough sunshine).

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    2. Saturday is looking very cold with highs struggling at 10C. Is it true that we will see another shot of cold air after the brief warm spell we get mid next week?

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  22. JJ. I've been hearing talk of a La Niña developing for this upcoming winter. Does this mean we could be in for a cold one? La Niña years typically seen to correlate with frigid winters and cool springs. Although last year was a La Niña and we ended up having a warm winter.

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    Replies
    1. This only increases my thinking that this could be a colder winter coming our way (La Nina + fact we've already 3 consecutive warm winters). However, we have certainly had warm winters in La Nina conditions in the past. Other signals can overpower ENSO (such as AO, NAO etc.) but these other signals we can't really predict months in advance.

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    2. I agree with you on this. However wasn't last year a La Niña and we still ended up getting a very warm winter? And yes the last 3 have been warm but 2014/15 wasn't even in the 30 warmest. It was 33rd warmest. But with 2015/16 as the 9th warmest and 2016/17 as the 14th warmest I agree we are due for a record breaker of a ( cold ) winter.

      Interesting that there has only been one top 30 coldest winter since 1978/79. And that was 2013/14.

      With a La Niña could that potentially mean our winter could be as brutal as the 2013/14 winter? That was truly the harshest winter I'd seen in my life. Are there similarities in the pattern this year?

      Apparently La Niña also leads to colder springs, which we are due for after 3 consecutive warm springs as well.

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    3. I'm not saying it will be record cold, but I personally lean toward colder than the last 3 simply based on the statistics I've presented (I haven't done any other kind of research). The only similarity to 2013/14 was the ridging over the west and troughing over the east, but this pattern is changing for this second half of September. I don't anticipate we will see a winter that cold again for many decades because it was truly an exceptionally cold winter.

      I haven't done as much research as others might have done with respect to forecasting this upcoming winter, so I definitely recommend checking some other sources as well.

      Keep in mind that the 2013/14 winter was actually in neutral ENSO conditions and last winter was only a weak La Nina which was transitioning into ENSO-neutral conditions in the second half.

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    4. Thanks JJ. Most people would hate me for saying this lol but I actually enjoyed the winter of 2013/14. It was kind of cool to experience what people lived with almost every single year in the 1800's during the cold period in our records. Now to think they used to have winters that cold ( and colder ) almost every single year is truly mind boggling. The late 1800's were just so incredibly cold. People complain about the cold now but imagine living here back then! How did they cope with it I wonder? I love the cold though so I don't think I'd mind lol.

      I suppose nobody really knows, but it continues to fascinate me how our climate has evolved over time and it always amazes me how constantly cold the 1800s were.

      One period that truly amazes me is the winter of 1877/78. I wonder why that winter was so warm even when it was right smack in the middle of the brutal cold era. I suppose nobody really knows because there aren't any ENSO records for that far back is there?

      In that case, are you aware of what made 2013/14 so cold despite there not being a La Niña or any other climatic condition? It was like we were back in the cold period for the entire years of 2013 and 2014. And then such a drastic change to extreme warmth in 2015 and 2016.

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    5. The idea that was floating around at the time of 2013/14 was the very warm waters of the northeastern Pacific, continually reinforcing ridging over western North America and subsequent troughing to the east (meandering of jet stream). Then we had one of the strongest El Ninos on record 2015-2016 which really helped bring us back to a warmer winter pattern.

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    6. Thanks JJ. The 2015-16 winter was an extremely warm one, although 2016-17 was almost as warm. La Niña typically correlates with a colder winter, so I am curious as to what happened with last years La Niña?

      I am curious about your opinion on the trend of springs this decade. Are springs arriving earlier than they used to? As we can see 2010,2012,2015,2016 all had record early march melts. Given that I am still surprised that's all three spring months are cooling. Yet 2013 and 2014 had near record late springs.

      I wonder just how late springs arrived in the 1800's. it really sucks that we don't have snowdepth records from back then as that would be cool to see.

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    7. I'm wanting to do some correlation tests between Enso and anverage winter temperature here at some point. When I do, I'll try to remember to share it to you.

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    8. Thanks, I would actually be quite interested to see the data on that!

      AccuWeather seems to think we'll have warm weather up until the 4th week of October when things will drastically change and get cold and snowy. According to them we could use winter snow before Halloween!! I sure hope so!

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  23. JJ. Do you know how much rain winnipeg airport recorded?

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    Replies
    1. 7.9 mm at the Airport and 9.2 mm at The Forks. Appears the highest amounts were in south St Vital with 12.7 mm at my place. Overall, much of southern Manitoba received much less rain than anticipated. Models significantly overforecast rainfall amounts (even the ensemble models). The highest amounts were in the extreme southeast corner with 30 to 50 mm in the Sprague to Vita area.

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    2. Thanks JJ. Yeah that rain event really was a rip off. We needed more than that. Rob didn't get much more at his station either. We needed rain for sure.

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  24. Hi JJ. I'm curious about this, the record high for February 17th is 5.4C in 1986 according to your record books, but I recall that day reached 5.6C this year and even environment Canada issued a statement saying we broke the record high at the time. The climate logs for the current active station also show a high of 5.6C. I am curious, is there a reason it isn't counted in your records?

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    Replies
    1. Environment Canada accidentally used that 5.6°C value from the CYWG station in their record summary when they shouldn't have because it isn't the official station (its daily data is unavailable to the public and can only be accessed internally). The CXWG ('A CS') station is currently the official Airport station for daily data and it reached 5.3°C that day, just shy of the record of 5.4°C in 1981.

      By the way, I'm not sure what you mean by the climate logs? Could you specify?

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    2. Thanks JJ. I looked again and you are right. When I said climate logs I meant the environment Canada historical climate data website.

      When did they switch over to using the A CS station? It must have been after 2002 as Octobers 2002's mean is -0.9C on the A CS station but only -0.5C in the record books. I know they used the other station for a while before.

      Also, do you happen to know how much extra rain fell today and what the maximum temperature was?

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    3. The CYWG station is the official station for as long as possible because it was a manned station. CXWG is purely automated and is used as minimally as possible for official records as a result. CYWG is still used for hourly data only. CXWG became the official for daily data as of October 3, 2013 when CYWG stopped producing daily reports.

      The Airport got an extra 1.2 mm today and the high was 9.1°C.

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    4. That's confusing how there's so many different stations. It's probably created some inconsistencies in the record databases over time. I'm surprised that we only got 1.2mm especially since it's been raining fairly steadily all day including right now.

      Would you be able to point me to the page where you can see all this airport data?

      Is there a reason that environment Canada is not manually observing anymore? I feel like it's important we have human weather observations still. Now we get these inconsistencies in the data collection and all these missing data days every month.

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    5. If you go under 'The Data' tab and then to 'Data Sources' on my record books website you will find the list of stations or sources used. Note that I am in the middle of doing another complete quality check of precipitation data from 2003 to 2017 which might or might not change the stations used for winter precip.

      The main downfalls with automation was the eliminatin of snow and rain measurements, unrepresentative snow depth observations, the elimination of manned quality checking and inconsistencies with precipitation measuring (The Forks seems to overestimate precip while the Airport seems to underestimate, especially in the winter). As far as I know, Environment Canada has had reduced funding for many years from the government and so it's had to work with less money and fewer resources.

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    6. Thanks JJ. I really do wish that our government would fund environment Canada better. Especially in the era of climate change it is more important than ever that our federal weather service is keeping track of our climate with accurate data, but that doesn't seem to be happening. The fact that snowfall measurements are no longer taken is absurd considering we have snow from November--March and often outside these months.

      Regarding the forks station, is there a reason it's so warm compared to the airport all the time? What is really the true temperature in most of the city? Say I'm standing on my city street in St James, what's more accurate, the airport or the forks? I'm not too far from the airport actually.

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    7. The difference between the Airport and The Forks is mostly apparent at night and in the winter. It simply has to do with all the concrete and buildings releasing heat at night and the lower albedo of the city (less reflection of sunlight in the winter). The temperature in the suburbs seems to be somewhat in between the two. In the warmer months without snow on the ground, the difference during the day is not as apparent.

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    8. Thanks JJ. I agree it is a good thing the airport is used for official readings because it is not artificially inflated like the forks is. It's important to have consistency in the data.

      What are your thoughts on tonight's rain/storm event? Could we actually get a good soaking this time?

      As for the weekend, it looks like we are cooling to seasonal values, then just slowly dropping from there. Do you think we could be cooling down for good now?

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    9. We cool down starting tomorrow for about a week. There could be a little warming up right at the end of the month but it's far to confirm. Overall, pattern continues to look variable to me.

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    10. Thanks JJ. It does look like this month is pretty much guaranteed to be in the top 30 warmest. CPC outlooks are calling more a warm first half of October, what are your thoughts on this?

      It also looks like we will be waiting until October for our first frost.

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    11. We may come close to a frost late next week. Otherwise, yes we will have to wait until October. Good news because it sounds like corn crops still aren't ready everywhere, or haven't been harvested yet. These types of crops require warmer longer growing seasons so our chilly summer has delayed them a bit.

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    12. It's probably going to be a top 30 latest first frost this year. How did the chilly summer delay crops?

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    13. Crops need warmth and moisture to grow to maturity (among other things). The cooler nights this summer diminished the mean temperature, resulting in less heat and slower growth as a result. Moisure wasn't as much of a limiting factor despite the lack of rainfall, thanks to a lot of soil moisture rom last year and of course, irrigation. I can't confirm if the crops really were later than usual this year, I was basing simply on what I've heard on social media.

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  25. Another miss for Winnipeg sadly. I received 5.8 mm at my place and just 3.0 mm at the Airport. The Airport has only had 16.7 mm so far this month which is way below the monthly normal of 47 mm. We still have a long ways to go to reach even near normal rainfall amounts. It will be tough to reach normal now because we have missed out on what will likely have been the 2 main rain events of the month.

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    Replies
    1. Yeah it really sucks that we missed the storms yet again. When was the last above normal precipitation month? It honestly seems like it's forgotten how to rain here. I hope this won't continue into winter as I don't want bare ground in December.

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    2. April was the last wetter than normal month (but not by much).

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    3. Thanks JJ. Yeah this year is gonna be a very dry one for sure. It'll be interesting to see if it ends up in the top 10 driest

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  26. This year has been so dry in Winnipeg that even normal precipitation through the remainder of this year wouldn't be enough to escape a dubious top 5 driest year on record since 1873. Only about 250 mm of precip at the Airport (approx due to use of Charleswood at times for winter precip) so far this year, which means we need at least another 70 mm through the remainder of the year for this to not be the driest year on record. Normal through the remainder of the year would be close to 100 mm which would only be enough to bring us to 3rd driest year on record. Wait and see what rest of year brings...

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    Replies
    1. Yeah it certainly isn't very good that's for sure. When's the last time we had a good rain storm? It's pretty much a guarantee this year will be in the top 30 driest, and maybe much higher on the list. Unless of course we get a couple major systems. How much precipitation would we need to bring this year back to normal?

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    2. JJ. What's the long term outlook for temperatures into October at this point? I see we cool down this weekend, but are we going to stay cool? What is it looking like for the next little while?

      Interestingly the farmers almanac is predicting a warm winter which contradicts La Niña, I don't know how they do their predictions though.

      Where is this year standing temperature wise so far? Are we in the top 30 warmest?

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    3. Close to impossible to get a normal yearly precip this year as it would require us to more than double the precipitation we've already had this year.

      I would take that seasonal forecast with a grain of salt.

      Up to August we averaged 5.2°C, normal is about 4.4°C.

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    4. Thanks!

      Would the warmth this year be enough to place it in the top 30 warmest so far?

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    5. Really depends what the rest of the year brings. We still have a quarter of the year left to go through so it would be a little premature to announce it will be a top 30 warmest year right now. What I can say is that if the rest of the year is either near normal or above normal in temperature, the year will finish in the top 30 warmest. If we start to fall well below normal later in the year we may not make it.

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    6. According to global news and the weather network late November through to New Years could be a cold period

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  27. Now that was some storm we had tonight! JJ how much rain fell?

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    Replies
    1. It was anything but wicked in the south end with only a little over 1 mm at my place in South St Vital. Thunder was unimpressive as well, mostly distant. Much more impressive in western and northern parts of the city with 12.5 mm in 1 hour at the Airport and some pea sized hail in Westdale reported. Overall, rainfall amounts haven't been too impressive across southern Manitoba today thanks to the quick movement of the storms. Hail was as large as toonies or possibly golf balls around Rathwell-North Dame de Lourdes according to pictures. A lot of hail, pea to dime sized, fell in Lockport.

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    2. It was pretty damn impressive here in St James! We were driving and it started pouring like I've never seen before and we had some small hail too. The streets were starting to flood. At least the airport got some rain to bring out totals up.

      We received some more rain after your post. Any idea how much more the airport received after 7:45PM?

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  28. Total rainfall was 25.2mm at the airport

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  29. JJ. Are we no longer in the running for driest year on record after all the rain of the last few days?

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    Replies
    1. Looks like we won't reach that milestone thanks to the rains of the past couple weeks. The Airport is close to 300 mm for the year which is only about 20 mm away from the precip amount in the driest year on record.

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    2. Thanks JJ. Is there still a good chance of a top 30 driest year? How many more mm would we need to not be in the 30 driest?

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    3. Likely yes because we are still 130 mm away from the 30th driest year.

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    4. thanks. Does it look like we are moving into a dry pattern again?

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  30. Are we looking at above normal temperatures through most of October? Unfortunately it doesn't look like that cold fall I was hoping for will materialize.

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    Replies
    1. Some models have been showing a warmer than normal first half of October. However, I don't think this is set in stone yet. The NAEFS has been hinting at ridging to our east and troughing to our west with Manitoba in between in the ''zone of uncertainty''. Seems to have been the story of the past several months here as we are constantly in between the heat and the cold.

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    2. It does seem to be the general pattern around here. It's either hot out west and cold out east or the opposite with manitoba in the middle with alternating periods of above and below temperatures. The prediction was for a colder than normal summer and they were right, mainly due to periods of below normal temps outweighing the above normal temps. We've gone 4 consecutive months of slightly below normal temperatures now. September will break that trend but it will be interesting to see how the remainder of fall plays out. So far it seems to be on a track similar to last fall but I highly doubt we'll see another record warm November. CPC outlooks are calling for slightly above normal temps for the first half of October. It does look like the upcoming week is going to be a warm one.

      Do you think we could switch to an extended period of colder temperatures at some point this fall?

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  31. Hey JJ. Could we be looking at our first frost for Friday morning? Many apps are saying a low of 3-4 degrees but environment Canada is calling for 0C. I'm surprised we still haven't froze yet. What are your thoughts on this?

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    Replies
    1. It's going to be a close call. It wouldn't surprise me if the Airport froze given it's cold reputation. The downtown area likely won't freeze and the suburbs within city limits may escape frost as well. Better chance for frost might be in southwestern Manitoba. There's also the chance for patchy fog. This is my take anyway.

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    2. Thanks JJ. After tomorrow night does it look like we will be frost free for a while again?

      I'm not liking the way this fall is turning out. I hope it won't turn out a repeat of 2016

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  32. Hi JJ. I think I noticed a mistake in the record books. On this page with the January dew point records http://privaterecords.weebly.com/jandpwpg.html

    The graph says February on it, so I'm not sure if it's the correct graph or not?

    Also, I noticed January 2017 has 9 dewpoint records including a high minimum of +0.7C. How is it even possible to have daily minimum dewpoints that high in January? I remember it being ridiculously warm and damp during those days though.

    Are we getting later and earlier occurrences of high dewpoints? Such as November 2016 had a huge amount of dewpoints records with ridiculously high dewpoints levels. March 2012 recorded a dewpoint higher than any ever seen in APRIL! March 2010, 2015, and 2016 saw similar events but not on the scale of 2012

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    Replies
    1. Thanks Matt. The problem is fixed. I'm not sure how these little errors happen from time to time but I appreciate you letting me know about them.

      Yeah, in mid January we had the longest period above freezing on record. It was very moist with dewpoints above freezing for 24+ hours. This was a very anomalous event and stands out from every other year.

      There has definitely been increasing humidity here in the last 25 years or so (since the 1990's). The increase in humidity is much more pronounced than the increase in temperature.

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    2. The increasing humidity is quite an interesting topic. I am fascinated by Winnipeg's climate history but this decade has been one of the most extreme we've ever seen. 2012 was incredibly warm, and then it's like we suddenly had a late 1800s style climate in 2013 and 2014 with consistent cold and that brutal winter of 2013/14. Another notable event was the latest date to reach the first 5C of the year ( April 24 ) in 2013. We had one of the earliest and warmest spring's ever in 2012 and one of latest and coldest in 2013.

      Then suddenly we got back into a warm period in 2015 and 2016 and now 2017 seems to be levelling off again. Is there any reason for the long scale pattern alternations for temperature we've seen this decade?

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    3. These cycles are natural and occur all the time. However, it is hypothesized that the jet stream may be weakening with climate warming, which would make it tend to become more wavy. This result in patterns becoming 'stuck' for long periods of time, accentuating the warmth/chilliness/wetness/dryness of the weather.

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    4. That makes sense. Because the contrast from year to year this decade has been quite extreme. Would you say we are in one of Winnipeg's most extreme periods ever? I know the 1930's were extreme as well too....

      Regarding the October outlook, is it now looking like that warm first half of October won't materialize now? The weather network seems to be predicting normal temperatures from the 3rd all the way through mid month.

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    5. Yeah right now it's looking like the core of the warmth will be to our east-southeast and the coldest relative to normal to our west.

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    6. That makes sense. I wish we wouldn't get stuck in between these warm and cold air masses. I want a cold one to settle over us. Do you think we are in for a repeat of last years November again? I hope not

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    7. It is extremely unlikely we will see a repeat of last year. Last year's November was the warmest on record by a long shot and it could very well be decades before we repeat it. Otherwise, it's really too early in my mind to say how much colder it will be compared to last year.

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    8. I agree with you on that one. Though novembers are trending warmer I am pretty sure it is almost guaranteed we will see a colder November this year.

      Our November's are another month that has been extremely variable in the last several years. We had a streak of warm novembers from 2003-2011. Then "12,13,14 novembers were all colder than normal, with 2014 being the coldest November ( and year ) since 1996. Then if I recall correctly 2015 November averaged -0.9C which was warm, but the bigger story was that it was the most humid November in record ( which 2016 beat by a huge margin just a year later )

      That +3.1C mean of last years November is off the charts extreme, wouldn't you agree? Probably of the same calibre as March 2012, which was the most freakish weather event I've seen in my life.

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  33. JJ how is the frost potential looking for tonight now?

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    1. Still looks like the best risk will be in southwestern Manitoba with patchier frost possible in frost-prone areas of the Red River Valley. Not too many places fell below freezing last night in Saskatchewan and Manitoba so it's possible this could be the case again tonight. Just have to see how quickly dewpoints and temperatures drop this evening. It also still looks like there could be some patchy fog developing in some parts of southern Manitoba. The recent rains and moist soils are certainly helping to keep dewpoints higher, resulting in less frost potential and more fog potential the next little while until we get colder air masses coming down and drying of the ground.

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    2. Temps not dropping very fast tonight. Looks like we may escape frost. And after that it looks like not much frost potential through the first half of October. Could we be looking at one of the latest first frosts ever?

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    3. If we don't get a freeze tonight, we will be in the top 30 latest anyway. Last year, the Airport didn't freeze until October 8, which was tied 5th latest, so we still have a week to go before the stat gets interesting.

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    4. I say it's gonna get interesting. The last few years freezes have been coming later. The last time we had an early freeze was in 2012.

      Interesting how at the beginning of the month we were talking about the potential for the earliest frost since the '40s and now we are talking about a potentially very late frost.

      October 1963-- according to the record books it average 12.8C. How is that even possible? That's off the charts extreme as well. That's normal for September! And that years first freeze didn't happen until October 30th, which is honestly just incredible. How could that have even happened? That first frost would have been more than 6 weeks later than normal.

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    5. If interested, you can type 'Weather and Circulation of October 1963' in Google to get details on that month, or follow this link to download a pdf research article https://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwiz-bfszcrWAhUpj1QKHSLyDsUQFggrMAA&url=http%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fdownload%3Fdoi%3D10.1.1.395.1988%26rep%3Drep1%26type%3Dpdf&usg=AFQjCNF-FBhTi_lB0A9iXaZz9kcvwbhUwA

      It was a very anomalous month across the central continent.

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    6. Thanks JJ I will take a look. Oct 1963 also holds our latest freeze on record, which under the new criteria is considered the latest on record

      Regarding some other extreme months, I was wondering if you could tell me a bit about them or point me to some information?

      Mainly December 1877 ( record warm ) December 1879 ( record cold )
      October 2002 ( record cold )
      March 2012 ( I have always been fascinated by this one, how did it even get so warm? )

      You are so knowledgable on the weather here and I would love to know a bit about these months and why they were so extreme!

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    7. March 2012 was amazing for many reasons. It was a very warm winter with very little snow so it did not take long for the snow to melt once temperatures increased in March. Once the snow melted, temperatures were allowed to rise to record values in the high teens and low twenties thanks to the much increased absorption of solar radiation. It was thought that a strongly positive Arctic Oscillation Index was a big reason for such a warm winter and start to spring. Warm air flooded the central and eastern part of the continent in March under the incredible ridging for that time of year and troughing on the Rockies/West Coast. This pattern continued for more than a week with prevailing southerly winds pumping in the warmth and humidity all the way from the Gulf of Mexico. It certainly isn't the first time we've seen temperatures as high as we did that March, but what was rare (in fact, unheard of before) was the high humidity and duration of the ''heat wave'' for that time of year. Winnipeg had a record humidex of 28.0C on March 19 along with the earliest thunderstorm on record (and it was a decent storm, probably the ''strongest'' t-storm Winnipeg has seen in March on record). If you want to learn more, there are definitely many articles you could find on Google as there has been a lot of research done on that event.

      I don't know much about October 2002 because I was too young and I wasn't yet too knowlegeable about the weather. You could do some Google searches on that one as well.

      As for the winter of 1877-1878, see 'Year Without a Winter' here: http://www.dnr.state.mn.us/climate/journal/1877_1878_winter.html
      It is assumed that there was a very strong El Nino that year (possibly strongest on record?) based on world weather that winter. This cannot be confirmed for certain given the absence of widespread ocean measurements.

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    8. Also, I did have an article written up for my top 10 weather events of 2012. It is quite long as I covered as much as I could find on the event given how extreme it was.
      http://jjwinnipegweather.blogspot.ca/2013/01/1-top-ten-weather-events-of-2012-in.html

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    9. Thanks JJ. I will take a look at that. I remember March 2012, and I was wearing shorts on March 19th!! Crazy and it felt like summer. Then the next 2 years were truly endless winters stretching on until the end of April. Talking about extreme weather.

      Why was 2011/12 period so crazy warm? And then in fall 2012 we switched to the exact opposite pattern ( consistent cold ) that persisted through November 2014, 2 full years. With 2014 finishing as the 28th coldest year. How did it flip so suddenly and dramatically to an opposite pattern. And then in 2015 and 2016 we switched to record warmth again. 2017 seems to be rather neutral. So given this cycle, could we be in for some cold times ahead?

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  34. Down to 4.9C at the airport as of 11PM. If it continues I wouldn't be surprised if it spiked below freezing tonight. However high humidity may keep us above freezing. Will be interesting to see.

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  35. Airport down to 3.9C as of midnight

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  36. It's currently -0.3C at Winnipeg airport. First frost of the season! It's official!

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  37. Airport dipped to -1.2°C, an outlier in Winnipeg as usual because most of the city did not freeze. Nonetheless, the first freeze for the Airport this fall, 6 days later than the 1981-2010 normal of September 23. Note I am going to be updating the first fall freeze table in my record books because I recently realised that Environment Canada considers 0.0°C as a freeze (I originally thought it had to dip below 0.0°C). This won't change much however, possibly just a couple dates and that's it.

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    1. Using the ECCC criterion, last year's first freeze was actually the 4th latest on record since 1872. This year's is tied for 20th latest.

      The page has been updated. I will also be adding a page for last spring freeze dates today.

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    2. Thanks JJ. Interesting how that had changed the dates. Making august 20th 2004 the earliest freeze on record. Quite incredible to have one that early. Still, those 3 occurrences of -1.1C in August are incredibly cold for that time of year.

      Yeah I didn't expect it to get as low as it did last night. Rob's Obs dipped to +0.9C, while the forks stayed at +4.5C. Airport the coldest at -1.2C however many backyard stations were close to freezing. There was light frost on our lawn this morning.

      The bit on last spring freeze is interesting. I had no idea that there was one year where the last freeze occurred in April.

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    3. Yeah, that August 20, 2004 only dipped to 0.0°C but under ECCC's criteria, that was the earliest freeze on record. The dates changed mostly prior to the switcheover to Celcius in the 1970s because 0.0C is exactly 32F (31F is -0.6C). Only whole fahrenheit temperatures were used, so some of those 0.0C readings were possibly actually more like 0.1°C or 0.3°C... etc.

      It's possible there was some frost on the ground in the suburbs despite above freezing temperatures because temperatures a taken a few metres above the ground. The inversion near the surface means temperatures could have been below freezing at grass level.

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    4. That's true and totally makes sense. So is it possible that there may be some inconsistency in the data then due to the Fahrenheit to Celsius conversions as well as other factors like station changes then?

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    5. Both of those factors have an impact on records/statistics, but I haven't quantified their impacts. St John's College was inside the city, which wouldn't have had much of a heat island effect in the late 19th century, but the effect would have become more noticeable from the 1890's onward as the city grew very rapidly (maybe this is just one of the reasons for the rapid increase in mean temperature observed???) (definitely would not be the only reason and probably not the main reason). The transition from °F to °C along with inches to cm/mm both change the precision of measurements and thus, have effects but I don't believe the effect is very large.

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    6. Thanks JJ. Yes that makes sense. One example is this

      If we were using the current A CS station in October 2002 that months mean would have been -0.9 instead of -0.5.

      Now we use that A CS station. If we used the old station we'd have broken the record high for February 17th this year. This is just an example of the Inconsistency caused by the station changes.

      It's a good thing we take the measurements from the airport where there is no heat island, especially since the heat island would skew the measurements

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    7. The A CS (XWG) station appears to be notoriously colder than the surroundings. It would have been better to keep the station where it was before (keep using YWG). It makes me wonder if warming this decade has been slightly masked by the XWG's cold bias.

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    8. That definitely is an interesting thought. But The warming has to stop eventually, doesn't it? We can't just keep warming forever.....

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  38. JJ. So after this weekend spell of above normal temperatures are we going to be returning to colder conditions again? I'm now hearing talk of below normal through mid October

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  39. Hey JJ! What were the final September stats?

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    1. I posted them in the monthly summaries tab on the rrecord books website

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    2. Thank you! I actually saw that just after I posted the comment

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  40. JJ. Does it look like we are now going to be above normal through the first half of October? It certainly looks like we will be this next week. What are your thoughts on how the month will play out?

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    1. Still looks variable to me. Models keep flip flopping between cold and warm.

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