Sunday, 28 September 2014

Summer Dream Ends; Fall Back as Scheduled

It was a wonderful week to take in the fall colours
     What a week last week turned out to be across Saskatchewan and Manitoba! Numerous records were shattered. Here in Winnipeg, the records broken were mostly related to the unseasonably high humidity. In fact, a total of 6 dewpoint records were broken:

Table: Daily dewpoint records broken during our ''heat wave'' last week in Winnipeg (records since 1953)

Date & type of record
NEW record
OLD record
Sept 24 – high minimum
9.1°C in 1992
Sept 25 – high maximum
16.8°C in 2008
Sept 25 - high minimum
11.0°C in 2009
Sept 26 - high maximum
16.6°C in 2008
Sept 26 - high minimum
12.2°C in 1986
Sept 27 - high maximum
13.9°C in 2010

     The dewpoint of 18.1°C on September 26 was the 4th highest on record for so late in the year. It was also very close to being the highest for so late in the year: a dewpoint of 18.6°C on October 8, 1997.

     Only one temperature record was broken however, perhaps because temperature records go back much further, all the way back to 1872. Nonetheless, a minimum temperature of 17.4°C on Friday the 26th shattered the old record high minimum of 14.4°C in 1950. This was also the highest daily minimum temperature for so late in the year.

     The heat and humidity on Friday also broke yet another record. A maximum humidex of 35.8 was the highest for so late in the year and the latest occurrence of humidex over 35 on record. A high of 30.2°C was just shy of the old record high of 31.7°C in 1952 and brings our total of 30°C days this year to 8 days. This is below the 1981-2010 normal of 14 days for an entire year.

     It was even hotter out west, where this burst of late September heat was basically unprecedented for so late in the year. In Brandon, temperatures exceeded 32°C for two consecutive days on Thursday and Friday. Highs of 34.0°C and 32.8°C, respectively, did not only shatter the old record highs, but were also the hottest temperatures ever recorded for so late in the year since 1890. Previously, the latest Brandon ever got that hot was on September 22, 1897 and 1938 with highs of 33.9°C. Humidex values reaching 37 were also unprecedented for so late in the year.

     The hottest temperatures recorded last week were 35.1°C in Wawanesa on Thursday and 35.1°C in Swan River on Friday.

     Fall-like conditions return today with temperatures remaining steady near 10°C. Periods of rain will continue until this afternoon. 5-10 mm is likely with locally higher amounts possible. Low cloud will likely remain tomorrow, keeping our highs in the low teens. Warmer for Tuesday and Wednesday with highs in the mid to high teens. A system will likely bring some showers Tuesday night into early Wednesday however. We cool down for late week. There is the potential for our first frost Saturday morning, but it's too early to confirm. Just keep in mind the possibility exists.

Tuesday, 23 September 2014

Near Record-Breaking Heat On The Way

Beautiful fall colours and cloudless sky on Monday evening
     If you thought it was warm yesterday, that 26.5°C high was only the beginning of what could possibly be a record-breaking end to the week.

     To start, today will be very similar to yesterday. Nothing but sun and a high around 26-27°C again. It will be windy from the south at 25 to 35 km/h or so. Clouds will increase tonight, giving way to a cloudier start to the day tomorrow. The clouds -should- clear out by the afternoon, giving way to highs around 22-25°C, depending on how early the cloud clears.

     Mother Nature really cranks up the heat on Thursday and Friday as very warm air moves in from the southwest. Highs in the low 30's look likely, with highs around 30-33°C on both days. This will come close to or break some record highs. The old record for Thursday is 31.1°C in 1950 and on Friday, 31.7°C in 1952. We'll stay quite mild at night as well, with lows in the mid to high teens, potentially breaking some high minimum records.

     The humidity will also be on the increase, making it feel a little uncomfortable for some. With dewpoints reaching the high teens, humidex values will push at least the mid 30's. We may come close to reaching the highest dewpoint values for so late in the season. We'll have to exceed October 8, 1997's dewpoint value of 18.6°C to break that record.

     Looks like we'll cool down a bit on the weekend, but models are not agreeing on how severe and prolonged the cool down next week will be. Will keep you all up to date on the records and possible cool down in the days to come.

Saturday, 20 September 2014

Rain & Storms Today Then Warming Up

You can access this webcam by CBC at any time here
     In case you slept in this morning, thick radiation fog blanketed the city early this morning. The CBC webcam just southwest of downtown (seen to the right) looked pretty cool this morning as it was above the fog. Winnipeg's skyscrapers were poking out above the fog.

     Another thing I want to mention was the supercell storm just south of the border last night. The storm dumped what appears to be baseball sized hail just south of Emerson as seen in this photo. The storm then dropped a tornado into Minnesota, just south of the Canadian border. This video possibly shows this tornado.

     For today, showers with embedded thunderstorms are expected to begin sometime after 10:30 am in Winnipeg and end in the afternoon. Showers may be heavy at times, especially in storms. Even after the main band passes through, the chance for showers and pop-up storms remain for the remainder of the day. A good 5-10 mm, more in storms, could fall today.

     A fairly cloudy start to tomorrow with possibly some patchy fog. Clearer skies for the afternoon and we should reach around 17°C or so, seasonal for this time of year.

     The warmup begins on Monday with nothing but sun and highs around 23°C or so. Similar on Tuesday with highs around 24-25°C. The warm conditions are expected to continue throughout the entire week and possibly even into next weekend. This will make for a fantastic end  to September and will coincide with the leaf-colour change to create some wonderful fall-photo opportunities. This will also be good news for farmers who need warm and dry weather. For the Winnipeg area, this will extend the growing season later than normal. The 1981-2010 normal first frost at the airport is September 24, but we'll be pushing it much later this year. We likely wont get our first frost until October this year.

Friday, 12 September 2014

Worst of The Cold Now Exiting

     It has been a very chilly past few days across the Prairies with temperatures some 5 to 15°C colder than normal for this time of year. At least for us here in Manitoba, we can be thankful we didn't get the cold and snow Alberta received. Calgary Int'l Airport's 28.2 cm of snow this past week puts this September as 7th snowiest since 1884 so far. Highs struggled to exceed the freezing mark on Tuesday and Wednesday. Thankfully, here in Winnipeg those types of temperatures were only at night; during the day we managed to reach low teens, still almost 10°C  below normal however. Thanks to cloud cover, we also managed to escape any frost this week around Winnipeg. Areas west and southeast of the city were not as lucky this morning, where temperatures dipped below freezing in the Carberry, Carman, Winkler and Steinbach regions.

     Despite the cold, it was still a fabulous evening today. I managed to capture a nice picture from Henteleff Park in south Winnipeg, seen above. I like to call the park a hidden gem because not too many people actually know about the park and it has limited access.

     A slow warmup is expected for the next few days. A low pressure system moving into southern Manitoba tomorrow will help to usher in some warmer conditions. Unfortunately, cloud cover and scattered shower activity will likely prevent us from seeing temperatures rise too much. We'll likely only reach around 14-16°C, perhaps 17°C if we get some sunny breaks. Cooler on Sunday behind the system, only reaching low teens again.

     Sunshine and warmer weather return on Monday. We should manage to reach high teens, potentially as high as 18-19°C.

     After a brief cool down mid week, early indications point to a more prolonged period of warmer weather late week into next weekend. Highs in the 20's look likely at this time. There might be some chances for rain however, so it wont necessarily be full sunshine at all times.

Tuesday, 9 September 2014

Frost Possible Friday Morning

     An early fall reality has set in for southern Manitobans. Highs over the next few days will be a good 10°C below normal for this time of year.

     However, keep in mind we aren't having it as bad as in Alberta. 11.8 cm of snow fell in Calgary yesterday as afternoon temperatures hovered near 0°C. An additional 10-20 cm is expected tonight and tomorrow in the area! Highs will struggle to exceed much above the freezing mark today there.

     Here in Winnipeg, we'll only reach about 10-11°C today, which sounds relatively balmy compared to out west. However, this will bring us quite close to the old record low maximum of 10.6°C in 1878 today. Will let you all know in the comments below this evening wether we broke the record or not. There could be a few breaks in the cloud this afternoon which could ruin the chance for a record if they do occur.

     For tomorrow, very similar to today, except there will be a little bit more sun. Only expecting to reach around 10-11°C once again. Very similar on Thursday, except with once again a little bit more sun.

     Frost isn't extremely likely tonight and tomorrow night. However, frost may be possible Friday morning. With clearing skies and lighter winds, temperatures could drop into the -1°C to +1°C outside the city and in the outskirts of the city. Patchy frost could be possible as a result. The potential will be clearer by Thursday. Within city limits in Winnipeg, frost should not be as big a worry due to the heat island effect which should keep our temperatures a few degrees warmer, especially close to downtown.

Monday, 1 September 2014

August Ends Historical 10-Month Cold Streak in Winnipeg

     It's official, the cold streak has finally ended (for now)! At 0.5°C above the previous 30-year (1984-2013) average mean temperature of 18.7°C, August was the first month since September last year to finish warmer than the previous 30-year average. This 10-month cold streak from October 2013 to July 2014 was the 4th longest on record and the longest streak of its kind since an 11-month streak in 1887-1888. The following table summarizes the cold streak by showing how much each month deviated from the previous 30-year average. A list of notable events and stats are also included.

Deviation from previous 30-year average mean temperature
Notable events
September 2013
October 2013

November 2013
December 2013
January 2014
February 2014
March 2014
April 2014
May 2014

June 2014

July 2014
August 2014

     Despite being slightly above normal, only 2 days reached 30°C in August, below the normal of 5 days. So far this year, we have seen 7 days over 30°C, below the normal of 13 days up to now.

Moist, stormy August

     With an average dew point temperature of 14.4°C, August 2014 had the 4th highest average dew point in August on record since 1953 and the highest since 2010 when the average dewpoint temperature was 14.9°C. 24 days saw dew point temperatures over 15°C, well above the normal of 18 days.

Thunderstorm near Warren, Mb, August 24
     Rainfall during the second half of the month was the biggest story of August. During the last 2 weeks of the month, generally 85 to 150 mm of rain fell over the Winnipeg area. The biggest rainfall events occurred on the 21st and 29th, associated with thunderstorm activity. On the 21st, a stationary storm over the city in the evening dumped 50-100 mm of rain from downtown to Whyte Ridge causing significant street and overland flooding. On the 29th, training thunderstorms in the morning south of the city dumped 50-100 mm of rain again, this time in the Niverville to Steinbach regions. Remarkably, much of this rain fell in just half an hour.

     In total, 104.4 mm of rain fell at the airport in August, the first wetter than normal August since 2010 and the 23rd wettest August since 1873. Higher totals fell in other areas, including: 110.7 mm in south St Vital, 137.2 mm in Charleswood, ~142 mm at The Forks and locally over 160 mm in the Lindenwoods area. There were also 6 thunderstorm days, bang on normal.