Tuesday 1 July 2014

The Month of The Deluge


     Rain will forever be remembered as the top story of June 2014. An active pattern for southern Manitoba in the second half of the month brought multiple weather systems with widespread thunderstorms and heavy rains.

Hailstorm northwest of Wpg June 21
     The first of these active periods was a multi-day rain event June 13-16. 69.9 mm of rain fell at the airport, making it the most significant rain event since the biblical rains of late May 2010. In general, 65 to 80 mm fell on the city. Heaviest rainfall totals were found just north and east of Winnipeg, including 93.5 mm in Beauséjour and 120.6 mm in Lockport. These locally higher totals were thanks to training thunderstorms on June 14. The wettest day of the month was on June 15 as a Colorado Low brought widespread heavy rains to southern Manitoba. With 40.1 mm of rain at the airport, this obliterated the old record high rainfall for the day of 18.3 mm in 1928.

     Yet another multi-day rain event occurred June 27 to July 1. Multiple waves of rain and thunderstorms drenched southern Manitoba, especially the southwest. A general 35 to 65 mm fell over Winnipeg. To our west, it was much, much worse, with 100-200 mm of rain in southwestern Manitoba and southeastern Saskatchewan. The following map shows rainfall totals across southern Manitoba June 27 to 10 am July 1.



    Brandon received 139 mm up to this morning, enough to bring the June total to 251.6 mm. This not only makes June 2014 the rainiest June on record in Brandon, but also the rainiest month ever since records began in 1890. They obliterated the old record rainiest month of 217.3 mm in August 1980. Creeks and rivers are at some of their highest levels ever seen this time of year in the area. Flooded basements and severe overland flooding are also an issue around the city. In Winnipeg, 147.1 mm of rain fell in June, ''only'' the 12th rainiest June on record since 1873. Higher totals fell in other parts of the city, including 170.1 mm here in south St Vital. Even higher amounts fell in more isolated parts around Southdale for instance.

Damaging winds also occurred June 29-30 across southern Mb
     Much of the rainfall in parts of southwestern Manitoba fell as a major low pressure system moved in from south of the border June 29-30. This system intensified rapidly with surface pressure dropping to unusually low levels for this time of year. In Winnipeg, the station-level pressure bottomed out at 95.78 kPa at 6 pm on June 29, the 4th lowest pressure minimum in June since 1953.



Table: Top 4 lowest station-level pressure minimums in June since 1953 in Winnipeg


Rank
Minimum station-level pressure
When?
1
94.86 kPa
June 7-8, 1954
2
95.37 kPa
June 6, 2008
3
95.74 kPa
June 21, 2000
4
95.78 kPa
June 29, 2014

     Other than the rain, temperatures averaged bang on normal with an average mean of 17.0°C.

     For my below normal months streak records, I use the normal of the previous 30 years. As a result, using the 1984-2013 normal June mean of 17.1°C, June averaged 0.1°C below this normal. Therefore, June was the 9th consecutive below normal month. This ties with 1949/1950, 2008/2009 and 2012/2013 for 4th longest below normal streak since 1872.

56 comments:

  1. Wow, feels more like the first day of October than July! However, we'll see clearing skies later this afternoon which will allow our temperatures to rise a bit. Old record low maximum is 13.9°C in 1954 which I don't think we'll break as a result of the clearing. However, it certainly could end up being a top 5 coldest Canada Day.

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  2. JJ, are there hints of a more summerlike pattern in July or is July going to be the 10th consecutive below normal month?

    Thanks, Anon

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    1. So far, I see a variable pattern with periods of hotter weather and cooler weather up until mid month. Overall, temperature signals aren't very strong, my best guess would be a July that is closer to normal, perhaps trending a bit below, but it's hard to say.

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  3. St Vital data and record books both now fully up to date.

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  4. A nice summary from Weather Underground about the record rains of the Plains in the US as well this past June. Most notable from their summary included Minneapolis which recorded 289 mm of rain this past June, eclipsing its previous June record rainfall of 249 mm in 1990. In southeastern South Dakota and northwestern Iowa areas have been hardest hit with locally 300 and even 400+ mm of rain in June.

    http://www.wunderground.com/blog/weatherhistorian/comment.html?entrynum=286&cm_ven=tw-cb

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    1. Thanks very much for those statistics JayC. I wasn't aware the river was at a record level for this time of year!

      I forgot to mention in this post that Brandon's 251.6 mm is well over half of Brandon's normal YEARLY rainfall. In a normal year, they'd only get just under 400 mm.

      In fact, Brandon has already surpassed 400 mm of rain for the year so far, meaning they've already had more than a year's worth of rain this year with still 6 more months to go.

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    2. And the numerical (unaudited ) for the last few days up to a few hours ago are available at
      http://www.wateroffice.ec.gc.ca/graph/graph_e.html?mode=text&stn=05OJ015&prm1=3&syr=2014&smo=06&sday=25&eyr=2014&emo=07&eday=03&y1min=&y1max=&y2min=&y2max=&max=0&min=0&mean=0&median=0&upper=0&lower=0&max2=0&min2=0&mean2=0&median2=0&upper2=0&lower2=0

      You can see the impact of opening the floodway offset by Assinniboine, LaSalle, and Seine Rivers increases.

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  5. Your monthly and seasonal summaries have become something I look forward to and enjoy Jj. Thanks for all the work you do and thanks also for making them so timely and interesting.

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    1. Thanks for those positive words Anon. Glad to see you look foreward to these posts every month.

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  6. High of 17.8°C at the airport today, tied 5th coldest Canada Day since 1873.

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  7. Interesting to note that the last time Winnipeg had a month of 100+ mm of precipitation was August of 2010 so its been nearly 4 years since we've really had a truly wet month. Shows you how dry it really has been in the last few years.

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  8. Also wanted to note that the last time we had a day with 40mm or more of precipitation was August 13, 2010. Now its June 15, 2014.

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  9. Unfortunately, a large bank of low cloud has set over southern Manitoba this morning. The cloud is already breaking up around Winnipeg now and should continue to do so. So overall, a pleasant day with just a light breeze and a high around 21-23°C.

    Another great day tomorrow with light winds and lots of sun. Should reach around 24-25°C.

    The heat begins on Friday with highs around 26-27°C. Saturday looks to be the hotter day as temperatures soar into the low 30's. Assuming sufficient sunshine, I'm calling for a high around 32°C in Winnipeg. With dewpoints in the low 20's, humidex values would be near 40 making for a very hot and humid day. There may also be a risk for some thunderstorms across southern Manitoba.

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  10. I see the Assinniboine River in Brandon is also setting records. Yes even higher than 2011 June and July remember the triple height giant sandbags on 18th street. My Name or
    http://www.wateroffice.ec.gc.ca/graph/graph_e.html?stn=05MH013&prm1=3&prm2=6&mode=graph&smo=6&sday=25&syr=2014&emo=7&eday=3&eyr=2014&y1min=&y1max=&max=1&y2min=&y2max=&max2=1

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  11. Looks like there's a pretty good risk of severe thunderstorms on Saturday as huge instability will be in place with some very hot and humid conditions. Hottest day of the year perhaps on tap.

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  12. A spectacular day today with plenty of sunshine and little to no wind. We should manage to reach around 25°C or so.

    Tomorrow, things begin to get a little more unsettled. There is a risk of some showers and thunderstorm activity in the afternoon and evening. Not an extremely high risk, but the risk is there. Assuming sufficient sunshine, we should manage to reach around 27°C or so.

    Saturday, as already mentioned, is the big day for heat and possibly thunderstorm activity. Temperatures will soar into the low 30's after a morning low of only 18-19°C. I'm anticipating a high around 32 or 33°C. With dewpoints in the low 20's in the afternoon, humidex values will push 40. As for the thunderstorm risk, there is the potential for severe thunderstorms in the afternoon and evening. Best risk may end up along the US border, but we'll have to wait and see how things trend in the next 48 hours.

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  13. Now that we're into July, here's a summary of how many severe thunderstorm warning days there have been per province so far this year up to this morning:

    Ontario 26
    Saskatchewan 13
    Québec 9
    Manitoba 9
    Alberta 8
    New Brunswick 2
    British Columbia 1
    Nova Scotia 1
    NFLD, PEI & territories 0

    Across Canada 43 (down from 46 last year up to July 3 & 48 in 2012)

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    1. You might wan to give 2012 an "*" for leap year. Techically we might of had one more day of potential.:-)

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  14. looks like severe weather is on the way once again
    from spc july 04 12:18am
    ...NORTHERN NORTH DAKOTA INTO NORTHWESTERN MINNESOTA...
    CONSIDERABLE SPREAD CONTINUES AMONG THE MODELS AND WITHIN THE MODEL
    ENSEMBLES CONCERNING SHORT WAVE DEVELOPMENTS WITHIN THE BELT OF
    WESTERLIES. HOWEVER...ENOUGH OF A CONSISTENT SIGNAL EXISTS WITHIN
    THE LATEST MODEL DATA TO INCREASE CONFIDENCE IN THE POTENTIAL FOR
    SEVERE STORM DEVELOPMENT ACROSS THIS REGION DURING THE PERIOD.
    INITIATION MAY TEND TO WAIT UNTIL AROUND 06/00Z OR AFTER...BUT IT
    DOES APPEAR THAT A SHORT WAVE IMPULSE MAY SUPPRESS INHIBITION ENOUGH
    ON THE NORTHERN PERIPHERY OF THE ELEVATED MIXED-LAYER PLUME TO
    SUPPORT DEVELOPMENT. GIVEN THE ANTICIPATED THERMODYNAMIC
    PROFILES...WITH CAPE ON THE ORDER OF 2000-3000+ J/KG...AN ASSOCIATED
    40-50 KT WESTERLY LOWER/MID TROPOSPHERIC SPEED MAXIMUM SHOULD
    PROVIDE SUFFICIENT SHEAR FOR ORGANIZED CONVECTION. THIS MAY INCLUDE
    SUPERCELLS...THAT COULD GROW UPSCALE INTO AN EVOLVING CONVECTIVE
    SYSTEM CAPABLE OF GENERATING DAMAGING WIND GUSTS...IN ADDITION TO
    LARGE HAIL.

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  15. The potential is certainly there for svr storms but that's about all there is, potential. Capping and lack of triggering may thwart any development so I wouldn't get my hopes up too much at this point. I'm in the mood for a good nocturnal can't even remember the last time we had one.

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  16. Revised/final forecast:

    Actually, today doesn't look too bad for thunderstorm activity in the RRV. Best risk will be south and southeast of Winnipeg, but can't rule out some thunder later this afternoon and evening in Winnipeg as well. Severe activity is possible. Large hail, damaging winds, tornadoes are all possible to our south mainly. Either way, a beautiful day with highs near 27°C in Winnipeg.

    Tomorrow, a scorcher. We should reach around 32-33°C in Winnipeg with humidex values pushing 40. Risk of thunderstorms will begin in western parts of southern Manitoba in the afternoon and push east. Thunderstorms are possible again in the evening for us. BEST risk MIGHT end up north of the Trans-Canada, but I'm going to wait until tomorrow morning to confirm that. Severe thunderstorms are possible.

    Sunday, things look calmer but still warm with highs in the mid to high 20's.

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  17. Lots of thunderstorm activity near the US border so far. Gradually, things are starting to develop further northwest. Winnipeg will have a chance of a storm late afternoon and early evening, but I would not be surprised if things just missed us to the southeast.

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  18. Focn45 only mentions a slight risk of severe weather for areas east of RRV not in west mb why is that the case tmrw? I like your Outlook better.

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    1. They mention the storm and severe risk shifting into southwestern Manitoba early evening as storms move in from Saskatchewan.

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  19. Well, if you went by E.C"s forecast, Winnipeg does not and will not have the threat for thunderstorms neither tonight nor tomorrow as no thunderstorms are in the forecast and they have tomorrow's high only 29C not the 32 or 33 that many are advertising.

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  20. So no storms I don't know who to believe now

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    1. The chance for tonight was never good for Winnipeg. Main risks were to be this afternoon and early evening and again late in the day tomorrow.

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  21. Me neither but knowing Winnipeg it wouldn't surprise me to see nothing as is usually the case 99% of the time.

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  22. I do not think we'll see anything in Winnipeg tonight. Looks like the storms to our south are drifting east and not continuing to build northward. However, the chance for a storm remains late in the day tomorrow and tomorrow night.

    Considering we reached 27°C today, and we could have gotten even warmer if it wasn't for the cloud, I think we've got a good chance at at least 30°C tomorrow assuming sufficient sunshine.

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  23. We are nowhere near 27C now though as it has cooled off, now only 22C

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  24. And the low for tonight is 21C. Not so sure about that.

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    1. I'm assuming that's a consequence of the GEM model's outlook for tonight, predicting a low of 21-23°C in Winnipeg. I'm going with more of a low 18°C or so tonight, something more in line with the NAM model.

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    2. Actually, a low around 19-20°C may not be out of the question tonight given the high dewpoints. Will be interesting to see if we even go below 20°C or not tonight.

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    3. Official low of 20.1°C at the airport this morning.

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  25. What are the odds of things shifting eastwards tomorrow, recent models show the main lift clearing the area by afternoon to the east. I know storms are possible tomorrrow but how likely is it that they'll get here given one storm system will be leaving our area?

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    1. Most models show winds veering to more of a westerly component tomorrow morning as a surface trough moves east. This may spark off storms closer to the Ontario border tomorrow... so east of Winnipeg, don't think Winnipeg will get anything from this as a result. We're going to have to hope for development in southeastern Saskatchewan and southwestern Manitoba, which could move into the RRV later in the evening or overnight.

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  26. I am sticking with my expectation of a high around 32°C today with humidex values pushing 40. In fact, a heat warning has been issued for the heat and humidity combined today.

    Our main risk for thunderstorms will come mid-late this evening and overnight as storms that develop in southwestern Manitoba and southeastern Saskatchewan today push east. Severe thunderstorm activity is likely today and tonight. Can't rule out an organised complex of thunderstorms pushing through the Interlake or RRV tonight, perhaps a squall line of some sort? We'll see how it goes later today. I might be going chasing out west today with the A Weather Moment team. We haven't decided yet if we're going.

    Calmer tomorrow after the overnight activity. Another warm day, likely reaching around 26-27°C. There is the potential for an evening shower.

    Looking unsettled on Monday with scattered showers likely. Perhaps a thunderstorm as well. Cooler, likely only reaching 21-23°C.

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    1. Looks like we are heading out west soon. It is encouraging that winds are still south-southeasterly in Winnipeg and have not veered yet. Due to this slower surface trough, looks like Winnipeg and RRV will be in the thunderstorm risk for this afternoon.

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  27. Yeah and a Severe thunderstorm watch is now in effect as a result.

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  28. We just saw a well-defined funnel cloud on the storm west of Winnipeg about 10-15 minutes ago. Since dissipated, but definitely a storm to watch.

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  29. Second funnel of the day we're witnessing right now just to the southwest of Winnipeg. Calling it in.

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    1. Tornado warning has been issued for Winnipeg following our report. The funnel has since dissipated but it's not over yet.

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    2. I was going to ask if any one else saw a waterspout or funnel cloud in the interlake around 5 pm in the interlake approx mile 88 road And a few? miles east of Petersfield.

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    3. I haven't heard of any funnels there personally, but I wouldn't be surprised if you had seen one given how today has been.

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  30. Jj what are the odds of us getting severe storms tonight?

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  31. I say Fairly good. A good complex of storms is expected to track across Southern MB tonight as cold front moves through.

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  32. High of 31.9 at the airport today, so looks like the hotter forecasts worked out. Mike, will have an answer soon, we just got back home.

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  33. I'd say there's a good chance Winnipeg will get SOMETHING tonight. My main concern is that the worst and the bulk of the thunderstorm activity drifts to our south... Which is possible, but not a guarantee.

    Hopefully we can at least get a good light show. It will also be fairly late in the night, likely around or after midnight for Winnipeg.

    Severe activity will be possible throughout the night, especially early on.

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  34. Severe thunderstorms in SE SSK now drifting into Manitoba. Will have to watch those storms for later. Pretty intense stuff.

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  35. Beginning to get the feeling that we'll see nothing here tonight in Winnipeg. Those westman storms are moving southeast so they will not be a factor for us.

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    1. My worry does continue, yes. The worst may miss us, but I would find it hard to believe if we got absolutely nothing.

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  36. Come on have hope we will see a storm where is your positivity. Well see I guess

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  37. Incredible, the line just collapsed as it got deeper and deeper into the RRV. Went south to view the lightning so we saw some decent strikes. Due to the rain and nasty mosquitoes, didn't get any video unfortunately.

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  38. While many areas in Southern Manitoba particularly Westman got hammered by severe storms last night, Winnipeg got nothing. Sounds familiar doesn't it. It is very rare that Winnipeg sees storms that originate in SSK or Southwest MB. In fact, it is very rare that Winnipeg sees a thunderstorm period. Winnipeg's not the place to be in you want to see storms, never has been never will be. I can honestly say that i'm not surprised that the storms basically disappeared by the time they got here and actually there was virtually no chance of those storms affecting us as they were moving southeastwards.

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  39. Many parameters were in place for severe storms here yesterday but the lack of low level support likely did us in. Although many funnel clouds were reported, none of them really had a legit shot at becoming tornadic. Will have to wait and see what the next potential severe weather setup brings, which likely won't be until next weekend at the earliest.

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