Friday, 1 August 2014

Dry and Cool-ish July

     This past July was good news for anyone seeing flooding. Overall, drier than usual conditions helped to dry things out. In Winnipeg, just 25.4 mm fell at the airport, putting July at 14th driest since 1873. This marks the 4th top 15 driest July since 2006, continuing the trend of drier Julys in the last 8 years. The lack of significant thunderstorm activity is a factor. The greatest daily rainfall was just 8.1 mm on July 13, most of which was not associated with thunderstorm activity. The lack of nocturnal activity, of which Winnipeg is notorious for, was also notable. Only 1 thunderstorm event occurred after sunset, on July 13, but even that event was not significant. Only occasional lightning strikes occurred.

July continues cold streak


     At 1.0°C below the 1984-2013 average July mean of 19.5°C, July went down as the 10th consecutive month colder than the previous 30-year average. This streak began last October and has now become historical. It is not only the 4th longest streak of its kind since 1872, but also the longest cold streak since the 1880's.

# of consecutive below normal months
18 months
Dec 1882-May 1884
14 months
Jul 1884-Aug 1885
11 months
Oct 1887-Aug 1888
10 months
Oct 2013-Jul 2014
9 months
1949/50, 2008/09 & 2012/13

     Two days were particularly cold: July 1 and 13. Canada Day featured a mean temperature of just 13.1°C, the 8th coldest July 1st since 1873. On July 13, the high was just a measly 15.7°C thanks to afternoon and evening rains. This broke the old record low maximum of 16.7°C in 1884 and 1950.

Funnel clouds & tornadoes


Funnel cloud near Oak Bluff July 5
     Although the month was pretty dull overall storm-wise, there were a few thunderstorm events that brought some close calls to the Winnipeg area. On July 5, thunderstorms developed west of the city and moved east into and just south of the city in the afternoon. A few funnel clouds were reported with these storms. One of these occurred near Oak Bluff just minutes before the storm hit Winnipeg. The funnel reached at least half way to the ground before dissipating. Tornado warnings were issued for Winnipeg and the surrounding area, but luckily nothing touched down. This was also the hottest day of the month with a high of 31.9°C at Winnipeg airport with a maximum humidex of 40.5. Severe thunderstorms had also occurred in southwestern Manitoba in the evening. Hail up to baseball sized occurred. A tornado might have also occurred near Hartney. Wind gusts to 131 km/h were also recorded in Pilot Mound.

     Cold core funnel clouds and weak tornadoes were the story of July 26. One of these occurred just south of the Perimeter near La Salle. It was confirmed as a tornado by Environment Canada. 2 other tornadoes were also confirmed near Waterhen in the Interlake. Other funnel clouds also occurred, such as west of Portage.

Storm east of Brandon July 26
Brandon flooding July 27


  1. Another great summar...y Jj.I guess it does resemboe the LIA as there is only a few months break from the previous consecutive cold streak.somewhat like the LIA two streaks.
    Speaking of thunderstorms and Lightening one of Canadas biggest Lightening rods the Burlington Skyway Bridge short cut too StCatherines Niagara Falls and Buffalo was s"truck down yesterday.Perhaps we' ll get some of the action now..

  2. Thanks Anon; yeah it's intriguing how we've been in such consistent patterns of late. We had the longest above normal streak of 15 months back in 2011-2012... just a distant memory now...

    Forgot to give update this morning on the forecast... I don't think the risk for storms in Winnipeg is very good tomorrow. Our best risk will be late in the overnight into tomorrow morning as the weak cold front passes through. Winds will be northerly in the afternoon and instability will be pushing south. I don't expect much redevelopment around here in the afternoon as a result, with the bulk remaining to our south. Next period to watch for storms might be mid-late next week, but that's still pretty far to gurantee at this point. Just a tad bit cooler behind the front for tomorrow and Sunday, reaching more like 24-27°C or so.

  3. Some decent storms in southwestern Manitoba this evening. I expect they will diminish significantly in the coming hours with the loss of daytime heating and as outflow boundaries run too far ahead of the storms. However, can't rule out redevelopment of elevated storms through the night. Winnipeg's best chance will be mid overnight through the morning.

  4. As expected, storms didn't last overnight so we were left with nothing in Winnipeg. However, scattered showers this morning with the risk of a thunderstorm exists. Non-severe in nature. Clears out this afternoon allowing us to reach around 23-24°C. Cooler behind the front for the next couple days with overnight lows around 8-11°C tonight and tomorrow night. Highs only around 24-25°C. A tad warmer on Monday, reaching more like 25-26°C.

    Some models switch the flow to more southwesterly instead of northwesterly by mid-late week, which may bring us into a bit more active period, but there is still uncertainty about that.

  5. Great summary JJ.. and a great prediction at the beginning of the month; when i asked you you said " perhas trending abit below normal! And it was!

    1. This cool summer is just a repeat of history so far. Back in May, I mentioned that of the top 15 coldest December to April periods, only 3 (20%) were followed by a summer that was warmer than the 1872-2013 average summer mean of 18.2°C. Only 2 (13%) were followed by a summer warmer than today's 1981-2010 normal summer mean of 18.4°C. This past December to April period was tied 10th coldest.

  6. A few brief downpours moving through the city at the moment. No thunder however. Should pass shortly and we should clear somewhat for the afternoon.

    1. Looks like extreme west end and central parts of the city may have gotten the brunt of the rains this morning with 3 mm at the airport and 2.5 mm at The Forks. Only 1 mm here in south St Vital and 0.3 mm in Charleswood.

    2. It rained?? South central must have missed us.

  7. Looks like thunderstorm chances may be ramping up later this coming week as more humid air moves in. Severe storms may be possible. Before then, there may be some pop-up thunderstorms across Southern Manitoba on Tuesday but this does not look widespread and certainly not a severe event either.

  8. Warm week ahead as high pressure dominates. Slight chance of a shower or storm today, tomorrow and Wednesday in Winnipeg, but the risk is very low. Best chance will once again be in the Parklands, southwestern Manitoba and the Interlake.

    Highs around 26-27°C today, 28-29°C tomorrow, 29-30°C on Wednesday and 28-30°C on Thursday.

  9. Enjoy the warm weather while it lasts because there's bad news in the long range. Models are hinting that the below normal regime will return by mid-month.

  10. JJ,
    The GFS has 30ºC+ temps for un till next Sunday!! with the heat peaking at 32.2ºC tomorrow and 34.7ºC!! Are they totally off their rocker or what??


  11. The 34.7ºC is on Sunday.

  12. I'd say they are. Don' think we even hit 30 tomorrow...Sunday maybe 30-32 C but certainly not 35C.

  13. The GFS seems to have been too warm lately. I don't think we'll be reaching 32°C tomorrow and I'll stick with my 28-29°C. There will certainly be some chances for 30°C later this week.

  14. I'm expecting a high around 29-30°C today in Winnipeg. Tomorrow is looking a little cloudier which may keep our temperatures a bit lower, more like 27-29°C. If there is more sun than expected, we may reach over 30°C. Shower or thunderstorm is possible across southern Manitoba including Winnipeg.

    Warmth continues through to the weekend, but it appears the pattern becomes more active. More widespread risk of thunderstorms possible sometime on the weekend as colder air moves back in. There is some consensus already that another storm system may bring more rain sometime later in the work week next week, but it's too early to confirm.