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500 mb pattern for Wednesday Aug 7
Note deep Hudson Bay vortex over
northern Manitoba |
Those waiting for summer heat to return to southern Manitoba will be disappointed this week as another surge of cooler than normal temperatures spreads across the eastern Prairies. A deep
Hudson Bay vortex (image left) will drift across northern MB into NW Ontario, bringing a surge of cool air over Manitoba for the next few days. Temperatures will struggle in the mid to upper teens over Winnipeg and the Red River valley, some 5-10C below normal for early August.
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Temperature graph for
Winnipeg past 30 days |
This will continue a trend of cooler than normal weather that began around July 19th over southern MB. Since then, Winnipeg has gone
19 consecutive days below normal as of today (August 6th) with temperatures more reminiscent of late August or September than mid summer. The upper vortex is forecast to slowly drift east into Ontario over the weekend, with a gradual moderating trend expected over southern Manitoba into next week.
Rob,
ReplyDeleteDoes this vortex have anything to do with the arctic oscillation that locked us in the deep freeze in March and April?
Andy... The AO has been slightly negative since mid July but not abnormally so, so I don't think it has a direct link with this Hudson Bay vortex. There's been a fairly persistent blocking upper ridge over western Canada into the western Arctic that has maintained a long wave trough over Hudson Bay into the Great Lakes. The longer this trough is in place, the more likely you'll see a deep vortex now and then.
ReplyDeleteRecord high for Winnipeg today is 40.6C on this date in 1949. It's the last time we've ever hit the 40C mark here, and one of only 3 times we've ever hit 40C since records began in 1872. We also hit that mark twice during the blistering July 1936 heat wave that saw our hottest temperature ever of 42.2C on July 11.
ReplyDeleteHeat waves in the summer? What a concept!
Had a rainshower pass through here not long ago (I'm in northwest Winnipeg near the Perimeter). Feels mighty chilly out there after the rain.
ReplyDeleteYes.. a lovely October afternoon out there.
ReplyDeleteWe may not be in low 40s but at least Winnipeg can be proud of the record low July 27 temperature a couple of weeks ago :(.
ReplyDeleteSo many grips about the cool WX. With the global warming trend a fact, it'll be much much hotter than desired in the next decades and I do feel sorry for my grand children who will have to endure a world altered (and possibly ruined) by heat. Enjoy the cool while ye' may ... it wont last.
ReplyDeleteLooks like our long awaited warmup next week will be delayed a couple days as another lobe of cool air aloft pushes across NW Ontario/Manitoba Monday into Tuesday on the backside of that upper low to our east. Once that moves out, then the real warm up can begin for us Wednesday through Friday as we finally get out of that annoying northerly upper flow, and start tapping some of that warmer air out west with a more westerly flow aloft and building heights. Progs showing the 570 dam height finally getting in here by Friday (it's been so long since I've seen heights like that here.. what should be fairly normal for mid summer!)
ReplyDeleteSo I think we'll still have to put up with convective cloud buildups Monday and Tuesday (sunny starts to the day then bkn CU building by midday) with temps in the low 20s.. then warmer weather Wednesday through Friday with temps finally getting back to more summerlike values in the 25 to 28C range.
So our flood forecaster is suddenly gone to Alberta, with rumor of other staff possibly also leaving. Interesting. I wonder what he'll be doing 99% of the time when flooding isn't a concern. At least working there won't be as stressful.
ReplyDeleteCBC forecast graphic is out to lunch again. Seems to happen every weekend.
ReplyDeleteCrossing my fingers that this weeks warmup pans out. Pretty good model concensus that we'll be near 30C by end of the week.
ReplyDeleteRob, with the warmer temps later next week, could that potentially bring in an increase threat of thunderstorms possibly severe next weekend or we will stay mainly dry for the next little bit?
ReplyDeleteOdd that the only media outlet with a broadcast meteorologist has the most trouble making a proper forecast.
ReplyDeleteLooks like hazy skies this evening with some smoke aloft moving in from the northwest..
ReplyDeleteSome big fires around the Brochet area and in northern SK. They didn't get much of any rain during that last cold/damp spell.
ReplyDeleteHere's a good GOES image:
http://i.imgur.com/bXOjXFg.jpg
-Garth
>> Anonymous said...Rob, with the warmer temps later next week, could that potentially bring in an increase threat of thunderstorms possibly severe next weekend or we will stay mainly dry for the next little bit?
ReplyDeleteAt this point, it looks like the warmup will be mainly dry although a couple models do hint at some convection with some minor impulses moving through later Thursday into the weekend that may or may not happen. GFS indicates a stronger cold front possibly coming through late Sunday into Monday with a chance of storms, but that's too far out to have much confidence at this point. Certainly as we get warmer and more humid, the potential for storms increases.. but you still need a good trigger and proper timing to get storms going.
Saturday's forecast high, now up to 33 for Winnipeg. Could we get even a little hotter and go for the mid 30's ??
ReplyDeleteThe forecasted high keeps changing (now it's down to 31 but Friday is up to 31). I think what we can safely say is that it's going to be HOT.
ReplyDeleteRob... I know you're not an entomologist, but out of curiosity, do you have any idea why there are so many grasshoppers this year? Anything to do with the weather? They're absolutely everywhere.
ReplyDeleteEvan.. They generally come out at this time of year, but I don't know why there seems to be more this year than usual. I've always thought they tend to be worse in dry years, but this year hasn't been that dry. Perhaps it's just a cycle where they're more frequent this year, but I can't say for sure...
ReplyDelete