Tuesday, May 08, 2012

Warmer weather on the way.. first 25C day likely Thursday

Cloudy and cool conditions over the past couple of days will give way to sunnier skies and warmer temperatures Wednesday and Thursday with temperatures climbing into the 20s. In fact, it looks like Winnipeg will see its first 25C reading of the year by Thursday as a southerly flow pumps in a warmer airmass over southern MB. A cold front will bring some showers and possible thunderstorms to southern MB Thursday night, with clearing and cooler conditions expected Friday. This should give way to a dry and pleasant weekend with temperatures rebounding back towards the 20C mark. Dry and warm conditions are expected through the first half of next week with temperatures in the 20s as an upper ridge of high pressure builds over the central continent.

36 comments:

  1. I'm interested in the storm potential on Thursday night. Moisture and instability aren't very high but there should be enough support for scattered storms along the front.

    The way the model have QPF displayed, we could be looking at a line of showers and storms moving through overnight.

    This will be our last chance at convection for awhile. Looks like a big time ridge building in for the weekend and next week.

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  2. If this May were to be above normal in terms of temperatures, if I understood correctly back in March, would this be the first time ever that May was above normal after a top 10 warmest March?

    I'm amazed at how long this warmth is continuing, will be interesting to see how many more consecutive months of above normal temperatures we will see (if this May is above normal of course).

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  3. Derek..

    NAM brings in dewpoints of 10-13C over southern MB Thursday with SBCAPEs of 500-1000 J/kg by evening along with good height falls and a strong 70-80 kt 500 mb jet. Good setup for a frontal squall line of showers and thunderstorms Thursday night, provided we get adequate low level moisture. SPC not indicating any severe potential over Northern Plains Thursday, as they think low level moisture will be too limited to wwarrant a severe risk at this time.

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  4. anonymous..

    Yes, if this May ends up above normal, it would be the first time that a top 10 warm March was followed by an above normal May, in Winnipeg at least. All the other top 9 warm Marches were followed by cooler than normal Mays.

    April was our 10th consecutive month above normal, finishing at 5.9C (about 2C above normal) The bulk of the abnormal warmth however was during the first week of the month, after which April was generally near normal. Still, it's been quite awhile since we've seen an extended stretch of below normal temperatures (which is fine by me :)

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  5. How high will the dewpoint be getting tomorrow before the cold front slices through??

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  6. What is the thunderstorm risk level for tomorrow evening? Any chance for severe weather with the passage of the cold front or will the levels of instability be too low for severe weather?

    So, does everybody here think we will get to 27C or 28C tomorrow?

    I also see the long range guidance is pointing towards warmer and drier weather over the weekend and into next week...does this mean we could be in for a stretch of above normal again?

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  7. Dew points of about 6-8C are forecast over southern MB Thursday, with some pockets of 10C.. overall, pretty unimpressive low level moisture given afternoon highs in the upper 20s (which look likely). Dynamics and forcing look good with the sharp cold front pushing through at max heating time.. but I think the dry low levels will minimize any severe weather risk. Most likely a band of showers along the cold front with some embedded lightning giving some brief downpours and gusty winds Thursday evening/night.

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  8. NAM shows mixing tomorrow down from at least 850 hPa.. with temperatures at that level near 15 C, and SSW flow down to the surface, highs in the upper 20s are a good bet as mentioned.

    Most precipitation looks post-frontal overnite Thursday, in response to better forcing aloft. Instability looks meager, and along with the LLJ, will be focused southeast of the area. However, there is no QPF output from the models out ahead of the front.

    Daniel

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  9. Portage La Prairie's forecast high for tomorrow is 29C. Woohoo!!

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  10. Only caveat to tomorrow's forecast high, is chance for midlevel clouds to keep temperautres down a notch..

    Daniel

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  11. Sharp cold front will be moving through Winnipeg/RRV Thursday evening with a band of showers and possible thunderstorms. Bad timing for evening baseball and soccer games with showers starting up around 6-7 pm, continuing through midnight with about 5-10 mm of rain. Temperatures will fall from 4 pm highs of 27-28C on gusty south winds to 15C by 9 pm on gusty NW winds. Unfortunately, looks like a cool wet finish to a nice warm day.

    Looking at next week, GFS indicating 30+C temps possible for Winnipeg by Wednesday.

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  12. Hi from south of the border. A heads up to you folks... dual pol install is coming to most northern plains radars in the next several weeks. The install takes about 4-5 days to do and the radar will be down during that time.

    DLH radar is currently down and will be until the 14th...

    MVX (Mayville) radar is due to dual pol install May 16-21st and no radar data will be available

    Minot 88d (MBX) is scheduled next followed by Bismarck (BIS) and then Aberdeen (ABR).

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  13. Dan,

    If the ridging pattern continues, the timing may be perfect for the radar being down. There won't be much of anything to follow for a week or so after tonight.

    I am optimistic about how far north things have been this year in regards to storms. There's been some nice events in areas like Nebraska, South Dakota, southern Minnesota, and Iowa. Last year at this time we were talking areas much further south.

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  14. Thanks for the heads up Dan.. Hope things go smoothly and you don't have severe weather during the down time.

    Cold front pushing into western MB at this hour. Should be pushing into Winnipeg early this evening. Dew points ahead of the front generally in the 7-10c range.. with southerly winds gusting to 50 or 60 kmh in the RRV. Doesn't look like there will be too much activity ahead of the front (too dry) with showers mainly occurring behind the frontal passage this evening (as Daniel was alluding to). Up to 24c at my place now.. Should hit 28 or so later this afternoon under nice sunny skies and balmy south winds.

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  15. I love this weather, warm breeze, full sunshine, and touch of humidity!!

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  16. Rob what time do you expect the rain to hit Winnipeg?

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  17. Yeah I think there would only be widely scattered, high-based thunderstorms right along the front, with 500-750 J/kg CAPE and 20 degree spread in temp and dewpoint.. maybe producing gusty conditions from evaporative cooling, and picking up some dust.

    The better coverage comes later (with NAM showing precipitation starting only at around 10 PM) in response to forcing from jetstream. Instability rapidly drops off after 9 or 10 PM so will be showers or light rain as mentioned.

    Daniel

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  18. Daniel/anyone else,

    Do you have a vibe on what our storm season will be like? One thing that's encouraging, as I mentioned earlier, is how far north the storm track has been lately. With the continual buildup of warmth, it's not far fetched to think the jetstream will be in our neighborhood more consistently this year. We could see fireworks as soon as the ridge breaks down or shifts east late next week.

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  19. Rob,
    Do you think the frost-free season has begun early this year? *itching to plant tomatoes*

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  20. Daryl..

    Looks like showers will be pushing into Winnipeg a couple hours after the cold front passes through.. which looks like about 9 pm or so. That would mean rain movign into Winnipeg by 11 pm or midnight.. so the kids should be able to get in those baseball and soccer games this evening after all!

    Andy.. I'd be hesitant to say that we're out of the woods for frost this season, although it's certainly looking that way right now. We're about 2-3 weeks ahead of normal, so really.. it's like the end of May as far as ground temperatures and plants are concerned. However, this is still southern MB, and we're not really safe from frost until early June. Still, you're probably safe getting a head start on those tomatoes.. as long as you can cover them up on any chilly nights we may have over the next 2-3 weeks.

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  21. Convection beginning to fire south and east of Brandon.

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  22. Cold front just went through my place now (830 PM) in River Park South. Interestingly it briefly smelled like smoke as soon as the wind switched to more west/northwesterly.

    Looks like the temperatures will start plumetting, I see it is already down to 19 at your place Rob.. Dropped 0.5°C here in past 5 minutes.

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  23. Wow is that wind howling right now.

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  24. winds are just howling outside.
    For sure winds have increased since the 9:00 airport reading!!

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  25. 84 km/h wind gust in Manitou at 9:00 pm. Here in the city the sky is filled with dust as the winds have really picked up!!

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  26. NW winds gusting to 82 km/h past few minutes at YWG airport.. according to live RVR data. Very strong NW winds behind the cold front and ahead of the main rain band pushing into the western RRV at the moment. Peak gust of 71 km/h at my station just before 10 pm..

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  27. look at that drop in temperature from 28 C to 13 C in a few hours.

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  28. Lightning is impressive, at times out of town.

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  29. Yep... Lightning strikes showing up in the rain band west and southwest of Winnipeg.. heading towards the city.

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  30. Huge crash of thunder just a few minutes ago in south end, woke me out of my sleep..

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  31. Carman and Portage both hit 30C yesterday (30.1C) .. the first 30C readings of the year in southern MB. Winnipeg was a balmy 28.4C... nice taste of summer with more on the way by Sunday! :)

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  32. Hey Rob why was the rain/thunderstorms so far behind the cold front? Typically storms usually fire ahead of or right on the cold front.

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  33. Environment Canada's forecast is showing Monday as being the warmest day of the next week, when most models are showing Wednesday being the hottest. Winnipeg has a good chance of hitting 30 C mid week!!!

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  34. Dew point has dropped dramatically past hour at my place from +5C to -1C.. with westerly winds drawing that dry air from the west. Winds have picked up as well with the drier air.

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  35. Adam.. you're correct that typically showers/tstorms fire up along/ahead of the cold front. However, yesterday was too dry and stable ahead of the front for any convective development. Once the front went through, there was some mid level instability plus a strong upper jet maintaining lift to generate that post frontal band of showers and tstorms. In effect, the showers were mainly based in the mid levels, rather than tied to the cold front.

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  36. Lots of houses in La Salle missing shingles from last night's winds.

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