Wednesday, June 10, 2009

Gradual warm up this weekend.. summerlike warmth finally moving in early next week

It's been a long time coming, but models are finally indicating a return to more typical summerlike weather over southern MB by early next week. Temperatures have been struggling in the teens for the past 7 days, with our last 20C day back on June 3rd when we hit 23C, the normal high for this time of year. Temperatures will finally be climbing up to the 20C mark by Friday into Saturday with partly sunny skies, although lingering instability will likely lead to scattered "hit and miss" showers both days. More stable weather will begin Sunday with sunshine and temperatures in the low to mid 20s, climbing into the mid to upper 20s early next week. This will feel downright hot to Manitobans who have had to contend with below normal temperatures now for 6 consecutive months.


  1. Does the summer warm-up look fairly promising now?...a few days ago there was still a lot of skeptisism...

  2. This looks like the real deal!
    I have been waiting for "summer like"
    warmth for so long now.

    Does anyone see a chance of a severe thunderstorm tomorrow????

  3. Has anyone seen Justin Hobson???
    He had his live streaming video up for quite some time ( even on days with no storms) and now.....


    Justin where are you???????

  4. We look to receive at least some well deserved days approaching the mid twenties. Problem will still be blocking pattern in place. As Rob mentioned shortwaves dropping down from north will keep the weather somewhat cool and unsettled until Sunday.

    Low tracking over far northern prairies tries to drag warm air into S Manitoba... however it cannot make much progress. If anything, GFS shows cool high pressure over midwest retrograding west slightly on Monday. At the same time LLJ looks to advect clouds and cooler air north (you read that correctly). If clouds and 850 hPa temps of 10 C pan out... we may struggle to reach 25 C. (as Rob states, even this would feel downright hot.. so its all relative)

    GFS has consistently depicted the highest 850 hPa temps and clear air over the negative soil moisture anomalies in central Saskatchewan and Alberta. It wants to modify the airmass with clouds and higher soil moisture as the low and thermal ridge finally push southeast sometime around Wednesday. Looking at 850 hPa RH fields on GFS, I am not too optimistic that we will see a whole lot of sun.

    Beyond this point, the models are showing poor run to run consistency. GFS is struggling with complex split flow pattern, therefore I would not put much stock in any particular solution beyond 4 or 5 days.

  5. Line of convection moving in.. Cell trying to get organized over NW Winnipeg right now...

  6. Slight risk of severe storms today. Main limiting factor is the weak wind shear above 700mb. I think that nickel size hail and strong winds (90-100km/h) are possible, given the cold upper-air temperatures. Heavy rain may also be a concern if storm motion is slow.

    If dewpoints are between +10 and +14 like forecast, CAPE values will be 1000 to 1500J/kg.

  7. This forecast is looking better and better every day with temperatures forecast to hit 27 on Monday!

    Bring on the heat!

  8. I have a question that maybe someone will be able to answer!!

    Is it possible to get a dryline thunderstorm setup like in they have down in Texas and Kansas here in Manitoba????

    You never hear of that term "dryline"
    here in Manitoba.... you always hear about COLD FRONT!!!

  9. Scattered showers and thunderstorms developing over southern MB this afternoon. One thunderstorm cell just developed over Winnipeg with a couple of lightning strikes over south end. Dew points generally around 10C across southern MB, giving SBCAPES of 700-900 j/kg. Models were overdoing surface dewpoints for today.. Winnipeg sounding shows 7C dewpoints just above the surface revealing very shallow surface moisture.

    By the way, we've hit 23C today.. our warmest day of the year so far. Pretty sad stat..

  10. I was just going to post on this. Looks like an interesting afternoon shaping up with pre frontal trough and cold front moving thru. I am increasingly convinced that the urban infrastructure of Winnipeg acts as a mesoscale forcing mechanism for convection (much like lake breeze boundaries or differential heating along slopes).

    Model soundings show very shallow moisture as noted... on the day like today, does the weather office use mixed layer CAPE (MLCAPE) to estimate instability?

  11. Storm east of Winnipeg is flirting with severe limits. Small hail and gusty winds are probably occurring already, with nickel sized hail possible if the storm intensifies further.

  12. Pea size hail reported out of cell near St Genevieve, north of St Anne.

  13. Lake breeze enhanced cell along south shore of Lake Manitoba. From past experience.. I would say it has a decent chance of building down towards North Winnipeg...

  14. Hard to say if that cell is weakening (as it moves away from its forcing mechanism) or if there is a lot of radar attenuation. There were some blips of heavier returns hinted at briefly NW of the city.

    Finger of precip reaching all the way into downtown Winnipeg...

  15. Some close calls today, but no rain (except for at around 1:45) at all pretty much. Oh well. Wasn't an opportunity for VORTEX2 anyway.

  16. We lucked out with our clear skies today... low stratus deck (underneath cold pool) affecting areas 100 km NE of Winnipeg. Had this area shifted a bit SW, we would be stuck with low teens for temps right now.

    Sunday and Monday look to to be the nicest days... with warming 850 hPa temps, clear skies and light winds. I hope we can reach 24 C by tomorrow aft. Not sure if we can reach high 20's on Monday... light SSE flow (not good for mixing) and 13/14 C 850 hPa temps may let us reach 26 C.

    SW flow aloft begins affecting us by late Monday. Plenty of mid level moisture comes up in 850 hPa LLJ and 700 hPa trough/warm front. Several short waves embedded in flow will affect us... initially dynamics will be split with us in a 'no man's land'. Therefore I suspect we will see a lot of cloud (likely holding temps back) but not a whole lot in terms of convection.

    By mid-week, upper flow begins phasing together and t-storm/precip potential increases. Elongated polar vortex rebuilds over central and eastern prairies by late next week. One run of GFS depicted 850 temps below zero over us by Friday/ Saturday.

    Potential is certainly there for another round of cold temps... with perhaps wet snow in central Manitoba and frost in the south Saturday morning. That could be disastrous to agricultural/ horticultural interests (given the heat units we will accumulate this week). Too early to have much confidence in this, but something to keep in mind...

  17. Had a chance to look at GEM and ECMWF ...

    GEM is least aggressive with phasing of energy and keeps us much milder thru late week. ECMWF is slower with trough passage and tapping of cold pool. According to NWS office discussions, ECMWF solutions are being followed due to better consistency. I suspect GFS may be overplaying that narrow cold pool (I hope so)... Rob, do you tend to agree?

  18. I'm a bit concerned about the forecast for Tuesday and beyond. The models play with a lot of moisture and instability which could lead to mainly cloudy afternoons, with showers and thunderstorms. While I'm not opposed to thunderstorms, if they manage to be non-severe and just cloud up the sky, it could lead to a less than ideal situation. Surface temperatures will be decreased as a result and nice evening could be ruined with unnecessary rain showers. While the showers and storms may be isolated, they could still cause problems....something to watch.

  19. Daniel..

    GFS has a tendency to overamplify things in the long term.. so I'm hopeful that the GEM/EC handling of the Arctic vortex later next week is correct.. namely shunting most of the energy across Hudson bay instead of deepening it over the eastern Prairies. We do get cooler late week, but it would be a modified Pacific airmass rather than pulling down that dreaded Arctic airmass again.

    Today was a hopeful sign that things are getting better. I thought we were going to be cooler with that central MB high close by, and a bit of cooler air at 850. But turned out to be a beauty day. Maybe we've turned the corner after all!

  20. Scott.. we do get more unsettled by mid week as dewpoints start to rise (mid teens likely) and some impulses track across the Dakotas. But it still should be warm. After the stretch we've been through, I'll take a bit of warm unsettled weather any day! (although I agree a week of sun and warmth would be welcome)

  21. I would definately take the warm unsettled weather as well. It would be nice to get some severe storms for once!