Friday, May 29, 2009

Weekend outlook

The final weekend of May will finish the month with cooler than normal conditions along with a chance of showers Saturday night into Sunday morning. High pressure building in for Saturday will give a sunny but cool start to the weekend, with patchy frost early Saturday morning outside the city. Afternoon highs are expected to reach 15 or 16C, but light winds and sunny skies will make those temperatures feel warmer. A system tracking through southern Manitoba Saturday night will bring a few showers across southern MB Saturday night into Sunday morning, with even a chance of some scattered thunderstorms. The unsettled weather should move off Sunday morning leaving partly sunny skies and afternoon temperatures near 20C. So all in all, it shouldn't be too bad a weekend, but those waiting for summerlike weather will have to continue to wait. Model guidance is not suggesting any change to above normal conditions over southern MB through the next week or two. As for May, it looks like it will finish with a mean temperature around 8.3C at Winnipeg airport, some 4 degrees below normal, and the 15th coolest May since 1872.


  1. This from Brett Anderson of Accuweather:
    "The model shows no significant warmth anywhere across southern Canada through the third week of June as blocking in the northern latitudes keeps the cool stuff trapped farther to the south compared to normal. By the last week of June, the model hints at a noticeable warm-up"
    This is going to be a short summer.

  2. The real depressing part is that we are right on the edge of the warmth!

    The low pressures will passing right over us with the warm air so close only to have the next cold front after cold front pass us!

  3. Tomorrow morning/midday looks interesting...

    With disturbance tracking ESE from the western prairies thru N Dakota, warm front will set up just south of international border. 40 kt LLJ cranks up and will intersect strong baroclinic zone at 850 hPa over S Manitoba. Moisture return will be key ... GFS delays the return of 10 C 850 hPa dewpoints until after the LLJ has shifted east of RRV. This has caused the QPF bullseye to shift a bit to the NE mid morning Sunday.

    By that time there may also be better interaction with right exit region from upper jet over the
    Interlake and Bisset areas. I think an area of elevated showers and possible tshowers as Rob mentioned will form over SE Saskatchewan/ SW Manitoba and expand in coverage by mid morning over interlake and SE Manitoba as the better moisture gets tapped.

    If moisture return gets better organized sooner, expect Winnipeg and RRV to get in on the higher QPF tomorrow morning. Models are aggressive in clearing us out by afternoon. Incoming solar will fight against cold advection to hopefully give us decent temps as Rob suggested.

    Btw...could be an outbreak of strong surface based convection over WC Minnesota along cold front and warm sector tomorrow afternoon. CAPE may trend a bit higher again depending on moisture return. Shear looks quite good with LLJ and upper jet core.

  4. Edit: that should left exit region of upper jet...

    Also worth mentioning how low our dewpoints are currently. We really lucked out on the timing of this high... had it moved in a bit sooner, we'd be dealing with a hard freeze with -7 C dewpoints and 850 hPa temps just above freezing. Btw, Geralton ON (under the upper low/cold pool) is overcast and 3 C this afternoon... unbelievable for nearly June.

  5. Amazing.. we can barely crack 15C today, and southern SK hits 30C+ in a warm sector that will bypass us to our south tomorrow. 30C has now occurred to our east, south and west..

  6. Rob!
    The weather network is calling for a rain/ snow mix for tonight in Winnipeg!

    Is the weather network completely out of their mind or is that possible????

  7. Rain/snow mix with a low of 7C? plus warm advection tonight with thunderstorms over southeast SK? No, I don't think we'll be seeing snow tonight.. although we could see some small hail if we get one of those thunderstorms overnight.

  8. Another cool week ahead.. Thursday looking especially bleak with an unseasonably cold outbreak pushing into southern MB.. 534 dam thickness, 850 temps of -5C or lower and gusty NW winds.. sheesh.. If the timing is right (or in this case, wrong) we could be getting that snow in June that Chris predicted last week!

  9. Large convective complex giving copious rain to NW Ontario between Kenora and Dryden. Amazing to me how often LLJ and moisture return get better organized just east (and south) of the RRV. I suspect there may be some kind forcing mechanism which favors the extension/enhancement of the LLJ into SE Manitoba and NW Ontario.

    The persistent NW flow will not exactly be conducive to moisture return either this next week.

  10. 29 C for a high today in Fargo ND.
    the warm air is so close, yet so far way....

  11. Please note that current conditions on my website are not updating properly due to a problem with the Shaw webserver. Refreshing or restarting the website does not get the latest conditions. Not sure when it will be fixed..

  12. Looks like there is a risk of some thunderstorms today forming first in western Manitoba then heading into south eastern Manitoba later this evening!