Friday, November 03, 2006

Warm up next week..

Models are indicating a break in the cold weather that has persisted over the eastern Prairies over the past few days.  In fact, Winnipeg has been below freezing since midnight of Oct 30th,  5 straight days below freezing!  (normal highs are still around +4C for early November)  


Relief is expected beginning this weekend as a more zonal flow overspreads the Prairies, bringing in milder Pacific air from the west. In fact, temperatures in southern AB are forecast to hit 20c by Monday!  In Winnipeg, this will finally mean temperatures climbing above the freezing mark by Sunday, and around 5 or 6c by Tuesday.  (EC currently forecasting +10C for Tuesday.. but that appears a bit optimistic given the snowcover still on the ground.)  Hopefully the mild temperatures will be enough to significantly reduce the snowcover that has arrived a little too early in Winnipeg this year!


  1. I see EC has downgraded Tuesday's lows significantly. 10C was too good to believe. With all the cold weather we've had the ground is too cold for that, IMHO. Weather is rarely "normal" but I wish we had some that wasn't at one extreme or the other!

    You used the term "zonal flow." I hear this quite often, but what does what it mean?

    Also, during our snowy period they referred to an "arctic vortex." I assume this is a low. Is there something special about it to be called a "vortex?"

  2. "Zonal flow" refers to a prevailing westerly flow of air in the upper atmosphere. This tends to bring milder air in from the Pacific over the Prairies, and often moderates the eastern Prairies from a period of cold weather. When the upper wind flow is from the north or northwest, then that usually means a period of cold weather for us.

    As fas as the Arctic vortex is concerned.. yes, you're right.. it's a fancy term for a low pressure area in the upper atmosphere that tends to bring colder unsettled weather over an area. Often this Arctic vortex will become established over Hudson Bay bringing a counter clockwise circulation of cold air around it from the Arctic. Sometimes this feature can persist for weeks on end, giving a prolonged period of below normal temperatures over Manitoba.

    the eatsrn Prairies.