Thursday, October 04, 2007

Thanksgiving weekend outlook

A slow moving complex area of low pressure developing over the central American Plains will give a mixed bag of weather over southern MB this holiday weekend. Models have been struggling to find a consistent solution with this upcoming system, which explains the large swings and flip flops in the forecast this weekend. Initially it appeared as if this system would bring a prolonged period of rain over southern MB through the weekend. It now looks like much of the rain will fall over southern SK and southwest MB Friday into Saturday before moving into the rest of southern MB Saturday night into Sunday. At this point, the bulk of the weekend rain is expected through southwestern MB and the interlake (perhaps 20 -30 mm), with lesser amounts expected over the Red River valley and southeast MB (5-15 mm)

Saturday looks interesting as the storm system sharpens over the US midwest sending a pronounced warm frontal tough towards southern MB. This warm front will mark the leading edge of much warmer air which will be surging north into North Dakota and Minnesota on Saturday. The front may push into extreme southeast MB on Saturday with 25C temperatures possible along the US border. At this point, it appears Winnipeg will stay on the cool side of this front with temperatures in the mid teens. However if the front pushes far enough north Saturday afternoon, Winnipeg may get into the low 20s (as current forecasts suggest) The frontal trough will move east Saturday night into Sunday with showers and possible thunderstorms over southern MB with locally heavy rain possible. Another system threatens showers for Monday.

Summing up.. unsettled Saturday with showers over southwest MB and the interlake - drier with a warming trend over southeast MB. Showers and thunderstorms Saturday night with locally heavy rain possible. Showers ending Sunday. A few showers possible Monday. Have a good long weekend whatever the weather!


  1. Well, not surprisingly, the forecast high for Winnipeg today has dropped significantly, from yesterday's 23 to 15 today, and even that may be optimistic. That warm front will not move as far north as previously expected, hence the cooler forecast. Areas near the US border might tap into the milder air with temperatures near the 20c mark over northern ND and MN, but the rest of southern MB will stay on the cool side today.

    It also now appears that things will be drier for the latter half of the holiday weekend, with showers no longer expected Monday as that system moves further south and east of MB.

  2. Well, models have flipped again for Monday. Now, significant rainfall is expected over southeast MB including Winnipeg on Monday, as that new system strengthens over northwest Ontario.