Last week’s forecast came about as close as you can to nailing it. We saw plenty of sunshine and warm to record-breaking-warm temperatures. The only parts that were off were the showers and thundershowers that impacted west-central Manitoba instead of eastern regions and the extended forecast that called for colder weather over the Thanksgiving long weekend.
This forecast period starts where the last forecast left off. A persistent trough of low pressure over western North America is helping to build a ridge of high pressure across central North America. This ridge, combined with the southerly flow on the eastern side of the trough, will continue to bring summer-like daytime temperatures to our region. In fact, we could start off this forecast period with more record-high temperatures. The weather models keep pushing the idea that the western trough will eventually kick out an area of low pressure that will track through our region.
The first area of low pressure is forecasted to lift northeast out of the trough on Friday or Saturday. The models show a fairly compact low, which means any deviation from its path could greatly affect the low’s impact. It looks like most parts of southern Manitoba will see showers or some steady rain during this period. Temperatures will cool down with the cloud cover and rain, but overall, it will stay relatively mild.
Usually, we cool down once a low passes by, but just like we saw in the last forecast period, the western trough will quickly re-establish a southerly flow across our region, pushing temperatures back to well above average by Monday. This is when things might get interesting; by Tuesday or Wednesday the weather models are kicking one last low out of the western trough and this low could bring significant rain to a large part of southern and central Manitoba as it slowly tracks into northern Manitoba sometime around Oct. 12 to 14. This time, the weather models are showing a strong push of cold air behind the low which would bring an end to our summer-like temperatures. Should this system develop and track as forecasted, we will finally see our first widespread frosts around Oct. 14 or 15.