Forecast issued Nov. 13, 2020, covering the period from Nov. 18 to 25, 2020
Due to a missed deadline last week (life got a little away from me) I can’t really discuss how good or bad the forecast was (it was really good, trust me).
For this forecast period, overall confidence is not that high, which is not that unusual for this time of the year. As the atmosphere undergoes the switch from a fall to winter regime, the weather models often struggle with the finer details due to rapidly changing surface conditions. With that said, the current medium- to long-range forecasts are looking not too bad if you like milder temperatures and a little snowfall.
Starting on Wednesday, Nov. 18, the weather models show a trough of low pressure moving across our region, bringing a swath of snow across central and northern regions of agricultural Manitoba. Temperatures look to be mild as southerly winds ahead of this system push daytime highs to around 0 C, or even a little warmer over snow-free areas. Weak high pressure will build in behind this trough, bringing sunny to partly cloudy skies from Thursday to Sunday, with temperatures slowly cooling down. Expect daytime highs to drop into the -4 to -8 C range with overnight lows falling to around -15 C.
The weather models then show a deep trough of low pressure digging in across western North America from Monday, Nov. 23 to Wednesday, Nov. 25. This trough will help to develop a deep flow of southerly winds up through central North America. This flow should push our daytime highs back toward or even above the 0 C mark by Wednesday. This western trough of low pressure is then forecast to develop an area of low pressure that will eject to the northeast on Wednesday, bringing a chance of snow to our region. But, as I stated earlier, confidence in this system is low.
Usual temperature range for this period: Highs, -9 to +3 C; lows, -18 to -4 C. Probability of precipitation falling as snow: 95 per cent.