As usual for this time of the year, small changes in the way weather systems move can have a big impact on our weather. Last week’s forecast indicated an area of low pressure would develop to our west and bring nice mild conditions. Not surprisingly, this low now looks like it will take a more southerly route, bringing cooler weather into our region to start this forecast period.
For those of you interested in trick-or-treaters this Friday, the current weather models call for dry weather as arctic high pressure builds in from the north. This arctic high will track through northern Ontario late this week and into the weekend, which means we’ll be on the western side of the high. This should bring us mostly sunny skies and cool weather, with highs only making it to about 5 C on most days and overnight lows dropping to about -5 C.
Over the weekend the arctic high should slide to the southeast and this will put us into a warmer southerly flow. Daytime highs should moderate toward the 10 C mark, but strong south winds will make it feel cooler.
The weather models then forecast a strong area of low pressure developing to our southwest early next week. Confidence in this part of the forecast is not that high, but should it play out as expected, we should see plenty of clouds and showers to start next week, with a slow trend toward the showers changing to flurries, especially during overnight hours.
Looking further ahead, the weather models are not showing any sign of a strong push of cold arctic air or any other strong areas of low pressure. That said, we need to remember that especially for this time of the year, things can change very quickly.
Usual temperature range for this period: Highs, -1 to 10 C; lows, -11 to 0 C. Probability of precipitation falling as snow: 55 per cent.