Story by Lance Quackenbush
Edited by Francis Lavigne-Theriault
The Thanksgiving long weekend will be quite pleasant for most parts of the country for at least part of the weekend, with the Prairie Provinces seeing the most unsettled weather. Let’s take a look at what is going to happen for your long weekend!
To start the long weekend, a strong low-pressure system will move off the Pacific Ocean into British Columbia on Friday, bringing heavy rain to the west coast and Vancouver Island. Vancouver could see 25+mm of rain with higher amounts on Vancouver Island and for the higher terrain. Some mountain snow will also be possible, as well as some snow for northern parts of the province. Showers will continue into Saturday before changing to isolated showers Sunday.
Daytime Highs will generally be around the mid teens. Another low pressure system will impact the province Sunday night into Monday with some possible short breaks in precipitation on Sunday, making it the best day of the long weekend. Interior British Columbia will see some showers Friday night into Saturday with highs falling from the upper teens to lower teens after the rain passes.
The Weekend will start very warm for the southwestern Prairie Provinces as a ridge builds in ahead of the Pacific storm. Sunny skies are expected with highs in the upper-teens to low 20s across southern Alberta and Saskatchewan on Saturday.
The redeveloping low (Alberta Clipper) on the lee side of the Rocky Mountains will slide eastward during the day, perhaps bringing some light showers along the cold front late in the day to Alberta, and eventually some clouds and a chance of showers to central Saskatchewan on Sunday. Behind the front, temperatures will fall from the low 20s to the low to mid teens for southern Manitoba, and to near or below freezing in the north. The low will intensify as it slides east, reaching Manitoba by Sunday, where it should begin to occlude and stall and bring down much colder air into Saskatchewan and Manitoba.
Southern Manitoba will see lots of sunshine on Saturday and Sunday, with clouds increasing later Sunday in response to the approaching low. A couple of showers will be possible for the southern part of the province with the highest chance of precipitation being over northern Manitoba where the low will be passing through. Highs will be in the mid-teens to near 20C for Saturday and Sunday and dropping to the lower-teens behind the front Monday.
Northern Saskatchewan and Manitoba could see significant snow as the colder, air circulates down from the north behind the Clipper system. Temperatures will fall to around the freezing mark with some areas below freezing in northern Saskatchewan and northwestern Manitoba. Current estimates show moderate impacts where 10-30+cm of snow could occur for a wide area up north near and to the northwest of the low. There is some uncertainty as to how intense the low gets and how long it lingers over the region, however it is looking like an impactful storm to end off the long weekend with the rain/snow line extending over west-central Manitoba into northern Manitoba as the low stalls out.
The long weekend will start out with lots of sunshine and above seasonal temperatures for southern Ontario. Highs should reach the upper teens, to low 20s in some cases ahead of a cold front that passed through northern Ontario, where temperatures will be chilly and in the low to mid-single digits north of the Nickel Belt. A spotty shower cannot be ruled out, mainly for eastern Ontario.
Sunday will be cooler for southern Ontario, with highs in the low to mid-teens. A warm front will push into NW Ontario, warming temperatures up to the double digits.
Monday’s forecast is a bit uncertain. It will feature a cold front moving through the province from west to east as a low-pressure system begins to occlude over northern Manitoba. The remnants of Hurricane Delta will be moving up into the Ohio Valley and could bring a chance of a shower. Highs should reach the upper-teens to low 20s across southern Ontario with rain showers from the Manitoba low reaching the area overnight into Tuesday. Highs could be lower however if showers from Hurricane Delta do affect southern Ontario and are more widespread.
An area of low pressure will move into Quebec on Saturday, spreading in showers for the southern part of the province by the afternoon and snow farther north. Highs will be in the mid to upper-teens across southern Quebec and into New Brunswick, PEI and Nova Scotia. Sunshine will be the most abundant for Atlantic Canada on Saturday. Showers look to impact New Brunswick and PEI by the evening hours as the low quickly moves up into Labrador by Sunday morning, with a warmer airmass making its way to Newfoundland and snow expected on the northern side of the low with temperatures nearing the freezing mark over Labrador and portions of Quebec.
Showers will affect Nova Scotia and western Newfoundland and Labrador Saturday night before gradually ending, with snow up in Labrador. The rain should spread eastward into St. John’s by Sunday afternoon before ending late in the day. Highs will be in the upper single digits to low teens for southern Quebec and into the Maritimes. Highs will be in the mid-teens for eastern Newfoundland in the warm sector. For Monday, and area of high pressure will move into Quebec, with sunshine expected. Highs will be in the lower-teens for southern Quebec and the Maritimes, with Newfoundland seeing highs in the mid to upper single digits behind the cold front.
Overall, there should be at least one good day for most parts of the country and even some more summer heat for parts of the Prairies and southern Ontario this long weekend. Enjoy your holiday!