Large Winter Storm Coming
Friday, December 22, 2006

Brett Anderson
Canadian Weather Expert

Major eastern Canada storm possible later Monday night through Tuesday.

The seeds are being planted for a major storm to impact eastern Canada early next week. For a lot of places it will come a little too late for a white Christmas, but maybe you will be able to put those new sleds, snowboards or skies to use Tuesday and beyond. It is still a little early in the ballgame to get too specific about the exact timing and the amounts on this storm. The computer models are now just starting to get a decent handle on it, though a couple of models had the storm a few days ago. Right now it looks like we will be dealing with two storms initially, then one big one. I expect to see one storm to move up along the west slopes of the Applachians Monday night. At the same time, a second storm will begin to quickly intensify over eastern Virginia. By Tuesday morning, the western Appalachians storm will be absorbed by the larger storm to the east. The large storm should slowly move up into New Jersey or eastern Pennsylvania during the day Tuesday, then into northern New England Tuesday night. This storm will have a lot of moisture to work with as there will be a feed in from the Gulf of Mexico and Atlantic. For snow lovers, the question will be the track and how much cold air there is intially available. As the storm rapidly winds up late Tuesday and Tuesday night it will be able to manufacture its own cold.

In terms of snowfall, I think we will see a mix of rain and wet snow initially Monday evening and night across southwestern Ontario. Farther to the north, from central and eastern Ontario over to southern Quebec we should see wet snow overspreading the region later Monday night. Any mixed precipitation should quickly change to snow Tuesday across southwestern Ontario as colder air gets wrapped in behind the storm on gusty northerly winds. I think there can be a band of heavy, wet snow setting up during the day Tuesday from North Bay to Barrie and perhaps even Toronto, then up and over to near Ottawa. Places to the south across southwestern Ontario may get into the steady snow as well. Farther to the northeast, the storm may track too close to Montreal, so there may be a mix of precipitation there during the day Tuesday before a change to snow Tuesday evening and night. Heavy snow may end up spreading into the Quebec City area later in the day Tuesday and Tuesday night. It will be a close call across northern New Brunswick with the storm between rain and wet snow. Areas to the east and south, including PEI, Nova Scotia and Newfoundland should see mostly rain and strong winds with this storm Tuesday and Tuesday night. Snow will taper off from southwest to northeast Tuesday night across Ontario.

Again, this storm certainly has the potential to produce a lot of snow (in excess of 30 cm in some spots) so stay tuned. I will update Sunday since I will be off Saturday finishing up my shopping. I will also be in on Christmas Day, so expect an update later Christmas day as well. Brett.

Questions or comments anytime andersonb@accuwx.com

Updated White Christmas chances

Site................................................% chance of a White Christmas (morning and day)

Whitehorse, Yukon...........100%
Yellowknife, NT...............100%
Prince George, BC...........100%
Kamloops, BC..............up to 80%
Kelowna, BC............40%
Vancouver, BC........5%
Victoria, BC..........0%
Grand Prairie, AB...........100%
Fort McMurray, AB........100%
Edmonton, AB...........90%
Calgary, AB..........10%
Lethbridge, AB.........5%
Regina, Sask........up to 80%
Saskatoon, Sask......70%
Winnipeg, Man..........up to 70%
Thunder Bay, Ont.......up to 70%
Sault Ste. Marie, Ont..........up to 60%
Sudbury, Ont.........40%
North Bay, Ont........50%
Windsor, Ont.......20%, but snow possible at night
London, Ont........30%, but snow possible at night.
Toronto/Hamilton, Ont........10%, but it may snow later Christmas night
Barrie, Ont.........50%, good chance snow later at night and Tuesday.
Kingston, Ont........20%
Ottawa, Ont......down to 20%, but it may snow Tuesday
Montreal, Que...........down to 20%, but it may snow Tuesday.
Sherbrooke, Que.......down to 20%, but it may snow Tuesday night
Quebec City, Que..........down to 40%, but watch for snow Tuesday
Rimouski, Que.........60%
Edmundston, NB........40%
Fredericton, NB........20%
Saint John, NB........10%
Moncton, NB..........10%
Halifax, NS.........10%
Sydney, NS........20%
Charlottetown, PEI.......down to 10%
St. John's, NF..............20%
Gander, NF.........40%
Deer Lake, NF........60%

Updated: 12/22/2006 3:50 PM

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