Rain then Flurries in transition. Snow dumps possible East/South Island

Before I get to the cold and snow and whatnot, let’s talk about Friday.

It is already showery out there, you can expect showers on and off all day. The models show the first shot of serious rain will start around 5-6PM.
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That rain will last through the night but should dry up a bit on Saturday. The fun and intrigue begins on Sunday. What I will do now is turn it over to Environment Canada’s special weather statement, and augment their words with pictures. I will leave out the parts about the North Coast.

Warning Statement

Arctic air to reach the BC coast…
A major change in the weather pattern will occur this weekend and Monday. The change will take place in two steps – the arrival of a Pacific front followed by an Arctic front.
….
The Pacific front will cross the South Coast on Sunday night.

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In the cool moist unstable air behind this system rain showers may turn to snow flurries – even at sea-level.
In this scenario, the intensity of the rain is important: the air will cool near heavy rainshowers and this cooling may prompt a local phase-change from rain to snow with local accumulations of a few centimetres.

Chris says: This scenario is the most likely one to cause snowfall in the Alberni Valley, but is also the most difficult to predict.
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Late Monday the Arctic air will begin draining out of the South Coast mainland inlets. Residual moisture from the previous front may result in a brief period of snowflurries and local accumulations of a few centimetres. Again, with strong winds accompanying the flurries, local white-out conditions are possible in some preferred locations on the South Coast: Sumas Prairie in the Fraser Valley, Howe Sound and possibly the East Coast of Vancouver Island if the Arctic ‘push’ is strong enough.

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By Tuesday morning the South Coast will be bathed in brilliant sunshine but the windchills will continue as usual in the Fraser Valley Howe Sound and the East Coast of Vancouver Island. Right now it appears the brilliant but cold conditions will persist through next week as another blocking ridge sets up over the Pacific. However an Arctic outbreak often leads to significant snowfall events on the BC coast.

And that’s all Environment Canada has to say for now. Stay tuned through the weekend. What is a sure thing at this point is the cold air is coming. What will make all the difference is how fast it comes and how much moisture is lingering, and how much instability there is on the East Coast for big snowfall, before everything dries out and it turns sunny.

Keep your eye on Facebook, Twitter, and this blog as I will update it tomorrow and Sunday too.

Fingers crossed for some fun, but safe, winter weather!

Rain First, then an Arctic warning from EC

Expect showers throughout the day today. Nothing serious, but you will have a chance of getting wet all day.

On Saturday things get more serious. The rain will begin Friday night and go into the morning Saturday. We should get some breaks in the day on Saturday but a second, stronger wave will come through Saturday night and Sunday morning. The map below shows we can expect up to 30mm of rain (blue) in our Valley between 4AM Saturday and Sunday.

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The rain will bring warm winds possibly into the double digits.
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But don’t expect that warmth to stick around. The winds are going to shift through Sunday bringing in Arctic air and cold and possibly snow.

Sunday evening we should be back near zero.
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And as those temperatures fall, there will still be some precipitation around so there is a possibility for some snowflakes to fly, especially at higher elevations.
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But Monday will be the most interesting. As the deep freeze and Arctic outflow sets in, there will be strong Easterly winds hitting the East Coast. This might lead to some Strait effect snow in the Oceanside, Nanaimo and Gulf Island areas perhaps spilling over to us. The models are really not good at picking up this kind of activity, but you can see the winds and the little patch of snow forecast for Monday morning around Nanaimo.
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That will be something to watch and Environment Canada is issuing Special Weather statements about it that I will continue to post on the Facebook page and twitter account. If any warnings are posted, I will of course update this page but I wouldn’t expect those unto Saturday night at the earliest. Stay tuned.

Here is the latest statement:

Special weather statement continued for:
East Vancouver Island, B.C. (081300)
West Vancouver Island, B.C. (081400)
Inland Vancouver Island, B.C. (081500)

Colder conditions with some snow is expected to develop Monday.

A major change in the weather pattern is expected to occur Monday. A frontal system developing over the North Coast on Saturday will push southwards and cross the South Coast during the day Monday.

Outflow conditions will set up in the wake of the front with cold air from the B.C. Interior pushing out onto the BC coast. This modified Arctic air will interact with the milder marine air and snow is likely to develop in some coastal locations. The location and amount of snowfall are still quite uncertain at this time. The public is advised to closely monitor forecasts as we get closer to this event and confidence in the details of the pattern emerge.

Cold and generally dry conditions are expected to prevail along the coast behind the Arctic front from Tuesday through the work week.

Monitor the latest forecasts and warnings from Environment Canada at www.weatheroffice.gc.ca.