What the general public wants to know:
1) When is it going to snow?
2) How much is it going to snow?
3) How long is it going to stay cold?
4) Just how cold is it going to get?
*Spoiler Alert* I don't have any definitive answers for any of these seemingly simple questions right now. I'm sorry, I'm just being honest. Model run-to-run consistency has been absolutely awful and inconsistent in the long range.
We have to get through a 48 hour period of fairly heavy rain, just below warning criteria. An atmospheric river system is originating from Hawaii, but the brunt of this moisture will impact Washington State. Any terrain above 1500 m is projected to get ample amounts of snowfall (snowboarders and skiers all breath a collective sigh of relief!!). In fact those North Shore mountains will look stunning come the sunshine on Tuesday and fresh show down to the bases. It's going to have quite the Christmas feel this December.
Here's the latest example that will paint the inconsistent picture and highlight some serious model inconsistency that I can pretty much guarantee is going to give Environment Canada and National Weather Service meteorologists a few migraines.
What forecasters look for is consistency between different model runs. It indicates higher chance of a model prediction verifying.
Monday 10 pm Euro ECMWF comparisons:
Good so far.
When you compare the two above pictures with the larger one above, it becomes obvious arctic air has begun to infiltrate Western Canada and the Pacific Northwest.
Vancouver, look for wet snow on the higher hills as 1500 m level temperatures of -6C or -7C will support snowfall on the higher hills, so if your elevation is above 100 m, be prepared for some accumulating snowfall. Just a heads up as temperatures are likely to fall during the day on Monday.
It's going to be a race between how fast the temperatures fall to freezing, just as precipitation begins to taper, as precipitation and moisture will quickly dry out by Monday afternoon/evening, but scattered snow flurries can still be expected.
Winds from the Fraser River Gap will be screamin' Monday evening, so wind chill values will also be factor at the usual suspect areas (San Juan Islands, Bellingham etc.).
But here's where model consistency fail starts to fall off a little bit. Notice how the cold air is attempting to reload into Central BC in the right image. This wasn't apparent in the 00Z model run to the left:
But now looking FURTHER ahead the model consistency for the European model run takes a major hit. Below are very two different scenarios as a major arctic reload is featured in the latest run, with -15C 850 hPa temperatures over #YVR. That would rival December 2008 for cold intensity and duration.
Another problem that hasn't resolved itself is the GFS (Global Forecast System) ensemble members are all substantially cooler than the operational run of the GFS.
This is a nightmare! One model is bound to give into the other, probably during the model runs tonight.
Anyway, Vancouver high temperatures will have a real hard time breaking freezing from Tuesday until next weekend, the coldest air since January 2012.
Once the cold air becomes entrenched in our region, there's always the possibility of a large overrunning event with a warmer pacific front gliding over the dense, cold air creating the very real possibility of a heavy snow event in our future.
One local meteorologist has already stated that there's a very real possibility:
Vancouver Major snow event more likely next wknd as arctic air gets flushed out than late Sunday when it moves in. Models have 20cm— Michael Kuss (@ctv_michaelkuss) November 30, 2013
What do the latest ensembles say for YVR temperatures:
Still a lot of uncertainty 120 hours out.
But, nothing we can do about that. So this cold event can go a couple ways. I Wish I had all the answers for you all.
1) Cold (but not historically cold), with an overrunning event potentially next weekend (snow to rain). Any snow cover we get Monday morning will be very beneficial for breaking temperature records as it give the radiation cooling processes at night a real boost.
2) Historically cold (similar to 2008), with a reloading burst of arctic air like the 'prized' EURO model is hinting at. Still can't fully rule out a 12+ day cold snap.
Did you Know?
The Nenana Ice Classic
The Tenana River in Alaska is home to one of the most unique competitions in the world. People from around the globe cast their vote for when they anticipate the river will start to melt.
Guess correctly and you win a massive sum of money!
If you take the time to watch the video below, you'll see the organizers have constructed an ice tripod. The tripod is attached to a clock and once it moves, the clock stops.
One man in particular, Tom Walters, has won the competition three times, and he has a system where he quantitatively figures out ice thickness through precise measurements and then buys a vast amount of tickets around the time his calculations suggest.
Interested? tickets go on sale on February 1st.