A couple days ago, I noted how a few weather models were “hinting” at some arctic air sneaking into Western Washington sometime around Martin Luther King, Jr. Day. Now, just two days later, both the European model and the main American model (the GFS), in addition to the Canadian model (the GEM), are all in agreement that a very cold air mass will infiltrate our area sometime over the long holiday weekend…with moisture from the Pacific Ocean lurking close by.
We all know what that means–a chance for snow across the greater Puget Sound region!
The Seattle National Weather Service (NWS), in its latest forecast discussion, mentions as much, then notes that the pattern could get even dicier after the holiday weekend:
"All OF THE ABOVE MENTIONED GLOBAL MODELS AGREE ON UNDERCUTTING OF THE RIDGE BY TUESDAY OR WEDNESDAY. THIS COULD INJECT SIGNIFICANT MOISTURE INTO A VERY COLD AIR MASS WHICH COULD GET QUITE MESSY.
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| Snowman-building time next week? Right now, the odds are 1 in 3! |
The NWS then goes on to state the typical disclaimer, i.e., forecast uncertainty, the difficulty of predicting snow in Western Washington, etc. This is the understatement of the day: it is extremely difficult, if not darn near impossible, to nail down snow details in 1.) Seattle and 2.) five-plus days out. Right now, there is remarkable consistency among all the forecast models, which makes it very easy to jump on the “it’s going to snow in Seattle” train. However, as recent near-misses have demonstrated time and time again, forecast models often change their tune as we get closer to the expected snow event.
That said, given that this is a La Nina year (where cold and snow are much more likely across the region), and given that the European model–which tends to be far more accurate than its American and Canadian counterparts–is solidly on board with a cold snap for this weekend, I’d give Seattle a 1 in 3 chance of seeing measurable snowfall (enough to build a snowman with!) within the next week. It goes without saying that we’ll have a much better chance of seeing where we stand, snow-wise, as we head into the latter half of the week.
Stay tuned!
