Have you ever seen someone playing fetch with their dog, where the guy will hold the stick out and get the dog all excited, and then fake throwing the stick, to have Fido go wildly chasing after it, only to then stand around looking confused at where the stick went?
Well, Mother Nature is once again dangling a stick in front of weather forecasters, going "ready, boy? Go get the stick -- go get it!" But in the back of our minds, we're still thinking: "Is she really going to throw it this time? (And how long until dinner?)"
Yes, once again, we're being teased with possible snow in the forecast. Although this one has a new stick to chase: freezing rain. But while we don't think this will be a big snow or freezing rain deal in most of the area -- just rain or brief freezing rain then rain -- there are some spots that could get picked on.
This scenario is a little bit more traditional in how we usually get snow or winter weather around here -- with a warm, moist system moving in over cold air already entrenched.
We do have some pretty cold air in place, courtesy of a strong arctic high pressure system parked over western Canada. That's feeding some of that air into western Washington via the Fraser Valley and the Cascade passes. It's also feeding cold air into the Portland area through the Columbia River Gorge.
To wit, take a look at some of this morning's lows:
(It's much colder in Eastern Washington. The low was 0 in Spokane and -14 in Deer Park.)
Under clear skies, low temperatures tonight will also be in that same range -- maybe 1-3 degrees warmer with some increasing clouds, but still well below freezing.
Meanwhile, a very warm and moist system out in the Pacific is heading our way. It is expected to arrive in the Portland area early Saturday morning (perhaps late tonight) and then spread north during the day Saturday, reaching the Seattle area by midday-early afternoon and to the North Sound Saturday evening and night.
That warm moist air will fall into some cold air still stuck around here from Friday night before it scours out, meaning the precipitation could start as snow or freezing rain.
(A quick explainer on freezing rain: it's caused when you have a warm mass of air in the middle altitudes between the ground and the cloud deck, followed by a pool of freezing air near the surface.
When the precipitation falls from the cloud, it will generally be snow. As it encounters the warm air, it will melt into the usual rain. But right before it reaches the ground, it enters the below-freezing air and quickly turns to ice. On impact, it usually freezes to whatever it lands on. That can turn streets into skating rinks in no time and is very dangerous to drive in.)
We'll break this down by region:
Portland Area/Southwestern Washington
The greater Portland area north to about Longview is where the greatest chance for snow and freezing rain lies. A WINTER STORM WATCH is in effect for that area from Friday night all the way until *Sunday afternoon* for a myriad of snow and freezing rain.
Here, we've got arctic air blowing west through the Columbia Gorge at speeds of 30-40 mph, gusting to 50 mph. That will provide a constant pool of freezing-cold air near the surface. When that system arrives, it will mostly likely start as snow, but will change to freezing rain as the warmer air moves in at higher altitudes.
This could go for several hours and into Sunday afternoon as long as that Gorge wind blows. Travel around the greater Portland area will be very difficult, and this typically also causes several delays at Portland airport.
For Longview up to about Chehalis and west to the coast, we're looking at snow to start, then changing to freezing rain, then rain, with the changeover occurring much quicker.
Kitsap Peninsula -- More Snow
With easterly winds coming through the Cascades, that will push the cold air up against the Olympics, keeping the western Kitsap Peninsula and Hood Canal area (Brinnon, Hoodsport, Quilcene) cold enough to snow for a while before they eventually scour out, but it could be as late as Sunday morning, and it could snow some 2-4" until then.
Main Seattle/Tacoma/Everett/Olympia/ Central Sound/ Cascade Foothill areas/ North Sound/ North Olympic Peninsula -- Freezing Rain Or Just Rain
For most of the populated greater metro areas, this could begin briefly as snow or freezing rain before it changes to rain, but the type of frozen precipitation at any given spot will be somewhat random. A cold pocket could mean snow for one mile, freezing rain a second mile, and plain rain for the third mile.
If it does snow at your area, it could bring a quick accumulation of an inch or two before changing over.
This will turn over to rain somewhat quickly as that warm air moves in -- especially in east-wind-sheltered areas, but it will be very treacherous in spots where we do get freezing rain and could cause several accidents as cars basically slide (remember, 4 wheel drives don't help you stop any better on ice.) So just be really careful if you have any travel plans Saturday afternoon and evening. Might be a good evening to stay inside and watch a movie or something. Really, by Saturday night this should all be rain, if not sooner.
There is a greater chance of freezing rain near the gaps of the Cascade passes where that cool east wind is blowing -- along I-90 east of Issaquah and down in the Enumclaw and Maple Valley areas. The approaches to Snoqualmie and Stevens Pass could also be quite icy.
Temperatures will be in the low-mid 30s before the rain arrives, but will be warming through the evening and night, to where we'll be in the low-mid 40s by Sunday morning.
Whatcom County / San Juan Islands -- More Snow
Well, this should be a familiar forecast here. With the bone-chilling cold air here and more blowing out of the Fraser Valley like an icy hair dryer, when the moisture gets up here Saturday afternoon or Saturday evening, it'll just be snow, plain and simple. However, as we get through the evening and night, this too could and should change to freezing rain as some warmer air mixes in aloft.
That will hang on into Sunday morning when the front passes and the north wind shuts off, and temperatures rapidly rise into the 40s (which will seem tropical after the past two weeks.) Snow totals are still a wild card, depending on how long it takes to scour out and if it changes to freezing rain. Could be quite a bit, so be on guard.
The Coast -- Rain
Except for the south coast near the Columbia River, this is pretty much rain from the get go.
Then, Rain For Everyone
By the time we get into Sunday midday, everyone should be in just the warm rains and any snow will quickly melt. We stay wet and warm through the week -- and by midweek, we're pushing 50 for highs. Overnight lows will be in the mid 40s -- imagine that!
In the meantime, if *this forecast* doesn't pan out, I think we're going to bite Mother Nature on the leg. :)