An approaching warm front is going to eventually warm us up on Thanksgiving, but not before perhaps dropping an inch or so of new snow on the ground before the warm air arrives.
The thickening clouds Wednesday afternoon was the start of the transition to more familiar autumn weather in the Northwest as the winds turn from the north to the west, ushering in milder air off the Pacific Ocean. In addition, a weak warm front will approach the area late Wednesday night into Thursday morning.
Until then, we'll see a few spots of flurries here and there this evening - nothing to worry about though. Just a product of the thickening clouds -- there are no organized weather systems here yet. Temperatures overnight will likely remain steady in the mid 20s.
Then, a warm front arrives early Thanksgiving morning. This storm has no arctic bones about it -- it's a rainy-and-45 storm at its core, but we still have some cold air entrenched to deal with.
Thus, it is looking more and more likely that Thanksgiving morning will begin with areas of snow around the area BUT! this is a whole lot different than what we went through Monday. For one, the precipitation is light, and second, it'll be warming. So best forecast now is for areas of light snow Thursday morning to change to rain by midday, except far north where it'll take until the evening.
A Winter Weather Advisory is now in effect from 6 p.m. Wednesday for just about all of Western Washington. For the greater Seattle area and most of the rest of the state, the advisory is in effect until 1 p.m. Thursday. For Bellingham/San Juan Islands, it's in effect until 6 p.m. Thursday.
Models suggest roughly up to 1" of snow possible in the snow before it changes over, with potential for brief sleet and/or freezing rain during the changeover. Freezing rain can make for instantly slick travel so keep an eye out for ice, but it should change over to plan rain.
Up near Bellingham, 2-3" of snow could accumulate before the changeover, which could also include a period of freezing rain or sleet.
I'll be home for the holiday but still plugged in to weather and will be Tweeting any urgent updates at @ScottSKOMO. By Thanksgiving afternoon, most areas should be in the warmer rains, and whoever isn't will be shortly. Temperatures will eventually reach the low 40s by afternoon. Sometimes the transition can take longer in some spots, so I wouldn't be surprised to see some areas still clinging to snow in the afternoon, but as I said, most showers should be rain by the time the afternoon football game kicks off.
Up in the mountains, the snow will be heavy at times starting late Thursday and remain snowy through Friday. A Winter Storm Watch is in effect from Thursday afternoon through Friday afternoon for up to a foot of new snow by Friday afternoon.
Thus, if you want to travel and not have to worry about any snow, even though the snow shouldn't be that heavy, best advice is to try and join the masses this evening/tonight or go Thursday afternoon in the city. If going over the mountains, the sooner the better, despite heavy Thanksgiving traffic. The mountains could see a period of freezing rain too late Thursday morning to Thursday afternoon before it changes to snow. S
Now, Thursday night, our attention turns to more traditional November weather -- rain and wind.
We'll see rain developing overnight with gusty southeast winds north of Everett in the usual November-storm windy spots (Island County, San Juans, Port Townsend) and along the coast that could reach up to 40-45 mph. Not too windy elsewhere. Lows will be in the mid-upper 30s.
Friday is a rainy and breezy day with rain tapering to showers in the midday and afternoon hours with highs in the mid 40s. South winds will pick up in the Puget Sound area but gust 20-30 mph.
The rest of the weekend features scattered rain showers on Saturday then drying on Sunday with highs in the low-mid 40s. Try not to overheat... or overeat :)
Have a happy and safe Thanksgiving!