Plunging temperatures set to make for icy Friday commute

SEATTLE -- The snow, or what passed for snow Thursday, is just about done for the Puget Sound area. There is still a straggling convergence zone that will pester southern King County and Pierce County through the evening and then fizzle and it could put down a slushy dusting to 1" in the hills east of I-5, but really the snow is not going to be much of a factor besides a reason to snap a few photos on your phone.

But that snow and/or rain has set up a serious issue for Friday morning's commute: ice. Because whether it snowed or rained at your house today, the impact will be the same -- your roads are wet, and with clearing skies overnight set to allow temperatures to drop into the 20s, all that water is going to freeze.

So ironically, the commute with the least amount of moisture falling from the sky will end up the most treacherous of the week as icy conditions are expected across the Puget Sound area and beyond for Friday morning.

King County says in anticipation of the icy roads, as many as 12 trucks will be out and will remain on duty throughout the night. In addition to anti-icing operations, crews will be sanding roads and plowing slush or snow when necessary. The state Department of Transportation says they too will be out treating roads through the night.

Once the sun comes up Friday, it won't have any clouds in its way and we're looking at a mostly sunny, but chilly day with temperatures struggling to get into the upper 30s.

Another very cold night for Friday night -- likely even colder than Thursday night -- with lows in the 20-27 range. The roads won't be as wet but black ice is again another concern for Saturday morning.

Saturday will be mostly cloudy. We've been talking all week about perhaps some snow then but latest models are now considerably weaker with the system and keeping what little moisture there is west of Puget Sound -- maybe even just hugging the coast. And even then, maybe 1". For the Puget Sound region, just a chilly day with clouds and maybe a few flurries here and there with highs in the 30s.

Then a big, big, BIG ridge of high pressure begins to form and drop anchor right over the Pacific Northwest. It'll bring in an extended dry pattern that could last a week to perhaps 8-9 days. Suffice to say all next week will be dry and sunny after some patches of fog (especially earlier in the week). Highs will gradually warm to the mid 40s with still very cold nights in the mid 20s to low 30s. We'll have to watch for inversions and burn bans and the like but what we won't have to watch for is snow. Or rain.

Next chance of rain right now is sometime in the early January 20s.

Stay warm out there!