Washington Daily Snow
By Luke Stone, Forecaster Posted 3 months ago November 29, 2023
Overall the trends have been positive over the last twenty-four to forty-eight hours, with cooler temps, much more snow, and a shorter period of rain over the next seven days. The snow will really stack up from midday Thursday through Sunday before the atmospheric river and its warm air arrive. With the amount of snow now expected, the rain early next week is not as troubling.
Short Term Forecast
I am starting to get really excited about this storm cycle. During the last two posts, I had considered using a title along the lines of "The Washout in Washington", but I held off considering there was some guidance showing more substantial snow totals this week. The models have all trended in this direction, with 18 - 30 in now looking very likely in the western Washington resorts. East of the Cascades, totals will be signifcantly less, in the 5 - 10 in range.
There are a few reasons for the increase in snow totals. The first storm in the cycle is taking a more favorable track for Washington, temperatures will stay cooler throughout the storm, and overall all three waves in the cold phase of this cycle are well positioned to deliver healthy totals to the region.
So, we'll have three upper-level disturbances move through the Northwest from Thursday through Sunday. There is good model agreement on the total precipitation during this cold phase of the storm, with all models showing 2.5 - 4 in the Cascades, as you can see below.
Let's take an initial stab at the timeline and snowfall for this long duration event.
Snow will begin Thursday around midday, with light to moderate snow through Friday morning. Expect 2 - 5 in during this time. There may be a brief Puget Sound Convergence Zone (PSCZ) Thursday night that could enhance totals at Stevens and Snoqualmie.
Snow will become heavier on Friday, with another 4 - 8 in falling throughout the day. The heaviest snow arrives Friday night, with another 5 - 10 in likely, perhaps more at Stevens and Snoqualmie due to the another PSCZ.
Heavy snow continues on Saturday, with 5 - 10 in expected throughout the day, with more possible at Stevens and Snoqualmie again due to a PSCZ.
Snow will decrease in intensity Saturday night, but by Sunday morning 2 - 5 in are likely.
Let's take a look at the latest snow forecast from the National Blend of Models.
On Sunday, the warm phase of the storm cycle begins, with a warm front moving through in the morning as the first of two atmopsehric rivers arrives. Snow levels will rise and eventually turn things over to rain at lower elevations, though a few more inches are possible before this happens. This system will bring rain and high elevation snow through Monday morrning.
We'll have a brief break before the next atmopsheric river fueled system arrives Monday night for a more prolonged period of rain. This is a slower moving, stronger upper-level low that will sit off the coast for a few days. We're getting more than five days out on these details though so there's still some time for this to trend cooler or drier.
This next system may linger through midweek before coming on shore with some perhaps a brief changeover to snow at the end. The pattern looks to remain active beyond that with more storms into the second week of December.
Thanks for reading the Washington Daily Snow!