A few social media sites are predicting as much as a foot of snow in Seattle next week.
Why such excitement?
Some weather prediction systems are predicting something quite unusual for mid-March: lowland snow.
Not everywhere, but in favored locations. And not every weather modeling system.
Consider the predicted snow total from the NOAA/NWS model for the 24-h ending 2 AM on Thursday (below). Lots of snow in the mountains, with a snow band across Puget Sound, probably from a Convergence Zone.
Plotting the GFS model snowfall prediction for Seattle from its ensemble system of many forecasts shows that several of the predictions included several inches of snow, although there is a lot of disagreement. Disagreement means uncertainty.
Now, let me prove that I lack promise as a YouTube channel host.
I suspect that such forecasts of bountiful lowland snow are problematic.
Let me start by noting that the climatology of significant snow in Seattle plummets after the first week of March, as shown below. Yes, late March snow has occurred, but it has never been significant.
Another issue is the temperature of the air, as shown by the forecast for Tuesday morning below. The air over us will be cool, but not the primo Arctic air required for serious lowland snow in our region. And there is onshore flow from off the mild Pacific. But cold enough for PLENTY of snow in the mountains. Get your skis out!.
The US GFS model has a long history of overdoing lowland snow in our area....its forecasts are generally too cold. In contrast, the UW WRF model shows substantial snowfall in the mountains, but essentially nothing in the lowlands (accumulated snowfall through 5 PM Wednesday shown below).
In short, plenty of snow in the mountains (which should address many concerns about this issue), but virtually nothing in the lowlands, although a few of you might see some melting snowflakes.
Precipitation totals during the next weeks should be impressive, providing water exactly when it is most valuable before the dry season starts in 2-3 months.
Announcement
I will hold a special online Zoom session at 10 AM on Saturday for Patreon supporters. Will answer questions and talk more about the snow situation.
Great Blog Cliff, were just north of Arlington and back in 2008 we had 5" on May 5th at 400 foot elevation, it was from an over night convergence zone setup. Lots of tree damage from the foliage on the Alders and Maples.
ReplyDeleteWeather Underground is predicting snow for out neighborhood (mile north of Snoquamie Falls, 560ft MSL) next week. The ground's too warm for it to stick. Low temperatures are forecast to be as low as 33F. I won't have to worry about using my snow blower, which has been put back into storage for next fall.
ReplyDelete"Lots of snow in the mountains"
ReplyDeleteFinally! Hurray! Just when it seemed like this year was a total bust for skiing we get one of the best snow storms of the season. It will be weird because the sun is strong (as you wrote earlier) which means that any break in the clouds will result in slushy conditions but I'll take it. Winter isn't over, baby!
Yeah, I agree about being skeptical when it comes to Seattle snow. Too many things have to line up just right and I doubt it will happen. Maybe some slush but I doubt it will stick.
But but but The Times wants it to be all rain so that our snow pack is low so they can maintain their globalist "the sky is falling agenda"
ReplyDeleteThank you for the heads up, Professor Mass! It'll be interesting to see if this materalizes.
ReplyDeleteHumbug. This whole winter in one word: humbug.
ReplyDelete