[Article by Ryan Porter of Snoqualmie Weather]
UPDATE |October 21st
According to Ryan, it is still early but models still say snow event Friday.
Incredibly low snow level for mid-Oct (~1,500-2,000sf) Friday/early Saturday.
Can’t rule out few wet flakes on higher hills Snoqualmie/North Bend Passes could see 6″+ accumulation with this front and first snow cover to swaths of Eastern Washington.
Could this be a similar view for us next weekend (October 24th)?
Very possible! Models aren’t saying this is a totally crazy idea.
Well…what about this one?
The past few days, several folks in the weather community have pointed out that a few GFS ensembles show very chilly temperatures by next weekend (~24th-26th). While a few model outliers in the context of bucking strong seasonal odds (it’s only October!) is usually dismissed as ‘Fantasy,’ now the higher resolution Euro model does seem to be in agreement for some kind of major cool down. Not quite as extreme a forecast, but certainly an eye-opener for this time of year.
All the early buzz is pinned on the likelihood high pressure remains steadfast over the northeastern Pacific, feeding persistent northwest flow down into the Pacific NW, bringing a pattern of unseasonable cool air and weak frontal activity that might just eke out a wet snow shower or two down below pass levels.
While there’s always inherent variability in long-range forecasts, to begin with, the thought of a wintry event this early really feels like a long shot, doesn’t it? Nevertheless, this is something to watch as the week progresses.
As for our mountain passes, not so uncommon to have snow in October (~20″/yr on average at Snoqualmie Summit), and a white Halloween up in those communities (e.g. Hyak, Easton) certainly happens.
In the interim, after wrapping up a soggy Sunday into Monday (tomorrow), steadier rains should taper but still looking like showery first half of the week with High temperatures cooler than normal (upper 40s-low 50’s).
For this week (Oct 18-25) in Snoqualmie Valley, the average High is 58° and the average Low is 41°.
Have a great week!