11/16/2012 Stevens Pass Mountain Weather Forecast

General Discussion: A series of highly complex and wet weather system will approach the PNW today and continue through most of next week. The show will begin today with bands of snow showers separated by short dry periods lasting through the weekend. Snow totals by noon Sunday are currently calculating out to be 6-10”.

Long-term: The main event will occur late Sunday night as a strong warm front approaches the PNW from the southwest. Freezing levels continue to be a crucial question throughout the weather forecasting community. As of now, the freezing levels appear to be +- 4500’ through early Monday morning. Models then show the freezing levels rising to 5000’ on Monday and staying there through Wednesday. At this point, rain appears likely below 5000’ on Monday and Tuesday.

By the numbers: At present, precipitation total starting at 4am today and ending Wednesday at 4am:
Water equivalent (if all rain) = 2.75”
Snow totals above Pass level (if all snow) = 14”-18”

24hr Accumulative Precipitation Totals Starting at Noon Today:
“Water by midnight= .25
“Of additional water by 4am=>.10
“Of additional water by 12pm= .10

24hr (12pm-12pm) Inches of Water = .25-.5

24hr (12pm-12pm) Inches of Snow = 4-6

Trend and Timing:
Snow showers will develop this afternoon and continue through most of the night. There will be brief dry spell tomorrow with more snow tomorrow night.

24hr Base Area Temperatures (F) Starting at Noon Today:
Low: 26 High: 30
Freezing level: 3500’ 4000’

Trend and Timing:
Temperatures will remain just below freezing for the next 24hrs. Surface temperature will inch up to the low 30’s tomorrow.

24hr Winds Speed (mph)/Direction Starting at Noon Today
Base:0-5 E
Ridge Top:0-10 E

Trend and Timing:
East winds will continue to flow through the pass until tomorrow afternoon. SW flow will develop and strengthen tomorrow afternoon.