A strong cold front will push through western Washington on Sunday afternoon. A few hours of heavy rain will precede the front on Sunday morning with snow levels near 6000 feet. Once the front passes snow levels will crash down late Sunday afternoon and evening falling to near 2000 feet by late Sunday night.
At Stevens...Snoqualmie and White passes...rain will change to snow and become heavy at times during the late afternoon and evening. Travel through the passes will become challenging due to snow and wind. If you are trying to choose between traveling across the cascades on Saturday or on Sunday...Saturday will be the more favorable weather day for travelers. If you must travel on Sunday...you may beat the wintry conditions by traveling in the morning...but heavy rain will greet you instead on the trip through the mountains.
The strong cold front will also bring windy conditions for the lowlands...with peak wind gusts around 40-50 mph expected on Sunday.
Late Monday...windy Fraser outflow will start to affect the Bellingham area and the San Juan Islands...bringing a colder and drier air mass into western Washington straight from the interior of Canada. As the leading edge of the air mass slips south through the Puget Sound lowlands on Monday evening...a few snow showers may take place with spotty accumulations possible. At this time...it looks like many lowland locations will escape with little or no accumulating snow.
Regarding the possibility of lowland snow on Monday...it is important to note that there is a great deal of uncertainty with a 4-day weather forecast...so check back through this weekend for the latest forecasts...along with any possible watches or warnings.
Cold temperatures are expected Monday night through next Thursday with temperatures running from 10 to 20 degrees below normal for this time of year. Over the lowlands...lows in the upper teens to mid 20s will be common...with highs in the lower to mid 30s.
Areas Affected: San Juan county-western Whatcom county-southwest interior-East Puget sound lowlands-western Skagit county-Everett and vicinity-Seattle/Bremerton area-Tacoma area-Admiralty inlet area-Hood Canal area-lower Chehalis valley area-Olympics-eastern strait of Juan de Fuca-Eestern strait of Juan de Fuca-north coast-central coast-West slopes northern cascades and passes-West slopes central cascades and passes.
November 29, 2013 NWS