An upper low moving west off the british columbia coast and low level offshore flow will maintain dry weather through tuesday with below normal temperatures. Morning low temperatures will likely dip into the 20s monday and tuesday with some colder pockets possibly down to the upper teens. Shower chances will return around wednesday through the end of the week as an upper trough reaches western washington.
Latest observations indicate fraser outflow winds are beginning to ease, and are expected to remain below advisory criteria given that gradients appear to have already peaked. Went ahead and ended the advisory for western whatcom, western skagit, and the san juans. A few isolated gusts up to 40 mph are still possible this morning, mainly in whatcom county and near the coastline. Gradients should gradually come down through the day and winds should follow, with just breezy conditions expected in the north interior.
Satellite imagery shows some upslope clouds on the east side of the cascades, with a few flurries slopping over at the crest. Web cams and road reports indicate a some flurries at the pass summits near the crest. However, no accumulation or impacts are expected. The dry air should bring any isolated flurries to an end this morning and will not include in the forecast.
Temperatures will be colder, especially during the overnight and morning hours during the commutes monday and tuesday morning. Widespread lows in the 20s are likely with dry air and light flow, even in the metro areas. However, dew points are very low in the single digits and teens, so fog or freezing fog is not expected. Some patchy black ice in prone spots like underpasses cannot be rules out, but impacts on the morning commutes should not be significant. This still warrants drivers to use caution during this cold spell. Highs will warm to the mid 40s through tuesday. mercer
Previous discussion...models start to diverge on wednesday. The ecwmf and gem show an upper low offshore. Southerly flow ahead of this upper low brings up some moisture and showers, especially for puget sound eastward. The gfs is more zonal with the upper low further northeast and somewhat drier. The forecast is a blend for now.
Model differences continue into thursday and beyond. The general idea is an upper trough will cross the area on thursday for a better chance of showers. Some drying is expected friday and saturday as the upper trough moves inland and is replaced with some sort of weak high pressure aloft. Snow levels will be low through the period and the lowlands flirt with snow at times as snow levels vacillate between 500 and 1500 feet. Schneider
River flooding is not expected for the next 7 days.
Wa...none. Pz...small craft advisory until 4 pm pst monday for central u.s. waters strait of juan de fuca-coastal waters from cape flattery to james island 10 to 60 nm-coastal waters from cape flattery to james island out 10 nm-coastal waters from james island to point grenville 10 to 60 nm-coastal waters from james island to point grenville out 10 nm-coastal waters from point grenville to cape shoalwater 10 to 60 nm- coastal waters from point grenville to cape shoalwater out 10 nm-northern inland waters including the san juan islands- west entrance u.s. Waters strait of juan de fuca.
A strong, extensive area of canadian high pressure extends down the eastern side of the canadian rockies into montana and the great plains while a trough of low pressure extends from the washington coastal waters southward. This combination is giving offshore flow to the waters. The offshore flow will continue through tuesday, but will not be as strong as it has been since saturday night. The gale warning for the northern inland waters has been lowered to a small craft advisory, and small craft advisories for the waters from the eastern strait of juan de fuca southward through admiralty inlet and puget sound and hood canal have been cancelled. Albrecht
Northwesterly flow aloft will become more westerly overnight into monday morning as an upper level low develops west of vancouver island. Northeasterly flow at the surface will continue as high pressure remains over central british columbia. the air mass is dry and stable.
Vfr conditions prevail. A few lingering clouds at fl060 will dissipate this morning resulting in mostly clear conditions this afternoon through monday morning. Albrecht
Ksea...good vfr conditions. Winds east 9-14 knots becoming northeast this afternoon and tonight. Albrecht