Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
000
FXUS66 KSEW 221614
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
914 AM PDT Fri Jun 22 2018
.SYNOPSIS...An upper trough will move into Western Washington this
afternoon as onshore flow continues, limiting sun breaks and
producing a few showers at the coast, in the mountains, and in
the Puget Sound convergence zone this evening. An upper ridge will
bring sunny and somewhat warmer weather this weekend. An upper
trough will arrive Monday for a return to slightly cooler weather.
&&
.SHORT TERM...A weak upper trough will cross the area today. There
will be a few light showers but mostly it will be cloudy with only
partial afternoon clearing and highs slightly below normal. A
Puget Sound Convergence Zone is also possible this evening. An
upper ridge will move over the area on Saturday for dry weather.
Morning clouds should give way to some afternoon sunshine and
highs will creep up a few degrees. The upper ridge will shift
inland on Sunday with an upper trough offshore and an approaching
weak frontal system. It should be a mostly sunny day with highs
warming a few more degrees. Schneider
.LONG TERM...Previous discussion...A weak and weakening front
will move into Western Washington Sunday night, mostly likely
accompanied by a strong marine push. An upper trough will follow
the front on Monday and move east of the Cascades Monday night.
There should be some shower activity over the forecast area Sunday
night through Monday night, but precipitation amounts look light.
Models disagree somewhat beyond Monday, but broadly agree that
zonal flow will prevail Tuesday and Wednesday with another upper
trough moving in Wednesday night or Thursday. McDonnal
&&
.AVIATION...A weak upper level trough will move through the area
this afternoon, with westerly flow aloft becoming northwesterly
behind the front. Moderate to strong low level onshore flow will
continue today and tonight. The air mass is stable with low level
moisture. Radar shows isolated light showers which will continue
into tonight.
Ceilings this morning are around 2k ft with local IFR ceilings over
the Kitsap peninsula. Ceilings will generally rise today with low
end VFR likely in the afternoon. Ceilings will fall back to 1-2k ft
tonight.
KSEA...Discussion above applies. Model solutions have a convergence
zone over south King County tonight so will keep showers in the TAF.
Southwest wind 4-8 kt though there could be a few hours of northerly
wind this evening associated with the convergence zone. CHB
&&
.MARINE...Onshore flow will continue through the period. Westerlies
will continue in the Strait of Juan de Fuca--rising to at least 20-
30 kt each evening, but possibly reaching gale force for a few
hours. Forecast gradient tonight for KUIL-KBLI is more than 3 mb so
have issued a gale warning for 25-35 kt tonight. CHB
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 3 AM PDT Saturday for Central U.S.
Waters Strait Of Juan De Fuca-East Entrance U.S. Waters
Strait Of Juan De Fuca.
&&
$$
www.weather.gov/seattle
NWS SEW Office Area Forecast Discussion