Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA
FXUS66 KSEW 292146
Area Forecast Discussion
National Weather Service Seattle WA
246 PM PDT WED JUN 29 2016
.SYNOPSIS...Onshore flow will result in seasonable temperatures
with night and morning clouds and partly to mostly sunny
afternoons for the next several days. Weak upper troughs will
bring a slight chance of showers at times.
.SHORT TERM...Westerly flow aloft with low level onshore flow will
prevail through Thursday. Thursday should be similar to today -
morning clouds, some afternoon sunshine, and highs near normal.
A weak upper trough and an associated dying frontal system will
bring spotty rain Friday. The best chances will be coast and
mountains. Another weak upper trough will keep a slight chance of
showers in the forecast for Saturday. Highs will be near normal
both days. Schneider
.LONG TERM...An upper short wave will exit the region Sunday with
a slight chance of showers ending late in the day. Independence
Day looks dry with westerly flow aloft and low level onshore flow
Model solutions diverge starting Tuesday with an upper low and
showers moving through either Tuesday, Wednesday, or not at all
depending on which model you prefer.
Needless to say, confidence in the details is lower than normal
beginning Tuesday. For now, the forecast is a broadbrush than leans
a bit towards the Euro model. Schneider
.AVIATION...An upper level ridge will remain centered over Idaho
with southwest flow aloft over Washington tonight. At the surface,
moderate to strong onshore flow will continue. The air mass is dry
and stable except for marine stratus over the coast. The stratus
will return overnight bringing low MVFR ceilings to most terminals
and will remain in place until early Thursday afternoon. The
ceilings should lift by late Thursday morning and the stratus should
evaporate back to the coast by early to mid afternoon on Thursday.
KSEA...Southwesterly wind 4-8 kt will become westerly or remain
variable this evening before going back to southerly overnight.
Stratus with ceilings around 1k will move back in around 11z. 13
.MARINE...Moderate to strong onshore flow will prevail through the
weekend. Gale force westerlies are likely tonight in the strait with
small craft advisory strength winds in adjacent waters.
At least small craft advisory strength west winds will occur each
day in the central and eastern strait, but gale force westerlies
are also possible. 13
PZ...Small Craft Advisory until 11 AM PDT Thursday for Coastal Waters
From Cape Flattery To James Island 10 To 60 Nm-Coastal
Waters From James Island To Point Grenville 10 To 60 Nm-
Coastal Waters From Point Grenville To Cape Shoalwater 10
To 60 Nm.
Small Craft Advisory until 5 AM PDT Thursday for Admiralty Inlet-
Coastal Waters From James Island To Point Grenville Out 10
Nm-Coastal Waters From Point Grenville To Cape Shoalwater
Out 10 Nm-Northern Inland Waters Including The San Juan
Gale Watch from Thursday afternoon through late Thursday night
for Central U.S. Waters Strait Of Juan De Fuca-East
Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until 3 PM PDT this afternoon for Central
U.S. Waters Strait Of Juan De Fuca-East Entrance U.S.
Waters Strait Of Juan De Fuca.
Gale Warning until 5 AM PDT Thursday for Central U.S. Waters
Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of
Juan De Fuca.
Small Craft Advisory until 2 AM PDT Thursday for West Entrance
U.S. Waters Strait Of Juan De Fuca.
You can see an illustrated version of this discussion at