Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA
FXUS66 KSEW 300349
Area Forecast Discussion
National Weather Service Seattle WA
849 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...Onshore flow will prevail tonight and low level
stratus clouds will surge inland once again. The lowlands should
be covered by the clouds by mid morning...with an afternoon
burnoff similar to today. Otherwise, Wednesday will be dry and
A weak cold front and upper level trough will bring more clouds
and a few showers on Friday, mainly to the coast and mountains.
Another weak disturbance will pass through southern B.C. on
Saturday which may trigger isolated showers across Western
Washington. Temperatures will be close to normal. 33
.LONG TERM...Previous discussion...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 continuing.
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 centered over Idaho will give
southwest flow aloft over Washington tonight. On Thursday, the
upper ridge will drift east with more zonal flow over Washington. 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 will lift by late Thursday morning and the stratus will
evaporate back to the coast by early to mid afternoon.
KSEA...Mostly southwesterly wind 4-8 kt will continue. Stratus with
ceilings around 1k will arrive around 11z. CHB
.MARINE...Moderate to strong onshore flow will prevail through the
weekend. Strong gale force westerlies are occurring 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. Gale force winds are possible
Thursday night. CHB
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.
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