Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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FXUS66 KSEW 280400
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
900 PM PDT WED JUL 27 2016

.SYNOPSIS...Upper level ridging and weak low level onshore flow
will linger over Western Washington through Friday resulting in
sunny days and above normal temperatures. An upper level trough
passing to the north of the area will bring lower temperatures over
the weekend. A stronger upper level trough could arrive around
Tuesday.

&&

.SHORT TERM...
A very thin strip of stratus survived the afternoon
along the central and south Washington coast. Low level onshore flow
tonight will help push stratus back into the interior. Gradients are
weaker than last night, which will likely produce slightly less
coverage with stratus not making it much farther inland than Shelton
in the southwest and Puget Sound remaining largely clear. In the
north, Stratus will also probably reach Whidbey Island and
Admiralty Inlet.

The prevailing upper level ridge over the area coupled with the
weaker onshore flow and less morning cloud cover will help boost
temperatures Thursday well above normal.  Heights and 850 mb
temperatures look to peak on Thursday, likely making it out to be
the warmest day of the next two with highs in the interior reaching
the 80s to near 90 and the mid 70s along the coast.

Upper level heights weaken somewhat Friday, while the low level
onshore flow strengthens somewhat. This will help the coast cool 5
degrees or so, while the interior will only come down a few degrees
over Thursday. It won`t be until Saturday that the region feels the
full effect of an upper level trough moving through southern British
Columbia. Upper level heights will fall into the 570s, as well as a
decent marine push Friday night. Accordingly, more abundant cloud
cover and much cooler temperatures are to be expected for Saturday.

.LONG TERM...from previous discussion...
Sunday remains troffy and there could be a few light showers. Monday
looks dry and warmer. An upper level low moves through the region
around Monday night and Tuesday with some recovery in heights
Wednesday. Temperatures will be near normal each day and there is a
slight chance of showers, mainly in the mountains. Burke

&&

.AVIATION...There will be clear skies except for some areas of low
clouds and fog on the coast. There will probably be a few patches of
fog over the Strait and around Whidbey island by daybreak, but
mostly marine stratus and fog should be confined to the coast in the
night and morning hours.

KSEA...Clear skies.

&&

.MARINE...The small craft advisory over the outer coastal waters
has been extended to the inner waters as well--the wind at
Destruction Island was NW 20kts this evening, and I think it will
probably get up around 25kt tonight and again Thursday afternoon and
night.


&&

.SEW Watches/Warnings/Advisories...
WA...None.
PZ...Small Craft Advisory coastal waters and central and eastern
Strait of Juan de Fuca.

&&

$$

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You can see an illustrated version of this discussion at
www.weather.gov/seattle/gafd/latest_webafd.html


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