Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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FXUS66 KSEW 251616
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
915 AM PDT Mon Sep 25 2017

.SYNOPSIS...A weak front will break up over the area this afternoon.
A ridge with warm dry air and low level offshore flow will shift over
the region by Wednesday. A front is likely to reach the area Friday.

&&

.SHORT TERM...A weak front is moving over the area today and it has
been a drippy morning with some rain at times--mainly from Seattle
north. The front will break up this afternoon and precip on the radar
ought to dry up. A ridge will build into the region through Tuesday
and Wednesday with dry warm air and low level offshore flow by Wed.


.LONG TERM...Onshore flow will develop Thursday night ahead of a
front that might should reach the area on Friday for some rain.
Saturday could be a little drippy with clouds and a few showers,
maybe a PSCZ. Saturday night and Sunday could be dry and then a
stronger frontal system is shown by the 06z GFS reaching the area
Sunday night and Monday with some heavy rain and a deep low.

&&

.AVIATION...Northerly flow aloft will continue. A weak frontal
system moving across western Canada will result in light low level
southerly flow and light precipitation today. Expect areas of
MVFR CIGs/VSBYs during the day. The mtns will be obscd.

KSEA...In general, expect VFR conditions through this evening.
There will probably be occasional MVFR CIGs this afternoon. MVFR
CIGs are more likely late tonight or early Tuesday. Light
southerly winds will become light and variable tonight.

&&

.MARINE...
A weak frontal system passing north of the WA coastal waters
today will result in southerly flow across the area. The flow
will become northerly on Tuesday, and then offshore or easterly on
Tuesday. Onshore flow will return late Thursday.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 6 PM PDT this evening 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.

&&

$$

www.weather.gov/seattle

An illustrated version of this forecast discussion can be seen at
www.wrh.noaa.gov/sew/gafd/latest_webafd.html



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