Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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FXUS66 KSEW 261622
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
820 AM PST Sun Jan 26 2020

.SYNOPSIS...A front is moving inland and the associated low pressure
center is weakening as it moves into southern British Columbia this
morning. A trough will move through the area this evening. A parade
of additional weather systems will affect the region through next
week.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...So far, the surface low near
Vancouver Island this morning hasn`t brought with it as much wind
as expected. A trough will arrive this evening for another round of
precip and breezy weather. A wetter frontal system will arrive
Monday afternoon or evening and that front is followed by a low
pressure system and quite a bit of shower activity into Tuesday.
The 12z GFS has the surface low filling to a 1001mb low just off the
north coast around daybreak Tuesday. 19


LONG TERM /WEDNESDAY THROUGH SATURDAY/...Another frontal system
moves ashore Wednesday, spreading rain inland throughout the day and
into the evening before transitioning to showers. There is another
potential break in precip during the overnight hours and into
Thursday morning before the next frontal system moves in during the
day Thursday. Models are not exactly in sync with the timing of this
next system...but ultimately the pattern of weather system...then
brief break...then weather system has become etched into memory and
as such to see it continue offers no surprise at all. It is worth
pointing out that at this point...models do diverge in their
solutions as the GFS has the next system crumble apart as it moves
over the area while the ECMWF has it producing precip into Saturday.
Another thing to keep an eye on in this portion of the extended is
that the ECMWF is offering hints at the potential set up of what
looks to be something very atmospheric river-like toward the end of
the forecast period. The GFS is trying to pick up on this as
well...but it does not look as confident as the ECMWF positioning.
Still...that is out in the day 7 to 8 time frame...plenty can change
from run to run that far out.  18

&&

.AVIATION...Strong southwesterly flow aloft easing this afternoon
and becoming west overnight into Monday morning. A front moved
through the area early this morning with another system arriving
late tonight. Ceilings lowering down to around 2000 feet this
morning behind the front. Ceilings lifting again this afternoon into
the evening hours into VFR before the onset of rain with the next
system tonight lowers ceilings back down to MVFR.

KSEA...MVFR ceilings in scattered showers through midday then
ceilings improving later in the afternoon back up to 3500-5000 feet.
Rain ahead of next system beginning around 04z tonight. Southerly
winds 10-15 knots with gusts to 25 knots easing to 8 to 12 knots in
the afternoon and evening hours. Felton/27

&&

.MARINE...A strong front associated with a 995 mb low moving into
Vancouver Island moved through the waters early this morning.
Gale force winds are likely for all the waters except the central
Strait of Juan de Fuca and the Puget Sound and Hood Canal. Winds
easing to small craft over all the waters this afternoon.
Another strong system will move through the area tonight keeping
small craft advisory winds in the forecast for all the waters. For
most of the waters the small craft advisory winds will linger into
Monday. Active weather pattern continuing this week with a
significant system possible Monday night or Tuesday. Felton



&&

.HYDROLOGY...Although there are several weather systems that will
move through Western Washington through midweek the pattern is
fairly progressive with period of rain turning to scattered showers
periodically. The Skokomish river will remain high, probably
remaining above flood stage most of the time. Other rivers will be
running high but it looks like it will not be until late in the
week when more widespread flooding becomes a possibility.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory until 11 AM PST this morning for Admiralty Inlet
     Area-Central Coast-North Coast-San Juan County-Western
     Skagit County-Western Whatcom County.

PZ...Small Craft Advisory until 6 PM PST Monday for Central U.S.
     Waters Strait Of Juan De Fuca-Grays Harbor Bar.

     Small Craft Advisory from noon today to 6 PM PST Monday for
     Admiralty Inlet-Coastal Waters From Cape Flattery To James
     Island 10 To 60 Nm-Coastal Waters From Cape Flattery To
     James Island Out 10 Nm-Coastal Waters From James Island To
     Point Grenville 10 To 60 Nm-Coastal Waters From James
     Island To Point Grenville Out 10 Nm-Coastal Waters From
     Point Grenville To Cape Shoalwater 10 To 60 Nm-Coastal
     Waters From Point Grenville To Cape Shoalwater Out 10 Nm-
     East Entrance U.S. Waters Strait Of Juan De Fuca-Northern
     Inland Waters Including The San Juan Islands-West Entrance
     U.S. Waters Strait Of Juan De Fuca.

     Gale Warning until noon PST today for Coastal Waters From Cape
     Flattery To James Island 10 To 60 Nm-Coastal Waters From
     Cape Flattery To James Island Out 10 Nm-Coastal Waters From
     James Island To Point Grenville 10 To 60 Nm-Coastal Waters
     From James Island To Point Grenville Out 10 Nm-Coastal
     Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-
     Coastal Waters From Point Grenville To Cape Shoalwater Out
     10 Nm-West Entrance U.S. Waters Strait Of Juan De Fuca.

     Gale Warning until noon PST today for Admiralty Inlet-East
     Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland
     Waters Including The San Juan Islands.

     Small Craft Advisory until 6 AM PST Monday for Puget Sound and
     Hood Canal.

&&

$$

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