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Area forecast discussion 
National Weather Service Seattle Washington
830 am PDT sun Oct 4 2015 upper level ridge combined with low level offshore
flow will bring clear skies and warm afternoons to the area today
and Monday. The ridge will weaken Tuesday for partly sunny skies and
slightly cooler temperatures. A weak warm front may bring a little
rain Wednesday. Moist southwest flow aloft over the region will
maintain an unsettled weather pattern into next weekend.


Short term...the strong upper level ridge centered offshore along
133w will maintain dry northerly flow over West Washington through Monday
morning. The ridge will begin weakening tonight as it shifts
east...with the ridge axis moving over West Washington Monday afternoon. By Monday
night the ridge will have much less amplitude...and with the axis
over West Washington the region will be exposed to SW flow aloft.

The forecast remains on track for today and Monday. With the warm
ridge over the region and east-NE low level offshore flow
continuing...skies will remain mostly clear and afternoon
temperatures will warm into the 60s to middle 70s. Only isolated mainly
valley fog developed early this morning and it looks like that will
be the case again Monday morning.

Tuesday still appears to be a transition day. Moisture should begin
increasing in the SW flow there should be more cloud
cover around Tuesday afternoon. With the ridge weakening and a
switch to weak onshore flow...maximum temperatures will drop back to mainly the

Model consistency is the main issue from Tuesday night Onward.
The European model (ecmwf) and Canadian have taken a sudden swerve and now show some
light rain developing over West Washington Tuesday night rather than Wednesday.
The new 12z NAM has also shifted in that direction. The 06z GFS is
still consistent with previous runs...showing warm front rain
reaching the area Wednesday. However it would not be surprising to
see the 12z GFS change as well. Confidence is not very high for
Tuesday night and Wednesday right now and puts the rest of the
forecast beyond Wednesday in greater doubt. Kam

Long term...previous discussion from the 307 am afd...a warm front
is expected to move through the area later Wednesday. The best
chances for rain will be in the afternoon and evening and closer to
the coast.

Models are inconsistent after Wednesday. A second warm front that
was supposed affect the area Thursday is pretty much gone and it
is looking pretty dry in between fronts Thursday.

Models show a cold front approaching from the west on Friday with
this feature stalling offshore into Saturday...and perhaps moving
onshore later in the day. Confidence in these details is low. The
broadbrush chance of rain forecast will be left as is for now for
Thursday through Saturday. Schneider

&& upper level ridge over the NE Pacific will bring dry
northerly flow to western Washington today. The air mass is stable. There is
patchy ground fog in the south sound this morning otherwise skies
are mostly sunny with VFR conditions expected. High pressure will
remain in control tonight for a dry forecast. Patchy fog will reform
overnight...mainly in the SW interior. 33

Ksea...light northerly surface winds today with VFR conditions. 33


Marine...offshore flow will prevail across western Washington today with
high pressure over interior b.C. And thermally induced low pressure along
the coast. Easterly winds are greatest through the western Strait of
Juan Delaware fuca and a Small Craft Advisory is in effect through noon
today. Light offshore flow will continue on Monday then the flow
will flip back to onshore on Tuesday. A warm front will lift north
through the coastal waters on Wednesday...followed by another warm
front Thursday night. 33


Sew watches/warnings/advisories...
Pz...Small Craft Advisory western Strait of Juan Delaware fuca.




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