Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Seattle Washington
330 PM PST Tuesday Nov 24 2015
Synopsis...Fraser outflow will produce windy conditions in the
north interior and Kitsap peninsula through early Wednesday morning.
Cool dry weather will prevail through the weekend...with
clear skies and sub freezing low temperatures. Wet weather may
return by Monday night and Tuesday.
Short term...strong Fraser outflow continues this afternoon and
northeast gradients have not relaxed much since peaking earlier today.
With bli-ywl still up near +15 mb...solid Wind Advisory strength
northeasterly winds should persist tonight. The advisory for
western Whatcom and Island County were extended to include the
Admiralty Inlet and Kitsap peninsula areas as winds have gusted 45 miles per hour
in those areas this afternoon. Winds of this strength would usually only
cause isolated power outages but the northerly direction appears
to be causing more tree related damage than would normally be expected.
Clearing skies tonight and drier air filtering in across western Washington will
result in colder temperatures through Friday. It will be dry through the
end of the week with lows falling into the middle 20s to lower 30s. Highs
will be in the 40s with sunny skies.
Long term...a blocked high over low pattern continues over the
weekend and into early next week. The latest 12/18z model runs are
slower to bring Pacific frontal systems into the region. Dry weather is
now forecast into Monday with chance probability of precipitation for rain Monday night/Tuesday.
The westerlies should eventually punch into the region...it is just a
matter of timing. Temperatures will moderate gradually with lows
mostly in the 30s and highs in the 40s by Monday and Tuesday. Mercer
Aviation...the upper low will continue to move south and inland
and will be over Nevada on Wednesday. The upper ridge in the NE Pacific
will give dry NE flow over Washington. The air will be stable. Fraser outflow
between high pressure over b.C. And the departing low pressure will
Ksea...clear with a breezy northerly wind.
Marine...Fraser outflow will keep gale warnings up for the northern
waters and eastern half of the Strait. The swell on the coast will
continue to drop but the NE wind should stay up through the night and
there are small craft advisories up for all the area that don't have
gales. The northerly flow and NE Fraser outflow will ease on Wednesday.
Light to moderate offshore flow will then prevail for the rest
of the week.
Hydrology...flooding is not expected for the next seven days.
Washington...Wind Advisory until 6 am PST Wednesday for western
Whatcom...the San Juans...Admiralty Inlet...Hood Canal...and
Coastal Flood Advisory for minor tidal overflow until 5pm.
Pz...Gale Warning central and eastern Strait of Juan Delaware fuca and for
the northern inland waters...Small Craft Advisory coastal waters and
West Entrance Strait of Juan Delaware fuca...Small Craft Advisory
Admiralty Inlet...Small Craft Advisory and Puget Sound sound and good
Small Craft Advisory for rough conditions Grays Harbor bar.
You can see an illustrated version of this discussion at