Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Seattle Washington
330 PM PST sun Feb 7 2016
Synopsis...expect dry and mild weather Monday and Tuesday as a
strong ridge builds over the Pacific northwest. The ridge will shift
east by Wednesday opening the door to more frontal systems beginning
Short term...an upper level ridge over the Pacific northwest will bring dry
and mild weather to western Washington Monday and Tuesday. Offshore flow
will prevail for mostly clear skies. May see gusty east winds below
the Cascade gaps. Expect above normal temperatures with highs in the
middle 50s to lower 60s.
An upper level low will form over the NE Pacific on Wednesday which will
kick the ridge axis farther inland. Temperatures will drop a few
degrees but still remain slightly above normal. The tail end of a
front may clip the coast for a chance of rain. 33
Long term...a warm front will lift north through western Washington on
Thursday for an increase in clouds and a chance of rain across the
region. However models have been backing off on this system and may
not see much rain in the interior. Friday is looking wetter as an
upper level trough digs off the coast and moves inland. There is a
chance of showers on Saturday with onshore flow and a weak
disturbance aloft. We may see a break in the weather on
Sunday...then a wetter Pacific system arrives Sunday night into Monday.
Hydrology...river flooding is not expected in the next 7 days.
Aviation...an upper level ridge over the region will strengthen
overnight. Continued westerly flow aloft. The low level flow will remain
offshore. Areas of LIFR ceilings and visibilities /due to fog/ are anticipated
to develop mainly from kshn to ktcm southward. After 0600 UTC and persist
until 1800 UTC...
Ksea...northerly winds will persist but will become lighter late today or
early this evening. Shallow fog is expected late tonight or early
Monday. Although...a layer of cirrus may inhibit fog development later
tonight. For this reason...confidence in the forecast was not very
high. Will stay with the inherited idea of shallow fog reducing
visibilities to 2sm at the terminal early Monday.
Marine... lower pressure over the offshore waters with a 1040 mb high east
of the Cascades will keep the flow easterly through
midweek...although the surface high will weaken with time. A weak
warm front may clip the area on Wednesday.
Pz...Small Craft Advisory in effect until 6 am Monday for the coastal
waters from Cape Flattery to James Island out to 10 nm and the
West Entrance to the Strait of Juan Delaware fuca.
An illustrated version of this forecast discussion can be seen at