Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Seattle Washington
239 PM PDT Monday Jul 28 2014
Synopsis...high pressure aloft will remain over the area through
early next week.
an upper ridge will prevail over the region and low level onshore
flow will continue during this period. This will result in dry
weather with above normal daytime temperatures over the County Warning Area.
The onshore pressure gradient this afternoon was tighter than the
previous day and will tighten more on Tuesday. This will translate to
stratus spreading farther inland than this morning...especially
Wednesday morning. The surface pressure gradient is expected to weaken
slightly on Wednesday...resulting in less low clouds over the interior
Will need to keep an eye on subtle changes in the synoptic scale
features. Still think that any thunderstorms will remain south and east of
the County Warning Area but cannot completely rule out the possibility of a
disturbance /rotating north around the western periphery of the
Desert Southwest upper high/ clipping the southeast part of the
County Warning Area.
an upper ridge will remain the dominant feature over the western
USA through early next week. The primary differences in the medium
range solutions were in the details. As stated in the short term
section...will need to keep a close eye on disturbances rotating
around the upper high centered over the Desert Southwest.
Aviation...an upper level ridge centered over the southwestern US
will persist beyond Tuesday night giving southwest flow aloft to the
area. At the surface...high pressure over the offshore waters and
low pressure east of the Cascades will give light to moderate
onshore flow to the area. While some fog and stratus over the
coastal waters will work in through the Strait of Juan Delaware fuca and
onto the coastal zones during the late night and morning hours...the
air mass over the inland areas will be dry and stable resulting in
good VFR conditions. Stratus and fog over the coastal areas will
pull back into the waters of the Pacific during the afternoon and
early evening hours. Albrecht
Ksea...clear skies and VFR conditions will persist through Tuesday.
Expect northwest winds 8-11 knots to turn northeasterly 4-7 knots
after 05z this evening. Albrecht
Marine...high pressure over the offshore waters and lower pressure
east of the Cascades will persist for the next several days. Current
forecast models show onshore pressure gradients a bit higher Tuesday
evening than this evening or Wednesday evening...resulting in
slightly stronger onshore flow late Tuesday afternoon through
The forecast weather pattern will result in varying degrees of
onshore flow for the next week or so. Strongest winds will occur
through the central and eastern Strait of Juan Delaware fuca and over the
coastal waters during the late afternoon and evening
hours...likely resulting in Small Craft Advisory conditions at times
there. There is a slight chance that winds will briefly reach gale
force in the central Strait of Juan Delaware fuca Tuesday evening.
Areas of late night and morning fog can be expected over the coastal
waters and through the Strait of Juan Delaware fuca each day. Albrecht
Pz...Small Craft Advisory in effect for the coastal waters and
central/eastern Strait of Juan Delaware fuca.
For the graphical afd...visit