Small Craft Advisory 162, NWS Seattle, WA

Area Forecast Discussion
National Weather Service Seattle WA
902 PM PDT Sat Jul 1 2017

.SYNOPSIS...Weak high pressure aloft will move east Sunday
morning, allowing a weak low pressure system to prevail over the
region through Monday. High pressure aloft will return on
Independence Day. Onshore flow of varying strength will continue
for night and morning clouds.

&&

.SHORT TERM...
The low clouds cleared out across much of the coast late this
afternoon but will return late this evening. The surface onshore
pressure gradient was weaker than the previous day; therefore,
expect less stratus coverage Sunday morning than this morning.
Otherwise, expect a weak short wave ridge aloft to prevail
overnight.

Onshore flow will prevail through Independence Day with high
pressure over the NE Pacific. Expect a typical pattern of late
night and morning clouds with sunshine in the afternoon.
Temperatures will be near or a little above normal during the
period. The flow aloft will be zonal but 500 mb heights will
remain around 580 decameters.

There will be a slight chance of light rain or drizzle early
Monday morning on the central Puget Sound where there will be
weak low level convergence. Otherwise, expect mainly dry
conditions. 33/05

.LONG TERM FROM THE PREV DISCUSSION...
An Omega Block pattern will develop midweek and persist into late
next week across the CONUS. This blocking pattern will keep the
weather over Western WA dry. Temperatures will warm a few degrees
as the flow turns S/SW and onshore flow eases - expect highs in
the low to mid 80s in the interior. 33

&&

.AVIATION...A weak upper ridge over the area will shift inland on
Sunday with westerly flow aloft. At the surface, onshore flow will
prevail with high pressure offshore and lower pressure inland. The
air mass is stable. Stratus at the coast will spread inland
tonight and then burn back to the coast again later Sunday.

KSEA...Clear this evening. Low clouds should reach the terminal
around daybreak Sunday then burn off by midday. Westerly wind 3-6
knots will become southerly after midnight tonight and then
westerly again Sunday afternoon. Schneider

&&

.MARINE...Onshore flow will prevail for the next several days.
Gale force west winds are likely for the Central and Eastern
Strait the next couple of evenings with small craft advisory winds
for the adjacent inland waters. Expect small craft advisory west
winds in the Strait each evening next week as onshore flow
continues. There will also be small craft advisory northwest
winds over the Coastal Waters at times Sunday night through
Thursday. Schneider

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Gale Warning until 3 AM PDT Sunday for Central U.S. Waters
     Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of
     Juan De Fuca.

 	 Small Craft Advisory until 3 AM PDT Sunday for Admiralty
 	 Inlet-Northern Inland Waters.

	 Gale Watch from Sunday afternoon through late Sunday night
	 for Central U.S. Waters Strait Of Juan De Fuca-East Entrance
	 U.S. Waters Strait Of Juan De Fuca.

&&

www.weather.gov/seattle

An illustrated version of this forecast discussion can be seen at
www.wrh.noaa.gov/sew/gafd/latest_webafd.html