Small Craft Advisory 71, NWS Seattle, WA

Area Forecast Discussion
National Weather Service Seattle WA
230 PM PDT Sat Mar 25 2017

.SYNOPSIS...A few showers will end this evening. A front will bring
rain to Western Washington Sunday. A trough will dissipate over the
area on Monday. A warm front will brush the area Tuesday. A rather
wet frontal system will reach the area Wednesday. An upper trough
and onshore flow will keep showers in the forecast Thursday. Dry
weather is possible for the end of the week.

&&

.SHORT TERM...After isolated showers end this evening, tonight will
be dry under weak high pressure. A front will spread rain back into
Western Washington Sunday. The rain will break up or turn to showers
Sunday evening. A trough will keep a chance of showers in the
forecast Monday. Weak high pressure Monday night will give way to a
warm front and some rain again Tuesday.

.LONG TERM...A frontal system will move slowly through the area
Tuesday and Wednesday. Tuesday does not look too wet--it is just a
brush by warm front and most of the rain goes into British Columbia
during the day. That front sags south into Western Washington
Tuesday evening, and the rain picks up, and then a surge of heavier
rain should arrive later Tuesday night through Wednesday. The front
moves inland Wednesday night, and then a cool upper trough will move
through the region Thursday with a good chance of the PSCZ setting
up. Friday looks like it has a good chance to be a dry day under
high pressure, and that might extend into next Saturday as well.

&&

.AVIATION...A weak upper trough over central Washington this
afternoon will continue east inland tonight. Westerly flow aloft
over Washington. Air mass stabilizing tonight. The next upper trough
well off the coast is forecast to approach the coast Sunday with an
accompanying frontal system to spread clouds and rain onshore during
the day Sunday.

VFR conditions through midday Sunday. Remaining cumulus to dissipate
around sunset (02z) this evening with increasing mid/high level
clouds ahead of the incoming system arriving overnight. Anticipating
rain starting along the coast around 13z and spread into the western
interior by midday. Ceilings likely to decline in rain to MVFR with
the front moving onshore 21z-01z time frame.

KSEA...VFR conditions through midday Sunday. Scattered cumulus to
dissipate this evening with increasing mid/high level clouds
overnight. Rain starting 18z-20z Sunday. Ceilings may fall to MVFR
with the front around 00z late Sunday. SW winds around 10 kt to ease
this evening and become more SE overnight. Buehner

&&

.MARINE...A weak ridge of higher pres over Western Washington will
move east of the Cascades tonight. A Pacific frontal system about
350 nm offshore is expected to approach the coast tonight with
offshore flow developing. Have issued a gale warning for southerly
winds ahead of the front for the offshore outer waters Sunday.
Expect small craft advisory winds ahead of the front all waters
except south of Admiralty Inlet.

The front should move ashore late Sunday. The next frontal system is
forecast to arrive Tuesday with another moving onshore Wednesday
night. Looks to be another active weather week ahead to finish the
month with short breaks between systems. Buehner

&&

.HYDROLOGY...River flooding is not expected for the next 7 days
with the exception of the flood prone Skokomish river in Mason
County where heavier rain in the Olympics Tuesday night and
Wednesday could be enough to get the river above flood stage.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Gale Warning from Cape Flattery to Cape Shoalwater 10 NM
     out to 60 NM.

     Small Craft Advisory all other coastal waters except Puget
     Sound/ Hood Canal.
&&

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