03:25 PM Wednesday March 20

A transition to onshore flow starting tonight will bring marine air inland resulting in clouds, moisture and cooler temperatures into thursday. Light rain will spread northeast across the area friday marking the start of an active weather pattern through the weekend. Temperatures for the remainder of the week will be near normal.

SHORT TERM /TODAY THROUGH FRIDAY/

Looking at current observations...temperatures at any given location appear to be dependent on wind direction. Locations that retain low level offshore flow...aka easterly winds...are seeing temps in the mid to upper 70s while locations that are seeing northerly or westerly winds are reporting temps more in the mid to upper 60s range. The most notable stand out regarding temperature would be sea- tac...reaching 79 at 120 pm pdt this afternoon...that happening after the temp there jumped 8 degrees in the span of 20 minutes all thanks to the change in wind direction.

This looks like it will be the last hurrah of the little summer preview that has been in place over w wa the past couple of days. A transition to onshore flow will start to usher in some cooler air and additional clouds overnight tonight and into tomorrow. An upper level low passing well south of the area...down in central ca...may wrap some moisture into the area by thursday afternoon/evening...but models continue to be rather meh about it. Would not rule out a stray shower...mainly confined to higher terrain...but overall tomorrow should remain dry...albeit cooler and cloudier. temperatures tomorrow will end up being more in line with seasonal averages...although still may end up a few degrees warmer.

The next chance for widespread precip comes in the form of an approaching front expected to reach the wa coast early friday afternoon...spreading inland late in the afternoon and into the evening. The gfs has the front breaking apart as it moves eastward over the area although the ecmwf has it remaining far more cohesive. opted to not deviate too much from inherited forecast keeping pops in the high-end chance to low-end likely range. Temps friday look to not stray too far from what is expected on thursday...near to slightly above normal. smr

LONG TERM /SATURDAY THROUGH TUESDAY/

The upper level trough associated with the aforementioned friday front will keep showers in the forecast for saturday with the ecmwf proving to be the wetter solution with more moisture remaining over the area. This is probably a bit more true to what can be expected...as the gfs solution might be a touch on the optimistic side. Both models show the trough exiting saturday night with a shortwave ridge expected behind it for sunday. Neither model is terribly impressive with this feature but there is the general agreement that dry conditions will persist through the day and into monday morning. A storm system out over the pacific will be the next system down the conga line...bringing moisture up from the south and thus a return of precip by late morning/early afternoon monday. This system looks to churn over the pacific for the remainder of the forecast period...so although models agree that there might be a bit of a dry window for late morning/early afternoon tuesday...certainly not anything worth putting any stock in at this time. smr

HYDROLOGY

River flooding is unlikely over the next seven days.

SEW WATCHES/WARNINGS/ADVISORIES

Wa...none. Pz...small craft advisory from 11 pm this evening to 5 am pdt thursday for coastal waters from point grenville to cape shoalwater 10 to 60 nm-coastal waters from point grenville to cape shoalwater out 10 nm-northern inland waters including the san juan islands.

 small craft advisory for rough bar until 9 pm pdt this evening       for grays harbor bar.

 small craft advisory from 2 am to 11 am pdt thursday for coastal       waters from cape flattery to james island 10 to 60 nm-      coastal waters from cape flattery to james island out 10 nm-      coastal waters from james island to point grenville 10 to       60 nm-coastal waters from james island to point grenville       out 10 nm.

 small craft advisory until 5 pm pdt this afternoon for central       u.s. Waters strait of juan de fuca-coastal waters from cape       flattery to james island out 10 nm-west entrance u.s.       waters strait of juan de fuca.

MARINE

Offshore flow will persist through this evening. Breezy winds near the gaps of the coastal terrain - strongest easterly winds will be along the central strait of juan de fuca. Sca issued for tonight into tomorrow morning for coastal waters as a small scale surface low will push north along the coast.

Light onshore flow will develop on thursday ahead of a weakening front spreading into the region on friday. Westerly swell 10 to 12 feet will begin to affect the coastal waters friday night rising to 14 feet at 16 seconds saturday.

AVIATION

Southeasterly flow will continue aloft with low level offshore flow continuing into tonight. The air mass will remain dry and stable. Vfr conditions. Easterly winds will remain strong across portions of the southern sound through the evening. Winds generally east-northeasterly from 5 to 15 knots. Gusts up to 25 knots possible for ksea and khqm. Winds will turn more onshore later tonight with increasing high to mid level cloud cover tomorrow morning ahead of a weak frontal system.

Ksea...vfr conditions with easterly winds continuing through the evening. Gusts up to 27 knots possible. Increasing mid to high level cloud cover tonight with onshore winds generally following 09z. Jd