textproduct: Seattle/Tacoma

SYNOPSIS

Upper level ridge centered well offshore with northerly flow in the lower levels. Weak system moving by to the north Friday night and Saturday. Low level flow going back to onshore Saturday. Ridge moving east Sunday ending up over the area Monday into Tuesday with high temperatures inland just a few degrees short of records. Temperatures cooling Wednesday with developing low level onshore flow.

SHORT TERM /TODAY THROUGH SATURDAY/

Satellite imagery shows stratus over the Central and South coast extending as far east as Shelton at 3 am/10z. Clear skies over the remainder of the area. Temperatures were in the upper 40s to mid 50s except upper 50s in the Seattle metro area.

Stratus will not get much further east this morning and will dissipate by late morning. Upper level ridge centered offshore with northwesterly flow aloft. Light flow in the lower levels going northerly this afternoon. This will put a cap on high temperatures near the water. For the most part highs in the 70s and lower 80s inland and lower 70s along the coast.

Upper level ridge remaining offshore tonight into Friday. Flow aloft turning west southwesterly throwing a few high clouds over Western Washington at times. Lows tonight in the upper 40s to mid 50s. Highs Friday a few degrees warmer inland, in the 70s to mid 80s. Afternoon seabreeze along the coast keeping highs near 70.

Weak system riding by to the north late Friday night into Saturday. This will cool the temperatures aloft over the area and induce a weak marine push in the lower levels Saturday morning. The combination of these two variables will lower high temperatures Saturday by 5 to 10 degrees with upper 60s to mid 70s over the interior and lower to mid 60s along the coast. Lows Friday night in the upper 40s to mid 50s.

LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/

Upper level ridge offshore rebuilding Saturday night and Sunday. Ridge axis moving over Western Washington Monday and Tuesday. In the lower levels low level onshore flow Saturday night going light Sunday. Thermally induced surface trough moving up from the south reaching Western Washington Monday morning. The thermal trough will remain over the area through Tuesday night then shift east Wednesday.

Highs Sunday in the 60s along the coast and 70s to lower 80s inland. Monday and Tuesday will be the peak of the warm temperatures this round with 80s and lower 90s inland. Highs on the coast peaking Monday in the 70s before cooling back into the 60s Tuesday. Cooling trend starting Wednesday for the interior with highs in the 70s and lower 80s.

Moderate HeatRisk over the interior Monday and Tuesday will drop back down to the minor category Wednesday.

AVIATION

VFR conditions early this morning for interior terminals. Latest satellite imagery shows marine stratus continuing to develop along the coast. There is a 40-60% chance of MVFR cigs expected between 10z-16z, with a slight chance (10-25%) of IFR/LIFR cigs. Improvement expected in the afternoon along the coast. Widespread VFR conditions expected this afternoon. Another round of MVFR cigs possible (40-60% chance) along the coast tonight. Light to variable winds early this morning will increase this afternoon from the north to 8-12 kt. Winds will ease overnight.

KSEA...VFR conditions today with high clouds at times. Light winds this morning will increase this afternoon to 7-10 kt from the N/NW. Winds will shift NE this evening after 05z-06z at 5-7 kt.

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MARINE

Broad high pressure over the NE Pacific will continue into next week, maintaining northerly surface flow across area waters. Weak high pressure over are waters will weaken late tonight into Friday as a low pressure system passes over British Columbia. High pressure will rebuild over area waters on Saturday and strengthen into early next week.

A combination of elevated seas and winds will continue across the coastal waters through Saturday, likely requiring the extension of the small craft advisory. Diurnal pushes through the Strait of Juan de Fuca expected this Friday into early next week. The winds on Friday and the weekend look to remain below small craft criteria (25- 40% chance). However, the winds on Tuesday will be stronger with a higher chance (40-65%) of winds exceeding 21 kt.

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FIRE WEATHER

Elevated fire weather concerns Friday and again next Monday and Tuesday with minimum relative humidity values dropping to below 30 percent. In some locations Monday and Tuesday minimum RH values will be as low as the teens. Fuels will continue to dry and the atmosphere may become conditionally unstable with the surface thermal trough Monday and Tuesday. Even though the fuels have not reached critical levels fine fuels like grass and brush will ignite quickly with it being so dry. Lets be careful out there the next few days.

With the flow aloft out of the west smoke from Eastern Washington will not make its way into Western Washington. Felton

SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Small Craft Advisory until 5 AM PDT Friday 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-Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm.