Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA
Issued by NWS Seattle/Tacoma, WA
847 FXUS66 KSEW 111036 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 336 AM PDT Thu Jul 11 2024 .SYNOPSIS...Flat upper level ridge over Western Washington into the first part of next week. Upper level flow becoming southwesterly Tuesday or Wednesday in response to an upper level trough well offshore. Low level flow remaining onshore for the next week. && .SHORT TERM /TODAY THROUGH SATURDAY/...Satellite imagery shows stratus along the coast extending eastward a little down the Strait of Juan de Fuca. Clear skies over the remainder of the area. Temperatures at 3am/10z were in the mid 50s to mid 60s. Little change in the pattern for the next three days. Flat upper level ridge over Western Washington with 500 mb heights in the mid 580 dms. Low level onshore flow of varying degrees through Saturday. Stratus developing along the coast each evening/early morning moving eastward in the early morning hours but at this point it does not look like it will get east of the Puget Sound. High temperatures in the mid 70s to mid 80s over the interior with mid 60s to lower 70s for the coast. Lows with the onshore flow will be cooler than the readings the last few days, in the 50s and lower 60s. .LONG TERM /SUNDAY THROUGH WEDNESDAY/...Small change in the pattern Tuesday or Wednesday with the upper level flow becoming southwesterly in response to an upper level trough well offshore. 500 mb heights stay in the lower to mid 580 dms range. The operational GFS has a trough moving inland Monday but this solution is somewhat of an outlier looking at the ensembles. The ECMWF does not indicate a trough Monday. Low level flow remaining onshore through the period. Persistence a good forecast with some stratus developing along the coast each evening creeping inland overnight but for the most part staying west of the Puget Sound. High temperatures remaining in the mid 70s to mid 80s over the interior and mid 60s to lower 70s along the coast. Felton && .AVIATION...WSW flow aloft through the TAF period. Largely VFR for most terminals today but KHQM has a 40-50% chance of IFR to MVFR cigs developing between 11-13z before clearing towards 19-21z if manifests. Low-level onshore flow looks to prevail with an additional round of marine stratus possible overnight and into Thursday for coastal terminals and maybe a couple inland as well. VFR mostly elsewhere. KSEA...VFR throughout the TAF period. Surface winds varying between NE and NW around 5 to 10 kt. McMillian && .MARINE...A stout surface high well offshore will remain in place into next week with lower pressure inland. Currently, a gale warning is in place for the central and eastern strait but will be allowed to expire this morning. However, it`ll replaced by another round of SCA entering this afternoon-evening into the overnight hours. SCA are also in action for the coastal waters today, and may need to be extended well into Friday for the outer zones due to northerly winds. Persistent onshore flow will remain in place into the weekend with diurnally driven westerly pushes through the strait, possibly accompanied with additional headlines. Seas increasing to 6 to 8 ft today and nearing 10 ft tonight into Friday for the outer coastal waters. Seas should subside into the weekend. McMillian && .CLIMATE...Seattle average temperature for the first 10 days of July is 72.7 degrees. This is the 2nd warmest first 10 days of July in 80 years of records at Seattle-Tacoma airport. The warmer year was 2015 where the first five days of the month were in the 90s and the average temperature for the first 10 days of the month was 73.6 degrees. July 2015 is the warmest July on record in Seattle. Felton && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Gale Warning until 7 AM PDT this morning for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. Small Craft Advisory from 2 PM this afternoon to 5 AM PDT Friday for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. Small Craft Advisory from 2 PM this afternoon to 2 AM PDT Friday for Coastal Waters From Cape Flattery To James Island Out 10 Nm-Coastal Waters From James Island To Point Grenville Out 10 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm. Small Craft Advisory until 5 AM PDT Friday for Coastal Waters From Cape Flattery To James Island 10 To 60 Nm-Coastal Waters From James Island To Point Grenville 10 To 60 Nm- Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm. && $$