Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA
Issued by NWS Seattle/Tacoma, WA
900 FXUS66 KSEW 111651 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 951 AM PDT Thu Jul 11 2024 .SYNOPSIS...An upper level ridge remains over Western Washington through the weekend with continued low-level onshore flow. This will maintain above normal temperatures, but still notably cooler than the start of the week. Little change through the week ahead, with no rain expected and only subtle variations in the strength of the marine pushes each night. && .SHORT TERM /TODAY THROUGH SATURDAY/... Forecast remains on track this morning with no updates required. Previous discussion follows. 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 except for KHQM which will continue to have MVFR cigs before clearing towards 19-21z as marine stratus burns off. 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/Mazurkiewicz && .MARINE...A stout surface high well offshore will remain in place into next week with lower pressure inland. Small craft advisories are valid 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/Mazurkiewicz && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...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. && $$