FXUS66 KSEW 090857 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 157 AM PDT Thu Jul 9 2026 .SYNOPSIS... Weak high pressure aloft will lead to seasonal temperatures and dry conditions across Western Washington today. A weak front will bring increasing clouds and cooler temperatures to the region Friday into Saturday along with a chance for a little rain. High pressure will strengthen once again for warmer and dry conditions Sunday through Tuesday. Cooler conditions return by the middle of next week as onshore flow increases. && .SHORT TERM /TODAY THROUGH SATURDAY/... Mostly high level clouds are drifting across the area this morning in zonal flow aloft while onshore flow near the surface begins to ease. With less in the way of low cloud coverage this morning, high temperatures across interior areas will see a little boost. Onshore flow ramps up once again late today ahead of a weak front that will reach the area Friday afternoon into Friday night. As with most fronts this time of year, the best precip chances will be restricted to the Olympic Peninsula and North Interior, but it's not out of the question to see a few sprinkles reach Seattle metro...just don't hold your breath on that. We will, however, see cooler temperatures and plenty of cloud cover that will linger into Saturday as a trailing upper trough comes onshore before lifting northeastward into British Columbia. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... For Sunday through Tuesday, we'll be on the northwest periphery of a monster upper ridge building over the Rockies and Northern Great Plains. This will give us a mini warming trend with temperatures peaking in the lower (or mid) 80s in the warmest spots on Monday. Ensembles maintain anomalous upper troughing along the British Columbia coast into the middle of next week, but there's some disparity with regard to it's depth. We're quickly approaching the climatologically driest and warmest portion of the year in Western Washington. Most troughs approaching from the northwest by mid-July do little more than initiate increasing onshore flow to cool us down. Given that, a good day 7 forecast leans toward near climo temps and dry conditions. 27 && .AVIATION... Onshore flow continues through Thursday, though widespread stratus formation is less likely. There's a 30-50% chance of MVFR/IFR cigs returning along the coast after 09z Thu, though only a 20-40% chance it will push as far inland as KHQM. Additionally, there's a 15-30% chance of some marginal MVFR ceilings reaching inland to Seattle by daybreak. Where stratus does form, more rapid clearing is expected Thursday with VFR conditions for most TAF sites by 17-19z. A stronger marine push is expected Thursday night into Friday morning with an 80% chance of at least MVFR cigs developing along the coast by 06-08z Fri and a 40-60% chance of widespread MVFR cigs pushing inland to Seattle by daybreak Friday. Winds have settled overnight except for gusts up to 20-25 kts along the Strait of Juan De Fuca, impacting KCLM through Thursday. Elsewhere, winds remain lighter, generally less than 8 kts. KSEA...A pocket of stratus has lingered near the terminal since Wednesday evening, producing a ceiling deck around 3500-4500 ft. There's a 15-25% chance of marginal MVFR ceilings by daybreak. Ceilings are expected to lift above 5000 ft by 16-18z Thu with a scattered to broken high cloud deck lingering. There are better chances (40-60%) for widespread MVFR cigs to return by 12-15z Fri. Winds will be light through the period, from the southwest through Thursday morning, becoming west to northwest in the afternoon. && .MARINE... Surface high pressure over the coastal and offshore waters will remain in place today before weakening on Friday as aweak surface low shifts southward toward to just west of north Vancouver Island. An associated weak frontal system will cross the waters Friday afternoon into Friday night with little impact. High pressure rebuilds over the coastal waters Sunday into Monday. Diurnally driven increases in westerlies can be expected in the Strait of Juan de Fuca each the next several days. 27 && .FIRE WEATHER... The current onshore pattern will continue through the weekend which will lead to continued excellent nightly RH recoveries. A ridge of high pressure briefly rebuilds into the region early next week. While the onshore pattern will largely remain in place, warmer daytime temperatures and clear skies will likely lead to RH values dipping into the 30s and 20s, with the lowest values in the south interior and Cascades. This will allow fine fuels to continue to dry with elevated fire weather conditions. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until 5 AM PDT early this morning for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. && $$