383 FXUS66 KSEW 292153 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 253 PM PDT Mon Jun 29 2026 .SYNOPSIS... A broad upper level trough will continue to produce unsettled and cool conditions across Western Washington into midweek along with chances for mainly mountain showers. Drier conditions and a modest warming trend are expected for the upcoming holiday weekend as a weak ridge begins to build offshore. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... The overall weather pattern looks to remain consistent through the short term period with broad upper level troughing over much of the western U.S. Cool and cloudy conditions will prevail with high temperatures remaining below normal, in the mid to upper 60s. Low temperatures will remain around normal, in the upper 40s to mid 50s. Clouds will attempt to give way to some sun breaks, but mostly cloudy conditions will prevail through the vast majority of the day. Slight chances for isolated showers or drizzle from the marine stratus will persist over the mountains, but meaningful precipitation accumulation is not forecast. && .LONG TERM /THURSDAY THROUGH MONDAY/... A shortwave impulse looks to move over the area on Thursday, bringing a weak frontal system that will traverse the area. Models are keeping this system mostly dry, with the exception of some light precip over the northwest portions of the Olympic Peninsula. Otherwise, cloud conditions will continue for Thursday. Friday and into the holiday weekend, the model spread gets larger, but are hinting at weak ridging developing offshore. This should help to bring more sun back into the forecast, as well as warming temps closer to normal, up into the mid to upper 70s. && .AVIATION... Broad upper troughing over the interior West will maintain northwesterly flow aloft over Western Washington. MVFR cigs under stratus is very slowly beginning to break this afternoon. At this point, will likely just be a brief period of higher-end MVFR to low-end VFR cigs before clouds fill in and lower once again overnight. Localized IFR conditions will be possible early tomorrow morning. The pattern will repeat itself again with cigs gently raising and breaking up late morning into the afternoon. Southwest winds 5-10 kt will continue overnight into tomorrow. KSEA...MVFR cigs with stratus beginning to break up. Will likely only be a brief period this evening with low-end VFR before stratus fills back in and lowers to MVFR. Periods of IFR cannot be ruled out, particularly between 14-17Z Tue. The pattern repeats tomorrow with a slow lift of cigs with some breaks in the afternoon. Southwest winds 5-10 kt will continue overnight into tomorrow. 62 && .MARINE... Broad high pressure centered well offshore and lower pressure across the interior will remain the dominant weather pattern through Wednesday. This will maintain onshore flow with gusty northwesterlies and steep seas up to for the coastal waters, especially through the outermost waters where seas may reach up to 11-13 ft. Diurnally driven westerly pushes will occur in the Strait of Juan de Fuca as well for Small Craft Advisory winds each afternoon and evening through the next seven days. High pressure looks to weaken during the later half of the week as a broad surface low approaches the central British Columbia coast and may bring a weak frontal system through the coastal waters on Thursday. This will weaken onshore flow allowing winds over the coastal waters to ease and seas subside. 27/62 && .FIRE WEATHER... Little in the way of fire weather concerns remain in the picture into the week ahead as upper level troughing maintaining cool conditions, high RH, and periodic chances for shower activity. A trend toward more drier and more seasonable temperatures is indicated toward late week, but a significant warm and dry spell is not expected in the next 7 days. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory from 4 PM this afternoon to 2 AM PDT Tuesday for Central U.S. Waters Strait Of Juan De Fuca- East Entrance U.S. Waters Strait Of Juan De Fuca. Small Craft Advisory until 5 AM PDT Wednesday 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. && $$