FXUS66 KSEW 141736 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 1036 AM PDT Tue Apr 14 2026 .SYNOPSIS...Cool, wet and windy conditions Tuesday into Wednesday with periods of heavy snow in the mountains. Drier weather is in store Thursday and Friday with high pressure. Wetter weather returns over the weekend. && .SHORT TERM /TODAY THROUGH THURSDAY/...Rain continues to increase across Western Washington this morning. The primary change to the forecast was to issue a Wind Advisory for the Grays Harbor County coast, as well as the Admiralty Inlet and Everett region. Wind gusts will approach 40 to 45 MPH in these areas, with localized power outages possible. Previous discussion below: Wet and windy conditions on tap today as a strong Pacific storm system sweeps through western WA. The main impact will be periods of heavy mountain snow, including snow at all Cascade passes - Winter Storm Warnings are in effect. Snow levels will hover around 3500 ft today but will drop to 1500-2000 tonight into Wednesday. The bulk of the heavy snow will fall tonight but there will be lingering snow showers moving through Wednesday. Mean 48-hr storm total amounts range from 10 to 20" with highest amounts over the volcanoes. Heavy snow is also possible for the Olympics and a Winter Weather Advisory is also in effect (primarily for today and tonight). In addition, it'll be windy today with gusts to 20-30 mph common across most lowland areas. Winds will peak this evening but still remain in 15-25 mph range overnight. A deep upper low will be overhead on Wednesday with cool and showery conditions. As mentioned above, we'll still see snow showers in the mountains although snow rates will ease. The air mass is slightly unstable with a chance of thunderstorms too, especially near the coast. Showers will taper off Wednesday night as the low opens to a trough and exits east. It's not as windy but will be chilly with morning lows in the 30s and highs in the 40s to around 50. We're under dry northerly flow on Thursday as high pressure forms offshore. Morning temperatures will remain cool and in the 30s with freezing temps and frost possible across the south sound. Highs will be a little warmer and in the 50s with sunbreaks. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...High pressure will shift inland on Friday for more dry and stable weather. Morning lows will still track on the cool-side with possible frost around the south sound. The ridge departs on Saturday with a return of moist SW flow. Showers associated with an offshore low may clip the coast during the afternoon and evening. Showers will spread inland on Sunday as the low shifts farther east and inland. By Monday, this system shifts to our south, over CA/NV, with a brief break in the weather over western WA. 33 && .AVIATION...A frontal system will continue to push into the region today, producing a mixed bag of generally MVFR to localized LIFR conditions as precipitation and low clouds spread inland. Visibilities will deteriorate in heavier rain this afternoon, with widespread MVFR/IFR ceilings. Stratiform rain will shift southeastward of the area this evening, with a Puget Sound Convergence Zone favored to develop and showers streaming inland later tonight into Wednesday. Southwest surface winds will become breezy this afternoon/evening as the front passes, becoming generally 10-20 kt with gusts to 30 kt. Winds will gradually taper overnight into Wednesday becoming south to southwest 5-10 kt. Thunder is possible (low 15% chance) this afternoon for the coastal terminals and in the convergence zone, with increasing chances (20% chance) along the coast Wednesday, but confidence not high enough to include in the TAFs. KSEA...MVFR this morning in low ceilings and reduced visibility as rain spreads over the terminal. Rain will taper off this evening with showers overnight. MVFR conditions are favored to continue at the terminal through late tonight before VFR conditions develop Wednesday morning. A post-frontal convergence zone is favored to develop later this afternoon, but will likely stay north of the terminal. South to southwest surface winds will continue to increase this morning into the afternoon to 15-20 kt with gusts to 30 kt. Winds will ease after 06z Wed becoming south to southeast overnight. A lightning strike or two is possible at the terminal if convergence zone activity drifts southward, but is unlikely. Chances for thunder increase into Wed. 15 && .MARINE...A cold front will move across the waters through today resulting in strong southerly winds. Have issued Gale Warnings for portions of the Coastal Waters, as well as Puget Sound and Admiralty Inlet, due to the probability of gale force wind gusts ranging between 60 to 90 percent. South winds will be strongest near Everett and Admiralty Inlet for the inner waters. Small Craft Advisory winds are expected elsewhere as well. South winds will peak through this evening. West winds will increase through the Strait of Juan de Fuca this evening into tonight. SCA west winds are expected for the central and eastern Strait during this period, but will need to monitor the potential for gale gusts as well. Winds will decrease on Wednesday with onshore flow. Unsettled weather on Wednesday will result in a slight chance for thunderstorms over the waters. Drier weather returns Thursday through Saturday. Seas increase from 4-6 ft to 9-12 ft Tuesday, lingering at 8-10 ft through Thursday, then decreasing to 3-5 ft Friday through Sunday before building back to 8-10 ft. JD/HPR && .HYDROLOGY...No river flooding the next 7 days. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...Winter Storm Warning until 11 PM PDT Wednesday for Cascades of Pierce and Lewis Counties-Cascades of Snohomish and Northern King Counties-Cascades of Southern King County- Cascades of Whatcom and Skagit Counties. Winter Weather Advisory until 11 PM PDT this evening for Olympics. PZ...Small Craft Advisory from 2 PM this afternoon to 2 AM PDT Wednesday for Grays Harbor Bar. Small Craft Advisory until 2 AM PDT Wednesday for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca-West Entrance U.S. Waters Strait Of Juan De Fuca. Small Craft Advisory until 2 AM PDT Wednesday for Northern Inland Waters Including The San Juan Islands. Small Craft Advisory until noon PDT today for Admiralty Inlet. Gale Warning from noon today to 11 PM PDT this evening for Admiralty Inlet. Small Craft Advisory until 2 PM PDT this afternoon for Puget Sound and Hood Canal. Gale Warning from 2 PM this afternoon to 11 PM PDT this evening for Puget Sound and Hood Canal. Small Craft Advisory until 5 AM PDT Thursday for Coastal Waters From Cape Flattery To James Island 10 To 60 Nm- Coastal Waters From Cape Flattery To James Island Out 10 Nm. Gale Warning until 8 PM PDT this evening for 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. Small Craft Advisory from 8 PM this evening to 5 AM PDT Thursday for 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. && $$