Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA
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Issued by NWS Seattle/Tacoma, WA
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-- Discussion containing changed information from previous version are highlighted. --210 FXUS66 KSEW 300937 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 237 AM PDT Mon Jun 30 2025 .SYNOPSIS...-- Changed Discussion --High pressure aloft will maintain warm and dry conditions across the region early this week. As the high pressure weakens toward midweek, expect a return to near normal temperatures. Most areas remain dry through the week, though a few showers are possible near the coast and mountains by the end of the weekend.-- End Changed Discussion --&& .SHORT TERM /TODAY THROUGH WEDNESDAY/...-- Changed Discussion --High pressure remains in place over the region this morning, setting the stage for another warm and dry day across Western Washington. Expect temperatures to trend a few degrees warmer today than yesterday, with widespread 80s this afternoon and the warmest spots approaching or reaching the 90 degree mark. This will maintain an area of Moderate (Orange) HeatRisk across the interior from central Puget Sound southward, as well as in the foothills and Cascade valleys. Developing onshore flow Tuesday will usher in a cooler day for the coastal areas and spots west of Puget Sound, but not much relief for the urban corridor from Seattle to Tacoma. Similarly, warmer conditions linger eastward into the Cascade valleys will the cooling marine air won`t solidly arrive until Wednesday. This deeper marine push Wednesday will bring temperature down closer to normal. While precipitation isn`t expected, there should be some additional clouds in the morning and midday hours. .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...Confidence in the specifics of the pattern late in the week, including the Independence Day holiday, remains rather low with ensemble guidance continuing to exhibit a rather large spread in how the pattern may evolve. The forecast continues to reflect the most likely scenario of a generally zonal flow pattern that will provide for some morning clouds and temperatures close to (or slightly above) seasonal normals. This would leave the door open to perhaps a few light showers near the northern coast and in the North Cascades over the weekend, but even in these favored locations the chance of rain remains quite low (less than 20 percent) for the weekend. 12-- End Changed Discussion --&& .AVIATION...-- Changed Discussion --An upper ridge axis will continue to gradually shift east of the area today with light west to southwest aloft. The air mass remains dry and stable with the exception of a shallow marine layer along the immediate coast. VFR conditions will prevail across the majority of the region today. Increasing low level onshore flow will bring LIFR/IFR stratus inland through the Chehalis Gap and Strait of Juan de Fuca late tonight, but it is unlikely to reach terminals east of Puget Sound on Tuesday morning. KSEA...VFR. Surface winds northeasterly 7 knots or less early becoming N/NW 8 to 11 knots this afternoon. 27-- End Changed Discussion --&& .MARINE...-- Changed Discussion --Surface ridging centered over the offshore waters and thermally induced low pressure across the interior of Western Washington will lead to continued gusty northwest winds and choppy seas across the coastal waters into tonight. The thermal trough over the interior will gradually shift eastward tonight resulting in progressively stronger westerly pushes in the Strait of Juan de Fuca later today and again on Tuesday. A dissipating front and associated upper trough will swing across the waters late Wednesday before weak surface ridging rebuilds across the waters late in the week. 27-- End Changed Discussion --&& .FIRE WEATHER...-- Changed Discussion --High pressure over the region will maintain warm and dry conditions across the region through midweek. Expect daytime RH values to dip to around 30-35% across the Cascades and from central Puget Sound southward. Expect elevated fire weather conditions with a few spots perhaps approaching 25%. Light north or northeast breezes increase in the afternoons. Only modest RH recoveries Tuesday morning in the Cascades under the inversion, though areas west of Puget Sound will see some influence from a marine push. A deeper marine push Wednesday will bring better recoveries and cooler temperatures later in the week. However, outside of some 20% shower chances in the North Cascades and near the coast over the weekend, precipitation is not expected through the week ahead.-- End Changed Discussion --&& .SEW WATCHES/WARNINGS/ADVISORIES...-- Changed Discussion --WA...None. PZ...Small Craft Advisory from 5 PM this afternoon to 5 AM PDT Tuesday for Central U.S. Waters Strait Of Juan De Fuca- East Entrance U.S. Waters Strait Of Juan De Fuca. Gale Watch from Tuesday afternoon through late Tuesday night 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 Tuesday 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 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.-- End Changed Discussion --&& $$