


Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA
Issued by NWS Seattle/Tacoma, WA
796 FXUS66 KSEW 130922 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 222 AM PDT Sun Jul 13 2025 .SYNOPSIS...Warm and dry conditions will continue through the weekend with upper level ridging over the region. A brief reprieve in temperatures is likely on Monday as a system slides southward from British Columbia and skirts the area. Warmer and drier conditions are expected again around midweek, with highs potentially reaching the 90s for some lowland locations. && .SHORT TERM /TODAY THROUGH TUESDAY/...Warm and dry conditions continue across western WA today with broad high pressure over the West. Daytime highs in the interior will reach the 80s to lower 90s leading to Moderate HeatRisk. It`ll be cooler along the coast and in the 60s due to NW onshore winds. The air mass will be slightly cooler on Monday as a trough drops down from B.C. Expect highs in the 70s to lower 80s with 60s again along the coast. Showers with this trough are mainly north of the border and east of the Cascade crest. Heights rebuild on Tuesday with strong high pressure now centered offshore (along 140W). A thermal trough will form along the coast and the interior will see temps in the 80s to lower 90s again with Moderate HeatRisk. 33 .LONG TERM /WEDNESDAY THROUGH SATURDAY/...Strong high pressure will lead to warm and dry weather through Thursday, with elevated fire weather concerns as well. Temperatures will peak on Wednesday with interior highs in the 80s and 90s, and lows mostly in the 60s. The thermal trough will shift inland on Thursday with broader relief on the coast, but still warm in the interior. A weak push on Friday brings temperatures closer to average. Same for the weekend as onshore flow prevails. Still no precip in sight. 33 && .AVIATION...Upper level ridging continues to remain offshore for northwesterly flow aloft across the area. VFR for all terminals this morning will continue throughout the period. The exception being KHQM, where patchy marine stratus may bring brief MVFR/IFR conditions early this morning. Northerly winds will continue across the region with generally 8 to 12 knots, with KCLM seeing more westerly winds 10 to 15 knots later this evening and gusts up to 20 to 25 kts. KSEA...VFR this morning will continue throughout the period. N/NE winds this morning 4 to 8 knots will increase after 20z generally around 9 to 14 knots, with the potential of some gusts up to 20 kts as well. Northerly winds look to remain elevated throughout most of the evening. Mazurkiewicz && .MARINE...Surface high pressure remains offshore with gentle low level onshore flow throughout the area waters. Diurnally driven westerly pushes down the Strait will continue over the next several days. Latest guidance has shown more strength in the westerly push tonight, therefore have put out a Gale Warning for the Central and Eastern Strait for this evening. Northerly winds also look to increase over the coastal waters this evening along with steep seas, so A Small Craft Advisory has also been issued for this evening. Thermal troughing looks to build along the coast through midweek, with periodic increases of northerly winds through the area waters. Combined seas 4 to 6 feet look to gradually increase to 8 to 10 feet by early Monday. Seas will likely remain elevated throughout the first half of the week. Mazurkiewicz && .FIRE WEATHER...High pressure over the region will maintain warm and dry conditions across Western Washington this weekend. Modest onshore flow will provide for excellent overnight recoveries for most of the lowlands. However, Sunday afternoon will see RH values dip down into the 25-30% range for areas in the interior. A weak trough slides through the region on Monday, boosting cloud cover and humidities, as well as bringing cooler temperatures into the region. This is a short break as elevated fire weather concerns return by the middle of next week, with minimum RH values approaching critical thresholds. While flow remains mostly northerly or northeasterly, the combination of daytime breezes overlaying the lowest RHs may elevate concerns around Wednesday and Thursday for much of Western Washington as a thermal trough may build over the region. This could further enhance instability as well. That said, ensemble guidance continues to exhibit a wide range of potential outcomes for this time period and confidence remains a bit lower in the details of potential elevated or critical conditions during the middle to late portion of next week. Cullen && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Gale Warning from 3 PM this afternoon to 6 AM PDT Monday for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. Small Craft Advisory from 5 PM this afternoon to 5 AM PDT Monday for Admiralty Inlet. Small Craft Advisory from 3 PM this afternoon to 7 AM PDT Monday 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. && $$