![National Oceanic and Atmospheric Administration](/build/images/header/noaa.d87e0251.png)
![National Weather Service](/build/images/header/nws.4e6585d8.png)
![United States Department of Commerce](/build/images/header/doc.b38ba91a.png)
Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA
Issued by NWS Seattle/Tacoma, WA
047 FXUS66 KSEW 031112 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 412 AM PDT Wed Jul 3 2024 .SYNOPSIS...Dry and warm conditions continue this week. High pressure builds and moves over the region late in the week, bringing very hot temperatures this weekend and into the start of next week. The hot and dry conditions will also yield elevated fire weather concerns into the weekend. Some slight cooling is possible later next week, but temperatures are likely to remain well above normal. && .SHORT TERM /TODAY THROUGH FRIDAY/...Another round of low clouds along the coast and portions of the interior this early this morning. This will scatter toward early afternoon though, with another mild afternoon featuring abundant sunshine in store today. High pressure will continue to build over the eastern Pacific and slowly shift eastward through the next few days. This will lead to a steading warming and drying of conditions across the region through the remainder of this week. The initially warm conditions through the Independence Day holiday will transition to hot by the end of the week. Expect high temperatures approaching the 90 degree mark for much of the Puget Sound region Friday (with locally hotter conditions south). This will bring widepsread Moderate (Orange) HeatRisk levels by Friday. .LONG TERM /SATURDAY THROUGH TUESDAY/...The continued warm up looks to peak in magnitude for most of the region over the weekend. There remains strong agreement in the ensemble guidance supporting the ridge axis shifting more directly overhead Saturday and Sunday. While strong offshore winds are not expected, expect that at least some neutral or slightly offshore wind will eliminate any inland push of marine air and the very warm air mass will drive temperatures well into the upper 80s or 90s for much of the region. The forecast continues to closely trend with the 50th percentile data in the NBM, which remains warmer than the deterministic NBM for many days/locations. Overnight low temperatures will hover in the lower 60s for most of the region. These conditions will result in widespread HeatRisk levels of at least moderate/orange with some areas (including the urban heat islands) getting to the Major (red) category. Again, the overnight low temperatures are within a degree or two of the thresholds that would chage things from Moderate or Major in many locations so there may continue to be some fluctuations day to day. However, it`s worth noting that the temperatures for Sunday (and Sunday night) have continued to trend upward for the interior. The potential for several days with high temperatures into the 90s is increasing, and this level of heat can cause to heat-related impacts, especially when considering the accumlated effect of heat and the very mild nights. While some onshore flow will likely bring some relief to the coast Sunday, this is unlkely to push deeper into the interior until at least Monday. However, temperatures are still likely to remain well above normal through much of next week. && .AVIATION...Upper ridge centered offshore will continue to build into the region today with northwesterly flow aloft. The low level flow remains onshore. Low MVFR stratus along the coast will extend locally inland this morning. Much like yesterday morning, a stratocumulus deck is gradually filling in across much of the interior this morning. Ceilings will lower to 2000 to 3000 feet at times for the interior terminals this morning before scattering and clearing this afternoon. Stratus along the coast is expected to burn off 20Z-22Z, but will return by around 06Z tonight. KSEA...Ceilings lower to 2500 to 3000 feet at times this morning before lifting and scattering after 18Z. VFR conditions prevailing this afternoon and evening. Surface winds light S/SW this morning will veer N/NW 5 to 10 knots by mid afternoon into this evening. 27 && .MARINE...Light onshore flow will continue today into Thursday as 1030+ millibar surface ridge remains firmly in place over the offshore waters. Thermally induced low pressure will expand northward along the coast Friday and Saturday resulting in weak offshore flow at times. The thermal trough will shift into the interior on Sunday for a switch to onshore flow early next week. Quieter conditions are expected across area waters until late in the weekend when increasing onshore could necessitate some headlines for the strait and portions of the coastal waters. 27 && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until 11 AM PDT this morning 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 Point Grenville To Cape Shoalwater 10 To 60 Nm. && $$