Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
738 FXUS66 KSEW 260419 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 919 PM PDT Sat May 25 2024 .SYNOPSIS...Showery and cooler conditions will continue into Sunday as an upper level trough moves through the region. Upper level ridging will slowly begin to build east of our area through Monday for slightly warmer temps, with troughing over the Pacific still keeping an influence over western Washington. A frontal system will move through on Tuesday for another bout of rain and cooler temperatures. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
-- Changed Discussion --
Radar imagery continues to show isolated showers across western Washington, particularly over the Cascades, the Pacific Coastal regions, and through the northern Hood Canal up towards Port Townsend. These showers are being forced by a weak departing upper-level trough. Low temperatures tonight into the upper 40s. A weak frontal system will eject from a large upper level trough in the Gulf of Alaska and move through the northern part of our area tomorrow, weakening as it does so. The North Coast, the Northwest Interior, and the Cascades will receive the bulk of the rain, leaving only a few light showers with minimal accumulations expected for the remained of the region. Mostly dry conditions are expected south and east of Seattle. High temperatures similar to today, in the mid to upper 50s. An upper level ridge will start to build east of our area, in the Interior West, while broad troughing offshore will remain close enough to keep an influence over western Washington. Temperatures will also warm up a little on Memorial Day, with high temps in the upper 60s in the interior lowlands, while locations near the water will be in the lower 60s. Shower chances increase through the evening and into Tuesday morning as a frontal system approaches the area while the upper trough digs southward. Showers will start to push in through the interior Tuesday afternoon and largely continue into Wednesday. .LONG TERM /WEDNESDAY THROUGH SATURDAY/...Extended ensemble guidance agrees on upper level troughing continuing through late Wednesday, with showers decreasing in coverage on Thursday. Cluster guidance are in agreement on an upper level ridge building offshore western Washington into the weekend, providing drier and warmer conditions. Mazurkiewicz/LH
-- End Changed Discussion --
&& .AVIATION...
-- Changed Discussion --
Westerly flow aloft with a weak warm front moving over the area Sunday. Low level onshore flow continuing through Sunday. Ceilings mostly low end VFR tonight into Sunday morning. MVFR ceilings around KPAE due to some weak convergence. Ceilings lowering to MVFR with isolated IFR ceilings 12z-16z. MVFR ceilings continuing into Sunday afternoon with slow improvement to VFR after 22z as front lifts north into Southern British Columbia. KSEA...VFR into the early morning hours. Ceilings lowering to MVFr after 09z with ceilings continuing to lower down to near 1000 feet 11z-14z. MVFR ceilings continuing into Sunday afternoon with slow improvement after 22z and VFR ceilings after 03z. Southerly winds 6 to 10 knots increasing to 10-15 knots with gusts 20-25 knots after 18z. Felton
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
Onshore flow will ease tonight with with small craft advisory winds for portions of the Strait of Juan de Fuca coming to an end by midnight. A warm front will brush the area on Sunday then lift north into southern B.C. Sunday afternoon and evening. Another frontal system will cross western Washington on Tuesday, followed by onshore flow Tuesday night and Wednesday. 33/Felton
-- End Changed Discussion --
&& .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until 11 PM PDT this evening for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. && $$