Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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929 FXUS66 KSEW 090936 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 236 AM PDT Sun Jun 9 2024 .SYNOPSIS...
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One more warm and dry day today with a few showers over the Cascades as a weak upper-level trough passes through the region. Temperatures returning to near-normal this week with mostly zonal flow, except a chance of showers associated with a passing shortwave on Tuesday. Below-normal temperatures and a wetter pattern is expected to begin Friday through the weekend.
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&& .SHORT TERM /TODAY THROUGH TUESDAY/...
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Satellite imagery showing a weak frontal system encroaching along the coast. Otherwise, mostly high clouds across western Washington this morning with temperatures in the ranging in the 50s to low 60s in some spots. In the upper levels, water vapor imagery shows the incoming trough axis offshore with a ridge departing to the east. The trough and associated surface front will move through the region today, but with very limited moisture, most of the area should stay dry tomorrow. Cloud cover in the morning will give to a mix of sun and clouds in the afternoon, allowing one more warm day with highs in mid to upper 70s through the interior, and the upper 60s to low 70s along the coast. Low temperatures will be the upper 40s to low 50s. A few convective showers are possible over the mountains, in particular over the North Cascades, with lapse rates sufficient enough to allow for a few showers and perhaps a lightning strike or two. Widespread shower activity is not anticipated, with the majority occuring east of the Cascade crest. The trough departs Sunday night, with zonal flow, becoming almost weak ridging aloft, developing. This will allow temperatures to cool to closer to normal on Monday, with highs in the upper 60s to low 70s. The pattern of cloudy mornings breaking up to mostly sunny in the afternoon continues. A shortwave trough looks to move through the region on Tuesday, bringing cloudy and cooler conditions with highs in the 60s across the area. Low temperatures a touch cooler, in the mid to upper 40s. Best chances for showery precipitation will be through the northern half of the region and along the Pacific Coast. The Seattle area and the Southwest Interior has the best chances to remain dry on Tuesday. .LONG TERM /WEDNESDAY THROUGH SATURDAY/...Deterministic and ensemble model solutions generally in good consensus with the upper level pattern evolution. Zonal flow will continue after the trough departs on Wednesday, becoming a weak ridge on Thursday. Thursday looks to be the warmest day in the period with temperatures in the 70s region-wide. A larger trough will approach the region Friday and dominate through the weekend, bringing another period of below-normal temperatures and chances for showers across the region. LH
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&& .AVIATION...
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A weak upper level trough will move inland today with a chance of showers and thunderstorms over the Cascades. The flow aloft is westerly. Low level stratus clouds will mainly impact the coast this morning with MVFR to IFR conditions. The interior will remain VFR with a mix of mid and high level clouds. 33 KSEA...VFR today with S/SW winds 5-10kt. Low clouds and MVFR conditions, along with light/variable wind, overnight toward 12z Mon. 33
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&& .MARINE...
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High pressure will remain situated over the northeastern Pacific with periods of northerly winds over the coast and westerlies through the Strait of Juan de Fuca. Expect another strong push of westerlies down the strait tonight - a Gale Warning is in effect. 33
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&& .SEW WATCHES/WARNINGS/ADVISORIES...
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WA...None. PZ...Gale Warning until 5 AM PDT early this morning for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. Gale Warning from 5 PM this afternoon to 5 AM PDT Monday for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca.
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&& $$