Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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228 FXUS66 KSEW 180923 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 223 AM PDT Tue Jun 18 2024 .SYNOPSIS...
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High pressure aloft will gradually build through the week, allowing conditions to dry out and warm up. A pattern change is on track for the weekend as a trough brings wetter and cooler conditions to western Washington.
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&& .SHORT TERM /TODAY THROUGH THURSDAY/...
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High pressure will continue to build inland through the short-term, allowing clouds to scour out and temperatures to warm up. Lingering moisture over higher terrain may result in a few stray showers, especially over the Cascades, but will result in little to no additional accumulations. Onshore flow will help to moderate temperatures along the Pacific coast, while many inland areas reach 80 degrees by Thursday. .LONG TERM /FRIDAY THROUGH MONDAY/...Despite continued moderated temperatures along the coast, inland areas will see a warming trend to continue into Friday with potential to see the warmest day of the year so far. Temperatures across the lowlands are on track to peak in the low to mid 80s on Friday, which may generate localized areas of urban heat stress for vulnerable populations in the Seattle, Tacoma, and Olympia metro areas. However, low temperatures in the 50s will provide relief for the heat ahead of a pattern change. A deepening trough along the Pacific Northwest coast will increase cloud cover on Saturday, causing temperatures to lower a few degrees across western Washington. A frontal system is on track to slide across the region late Saturday into early Sunday, bringing cooler temperatures, another round of showers, and breezy winds. Temperatures Sunday and Monday will lower a few degrees below normal into the mid 60s, with ensembles maintaining a chance of precipitation across the region. Long-range rainfall forecasts show relatively light amounts with this system with no significant impacts expected through the forecast period. Lindeman
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&& .AVIATION...
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Northerly flow aloft will continue for much of the day today before turning northwesterly this evening. Surface winds trending southerly with speeds mostly less than 5 kts. These winds will shift more westerly in the late morning before turning northerly in the afternoon. Speeds will increase, but remain around 4-8 kts. W WA socked in with low clouds this early morning with these stratus leading to MVFR conditions along the coast and around the Sound. Remaining locations have stayed VFR...and while that might persist, cigs will likely lower to low-end VFR by 12Z. Conditions starting to improve late this morning with widespread VFR conditions expected in the afternoon. Skies will continue to clear out in the afternoon and evening, with only high clouds expected after 00Z late this afternoon. Of course, locations that typically see lower cigs may not clear out completely, but cigs will remain VFR. KSEA...MVFR conditions in place and likely to remain that way for the bulk of the morning. AOA 17Z, should start to see conditions improve to VFR with a gradual clearing throughout the afternoon. Only high clouds expected after 00-02Z with VFR conditions expected overnight. Southerly winds at the time of this writing 4-8 kts will turn westerly late in the morning, then northerly in the early afternoon and remaining there for the rest of the TAF period. Speeds will remain generally unchanged. 18
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&& .MARINE...
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Broad high pressure is centered just offshore in the NE Pacific and will dominate the pattern into this weekend. Occasional pushes down the Strait still appear to be on tap during this time frame, however at the time of this writing models suggest that speeds will not reach headline criteria for the remainder of the week. A frontal system will approach the waters this weekend bringing showers, but again winds do not appear to be of concern with the frontal passage. However, additional pushes down the Strait beginning Sunday may require headlines. Seas remain 4 to 6 ft through the remainder of this week, rising to 6 to 8 ft beginning this weekend. 18
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&& .SEW WATCHES/WARNINGS/ADVISORIES...
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WA...None. PZ...Small Craft Advisory until 2 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.
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&& $$