Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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417 FXUS66 KSEW 231003 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 303 AM PDT Thu May 23 2024 .SYNOPSIS...
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Weak high pressure will build in aloft for drier and somewhat warmer conditions today. Cooler and unsettled conditions return Friday and will persist into the weekend as another upper level trough traverses the region. Upper level ridging then looks to build into the interior West early next week, however troughing over the northeastern Pacific will continue and will bring additional chances of precipitation across western Washington at times.
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&& .SHORT TERM /TODAY THROUGH SATURDAY/...
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Weak high pressure will build in aloft today, bringing drier and slightly warmer conditions to western Washington. Morning stratus will lift for some afternoon sun. Afternoon high temperatures will climb a few degrees from Wednesday and look to top out in the mid to upper 60s across the interior and upper 50s to low 60s along the coast. Unsettled conditions return on Friday as an upper level trough and its associated surface front move into western Washington. Showers will start to move inland along the coast early Friday and will gradually move eastward throughout the day, with weak convergence showers likely developing Friday night into Saturday across the central Sound. Overall showers will remain rather light, with QPF generally coming in at a few hundredths to 0.25 inches across the lowlands through Saturday. The mountains will see some slightly higher amounts, generally between a quarter of an inch to half an inch of precipitation. High temperatures on Friday will be in the low to mid 60s across the interior, and mid 50s to low 60s along the coast. Temperatures will cool a few degrees on Saturday, topping out in the 50s to low 60s. .LONG TERM /SUNDAY THROUGH WEDNESDAY/...Upper level ridging will start to build into the interior West later Sunday into Monday, however western Washington looks to remain under somewhat of a troughing influence as an upper level trough deepens over the northeastern Pacific. This will keep precipitation chances in the forecast Sunday into Monday, mainly for the Olympic Peninsula and portions of the northern Sound. Uncertainty in the ensembles increases Tuesday and Wednesday, however ridging over the interior west looks to push further inland, allowing for the troughing offshore to nudge into western Washington and for precipitation potential to increase. Normal to slightly above normal temperatures are expected Monday into Tuesday, with temperatures cooling a few degrees on Wednesday. 14
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&& .AVIATION...
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Mainly VFR to MVFR with areas of low stratus developing along the coast and south Puget Sound. Isolated areas of IFR are possible at the terminals through the morning. Building high pressure will allow conditions to improve after sunrise, bringing conditions across the region to VFR. Surface winds generally S/SW throughout the day 5-12 kt. KSEA...MVFR stratus will develop this morning before scattering out to VFR conditions by 18z-20z. Winds will stay out of the SW with light winds this morning increasing to 8-12 kt this afternoon. AL
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&& .MARINE...
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Conditions will continue to trend calmer as high pressure builds towards the coast, with seas decreasing to 4 to 6 ft by Thursday afternoon. Building high pressure will cause a westerly push through the Strait of Juan de Fuca, but winds will stay below SCA criteria. The next frontal system will cross the waters on Friday, bringing in a NW swell with waves increasing to 7 to 9 ft and breezy winds through Saturday. High pressure will allow conditions to calm towards the end of the weekend and into early next week. AL
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&& .SEW WATCHES/WARNINGS/ADVISORIES...
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WA...None. PZ...None.
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&& $$