Radar — KATX
Surface Analysis — Western U.S. (North)
Satellite
Nearest monitored road: 4th Avenue (Primary)
A weak front will exit the region tonight followed by dry and mild weather wednesday and thursday. High pressure will lead to warmer conditions on friday. An upper level low will shift inland friday night and saturday for cloudy and cooler weather with a chance of showers. High pressure returns early next week.
Frontal system largely on the way out this evening with latest satellite showing clear skies over much of the western cwa and some break-ups over the eastern. Latest radar imagery remains quiet, helping to affirm that W wa is on the back end of the front. Inherited forecast remains on track. For further details, please refer to the previous discussion section below. 18
From previous discussion...broad low pressure will spin off b.c. Wednesday and thursday with generally dry and mild conditions over western wa. Near the surface, onshore flow prevails, for a mix of morning clouds and afternoon sunbreaks. Temperatures will track in the 60S and 70S again, a degree or two shy of average. 33
Low pressure continues to spin offshore on friday while high pressure builds inland. The air mass over western wa will be a little warmer and drier with daytime temps in the low to mid 80S across the interior. The coast will be in the 60S to lower 70S. The low starts to slowly shift inland friday night and saturday with a chance of showers. We may also see showers with a convergence zone over the north sound saturday afternoon with a chance of thunderstorms in the north cascades. The upper departs N/NE on sunday with a return to dry and stable weather. A weak upper level ridge will lead to warmer conditions early next week with interior lowlands seeing the 80S again. 33
Southwesterly flow aloft, with low level onshore flow across western washington. Nonetheless, mostly VFR observed across the taf sites. VFR conditions the rest of the evening but ceilings will lower again to 2500 to 3000 ft, with some areas below 2000 ft by early wednesday morning.
Ksea...VFR ceilings above 5000 feet through tonight. Both lamp and refs guidance showing a 25-35% chance of of a brief period of ceilings less than 3000 feet around 14-16Z. Southerly winds easing this evening, and then are expected to shift to northerly. 75% of refs members have this shift by 04Z.
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High pressure will return to area waters wednesday through friday. Another weak system will reach the waters over the weekend. Periods of small craft advisory winds remain possible with onshore flow via the strait of juan de fuca particularly thursday evening and again friday evening into saturday morning. Seas over the coastal waters are expected to remain in the 4 to 5 foot range into the weekend.
Drier and warmer conditions return wednesday through friday, with minimum humidity values dipping into the 30S on friday. However, low- level flow remains onshore to provide for good to excellent overnight recoveries, and this looks to be a short-lived trend as the pattern shifts back to cooler and cloudier conditions for the weekend.