textproduct: Seattle/Tacoma

SYNOPSIS

Dry and steadily warmer conditions develop across Western Washington today through Friday as high pressure builds over the region. The next disturbance shifts over the area late Friday through Saturday, bringing cooler and cloudy conditions along with rain chances. High pressure returns early next week, bringing back dry and warmer conditions.

SHORT TERM /TODAY THROUGH FRIDAY/

Dry and steadily warmer temperatures will continue across western Washington through the next several days as low pressure remains off the B.C. coast and gradually rising heights across the region. Modest onshore flow continues in the lower levels of the atmosphere each of these days, maintaining some degree of clouds each morning that give way to mostly sunny skies in the afternoon. Temperatures through the interior climb through into the 70s today and tomorrow, with cool nights limiting the HeatRisk to minor levels. Even with the warmest day of the week on Friday, as temperatures reach the lower 80s, will maintain only a minor risk of heat-releated illness.

LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/

Ensemble guidance continues to favor a shift in the pattern late Friday into Saturday across the region, as the next upper low shifts inland. This will usher the arrival of a more solid cloud deck, cooler temperatures, and even some rainfall chances. These rain chances will be highest along the coast and in the Olympics, but a potential Puget Sound Convergence Zone behind the system will also be another focus for shower chances. While lightning chances remain generally low (10-15%), a thunderstorm or two can't be ruled out across the northern portions of the area. This will be another short break, however, with ensemble guidance continuing to favor the return of warmer and dry conditions again for the first part of next week.

AVIATION

Southwest flow aloft throughout the period. At this hour, mostly VFR is observed across area terminals. However, onshore flow will be conducive for the development of marine stratus across W WA as the morning progress. Spatial coverage mostly favors the coast, Olympic Peninsula and SW interior but a 25-30% chance for MVFR cigs is expressed for Puget Sound terminals (KSEA, KBFI & KPAE) between roughly 14-17z. Any remaining stratus will scatter by 20-22z with VFR expected into the afternoon and evening. An additional round of low stratus expected again early Thursday morning.

KSEA...VFR ceilings so far this morning. LAMP guidance showing a 25- 30% chance of a brief period of ceilings less than 3000 feet around 14-16z. Otherwise, confidence leans towards VFR for most of the day and evening. Surface winds are forecast to range between the W-NW today, light this morning before increasing between 5-10 kt during the afternoon.

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MARINE

High pressure will return to area waters Wednesday through Friday. As a result, low-level onshore flow will become a recurrence. A SCA has been issued for the central/eastern Strait of Juan de Fuca Wednesday evening through early Thursday morning due to frequent gusts meeting criteria. The next disturbance will reach the waters Friday night into Saturday with the potential for more headlines. Seas over the coastal waters are expected to remain in the 4 to 6 foot range into early next week.

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SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Small Craft Advisory from 7 PM this evening to 5 AM PDT Thursday for Central U.S. Waters Strait Of Juan De Fuca- East Entrance U.S. Waters Strait Of Juan De Fuca.