textproduct: Seattle/Tacoma

SYNOPSIS

An upper-level trough offshore will push inland over the weekend, bringing cooler temperatures to the area and additional chances of showers. Troughing will persist through early next week, allowing for temperatures to trend just below to near normal with continued PoPs. Drier conditions favored midweek onward.

SHORT TERM /TODAY THROUGH SUNDAY/

The upper-level pattern can be characterized by an upper-low over the NE PAC and stout ridging centered over the SW US. At the surface, low-level onshore flow is ongoing across W WA with developing marine stratus this morning. It'll become widespread before retreating back to the coast this afternoon with help of diurnal heating. Today, subtle ridging is amplifying across the region, bringing a brief spell of above average temperatures. Interior highs are forecast to range between the upper 70s to mid 80s. Coastal areas of course cooler in the lower to mid 60s. Dry conditions again tonight but the aforementioned upper-low will begin to show signs of progression as it becomes ingested within the mean flow. Marine stratus on track to redevelop overnight into Saturday morning under continued onshore flow. Min temperatures will fall between the lower to upper 50s.

The upper-low will finally move inland on Saturday as PoPs return into the forecast, primarily over the coast and mountain areas. Models have rain showers straggling into Sunday as well as upper-troughing becomes the main influence across W WA. This pattern favored onshore flow as reoccurring spells of marine stratus and slightly below-normal temps trend throughout the weekend with highs 70s.

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LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/

Looking forward into next week, upper level troughing remains the dominant influence across the area as several systems move down from the Gulf of Alaska. Some model solutions show the upper level high over the Four Corners region retrograding westward, which may allow conditions to trend drier and warmer towards the second half of the week. Otherwise temperatures generally remain around climatological normals.

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AVIATION

Weak upper level ridging is over western WA today for dry and stable weather. Near the surface, onshore flow prevails with marine stratus clouds filling in across the lowlands this morning - expect IFR to MVFR conditions across most areas. Low clouds will burn back toward the coast this afternoon with VFR conditions in the interior. Low clouds will return overnight as onshore flow continues. 33

KSEA...Low clouds filling in the morning with MVFR to IFR conditions. Stratus will burn off by 18-20z. S to SW winds around 5-10kt today. 33

MARINE

Low level onshore flow continues today with strongest winds through the central/east Strait of Juan de Fuca - a Small Craft Advisory is in effect. A frontal system will stall offshore on Saturday then shift inland late Sunday. Another front will cross the waters on Tuesday. 33

FIRE WEATHER

More benign fire weather conditions expected today through early next week. The low offshore will finally make its way over the region. This will result increased onshore flow with cooler temperatures and shower chances through the weekend into the first part of next week easing fire weather concerns. Additional thunderstorms are not likely but can't be ruled out at this time.

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SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Small Craft Advisory 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.

Small Craft Advisory from 5 PM this afternoon to 5 AM PDT Saturday for Central U.S. Waters Strait Of Juan De Fuca- East Entrance U.S. Waters Strait Of Juan De Fuca.