textproduct: Seattle/Tacoma

SYNOPSIS

A weak frontal system will traverse the area tonight into Sunday, bringing cool and cloudy conditions as well as chances for showers. Temporary high pressure Monday before another weak front arrives Tuesday. Dry and warmer weather Wednesday into next weekend as an upper level ridge centered over the southwest builds back towards the Pacific Northwest.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/

Mostly cloudy conditions prevail across most of the area this afternoon, through much of the Seattle metro and central Puget Sound remains partly cloudy. Light rain showers are being reported along the coast. These conditions will persist through the rest of the day today as a frontal system works it was across the area tonight. High temperatures remain on track to reach the 60s to low 70s across portions of the interior with the most sunshine. Chances of showers will continue overnight into Sunday, with the best chances remaining along the Olympic Peninsula, through also expanding into the northwest Interior during the day on Sunday as well. This will help keep temperatures unseasonably cool, with highs remaining in the low 60s on the coast, with upper 60s to near 70 across the interior, with the warmest temperatures across the southeastern portions of the area.

Monday looks to warm back up closer to normal, in the 70s to near 80 with more sunshine during the day.

LONG TERM /TUESDAY THROUGH SATURDAY/

An upper level low will remain sitting off the coast of British Columbia through the first half of the week, with another shortwave trough moving over the area on Tuesday. That will bring us another round of cooler, below-normal temperatures Tuesday as well as chances for showers and breezy winds.

By Wednesday and through the end of the week, the upper level high centered over the Four Corners region will begin to expand and retrograde west towards the Pacific Northwest. Heights will rise through the end of the week. Troughing off B.C. will get pushed north, but there are the potential for a few shortwaves moving through the flow that may keep us cooler than otherwise possible. Onshore flow in the low levels will also help to keep conditions temperate with at least clouds in the morning. Temperatures generally look to remain right around or slightly below normal through the end of the week.

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AVIATION

Southwest flow continues aloft with an upper level trough moving into the Pacific Northwest. Mostly VFR ceilings continue for interior areas this afternoon with MVFR/IFR persisting near the coast with occasional light showers. Deeper moisture with a frontal boundary arrives on Sunday with low MVFR or occasional IFR in stratiform precipitation developing along the coast and interior areas from around KPAE northward. A period of MVFR ceilings for central/south sound terminals is also expected Sunday morning.

KSEA...VFR ceilings are expected to continue into tonight, but confidence has increased in a period of MVFR ceilings developing 12Z- 20Z Sunday. Surface winds S/SW 5 to 8 knots except 12 gusting 15 to knots through 03z this evening.

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MARINE

A stalled front offshore today will move inland Sunday into Sunday night. High pressure will build behind the front Monday. Another front will move into the area waters Tuesday with high pressure again building in behind the front Tuesday night and Wednesday.

Small craft advisory winds over the coastal waters today will ease tonight. Diurnal westerly pushes through the Strait of Juan de Fuca in the evenings in the middle of next week could produce small craft advisory winds. Felton/27

FIRE WEATHER

Cooler and cloudier conditions are expected across western Washington this weekend as a weather system moves across the area. Showers will remain possible through the weekend, primarily along the coast, west slopes of the Olympics, and portions of the Northern Interior as a front moves inland on Sunday. Chances of wetting rains on Sunday are between 65-75 percent along the North coast and the west slopes of the Olympics. Another frontal system will move across the area on Tuesday, helping further mitigate fire weather concerns through the near term.

Warmer and drier conditions return by late next week. However, with low level flow remaining onshore, expect good relative humidity recoveries during the overnight hours and minimum relative humidities to remain above critical thresholds at this time.

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SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Small Craft Advisory until 5 PM PDT this afternoon for Coastal Waters From Cape Flattery To James Island 10 To 60 Nm- Coastal Waters From Cape Flattery To James Island Out 10 Nm-Coastal Waters From James Island To Point Grenville 10 To 60 Nm-Coastal Waters From James Island To Point Grenville Out 10 Nm-Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm.