textproduct: Seattle/Tacoma

SYNOPSIS

A series of weather systems will move across western Washington over the next week, bringing periods of lowland rain, mountain snow, and breezy conditions at times.

LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/

Conditions generally look to remain rather active through the long term, with ensemble clusters in decent agreement of an upper level trough digging across the northeastern Pacific and swinging additional disturbances across western Washington. With snow levels expected to remain below pass level, this will bring additional rounds of mountain snow and lowland rain through the first half of next week. Winds will also be breezy at times as these systems move through.

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AVIATION

Generally low end VFR to MVFR this morning in low ceilings and pockets of patchy fog. Widespread rain will continue, lowering visibilities and ceilings in heavier activity. An incoming frontal system this afternoon will bring gusty winds to the western Washington terminals, with southerly/southwesterly gusts reaching up to 40 kt generally between 22z to 2z. Winds will gradually ease throughout the TAF period but will remain somewhat gusty overnight. Ceilings may briefly lift to low end VFR overnight, but a majority of terminals are expected to stay MVFR with continued shower activity.

KSEA...Generally high end MVFR to low end VFR this morning with rain over the terminal. A frontal system will bring gusty southerly winds to the terminal this afternoon between 22z and 2z, with gusts peaking between 35-40 kt. Ceilings may also lower to IFR as the front moves through in heavier rain showers. Winds will slowly taper through the forecast period, but will remain gusty around 20 kt overnight. Ceilings will remain between low end VFR and high end MVFR overnight as showers continue.

MARINE

A frontal system will move across the waters today, bringing elevated winds and seas to the region. The strongest winds will be along the coastal waters and along the Eastern Strait of Juan de Fuca, where gales with frequent gusts to 45 kt will be likely. Winds across the remainder of the interior waters will be gusty as well. Small Craft Advisories for the Northern Interior Waters and Admiralty Inlet have been upgraded to a Gale Warning this morning based on recent observations and increasing confidence. A strong westerly push in the wake of the system will bring another round of gales to the central and east Strait this afternoon and evening before conditions ease somewhat. The overall pattern remains active over the weekend and into early next week as additional systems move across the area waters.

Seas will build towards 14-17 ft today and look to gradually subside back below 10 ft over the weekend. An uptick in seas is likely again next week as additional disturbances move across the waters. 14/29

HYDROLOGY

The next wave of precip is already moving into the western half of the CWA this early morning bringing another round of steady rainfall to the area. Snow levels will remain lower this morning, around 2500 to 3000 feet, but are still expected to rise to 5000 to 7000 feet this afternoon. Snow levels will fall again to 1500 feet Friday. QPF amounts through Friday morning will range 2 to 3 inches for the majority of the Olympics and Cascades, with localized higher amounts over the Cascades of Pierce and Lewis Counties.

Ongoing river flooding continues for numerous rivers off the Cascades, as well as the Skokomish River in Mason County. Rivers will continue to remain elevated due to the continued precipitation. However, as this system is not expected to have the same intensity as the previous AR events, some rivers will still see levels slowly recede even with the incoming rainfall. Additionally, given the general break in precip yesterday, there will be a little bit of a lag in rivers that do react to this current incoming system. Rivers that do see levels rise because of this may not see impacts until late tonight or Friday. Stay tuned to the latest hydrological forecasts for any rivers in your area, as the risk for additional flooding is still possible.

That said, a Flood Watch remains in effect for Skagit, King, Pierce, Thurston, and Grays Harbor Counties through Friday afternoon due to this additional incoming precip and area rivers currently running high.

The landslide threat will remain high through at least Friday.

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SEW WATCHES/WARNINGS/ADVISORIES

WA...Wind Advisory until 11 PM PST this evening for Island County- Lowlands of Western Skagit and Northwestern Snohomish Counties-Lowlands of Western Whatcom County-San Juan County.

Winter Weather Advisory until 4 PM PST this afternoon for Cascades of Pierce and Lewis Counties-Cascades of Snohomish and Northern King Counties-Cascades of Southern King County-Cascades of Whatcom and Skagit Counties.

Flood Watch through Friday afternoon for Cascades of Pierce and Lewis Counties-Cascades of Snohomish and Northern King Counties-Cascades of Southern King County-City of Seattle-Eastside-Foothills and Valleys of Central King County-Foothills and Valleys of Pierce and Southern King Counties-Foothills and Valleys of Snohomish and Northern King Counties-Foothills and Valleys of Thurston and Lewis Counties-Foothills of the Western and Southern Olympic Peninsula-Grays Harbor County Coast-Lower Chehalis River Valley-Lowlands of Lewis and Southern Thurston Counties- Lowlands of Pierce and Southern King Counties-Middle Chehalis River Valley-Olympia and Southern Puget Sound- Olympics-Shoreline / Lynnwood / South Everett Area- Willapa and Black Hills.

Wind Advisory until 7 PM PST this evening for City of Seattle- Downtown Everett / Marysville Area-Eastern Kitsap County- Eastside-Foothills and Valleys of Central King County- Shoreline / Lynnwood / South Everett Area.

Wind Advisory until 7 PM PST this evening for Foothills and Valleys of Pierce and Southern King Counties-Foothills and Valleys of Thurston and Lewis Counties-Grays Harbor County Coast-Lowlands of Lewis and Southern Thurston Counties-Lowlands of Pierce and Southern King Counties- Northern Washington Coast-Olympia and Southern Puget Sound-Willapa and Black Hills.

Coastal Flood Advisory until 1 PM PST this afternoon for Eastern Strait of Juan de Fuca.

PZ...Small Craft Advisory until 6 PM PST this evening for Grays Harbor Bar.

Small Craft Advisory until 4 PM PST this afternoon for Puget Sound and Hood Canal-West Entrance U.S. Waters Strait Of Juan De Fuca.

Gale Warning from 4 PM this afternoon to 4 AM PST Friday for Central U.S. Waters Strait Of Juan De Fuca.

Gale Warning until 4 AM PST Friday for East Entrance U.S. Waters Strait Of Juan De Fuca.

Gale Warning until 4 PM PST this afternoon for Admiralty Inlet- 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- Northern Inland Waters Including The San Juan Islands.