textproduct: Seattle/Tacoma

SYNOPSIS

A weak system will move into Oregon and southern Washington through today. Unsettled weather will continue into early Tuesday with weak troughing. Conditions will dry starting midweek. Another system Thursday into Friday for additional precipitation, with active weather continuing into the weekend.

SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/

Recent satellite imagery shows a distinct cloud layer moving from the south, stretching southeastward across our area a a system tracks into Oregon. This system is rather weak and have most of the precipitation confined south of Seattle, with most of the QPF being centered over Lewis County. Elsewhere, expect a mix of sun and clouds throughout the remainder of the evening. Snow levels will lower this afternoon to 3000 to 3500 feet, with some light accumulations in the mountains, and over the passes.

A weak round of showers will move onshore tonight and into Monday morning, dissipating throughout the day. Light snow accumulations will continue, with 2 to 4 inches likely at Stevens and Snoqualmie Passes. High temperatures in the upper 40s and lower 50s.

Showers will taper by Tuesday evening as the pattern splits, and weak upper level ridging nudges into the area. High temps in the low 50s.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Weak upper level ridging will keep the western Washington mostly dry on Wednesday, with areas of fog in the morning. The ridge begins to flatten into Thursday, allowing for more southwest flow and systems to approach the area. Precipitation chances increase late Thursday into Friday, with troughing likely into the weekend with unsettled weather and cooler temperatures.

Mazurkiewicz

AVIATION

Ceilings have generally lifted to VFR levels and even clear skies for the northern third of western Washington this afternoon. The exception is the interior terminals from the south Puget Sound southward, and west to the KHQM, where IFR to LIFR conditions continue to linger. These lower ceilings may lift through the afternoon into the early evening, but won't likely fully clear out before evening. Expect more widespread MVFR conditions into Monday morning with pockets of IFR and LIFR particularly south of Puget Sound and the coast. Light northerly winds will back to the south/southwest this evening and strengthen to 5-10 kt overnight tonight into early Monday.

KSEA...VFR conditions will persist through this evening then lower to MVFR levels after 10Z. The typically under representative LAMP guidance continues to show 50% to nearly 60% probabilities for ceilings less than 3000 feet at the terminal from 11z to 17Z. Light northerly winds will back to the S/SW by 03Z Mon and begin to increase to around 8-12 kt by 12Z Mon.

MARINE

Winds over area waters will remain generally light through the evening. A weak frontal system will moving across area waters on Monday will boost winds somewhat - with the notable exception of remaining well below small craft advisory wind thresholds. Seas running around 8 to 9 ft are expected to rise slightly to around 10 to 11 ft at 11 to 12 seconds tonight into Monday. Seas then fall Tuesday to around 5 to 7 ft through Thursday when seas look to rise back up above 10 ft. A small craft advisory for seas remains in effect through Monday afternoon. Benign marine conditions return Tuesday and Wednesday as broad high pressure briefly builds across the area. The next frontal system will move through the area Thursday into Friday bringing the potential far another round of marine headlines and impacts.

HYDROLOGY

The Skokomish River has crested early this morning below flood stage, and will continue to recede through this afternoon. No river flooding is expected over the next 7 days.

SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Small Craft Advisory from 7 PM this evening to 4 PM PST Monday 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.