textproduct: Seattle/Tacoma

SYNOPSIS

A system will move into Oregon and southern Washington through today. Unsettled weather Monday into early Tuesday with weak troughing. Drier weather midweek. Another system likely late week for additional precipitation.

SHORT TERM /TODAY THROUGH TUESDAY/

A mix of clouds and some clearing early this morning in a post-frontal airmass. Weak convergence has led to stratus in areas of King/Snohomish Counties with additional clouds mainly south of Olympia ahead of the next weather system. This system will track into Oregon today, with precipitation through the afternoon mainly confined south of Seattle, with the majority of QPF mostly over the Cascades of Lewis County. Otherwise, some sunshine will be around, especially along the Olympic Peninsula and north of Everett.

Another round of showers will move onshore tonight, with showers continuing at times on Monday for Western Washington. Snow levels will also be around 3000 to 4000 feet through Monday, resulting in light to moderate snow accumulation for the Cascade Passes. Snow amounts through Monday evening are expected to range 1 to 4 inches for Stevens and Snoqualmie Pass, with 6 to 8 inches of snow for White Pass due to the additional precipitation today. Temperatures will remain in the upper 40s to low 50s for highs through Monday.

Precipitation chances taper off on Tuesday, initially for southern areas, with dry conditions expected for Seattle southwards on Tuesday, and some light precipitation lingering near BC into the afternoon.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/

Ridging begins to nudge into Western Washington Tuesday night through Wednesday, resulting in drier weather midweek. Mostly clear skies will promote fog development Wednesday morning. The ridge is rather transient as the ridge flattens and southwest flow aloft increases on Thursday. Precipitation potential begins to increase on Thursday, with higher probabilities on Friday as a weak front moves across the area. Uncertainty increases in ensembles by next weekend, however, troughing is the general theme, and thus unsettled weather, and cooler temperatures, are expected next weekend. JD

AVIATION

A bit of a mixed bag of ceilings early this morning across the area. Much of the northwest and the Olympic Peninsula are seeing clear skies with areas of fog in some of the valleys. Low clouds remain in place over the central Puget Sound as a weakening convergence zone persists over the area. Ceilings should slowly improve this morning, becoming VFR for much of the day as clouds scatter with the system far to the south. Areas of fog may dvlp this morning for areas with clear skies but that will also clear out later this morning. Another rounds of MVFR to IFR cigs are expected to return around the end of the TAF period early Monday morning as a weak frontal system begins to move through the area. Winds are still slowly coming down but will be light and variable area-wide this morning. Winds remain mostly light through the day, generally out of the north. South to southwesterly winds begin to pick up this evening up to 5-10 kt overnight tonight into early Monday.

KSEA...MVFR to VFR cigs early this morning under a weakening convergence zone. Ceilings are already showing improvements but periods of MVFR cigs may continue through 15-17Z. VFR conditions return and will prevail through the remainder of the TAF period. Ceilings will begin to lower at the end of the period as another weak front moves through the area, but MVFR cigs aren't expected until after 12-15Z Mon. SW winds under 5 kt will become light and variable through late morning. Winds switch to light northerly after late morning before returning to S/SW by 03Z Mon and begin to increase to around 8-12 kt by 12Z Mon.

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MARINE

Small Craft Advisory level winds continue through portions of the central and Eastern Strait of Juan de Fuca early this morning but continue to decrease and should ease before sunrise this morning. Elsewhere, winds remain fairly light. A weak frontal system will move across the area waters on Monday but winds look to remain well below thresholds. Tranquil conditions are in store Tuesday and Wednesday as broad high pressure briefly builds across the area. The next frontal system will move through the area Thursday into Friday which may require the next round of headlines.

Seas around 8 to 9 ft will rise slightly to around 10 to 11 ft 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.

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HYDROLOGY

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

SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Small Craft Advisory until 3 AM PST 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 until 4 AM PST early this morning 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.