textproduct: Seattle/Tacoma

SYNOPSIS

Cold front has moved east of the Cascades early this morning. Cool upper level trough remaining offshore through Monday before moving inland Monday night. Next system moving southeast Tuesday will move inland Wednesday south of the area. Short blocked upper level pattern Wednesday night through Friday giving Western Washington a dry spell. Next system weakening as it approaches Saturday.

SHORT TERM /TODAY THROUGH TUESDAY/

Satellite imagery this morning shows plenty of cold cu off the coast but the parent low associated with the trough is moving north northwest towards the Gulf of Alaska. This will pull the coldest post frontal air northwest of the area through Monday. Air mass somewhat unstable so showers remaining in the forecast with the highest pops along the coast. Snow levels near 5000 feet only lowering to 3500 to 4000 feet by Monday. A few inches of new snow in the higher elevations today but by the time the snow levels drop down to the pass levels new snow accumulations will be light. High temperatures today, in the lower to mid 50s, could occur this morning with little change in the temperatures throughout the day. A little cooler Monday with highs a couple of degrees either side of 50. Lows tonight in the mid 30s to lower 40s.

A coastal flood advisory remains in effect for the Northern Inland Waters this morning between 8 am and noon for possible minor coastal flooding with the combination of high tides, lower surface pressure and winds.

Current wave forecasts are a little lower than previous forecasts for later today into Monday morning. Have cancelled the high surf warning for the beaches beginning at 10 am this morning and extended the high surf advisory through Monday morning. The beaches will still be a dangerous place to be even with an advisory. Still could see waves in the 20 foot range into Monday morning.

Upper level trough moving through the area Monday night keeping a chance of showers in the forecast. Snow levels 3500 to 4000 feet but not much in the way of moisture with the trough passage. Lows in the lower 30s to lower 40s.

Split flow aloft Tuesday with the next system digging south well off the coast giving Western Washington a dry day. Light surface gradients in the morning could produce areas of low clouds or fog. Even with some afternoon sunshine highs remaining near 50.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/

Models in good agreement with the mid week system moving inland south of the area. The Southwest Interior could get brushed by the northern portion of the system Wednesday. Short lived upper level blocking pattern setting up Wednesday night through Friday with an upper level ridge to the north and an upper level low to the south keeping Western Washington dry. If the models light surface gradient scenario works out there could be areas of fog Thursday and Friday morning.

Model solutions showing more variability Saturday as the next system develops off the coast. No real clear winner in the ensembles so for now will go with a broadbrush chance of rain.

Highs staying around 50 through the period. Lows in the 30s and lower 40s cooling to the upper 20s and 30s Thursday through Saturday.

The first two weeks of November have been quite mild. For Seattle the average temperature of 51.6 is the 5th warmest in 82 years of records at Seattle-Tacoma airport. Saturday was the 6th day of the month with a high in the 60s. Only three Novembers have had more 60 degree plus days, 2016 with 9 days, 1976 with 8 days and 1949 with 7 days. With the 3 am temperature of 55 degrees this makes the 13th day in a row with a high of at least 55 degrees in Seattle. This is the longest streak of its kind. The previous longest, two 12 days streaks November 1-12, 2016 and November 3-14, 1949. Felton

AVIATION

Most terminals are experiencing VFR ceilings this morning under scattered post-frontal showers, through under heavier showers some brief periods MVFR cigs are being observed. This will be the reigning pattern for today, until shower coverage begins to decrease this evening. Scattered showers will remain overnight, particularly along the coast, but the decreasing coverage may open up some more clearing and the potential for some patchy developing low clouds in spots by early Monday morning. There is a 30-50% chance of MVFR cigs by 17Z Mon. Additionally, there is a low (15-20%) chance of isolated thunderstorms, mainly along the coast this afternoon. Breezy south/southwesterly winds are to remain today with continued gusts of 15-25 kt before gradually decreasing tonight.

KSEA...VFR throughout the period. There is a chance (20-30%) of MVFR cigs between 13-19Z Mon morning. Surface winds southerly but could sway between the SW and SE at times. Winds mainly 8-12 kt before gradually decreasing to 3-6 kt later tonight. Can't rule out isolated gusts near 20 kt until this afternoon.

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MARINE

A vigorous front has pushed east of the waters but elevated winds and seas will remain today. Small Craft Advisories remain in effect for the coastal waters as well as the northern Salish Sea waters including Admiralty Inlet and areas north. Winds will gradually ease over the waters and later tonight. Waves 15-18 ft this morning will rise to 20-25 ft with a period of 15-16 sec this afternoon with the highest waves over the offshore waters. High pressure is still on track to build across the area on Monday allowing for a brief reprieve. Winds are to be generally benign as seas lower to 10-12 ft, still SCA for the coastal waters but much lower than we've seen recently.

A low pressure system will form over the open northeast Pacific and move off south and away from WA's coastal waters Tuesday into Wednesday before tracking into CA later on Wednesday. While somewhat distant, this system will allow winds to turn offshore and increase, as well as increasing waves for the next round of headlines mid- week. Calmer conditions under high pressure are then favored Thursday into the end of the week.

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HYDROLOGY

A Flood Warning remains in effect for the Skokomish River. The river is expected to crest today and recede back below flood stage tonight or early Monday. The river will remain below flood stage for the remainder of the week.

River flooding not expected on the remainder of the rivers in the area for the next 7 days. Felton

SEW WATCHES/WARNINGS/ADVISORIES

WA...Coastal Flood Advisory until noon PST today for Lowlands of Western Whatcom County-San Juan County.

High Surf Advisory until 10 AM PST Monday for Grays Harbor County Coast-Northern Washington Coast.

PZ...Small Craft Advisory until 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-Grays Harbor Bar.

Small Craft Advisory until 10 PM PST this evening for West Entrance U.S. Waters Strait Of Juan De Fuca.

Small Craft Advisory until 4 AM PST Monday for Admiralty Inlet- East Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland Waters Including The San Juan Islands.

Small Craft Advisory until 1 PM PST this afternoon for Puget Sound and Hood Canal.