textproduct: Seattle/Tacoma

UPDATE

Shower activity will continue to taper off throughout the day today, primarily over higher terrain. Any rain and snow that continues to fall will generate light accumulations. The Winter Storm Warning has been cancelled for the North Cascades this morning as precipitation decreases and the convergence zone showers dissipate. The remainder of the forecast remains on track today with mild temperatures and quieter weather settling into the region.

SYNOPSIS

An upper-trough will exit the region today as ridging builds offshore. This ridge will progress gently across the PNW over the weekend bringing drier weather. Active, but generally low impact systems will return next week.

SHORT TERM /TODAY THROUGH SUNDAY/

Today will be the start of a transition with zonal flow aloft turning more northwesterly as an upper-ridge builds offshore. An occluded front that brought yesterday's rainfall is now east of the Cascades this morning. Now, scattered showers remain in it's wake, persisting through the day while decreasing in coverage. A Winter Storm Warning over the North Cascades has been cancelled this morning as snowfall winds down. The High Surf Advisory for the coast will also be allowed to expire later this morning, but a Coastal Flood Advisory is expected to remain in effect into the afternoon for Grays Harbor County. A Flood Warning remains in effect for the Skokomish River in Mason County until Saturday morning.

Dry conditions rebound tonight and last into Sunday as the aforementioned upper-ridge builds into the region. Temperatures won't stray too far from average, but highs on Sunday could approach or exceed 60 degrees as large-scale subsidence ensues. Morning fog will be the primary concern during this time.

LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/

A weak front will arrive on Sunday night as the pattern turns more active. However, little to no impacts are expected. Probabilistic guidance shows occasional bouts of precipitation, but the amplitude and timing will limit the flood potential. Additionally, winds will generally remain below concerning levels and the combination of pressure and astronomical tides should keep water levels along the coast below flood thresholds.

41

AVIATION

Westerly flow aloft will gradually become more northwesterly through the day today as an upper level trough exits the region and upper level ridging starts to build in. Mostly VFR this morning with areas of high end MVFR in shower activity gradually tapering off throughout the day. Otherwise, more concern lies tonight into early Saturday morning as the conditions and probabilities for fog/low ceilings increase.

Southwesterly winds have remained breezy this morning, with some terminals still seeing gusts to 20 kt. Winds will gradually decrease throughout the day, easing to 5-10 kt between 18-21Z. Winds will then become light at 6 kt or less by late tonight, helping to promote fog/low ceiling potential.

KSEA...VFR conditions continue this morning with light rain showers possible at times, though shower activity will taper through the day. Southwesterly winds occasionally gusty to 20 kt this morning, but will decrease through the day, becoming 6-10 kt between 18-21Z. Winds will become light overnight, with a pretty good signal for fog/stratus development in the vicinity of the terminal by early Saturday morning.

14/15

MARINE

Winds have largely eased over the waters this morning. Seas do remain elevated and as a result the small craft advisories continue for the coastal waters and the west entrance of the Strait of Juan de Fuca today. Seas will hold in the 15-19 ft range this morning and will be slow to subside today before gradually reaching 10 ft early Saturday.

Expect a lull in the active pattern continuing late today into the weekend with high pressure building over the coastal waters. The only exception may be some breezy winds near the western Strait tomorrow with offshore winds developing. Otherwise, a splitting front approaches late in the weekend with disturbances brushing the outer coastal waters on the way to the B.C. coastline. Additional disturbances may reach the waters early next week, though confidence is low in timing any particular period of concern.

Cullen

HYDROLOGY

A Flood Warning remains in effect for the Skokomish River at Potlach, which crested in moderate flood stage. The river will recede throughout the day and will fall below flood stage by Saturday morning.

Otherwise, widespread rainfall has ended across western Washington, with lingering shower activity expected to taper throughout the day. This, along with snow levels falling back down to 3500-4000 ft, has largely helped to mitigate any additional flooding concerns. A few rivers flowing off the Cascades will continue to rise today as the pulse of runoff from this last system drains from the river basins, however no additional flooding will occur.

Additional systems will move into the area early next week, however rainfall amounts generally look to remain light, so no additional flooding is expected at this time.

JBB/14

SEW WATCHES/WARNINGS/ADVISORIES

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

Coastal Flood Advisory until 3 PM PST this afternoon for Grays Harbor County Coast.

PZ...Small Craft Advisory until 11 PM PST this evening for Grays Harbor Bar-West Entrance U.S. Waters Strait Of Juan De Fuca.

Gale Warning until 8 AM PST this morning for Central U.S. Waters Strait Of Juan De Fuca.

Small Craft Advisory until 5 AM PST Saturday 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.