textproduct: Seattle/Tacoma

SYNOPSIS

A warm front will lift north into British Columbia tonight, while a cold front stalls offshore Wednesday and into Thursday. Additional weather systems will move through Friday through Sunday for more lowland rain and gusty winds. After a brief break Monday, another front will arrive on Tuesday.

SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/

Western WA remains under strong and moist SW flow with rain and high elevation snow across the region. The warm front will lift north into B.C tonight and the interior will see a break in the precipitation. Wetter conditions will remain along the coast and Olympics through Wednesday as the cold front stalls offshore. Wednesday will be mild in the warm sector with temperatures in the 60s.

Several weather headlines are in place with the main impact being strong winds along the coast and North Interior. Expect south winds of 20 to 30 MPH with gusts to 50 MPH. Winds will ease Wednesday afternoon. In addition, there's potential for large waves crashing along the coast leading to a High Surf Advisory. Minor coastal flooding is also possible near Wednesday morning's high tide in the San Juans and western Whatcom County. Lastly, due to heavy precipitation, the Skokomish River in Mason County is seeing sharp rises with Minor flooding possible.

The cold front will continue to stall and weaken offshore moving into Thursday. The coast and Olympics may see periods of light rain but the interior and Cascades will see a brief break. There's more active weather starting Thursday night. 33

LONG TERM /FRIDAY THROUGH TUESDAY/

From Thursday night into Friday, there's another strong Pacific storm system moving in for more lowland rain, high elevation mountain snow, and gusty winds. Winds will be the strongest along the coast where the probability of seeing gusts of 50 MPH is 70-80 percent. It will be windy in the interior as well with gusts to 30-40 MPH. This system will weaken as it moves inland on Saturday. We will then see a second system track through on Sunday for more wind and rain. Additional rainfall will keep the Skokomish River running high with the possibility of river flooding. These systems will generate large waves with the potential for High Surf and beach erosion along the Pacific coast. Minor coastal flooding will also need to monitored around the time of high tides across the Salish Sea.

Moving forward, there appears to be a brief break in the pattern on Monday. By Tuesday we see more breezy winds and rain as the next front moves in. 33

AVIATION

The front continues to lift north across the region, bringing the steadiest precipitation mostly north of a KNUW-KAWO line and just a few lingering showers elsewhere. Expect ceilings to remain VFR with some patches of clearing allowing some low clouds to develop in places like KPWT and KOLM south through KCLS. Otherwise, breezy southerly surface winds through Wednesday morning with continued VFR ceilings. Winds across the northern terminals including KBLI likely to remain gusty to 25-30 kt into much of Wednesday.

KSEA...VFR conditions tonight with showers mostly pushing north and west of the terminal area. Southerly winds around 10 kt continue into Wednesday morning, with continued VFR conditions.

MARINE

Winds will continue to increase over the area waters this afternoon, peaking this evening and remaining elevated throughout the overnight hours. A Gale Warning remains in effect for the coastal waters until Wednesday evening as these wind speeds persist. A Gale Warning is also in effect for the East Strait of Juan De Fuca, along with the Northern Inland Waters. Elsewhere, A Small Craft Advisory will continue for Admiralty Inlet and the West Entrance of the Strait until Wednesday evening when winds will start to ease across the whole region.

Seas this afternoon generally around 16 to 18 feet this afternoon, remaining high through Wednesday morning. Seas will ease towards more of a 12 to 14 feet on Thursday.

Another strong low pressure system will start to move towards the coastal waters late Thursday night into Friday, bringing stronger winds and higher waves. Latest guidance still suggests a 60-70% chance of storm force wind gusts over the coastal waters. Winds may ease slightly Friday night before another round of strong winds arrives on the coastal waters, with a 30-40% chance of storm force gusts over the waters. Winds will slowly ease late night Sunday as these systems move away from the area.

Additionally, guidance suggests building large waves over the coast, generally above 20 feet starting on Friday afternoon. GEFS and ECMWF probabilities continuously has shown a 20-30% chance of seas above 25 feet heading into late Friday into early Saturday morning. Subtle shifts in the low pressure may change waves and where the largest waves generate, with seas nearing 30 ft not out of the equation, especially near the southern portions of the waters.

Mazurkiewicz

HYDROLOGY

Steady rain throughout the day and evening over the Olympic basin contributed to a rapid rise on the Skokomish River near Potlatch, prompting an upgrade to a river flood warning. 24 hour precipitation totals show that the area has received between 4 and 4.5 inches of rain. The river has been observed at 16.76 feet and will continue rising over the next several hours as the rain begins to taper off. The river and associated forecast will continue to be monitored throughout the night.

River flooding not expected on the other rivers in the area in the next 7 days. 33/21

SEW WATCHES/WARNINGS/ADVISORIES

WA...Wind Advisory until 7 PM PST Wednesday for Grays Harbor County Coast-Island County-Lowlands of Western Skagit and Northwestern Snohomish Counties-Lowlands of Western Whatcom County-Northern Washington Coast-San Juan County.

Coastal Flood Advisory from 5 AM to 11 AM PST Wednesday for Lowlands of Western Whatcom County-San Juan County.

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

PZ...Small Craft Advisory until 7 PM PST Wednesday for Admiralty Inlet-Grays Harbor Bar-West Entrance U.S. Waters Strait Of Juan De Fuca.

Gale Warning until 7 PM PST Wednesday 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-East Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland Waters Including The San Juan Islands.