textproduct: Seattle/Tacoma

SYNOPSIS

Strong high pressure will remain the predominant weather feature into early next week resulting in continued dry conditions. Morning fog is expected at times during this period, with some clearing most afternoons.

SHORT TERM /TODAY THROUGH FRIDAY/

Widespread stratus across Western Washington early this morning. Fog has been slow to develop due to the stratus, however, areas of fog will exist this morning. Fog may be dense in some locations. Otherwise, clouds will likely remain low for much of Puget Sound through this afternoon, with some clearing along the coast.

The upper ridge overhead will flatten briefly into this evening as a front weakens offshore. The ridge then rebounds Thursday and will remain offshore through Friday. Fog may again redevelop tonight into Thursday morning. Offshore flow will increase late Thursday through Friday, allowing for a better chance for clearing in the afternoon, especially on Friday. East winds peaking Thursday night through Friday may result in gusts ranging 15 to 25 MPH in the Cascade gaps and along the north coast. Both high/low temperatures will need to be monitored through this week as fog/clouds will limit daytime heating and overnight cooling.

LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/

The upper ridge will dominate the pattern through early next week. Fog coverage looks to remain more limited Saturday morning, with the potential of more expansive AM fog development early next week. Otherwise, dry conditions will continue for the area through Tuesday. JD

AVIATION

Low stratus has limited/slowed fog development early this morning. Regardless, widespread IFR/LIFR cigs remain over area terminals with visibilities ranging between 5-6SM. The latest guidance continues to back off on IFR/LIFR probabilities for visibility, now ranging between 20-40%. If any fog does develop this morning, the best chances look to be between 12Z-20Z. However, confidence is low on whether any fog will develop. Marginal improvement expected in the afternoon to low-end MVFR. Another chance of IFR/LIFR low stratus/fog Thursday morning.

KSEA...Low IFR stratus over the terminal continues to hinder fog development. The latest high-res guidance has backed off on IFR/LIFR visibilities this morning, with the latest probabilities at 20-30%. Confidence is low on whether fog will actually materialize but should fog develop, it will be between 12Z-20Z. Slight improvement expected in the afternoon to low-end MVFR continuing into the evening. Another round of IFR/LIFR low stratus/fog Thursday morning. Calm to variable winds this morning will shift northeasterly in the afternoon at 4-6 kt.

29

MARINE

A weak frontal system will dissipate over the Coastal Waters later today. Surface high pressure will then strengthen offshore and move into interior British Columbia Thursday while a thermal trough builds along the coast. Offshore flow will develop late Thursday and continue into the weekend at varying intensity. This may result in gusty winds at times, mainly offshore of Grays Harbor County, in the northern Coastal Waters, and portions of the west and central Strait. In addition, dense fog is expected to develop over the next few nights, which may reduce visibilities down to 1 nautical mile or less.

Seas will build to 10 to 12 feet this afternoon as a decaying swell train moves into the Coastal Waters. A Small Craft Advisory remains in effect for the Coastal Waters and western Strait of Juan de Fuca due to seas near or above 10 feet. Seas will then gradually subside on Thursday, and range between 4 to 6 feet by Friday. JD

HYDROLOGY

The Skokomish River has dropped below flood stage and will continue to recede through this week. No river flooding is expected over the next 7 days.

SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Small Craft Advisory from 10 AM this morning to 7 PM PST this evening for Grays Harbor Bar.

Small Craft Advisory until 1 AM PST Thursday 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.