Marine Weather and Tide Forecast for Issaquah, WA

SHORT TERM /TONIGHT THROUGH MONDAY/
Rain over Neah Bay this evening and spreading south along the coast tonight. Warmer with lows in the 40s (no 30s compared to this morning). Wetter day ahead on Friday for the rest of western WA. Current trends remain on track. 33

Previous discussion...Skies have become mostly sunny across Western Washington this afternoon under some passing high clouds.
Cloud cover will increase from the northwest this evening and especially tonight, however, as the next frontal system continues to approach the area. Expect rain to reach the coastline after midnight tonight and continue to spread inland through the day on Friday. This will bring a fairly solid shot of rain to the region with around a half inch of rain through the interior lowlands and about an inch (with local amounts up to one and a half inches)
along the coast and in the mountains. While these amounts are not likely to cause any significant hydrologic impacts, will need to monitor the rainfall rates at the peak of the front for two reasons - first, burn scar areas (such as Bolt Creek) could be impacted by local bursts of heavy rain (especially in a possible Puget Sound Convergence Zone later Friday), and second, urban areas could see some drains and gutters blocked by leaves that come down and limit the efficiency of draining rain. However, at this time, either of these impacts remain relatively low likelihood scenarios.

The arrival of the front and the following cold air will bring daytime high temperatures several degrees cooler than today with many spots only topping out in the 50s to around 60 on Friday afternoon. Snow levels will also fall, but the cold air will trail the moisture so outside of the highest Cascade elevations snowfall is not expected to me a major concern. One other note for later Friday is that stronger onshore flow in the wake of the front may lead to prolonged showers in a potential Puget Sound Convergence Zone. With slightly enhanced instability as lapse rates steepen, could see a lightning strike or two in this area.

High pressure rebuilds over the weekend, allowing daytime high temperatures to again climb into the upper 60s and near 70 for Saturday and Sunday through much of the region. Some low clouds are possible, but plenty of sunshine each afternoon can be expected.

LONG TERM /TUESDAY THROUGH FRIDAY/
Ensemble guidance remains in good agreement for the start next week, with the next frontal system a touch faster in the latest guidance. This would bring a return of rain chances to the coast and spreading inland on Monday with some lingering precipitation through Tuesday. This will again knock a few degrees off of the temperatures each day and keep more widespread cloud cover over the region. Later next week, ensemble solutions remain rather well clustered in depicting a ridge over the western U.S. but shifting east toward the Four Corners region.
This would open the door to a few weak disturbances clipping parts of the area. As a result, some mention of precipitation chances (generally 20-40% remain) for much of next week. Cullen

AVIATION
Southwest flow aloft will increase overnight ahead of a frontal system and trailing upper trough approaching the area.
Ceilings will deteriorate to MVFR in rain along the coast late tonight with said conditions spreading into the interior lowlands mid to late Friday morning. Ceilings are expected to lift to VFR in scattered showers behind the front Friday afternoon except in and around an expected convergence zone Friday evening.
South/southwesterly surface winds will become gusty at times with and behind the front.

KSEA...Rain will move into the terminal early tomorrow morning, allowing ceilings to drop to MVFR by mid-morning. Rain will devolve into showers Friday afternoon, allowing ceilings to slowly lift to low-end VFR. Surface winds light tonight switching to south/southwesterly early Friday morning and rising to 10 to 15 kt with occasional gusts to 20 kt possible after around 20Z. 27/LH

MARINE
Winds will ease tonight before turning southerly tomorrow as a frontal system moves through the area Friday. Winds will increase across the area waters, with the strongest winds expected through the Central Strait of Juan de Fuca behind the front, where a Small Craft Advisory is in effect for Friday. A few gusts up to 35 kt are possible at times, but should largely be confined to the Canadian side of the Strait. A frontal system will pass by to the north this weekend, with the next system passing through the waters early next week.

Seas 7 to 9 ft this afternoon will continue to subside tonight.
Waves will rise up to 10 to 12 ft tomorrow in accordance with the frontal passage, for which a Small Craft Advisory is in effect for all the outer coastal zones. For the inner coastal zones, waves will be highest to the north near the Strait and decrease to the south, thus leaving out the zone between Point Grenville and Cape Shoalwater from a Small Craft Advisory. As the system develops and moves into the region, the forecast can be adjusted as necessary if waves are higher than currently forecast. By Saturday, seas will drop back down to 4 to 6 feet before building back to 6 to 8 feet next week.

LH

SEW WATCHES/WARNINGS/ADVISORIES
WA...None.
PZ...Small Craft Advisory from 8 AM Friday to midnight PDT Friday night 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-West Entrance U.S.
Waters Strait Of Juan De Fuca.

Small Craft Advisory from 11 AM to 9 PM PDT Friday for Central U.S. Waters Strait Of Juan De Fuca.