Marine Weather and Tide Forecast for Blyn, WA

SHORT TERM /TONIGHT THROUGH WEDNESDAY/
A trough continues to push across Western Washington this afternoon, bringing widespread showers. The trough axis will push east later this afternoon.
Behind the trough axis,there is general agreement among high- resolution models that a convergence zone will develop along the Central Sound and Cascades (along Snoqualmie and Stevens Pass)
this afternoon/evening (mainly after 5 PM). Snow levels this afternoon (~4000 ft) will drop overnight to 2500 ft. Rainfall and snow accumulations will be light, with 0.10 inches or less of rain in the lowlands and around 2-3 inches of snow along the passes.
Localized higher amounts expected along convergence zone showers, which may lead to additional inches of snow along the passes. In addition, weak instability may lead to a rumble or two (10-15% chance) with these showers. Post-trough showers will continue on Monday and gradually taper off throughout the day.

A weak shortwave trough will move over Western Washington during the early hours of Tuesday. Models have generally been consistent for the past runs in keeping this system relatively dry. If there is any precipitation, it will be light and limited to the mountains. While relatively dry, this trough will bring cooler overnight temperatures. Low temperatures in the southern interior will drop into the mid-30s. The combination of light winds, lingering moisture, and mostly clear skies overnight may promote the development of patchy frost across the southern interior valleys. The shortwave will push out of the region late Tuesday night.

An upper level ridge will bring dry and warmer conditions for Western Washington starting on Wednesday. High temperatures on Wednesday will be in the low-to-mid 60s with mostly clear skies.

LONG TERM /THURSDAY THROUGH SUNDAY/
Upper level ridging on Thursday will keep warm and dry conditions over Western Washington. Thursday temperatures will be slightly warmer, with high temperatures in the upper 60s to low 70s along the interior.
The ridge axis will move east into the Rockies late Thursday afternoon ahead of an incoming digging trough.

There is general agreement among ensemble guidance and deterministic models that cooler and unsettled weather will likely return Friday and continue through the weekend, with an upper level trough expected to traverse the region. However, current ensemble guidance is struggling with the intensity, trough axis location, and timing with this system.

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AVIATION
Northwesterly flow will persist aloft through the TAF period as an upper level trough swings through western WA tonight and exits the region on Monday. Terminals are primarily MVFR to VFR across the region this afternoon, with radar showing scattered shower activity across the majority of the region. Expect overall shower activity to gradually taper tonight, outside of a convergence zone that looks to develop across the central Sound late this afternoon and persist into early Monday. Most interior terminals are seeing southwest winds at 7-12 kt this afternoon, though the PSCZ may cause sporadic shifts in winds to the west and northeast between 23Z-06Z for the central Sound terminals. Winds for KHQM and KCLM remain west/northwesterly, with gusts to 20-25 kt possible through this evening. Expect winds for interior terminals to transition back to south/southwesterly overnight.

KSEA...VFR ceilings with showers in the vicinity of the terminal.
Winds generally persisting at 7-12 kt out of the southwest this afternoon. A convergence zone looks to develop close to or over the terminal between 23Z-04Z Monday. Wind shifts to the west and then northeast are expected within the convergence activity, before winds return back to the southwest between 07-09Z.
Ceilings and vis may briefly drop to MVFR in shower activity at times tonight, though expect ceilings to lower to MVFR by around 12Z Monday.

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MARINE
High pressure currently resides over the northeastern Pacific, while a weak disturbance continues to progress across the area waters tonight. Northwesterly winds across portions of the coastal waters will increase tonight again as a result and are generally expected to persist between 20 to 25 kt. Onshore flow will increase tonight again as well, with another round of small craft strength westerlies expected through the Strait of Juan de Fuca. Winds look to peak around 25-30 kt this evening, before easing late tonight. High pressure will build back into the coastal waters on Monday and persist through midweek, bringing generally calmer conditions to the area waters. The next frontal system looks to approach the area waters on Friday.

Seas across the coastal waters are generally persisting at 8-10 ft this afternoon. Expect seas to fall towards 6-8 ft on Monday and closer to 4-6 ft by midweek with high pressure over the region. Seas then look to increase towards 7-9 ft again late in the week in the wake of the next frontal system.

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HYDROLOGY
No river flooding expected in the next 7 days.



SEW WATCHES/WARNINGS/ADVISORIES
WA...None.
PZ...Small Craft Advisory until 3 AM PDT Monday for Central U.S.
Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca-West Entrance U.S. Waters Strait Of Juan De Fuca.

Small Craft Advisory until 11 AM PDT 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.