Marine Weather and Tide Forecast for Marblemount, WA

SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/
Skies have begun to clear early this afternoon with residual cloud cover lingering along the coast and southwest interior.
High pressure is building in earnest today through the end of the week, with highs climbing into the upper 60s and low 70s tomorrow, and again once more into the mid 70s by Friday. This will correspond to some Minor HeatRisk over these two days.
Given a moist atmosphere in the low levels and a light wind gradient, there is potential for some stratus and possibly fog on Thursday morning. Offshore flow will get a little breezy, particularly in the Cascades and foothills Thursday night. Gusts will be between 25-30 mph. RH values in the Cascades and southern Olympics could see minimums around 35-40%, with a more widespread reduction on Friday as the temperatures climb.
Minimums on Friday will range from 35-45%.

LONG TERM /SATURDAY THROUGH WEDNESDAY/
High pressure dampens over the weekend, with more southwesterly flow aloft. The next system arrives on Saturday, likely bringing rain to western Washington throughout the day. More of this rain is forecast to fall in the North Cascades with only a few hundredths of an inch expected in lowland locations. Areas of the Seattle Metro may be shadowed entirely. More notably, temperatures drop back into the low 60s which will be a sharp drop out of Friday's highs in the mid 70s.

Zonal flow with broad troughing in the NE Pacific keeps conditions cooler and drier on Sunday. Morning lows will drop into the low 40s for the Puget Sound region, and mid 30s in the Cascade foothills. Model guidance is still keeping that trough offshore into Sunday for less of a wind threat in western Washington, but this track will be monitored for changes.
Troughing will continue into early next week for additional chances for light rain, particularly on Tuesday. Beyond that, there is a bit of a discrepancy in what pattern is favored.

21

AVIATION
High pressure building into the region aloft will allow for northerly flow in the mid levels to become more southerly by Thursday morning. Clouds continue to scatter across the region this afternoon, allowing for conditions to gradually improve across the area terminals. Ceilings are mostly MVFR to VFR, with the exception of IFR lingering in thicker cloud cover along the coast. Expect ceilings to continue to scatter through the afternoon for a return to mostly VFR conditions by this evening. Southwesterly winds between 4-8 kt will become light and variable through the afternoon hours before switching to northerly around 00Z. Winds will generally remain light, at 6 kt or less, through the overnight period. Clearing skies, light winds, and ample low level moisture will allow for low stratus/fog development overnight into Thursday morning. IFR/LIFR conditions will be likely for terminals in fog, with fog expected to scatter by late morning.

KSEA...VFR conditions will continue through this evening. Fog will likely move into the terminal early Thursday morning, with probabilistic guidance suggesting a 25-35% chance of ceilings and visibilities dropping to LIFR between 9-12Z. Southwesterly winds this afternoon will switch to north/northeast between 22-01Z and remain light at 6 kt or less. Winds will shift to the northeast by Thursday morning and increase to 4-8 kt by the afternoon.

14

MARINE
High pressure will build back into the coastal waters tonight, while a thermal trough builds northward along the coast. Areas of fog will likely develop across portions of the local waters overnight into Thursday morning and may cause visibilities to drop down to 1 NM or less in spots through the early morning hours.

Winds will turn offshore by tonight and will persist through Friday morning, becoming breezy through the gaps in terrain Thursday afternoon and evening. At this time, winds are still favored to remain below small craft criteria, with probabilistic guidance only highlighting a 30-40% chance of gusts exceeding 21 kt across the west entrance of the Strait of Juan de Fuca and a small portion of the northern coastal waters.

The thermal trough will push inland on Friday as a front approaches the area, bringing the return of onshore flow to the waters. Onshore flow will then increase Friday night into Saturday as the system makes its way across the area. Another system may approach the area waters Sunday night into Monday, though there remain discrepancies in regards to its exact track.

Seas will largely persist between 4-7 ft through Friday, but will steadily build towards 8-11 ft over the weekend as systems move through the region. Seas could even build further early next week depending on the track of the systems, with the GEFS still indicating a 40-50% of seas exceeding 12 ft on Monday.

14

SEW WATCHES/WARNINGS/ADVISORIES
WA...None.
PZ...None.