Marine Weather and Tide Forecast for Glacier, WA

SYNOPSIS
The upper level ridge currently in place over the Pacific Northwest will shift west Thursday afternoon. A weak weather system will move through the area Thursday night into Friday. Upper level ridging will amplify offshore on Friday and move eastward by Monday. Ridging begins to weaken Tuesday into Wednesday.

SHORT TERM /TONIGHT THROUGH SUNDAY/
A beautiful day across Western Washington with mostly clear skies and a few thin high clouds passing by. Expect another round of patchy freezing fog Thursday morning mainly south of the Puget Sound. Upper level ridging will continue to dominate the upper level flow over the area until Thursday night. The ridge will shift westward and allow a weak shortwave trough to dig southward into the area that will bring light snow to the Cascades. The highest probabilities (40%-55%) still remain over the Northern Cascades for Thursday night. On Friday, there is a slightly lower chance of precipitation (20%-30% probability) over the central and southern Cascades. Less than an inch of snow with this system. No significant impacts expected. As for the lowlands and coastal locations, expect increased cloud cover with this system and even a brief drizzle. High temperatures on Friday will be in the low to mid 40s; low temperatures will be in the low 30s.

As the shortwave digs southward into Western Washington on Friday, the upper level ridge will amplify over the Pacific Ocean.
The ridge will gradually begin to move east toward British Columbia on Saturday, bringing drier conditions to Western Washington. Mostly clear skies on Saturday. High temperatures will be in the 40s, and low temperatures will be in the mid to upper 20s.

Cold overnight temperatures are expected to continue throughout the short term period. With clear skies and calm winds, patchy morning freezing fog possible this weekend in the Southwest Interior.

LONG TERM /MONDAY THROUGH THURSDAY/
There is good agreement between ensemble clusters that the upper level ridge will continue to dominate the upper level flow through Monday. On Tuesday, the cluster solutions show the ridge beginning to weaken slightly as the ridge axis begins to approach Washington's coastline. On Wednesday cluster solutions begin to differ. By Wednesday, cluster solutions favor moderate broad ridging over the Pacific Northwest, although there is some disagreement in ridge axis location and exact strength of the ridge. A small amount of ensemble members (12%) favor zonal flow over Western Washington, as an upper level trough moves over British Columbia.

Mostly clear skies and calm winds expected through Tuesday. High temperatures will be in the low to mid 40s Sunday and Monday. A slight warm up starting on Tuesday, with high temperatures in the mid to upper 40s. Low temperatures will be in the mid to upper 20s and warm up slightly to the upper 20s to low 30s by Wednesday.
Multiple rounds of patchy freezing fog possible while under the influence of the upper level ridge and temperatures below freezing.

MGF



AVIATION
Northwest flow aloft continues tonight as an upper level ridge remains centered offshore. The ridge will weaken overnight and increasing westerly flow aloft will develop on Thursday as a weak upper trough digs southward over British Columbia. VFR conditions prevail this afternoon across the region. Patchy LIFR/IFR fog and low clouds will redevelop overnight across the Southwest Interior and portions of central/south Puget Sound. Light surface gradients developing overnight are somewhat favorable for greater areal fog coverage 12Z-18Z Thursday morning.

KSEA...VFR with north winds through this evening. Guidance points toward a higher likelihood of some patchy fog in the vicinity of the terminal on Thursday morning. For now, will likely retain the mention of fog in the vicinity in the TAF and amend as trends dictate. Surface winds northerly generally 8 knots or less through the evening becoming light northeasterly overnight then light/variable much of Thursday. 27

MARINE
Surface ridging centered over the coastal and offshore waters will weaken on Thursday as a weak trough and associated front slide southward from British Columbia. Surface ridging rebuilds over the interior of British Columbia on Friday and remains in place over the weekend with broad troughing well to the south of the area for northerly flow. The flow turns more offshore early next week as a weak trough expands northward along the coast and high pressure remains in place east of the Cascades.

Seas will remain around 4 to 6 ft through early Thursday. Seas will then slowly build to 8 to 12 feet across the coastal waters Thursday night into Friday before subsiding once again this weekend.

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HYDROLOGY
No river flooding the next 7 days.

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