Marine Weather Net

James Island to Point Grenville WA out 10 NM Marine Forecast


TONIGHT

SE
WINDS
20 - 25
KNOTS

SUN

S
WINDS
10 - 15
KNOTS

SUN NIGHT

S
WINDS
5 - 10
KNOTS

MON

SE
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
PZZ153 Forecast Issued: 209 PM PST Sat Feb 15 2025

SMALL CRAFT ADVISORY IN EFFECT THROUGH MONDAY AFTERNOON
Tonight...Se Wind 20 To 25 Kt, Becoming S 15 To 20 Kt Late. Seas 8 To 11 Ft. Wave Detail: Sw 11 Ft At 11 Seconds And Sw 10 Ft At 15 Seconds. Rain, Mainly This Evening.
Sun...S Wind 10 To 15 Kt. Seas 8 To 10 Ft. Wave Detail: S 5 Ft At 9 Seconds And Sw 10 Ft At 12 Seconds. Rain.
Sun Night...S Wind 5 To 10 Kt. Seas 8 To 10 Ft, Building To 11 To 12 Ft After Midnight. Wave Detail: S 3 Ft At 8 Seconds And W 12 Ft At 15 Seconds. Rain.
Mon...Se Wind 5 To 10 Kt, Veering To Sw In The Afternoon. Seas 10 To 12 Ft. Wave Detail: S 2 Ft At 8 Seconds And W 12 Ft At 15 Seconds. Rain.
Mon Night...S Wind 5 To 10 Kt. Seas 8 To 10 Ft. Wave Detail: W 10 Ft At 14 Seconds. Rain Likely.
Tue...Se Wind 10 To 15 Kt. Seas 6 To 8 Ft. Wave Detail: Se 4 Ft At 5 Seconds, W 8 Ft At 12 Seconds And W 2 Ft At 18 Seconds. Rain.
Tue Night...Se Wind 15 To 20 Kt. Seas 6 To 7 Ft, Building To 6 To 9 Ft After Midnight. Wave Detail: S 8 Ft At 9 Seconds And W 4 Ft At 16 Seconds. Rain.
Wed...Se Wind 15 To 20 Kt, Veering To Sw In The Afternoon. Seas 8 To 10 Ft. Wave Detail: S 8 Ft At 9 Seconds, W 8 Ft At 14 Seconds And Sw 2 Ft At 17 Seconds. Rain.
Wed Night...Sw Wind 10 To 15 Kt. Seas 9 To 11 Ft. Wave Detail: S 6 Ft At 9 Seconds, W 10 Ft At 12 Seconds And W 2 Ft At 15 Seconds. Rain.
Thu...S Wind Around 10 Kt. Seas 6 To 9 Ft. Wave Detail: S 2 Ft At 8 Seconds And W 9 Ft At 15 Seconds. Rain.
Thu Night...Se Wind 10 To 15 Kt. Seas 6 To 8 Ft, Building To 8 To 9 Ft After Midnight. Wave Detail: W 9 Ft At 16 Seconds. Rain.
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Area Forecast Discussion
National Weather Service Seattle WA
235pm PST Sat Feb 15 2025

Synopsis
A frontal system will continue to bring widespread precipitation across the region through the weekend, including lowland rain, and heavy snow in the Cascades. Expect the unsettled wet pattern to continue through the week, with the chance for another organized system on Wednesday. Temperatures will slowly warm up through the week, with highs reaching the low 50s by the end of next week.

Short Term - Tonight Through Tuesday
Upper air analysis shows a ridge breaking apart over western WA this afternoon, giving way to an upper level low/trough over the northeast Pacific. There is a jet core on the lee side of the trough, funneling moisture down into southwest WA/OR. IVT analysis characterizes a small moisture pool embedded within the trough beginning to dissipate into Sunday/Monday. Not quite the strength of a full on atmospheric river, but any kind of extra moisture will help juice the atmosphere for the precipitation through the weekend. Compared to previous systems that were drier/colder, this will be the first good dose of Quantitative Precipitation Forecast over the region in a bit, with totals still expected to range from 0.50-0.75 inches in the lowlands, and 1-1.25 inches along the coast. There were significant increases in the Cascades and Olympics, with the Olympics up to 1.5-2.5 inches today through Monday, and Cascades receiving 1.5-3.0 inches of Quantitative Precipitation Forecast.

There is still however (even 24-48 hours out) quite a large range in ensembles in precipitation totals through the weekend (they vary as much as a quarter of an inch). This mostly comes from the slight perturbations in the track of the low/trough. While a quarter of an inch spread does not seem too significant, this will ultimately have somewhat of an effect on snow amounts forecasted in the Cascades through the long weekend. The HREF grand ensemble still has a majority of members agreeing on winter storm warning amounts of snow between now and Monday (mean is just shy of around 20 inches at Snoqualmie and Stevens Passes through Monday morning). There is a 75% chance of at least a foot of snow at both passes during this time, so with that confidence, will keep the headlines in place through the weekend for heavy snow in the Cascades above 2,500 ft. The most impactful times will be Sunday and Monday morning, where cool air aloft/post frontal convergence with west winds may enhance some heavier snow rates of 0.5-1 inch/hour.

Snow levels will slowly rise to above 3,500 ft into Monday afternoon, which will start to mix some rain in Monday afternoon in the passes. There is a low risk of wintry mix in between the rain/snow areas, but the risk will decrease into Monday once warm sector moves through. Precipitation amounts will decrease Monday afternoon into Tuesday, with another round of rain likely along the coast Tuesday with the next frontal system approaching from the west. Highs in the short term will be the coolest this afternoon (mid 40s in the lowlands, and upper 20s/30s in the mountains). Expect a warm up Sunday/Monday with more upper 40s, and potentially some 50s going into Tuesday.

Long Term - Wednesday Through Saturday
The previously mentioned frontal system Tuesday will continue into Wednesday, with widespread precipitation chances continuing through Thursday morning. Snow levels right now appear highest in Puget Sound/Pacific coast/Olympic areas with increases above 4,000 ft. Cascades will remain around 2,000 ft, but Quantitative Precipitation Forecast/snow totals remain below winter weather advisory level for any snow in the mountains midweek. Ensembles show above average chances of precipitation and warmer temperatures continuing into next week/weekend, with some hints of possible heavy Quantitative Precipitation Forecast next weekend. Highs in the low/mid 50s is possible by next weekend (a bit above average for this time in February).

HPR

Marine
A frontal system will shift inland tonight with elevated winds and seas - Small Craft Advisories remain in effect. A surface trough will shift inland on Sunday. High pressure builds over the region Monday and Tuesday. The next frontal system reaches the region Tuesday night and Wednesday. 33

Hydrology
A series of storm systems will move across western Washington this weekend into next week, bringing several rounds of modest precipitation to the area. Snow levels will remain in the 3000- 4000 ft range. Rivers are expected to see rises but no flooding is forecast at this time. The Skokomish River may rise into action stage on Sunday and remain there through mid-week.

NOAA Seattle WA Office: Watches - Warnings - Advisories
WA...Winter Storm Warning until 10am PST Monday for West Slopes North Cascades and Passes-West Slopes North Central Cascades and Passes-West Slopes South Central Cascades and Passes.

PZ...Small Craft Advisory until 4am PST Monday for
Grays Harbor Bar

Small Craft Advisory until 4am PST Sunday for
East Entrance U.S. Waters Strait Of Juan De Fuca-
West Entrance USA Waters Strait Of Juan De Fuca.

Small Craft Advisory from 6pm this evening to 6am PST Sunday for
Northern Inland Waters Including The San Juan Islands.

Small Craft Advisory until 4pm PST 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-
Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-
Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm.