Marine Weather Net

West Entrance U.S. Waters Strait of Juan de Fuca Marine Forecast


TODAY

W
WINDS
5 - 10
KNOTS

TONIGHT

W
WINDS
5 - 10
KNOTS

TUE

W
WINDS
5 KNOTS

TUE NIGHT

W
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
PZZ130 Forecast Issued: 849 AM PDT Mon May 12 2025

Today...W Wind 5 To 10 Kt. Seas 3 To 4 Ft. Wave Detail: W 4 Ft At 9 Seconds. A Slight Chance Of Showers This Afternoon.
Tonight...W Wind 5 To 10 Kt, Easing To Around 5 Kt After Midnight. Seas 4 To 6 Ft. Wave Detail: W 6 Ft At 10 Seconds.
Tue...W Wind Around 5 Kt, Rising To 5 To 10 Kt In The Afternoon. Seas 4 To 6 Ft. Wave Detail: W 6 Ft At 10 Seconds.
Tue Night...W Wind 10 To 15 Kt. Seas 4 To 6 Ft. Wave Detail: W 6 Ft At 10 Seconds.
Wed...W Wind 10 To 15 Kt. Seas 4 To 6 Ft. Wave Detail: W 6 Ft At 9 Seconds.
Wed Night...W Wind 10 To 15 Kt, Easing To 5 To 10 Kt After Midnight. Seas 3 To 5 Ft. Wave Detail: W 5 Ft At 9 Seconds.
Thu...Sw Wind 5 To 10 Kt. Seas 3 To 5 Ft. Wave Detail: W 5 Ft At 12 Seconds. A Chance Of Showers.
Thu Night...Sw Wind 5 To 10 Kt, Backing To S After Midnight. Seas 3 To 4 Ft. Wave Detail: W 4 Ft At 11 Seconds. A Chance Of Showers.
Fri...Se Wind 5 To 10 Kt. Seas 4 To 6 Ft. Wave Detail: W 6 Ft At 12 Seconds. Showers Likely.
Fri Night...S Wind 5 To 10 Kt, Veering To W After Midnight. Seas 4 To 6 Ft. Wave Detail: W 6 Ft At 11 Seconds. A Chance Of Showers.
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Area Forecast Discussion
National Weather Service Seattle WA
902am PDT Monday May 12 2025

Synopsis
Lingering moisture with an upper low passing to the south will keep scattered showers and possibly an isolated afternoon thunderstorm in the forecast today. Upper level ridging will start to build into the area midweek for the return of warm and dry conditions. A broad upper level trough will bring active weather back to the area for the end of the week.

Short Term - Today through Wednesday
No changes made to the forecast this morning as the forecast remains on track. The previous discussion can be found below along with an update to the aviation section:

Latest satellite imagery showing center of circulation for the current upper low over the coastal waters of the norther OR coast. As such, both on satellite and radar, seeing a wave of moisture being rotated up into the southern portions of the CWA (County Warning Area) with echoes moving to the west- northwest.

As this feature pushes inland today, that will keep the chance of showers in the forecast for W WA at least into the late afternoon before drying starts moving slowly over the area from west to east. The coast should see activity wrap up by late in the afternoon while locations east of the Sound seeing showers linger into tonight. Given the isolated thunderstorms that happened Sunday afternoon and with models suggesting some instability...will leave model generated ProbThunder alone...especially since it falls in a pretty narrow window of the mid to late afternoon time frame.

Models remain consistent in bringing in an upper level ridge into W WA late tonight resulting in largely dry conditions Tuesday. This is not a strong ridge by any means, being largely ineffective in scouring out any lingering moisture. Thus, though generally dry conditions are expected both Tuesday and Wednesday, there will still be a fair amount of clouds over the area and a persistent chance for showers over the Cascades.

High temp forecasts remain consistent with previous runs with little change throughout the near term period: lower to mid 60s for the interior, mid to upper 50s for the coast and water adjacent locations.

18

Long Term - Thursday Through Sunday
Deterministic models starting to fall in line with each other, bring the next system into the area Thursday...their timing about 3-6 hours off from one another. Ensembles provide some fine tuning for the return of chances for precipitation to the area...generally landing in the late afternoon/early evening. As has been the case with most of these recent systems, neither Probability of Precipitation nor Quantitative Precipitation Forecasts look terribly impressive...the former running 30-50 pct mostly and the latter falling short of 0.05 of an inch. Depending on where you look, there seems to be a more favorable opinion of the Friday system when it comes to generating rainfall. Deterministic models are not really doing a good job of handling it but ensembles provide a better picture with a strong preference for overnight Friday and into Saturday. Quantitative Precipitation Forecast values still fall short of meh, with the ensemble mean falling largely right around 0.05 of an inch, but there are a fair number of perturbations that clime to 0.10 of an inch or higher. As the trough responsible for this sinks southward for the remainder of the forecast period, some disagreement as to whether or not a closed low emerges. Regardless of that, ensembles show chances slowly eroding throughout the day Saturday and while not entirely gone Sunday, majority of locations see only a slight chance by then.

This generally troughy pattern will not allow for any significant change to the temperatures over W WA, with the bulk of the long term echoing those of the short term.

18

Marine
A 1000 mb low will weaken and shift east into Oregon today, with onshore flow increasing tonight. Small Craft Advisory winds are likely through the Strait of Juan de Fuca. Seas will also build to around 10 ft over the outer Coastal Waters. High pressure sets up offshore with lower pressure inland on Tuesday. This pattern will remain intact through Thursday with the next frontal system moving inland on Friday. 33

Hydrology
The daily hydrology discussion has ended until the start of the next rainy season; it will only be included as needed.

NOAA Seattle WA Office: Watches - Warnings - Advisories
WA...None. PZ...Small Craft Advisory from 5pm this afternoon to 5am PDT Tuesday for
Central U.S. Waters Strait Of Juan De Fuca-
East Entrance U.S. Waters Strait Of Juan De Fuca.

Small Craft Advisory from 5pm this afternoon to 5am PDT Wednesday for
Coastal Waters From Cape Flattery To James Island 10 To 60 Nm-
Coastal Waters From James Island To Point Grenville 10 To 60 Nm-
Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm.