Marine Weather Net

San Juan Islands and Northern Inland Waters Marine Forecast


TONIGHT

S
WINDS
15 - 25
KNOTS

SUN

E
WINDS
15 - 25
KNOTS

SUN NIGHT

SE
WINDS
25 - 35
KNOTS

MON

SE
WINDS
30 - 40
KNOTS

The Marine Weather Forecast In Detail:
PZZ133 Forecast Issued: 253 PM PDT Sat Oct 23 2021

SMALL CRAFT ADVISORY IN EFFECT UNTIL MIDNIGHT PDT TONIGHT ...GALE WARNING IN EFFECT FROM MIDNIGHT PDT TONIGHT THROUGH LATE MONDAY NIGHT...
Tonight...S Wind 15 To 25 Kt Becoming E 25 To 35 Kt After Midnight. Wind Waves 2 To 4 Ft Building To 4 To 6 Ft After Midnight. A Slight Chance Of Showers In The Evening.
Sun...E Wind 15 To 25 Kt Becoming Se 25 To 35 Kt In The Afternoon. Wind Waves 2 To 4 Ft Building To 4 To 6 Ft In The Afternoon. Rain In The Morning Then Rain Likely In The Afternoon.
Sun Night...Se Wind 25 To 35 Kt. Wind Waves 4 To 6 Ft. Rain In The Evening Then Rain Likely After Midnight.
Mon...Se Wind 30 To 40 Kt Easing To 25 To 35 Kt In The Afternoon. Wind Waves 5 To 7 Ft.
Mon Night...Se Wind 25 To 35 Kt Becoming S 20 To 30 Kt After Midnight. Wind Waves 5 To 7 Ft Subsiding To 3 To 5 Ft After Midnight.
Tue...S Wind 15 To 25 Kt. Wind Waves 2 To 4 Ft.
Tue Night...S Wind 5 To 15 Kt. Wind Waves 2 Ft Or Less.
Wed...S Wind 5 To 15 Kt Becoming Se To 10 Kt. Wind Waves 2 Ft Or Less.
Thu...Se Wind To 10 Kt Becoming S. Wind Waves 1 Ft Or Less.
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253 PM PDT Sat Oct 23 2021
Northern and Central Washington Coastal and Inland Waters - PZZ100
Deep low pressure will move over the nearshore waters Sunday as a strong front moves through Western Washington resulting in windy conditions. This low is expected to track toward northern Vancouver Island on Monday.
Area Forecast Discussion
National Weather Service Seattle WA
226pm PDT Sat Oct 23 2021

Synopsis
A strong front will move through Western Washington Sunday morning. A deep low pressure system will approach the area on Sunday and then weaken somewhat and move across Vancouver Island Monday afternoon. Periods of wet blustery weather will occur through next week as additional frontal systems move through the region.

Short Term - Tonight Through Tuesday
The strong frontal system and rapidly deepening low pressure center seem to be doing what the global models have been advertising. A storm will move through the offshore waters and pull up just short of the coastal waters before it starts to fill and curve toward Vancouver Island Sunday. The front will move through Western Washington Sunday morning, frontal passage might be as late as early afternoon in the north. Several hours of windy conditions are a good bet despite the low still being offshore- -the mesoscale models have enough wind through the gaps and in the normal windier locations to justify various wind advisories and warnings. Obviously this isn't the sort of storm we worry about for the Seattle metro area because the low center is so far away but even the initial front can have a pretty decent pressure fall/rise couplet, so I'll be surprised if it isn't blustery around Seattle for awhile on Sunday. As far as easterly winds through the Cascade gaps--the Seattle Wenatchee pressure gradient should get up around -10mb, so that falls short of what we might see later in the season when there is often colder air and higher pressure over Eastern Washington. That said, with a frontal passage Sunday morning, there might be winds aloft mixing down though I did not see anything startling in the mesoscale models that might indicate mountain waves surfacing so I'm not too keyed up about that idea.

The surf will build Sunday night and a high surf warning was issued for the coast. And as the low moves ashore Monday over Vancouver Island tide gages from Port Townsend to Cherry Point ought to be two feet above the tide table predictions, so it is a good thing we are not in a king tide cycle (that next occurs Nov 5-9th). Periods of heavy rain will fall in the mountains, but only the Skokomish River in Mason county will get up around flood stage late Monday or Tue. We might see a few thunderstorms, mainly near the coast behind the front--naturally any squalls could help kick up the wind.

As the deep low weakens and crosses Vancouver Island Monday afternoon and evening southerly gradients will peak around the Seattle metro area. Looking at the Euro, PDX-BLI ought to be up around 10mb, so that is about half of the sort of gradient we see with our big windstorms, but it is still significant being early in the season. The GFS20 PDX-BLI gradient forecast only peaks around +7mb Monday evening, surely that is too low, and would give merely breezy weather.

Another rather typical looking front moves ashore on Tuesday- -the low pressure center with that front is off Haida Gwaii so that should be another blustery day but would fall short of needing much in the way of advisories. 19

Long Term - Wednesday Through Saturday
Periods of wet and blustery weather are likely but it does not look like we will see any deep low pressure centers like the one Sun/Mon. The frontal system for Thursday and Thursday night could send the rivers up and no doubt it will be called an atmospheric river--although it falls short of what we used to call a Pineapple Express and looks fairly progressive to me. Looking at the UW wrfgfs integrated water vapor transport suggests that the Oregon coast might be more under the plume from Wednesday through Thu evening. 19

Marine
Winds will gradually subside this afternoon and evening but this will only be temporary, ramping back up overnight back into headline criteria. In addition, swells of 11-13 feet will make for hazardous seas for the West Entrance of the Strait and the Coastal Waters/Grays Harbor Bar.

Still expecting a very strong low pressure system to rapidly deepen tonight and into Sunday over the open Pacific Waters, well outside the outer coastal zones. Nevertheless, strong winds are likely, with storm warning thresholds expected to be met for the Coastal Waters with sustained winds in the 40-50kts range. Easterly winds will pick up through the morning Sunday, with gales likely over most of the interior waters. A strong easterly push down the Strait is likely to result in Storm Warning level winds around the West Entrance.

By Sunday night, large swells are expected over the Coastal Waters, with seas building to between 25 and 30 feet. This will result in High Surf conditions. A High Surf Advisory is in place. Expect dangerous beach conditions along the Coast through much of Sunday and Monday.

This continues to look like a longer duration event as strong winds are expected to continue through Monday along with high seas. Gales are likely to persist over the interior waters for Monday, with storm warning winds over the coastal waters eventually subsiding to gale. Winds and seas will gradually subside through Tuesday but it is very possible hazardous marine conditions may continue into Tuesday morning. Yet another front around Thursday could bring another round of wind headlines along with large swells, though nothing to the extent of what is expected for Sunday/Monday.

NOAA Seattle WA Office: Watches - Warnings - Advisories
WA...Wind Advisory from 6am Sunday to 6am PDT Monday for Eastern Strait of Juan de Fuca-Everett and Vicinity-Hood Canal Area.

High Wind Warning from 8am Sunday to 5am PDT Tuesday for Admiralty Inlet Area-San Juan County-Western Skagit County- Western Whatcom County.

High Wind Warning from 6am Sunday to 6pm PDT Monday for Central Coast-North Coast.

High Surf Warning from 6pm Sunday to 11pm PDT Monday for Central Coast-North Coast.

Wind Advisory from 5am to 6pm PDT Sunday for East Puget Sound Lowlands.

High Wind Warning from 6am to 6pm PDT Sunday for Western Strait of Juan De Fuca.

PZ...Small Craft Advisory until 5am PDT Tuesday for
Grays Harbor Bar

Small Craft Advisory until midnight PDT tonight for
Admiralty Inlet
Central U.S. Waters Strait Of Juan De Fuca-
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-
East Entrance U.S. Waters Strait Of Juan De Fuca-
Northern Inland Waters Including The San Juan Islands.

Storm Warning from midnight tonight to 5am 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-
Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-
Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm.

Gale Warning from midnight tonight to 5am PDT Tuesday for
Admiralty Inlet
Central U.S. Waters Strait Of Juan De Fuca-
East Entrance U.S. Waters Strait Of Juan De Fuca-
Northern Inland Waters Including The San Juan Islands.

Small Craft Advisory until 3am PDT Sunday for
West Entrance USA Waters Strait Of Juan De Fuca.

Storm Warning from 3am Sunday to 5am PDT Monday for
West Entrance USA Waters Strait Of Juan De Fuca.

Small Craft Advisory from midnight tonight to 5am PDT Monday for
Puget Sound and Hood Canal