Marine Weather Net

Cape Flattery to James Island WA out 10 NM Marine Forecast


TODAY

W
WINDS
20 - 30
KNOTS

TONIGHT

NW
WINDS
10 - 20
KNOTS

WED

N
WINDS
5 - 15
KNOTS

WED NIGHT

NW
WINDS
15 - 25
KNOTS

The Marine Weather Forecast In Detail:
PZZ150 Forecast Issued: 253 AM PDT Tue May 18 2021

SMALL CRAFT ADVISORY IN EFFECT UNTIL NOON PDT TODAY
Today...W Wind 20 To 30 Kt Easing To 10 To 20 Kt In The Afternoon. Wind Waves 3 To 5 Ft Subsiding To 1 To 3 Ft In The Afternoon. W Swell 6 Ft At 10 Seconds. A Chance Of Showers.
Tonight...Nw Wind 10 To 20 Kt Becoming 5 To 15 Kt After Midnight. Wind Waves 1 To 3 Ft. W Swell 6 Ft At 12 Seconds. A Chance Of Showers In The Evening Then A Slight Chance Of Showers After Midnight.
Wed...N Wind 5 To 15 Kt Becoming Nw 10 To 20 Kt In The Afternoon. Wind Waves 1 To 3 Ft. W Swell 7 Ft At 12 Seconds Subsiding To 5 Ft At 11 Seconds In The Afternoon. A Chance Of Showers.
Wed Night...Nw Wind 15 To 25 Kt. Wind Waves 2 To 4 Ft. W Swell 6 Ft At 11 Seconds.
Thu...Nw Wind 15 To 25 Kt. Wind Waves 2 To 4 Ft. Nw Swell 6 Ft At 11 Seconds.
Thu Night...Nw Wind 15 To 25 Kt. Wind Waves 2 To 4 Ft. Nw Swell 6 Ft At 11 Seconds.
Fri...Nw Wind 10 To 20 Kt. Wind Waves 1 To 3 Ft. Nw Swell 5 Ft.
Sat...Nw Wind 10 To 20 Kt Rising To 15 To 25 Kt. Wind Waves 1 To 3 Ft Building To 2 To 4 Ft. W Swell 4 Ft Building To 6 Ft.
SHARE THIS PAGE:           
253 AM PDT Tue May 18 2021
Northern and Central Washington Coastal and Inland Waters - PZZ100
Winds will remain breezy this morning over the water in the wake of a frontal passage, with gales possible over the Central and Eastern Strait of Juan de Fuca through sunrise. The flow will remain onshore through the end of the week as high pressure remains centered offshore, with westerly diurnal pushes down the Strait expected each evening.
Area Forecast Discussion
National Weather Service Seattle WA
846pm PDT Monday May 17 2021

Synopsis
A trough will keep showers in the region tonight. Showers and thunderstorms are possible at times through Thursday. Expect a warming trend and decreasing showers Friday into the early weekend.

Short Term - Tonight Through Thursday
Showers continue tonight with a trough over the region. The current forecast remains on track with no planned updates. 33

Previous discussion...Increased onshore flow have boosted moisture through the lower levels of the atmosphere with a mid- level overcast deck and cooler temperatures. This morning's drizzle has generally tapered off ahead of the approaching front, which is on track to push into the coast by late afternoon and advance to the Cascades overnight. This will bring more significant precipitation as well as breezy south/southwest winds across the area ahead of the front. Behind the front, a strong push through the Strait of Juan de Fuca will bring another round of stronger west winds into early Tuesday across the San Juan Islands and northern Whidbey/Camano Islands. Precipitation will remain generally modest, with locally higher amounts near the coast and over the higher terrain particularly over the Cascades from Stevens Pass northward.

Of more significant note - unusually cold air air will quickly filter into the region - sharply lowering snow levels to between 3,000 and 3,500 feet by early Tuesday into Wednesday night. Precipitation is expected to be more showery in coverage once the colder air in place, helping mitigate the potential impacts of the lower snow levels. However - an inch or two of wet snow remain possible along the higher stretches of SR 20 (N Cascades Highway) and US 2 near Stevens Pass. Warmer antecedent surface temperatures will also act to mitigate the potential for significant impacts due to snow accumulation. Even so, anyone heading up into the mountains should be prepared for much cooler conditions as well as some new snow.

Showers will continue Tuesday with increasing instability as the upper trough and colder air aloft shifts overhead. The forecast continues to reflect a chance mention of thunderstorms across the region particularly during the afternoon hours. Temperatures will remain cool - in the upper 50s. Stronger onshore flow Tuesday evening will set the stage for a Puget Sound Convergence Zone and the potential for locally heaver showers and even thunderstorms into the overnight hours through the Cascades of King and Snohomish Counties.

Wednesday will remain cool and showery as the upper low exits the area, though shower coverage may be less widespread. Lingering instability will support the potential for another round of afternoon thunderstorms.

Long Term - Friday Through Monday
Thursday morning will see a bit of a break, with a warming trend through the day. Expect afternoon showers and a chance of thunderstorms - mostly over the higher terrain as the upper level low takes it's time fully exiting the region. Temperatures should rebound to near normal levels with decreasing clouds. The forecast for the Friday- Saturday reflect a drying trend with warmer temperatures in the upper 60s to low 70s and partial afternoon clearing. The forecast reflects a bit more potential for showers as the upper level pattern shifts to something more zonal - but this may trend the other way depending on how the transition evolves.

Marine
A rather strong post-frontal onshore push is expected across the waters this evening. This will lead to gale force winds in the central/eastern Strait of Juan de Fuca and small craft advisory winds all other waters. Winds will gradually ease late tonight as onshore gradients relax somewhat.

Surface ridging will then remain centered well offshore through the week ahead with lower pressure east of Cascades. This will lead to day-to-day fluctuations in onshore flow with small craft advisory westerlies possible at times over the coastal waters as well as central/eastern portions of the Strait of Juan de Fuca. 27

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

.SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until 11am PDT Tuesday 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-Puget Sound and Hood Canal.

Small Craft Advisory from 7am to 4pm PDT Tuesday for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca.

Gale Warning until 7am 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 until 4pm PDT Tuesday for Northern Inland Waters Including The San Juan Islands-West Entrance U.S. Waters Strait Of Juan De Fuca.

Small Craft Advisory until 8am PDT Tuesday for Admiralty Inlet.