West Entrance U.S. waters Strait of Juan de Fuca Marine Forecast
|Today...W Wind 5 To 15 Kt. Wind Waves 2 Ft Or Less. W Swell 14 Ft At 12 Seconds. Rain In The Morning Then Showers Likely In The Afternoon.|
|Tonight...Sw Wind 5 To 15 Kt. Wind Waves 2 Ft Or Less. W Swell 12 Ft At 12 Seconds Subsiding To 10 Ft At 11 Seconds After Midnight. Showers Likely In The Evening Then A Chance Of Showers After Midnight.|
|Sat...Sw Wind To 10 Kt Rising To 5 To 15 Kt In The Afternoon. Wind Waves 2 Ft Or Less. W Swell 9 Ft At 10 Seconds. Showers Likely.|
|Sat Night...Sw Wind To 10 Kt Becoming E After Midnight. Wind Waves 1 Ft Or Less. W Swell 7 Ft At 10 Seconds.|
|Sun...Se Wind To 10 Kt Rising To 5 To 15 Kt In The Afternoon. Wind Waves 2 Ft Or Less. W Swell 6 Ft At 10 Seconds.|
|Sun Night...Se Wind To 10 Kt. Wind Waves 1 Ft Or Less. W Swell 5 Ft At 10 Seconds.|
|Mon...Light Wind Becoming E 5 To 15 Kt. Wind Waves 2 Ft Or Less. W Swell 5 Ft Building To 8 Ft.|
|Tue...Se Wind 10 To 20 Kt Becoming 5 To 15 Kt. Wind Waves 1 To 3 Ft. W Swell 8 Ft Subsiding To 6 Ft.|
| 851 AM PDT Fri Sep 25 2020 |
Northern and Central Washington Coastal and Inland Waters - PZZ100
A strong frontal system will move through the area today bringing gusty winds to area waters. A couple of weak systems will then brush across the area through the weekend. Offshore flow will develop early next week.
| Area Forecast Discussion|
National Weather Service Seattle WA
922am PDT Fri September 25 2020
Steady rain across much of the southern and central Puget Sound this morning as a strong front moves through. The front sliding along the Olympic Peninsula will move east into the afternoon. Breezy winds into the afternoon for the area. Areas of steadier rain will transition to more convective showers by late morning into the afternoon. A slight chance for t-storms across the coast and into areas around the central Puget Sound through today. A convergence zone this afternoon into this evening is expected in the Snohomish County area.
A damp close to the week is in store as a vigorous Pacific storm system brings rain to the area into the afternoon. Scattered showers will then continue through the first half of the weekend before a high amplitude ridge dries the area out from Sunday through most of the week.
.SHORT TERM /TODAY THROUGH SUNDAY/...The synoptic pattern this morning is characterized by strong polar jet oriented within a zonal flow regime across much of the far N Pacific, separating low pressure to its north over the Gulf of Alaska & thru the Bering Sea and high pressure to its south across subtropical latitudes. At the surface, a well defined frontal boundary was noted just offshore the Pacific Northwest, with warm frontal portion of the boundary beginning to move onshore and cold front still trailing over the offshore waters.
Around 230AM this morning, local radar imagery was picking up on an expansive area of stratiform rain across the Olympic Peninsula and across the Coastal Waters, associated with the warm frontal boundary and some PVA supplied by a nearby vort max lagging just behind the frontal boundary, per Storm Prediction Center mesoanalysis. Precipitation amounts across these areas thus far appear to be generally between 0.10-0.30 inches.
Going forward through the morning hours, a combination of favorable jet dynamics, height falls, and plenty of warm air advection in and around the vicinity of the warm frontal boundary and in the warm sector of the front will sustain the large shield of stratiform rain as it continues to spread inland, with just about the entire CWA experiencing light to moderate rainfall by daybreak. As the rain shield spreads inland, it will be accompanied by a strong LLJ between 925-850mb which will also translate to breezy to locally windy conditions at the surface. In general, expect highest winds to be confined more towards the Coast and the NW Interior (W Whatcom/Skagit Counties and thru the San Juan Islands and into Admiralty Inlet vicinity) where peak gusts may reach 45-50 mph. Elsewhere will be quite breezy with gusts 30-40 mph. Cannot rule out a few isolated areas reaching wind advisory criteria outside of the locations already mentioned, but in general think most areas will fall short. By the afternoon hours, bulk of the stratiform rain will push into the Cascades and east, with widely scattered showers picking up in the front's wake. Provided widespread cloud cover, widespread precipitation early in the day, and meager mid level lapse rates, do not anticipate thunderstorm development this afternoon/evening. As winds then turn more westerly in the wake of the front this evening, a good push down the Strait may be enough to generate a PSCZ over Snohomish County later this evening. Overall rainfall totals through tonight are expected to range from another 2-4 inches across the mountains to between 0.5-1 inch across the lowlands (could be locally higher). At current time does not appear to be enough for river flooding, tho do expect the potential for ponding on roadways and in areas of poor drainage- very similar to this past Wednesday's system.
Quasi-zonal mid/upper level flow will follow us into weekend, with a weak shortwave skirting the BC/WA border late in the day on Saturday. Will likely see continued shower activity into Saturday morning as W WA remains on the cyclonic side of the jet, with an enhancement in coverage through the afternoon as the shortwave approaches. All in all, Saturday will not be nearly as wet as Friday. Finally by Sunday, high pressure to the south of the polar jet over the far E Pacific and into California will build north, essentially pushing the storm track to our north. Guidance has continued to trend drier and so have opted to eliminate POPs for Sunday.
Long Term - Monday Through Thursday
The long term portion of the forecast will be dominated by a high amplitude pattern over the CONUS characterized by a Western US ridge and an Eastern US trough. This will imply a dry forecast for W WA through next week, with temps warming back into the 70s. The low level flow is expected to turn offshore during this timeframe, but given recent soaking rains, do not anticipate any fire weather issues. Also, given the time of year and the recent rains/residual low level moisture, could be beginning to look at the potential for morning fog, afternoon sun. All in all a rather tranquil extended appears to be in store.
Winds starting to ease very gradually in the wake of a passing front this morning. Gales have already ended in Admiralty Inlet area and are expected to end over remaining Gale Warning areas by 11am PST this morning before transitioning to SCAs. A brief strong westerly push down the Strait of Juan de Fuca is still on tap for this afternoon and as such inherited headline there looks good. A couple of much weaker weather systems will move through the area this weekend with light onshore flow. Offshore flow will develop early next week as a thermal trough builds north into the Coastal Waters. Schneider/18
Persistent rains followed by widespread showers will continue to impact area rivers in W WA throughout the day today. While no river flooding is expected...rivers are expected to continue to see levels rise during this prolonged event. The Skokomish...as usual...remains the river to be watched...although current forecasts have river levels remaining below flood at this time. 18
.SEW WATCHES/WARNINGS/ADVISORIES... WA...Wind Advisory until 10am PDT this morning for Admiralty Inlet Area-Central Coast-North Coast-San Juan County-Western Skagit County-Western Whatcom County.
High Surf Advisory until 2pm PDT this afternoon for Central Coast-North Coast.
PZ...Small Craft Advisory until 11am PDT Saturday for Grays Harbor Bar.
Small Craft Advisory until 11am PDT Saturday 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 until 11am PDT this morning 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-East Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland Waters Including The San Juan Islands.
Small Craft Advisory until 11pm PDT this evening for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until 6pm PDT this evening for Northern Inland Waters Including The San Juan Islands.
Small Craft Advisory until 5am PDT Saturday for West Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until 6pm PDT this evening for Admiralty Inlet.
Gale Warning until 9am PDT this morning for Admiralty Inlet.
Small Craft Advisory until 6pm PDT this evening for Puget Sound and Hood Canal.