Marine Weather and Tide Forecast for Clinton, WA

UPDATE
A broad area of precipitation is making its way across western Washington late this morning. Destabilization could lead to thunderstorm activity today with at least a 15-20% chance of thunder area wide, meanwhile the best chances (25-35%)
will be along the coast and into the north interior. Lightning, small hail, and brief heavy downpours will be the primary hazards. A Winter Weather Advisory was added for the mountains of western Washington above 4000 feet. This was put out mainly as a heads up for those with outdoor recreation plans today through Saturday night. Snow showers and thunderstorms cannot be ruled out. Road travel conditions could see minor temporary impacts, but generally ground temperatures will be warm enough to limit road accumulation.

Widespread chances for thunder exist through Saturday, though the focus of the convective potential will shift into the central Puget Sound south through SW Washington (peaking in the 25-35% range).
-Wolcott

SHORT TERM /TODAY THROUGH SUNDAY/
Satellite imagery shows mostly cloudy skies over Western Washington early this morning. Doppler radar has widely scattered showers mainly over the northern portion of the area.
Temperatures at 2 am/09z were in the mid 40s to lower 50s.

Main story for the next two days is the very cool upper level trough over Western Washington. The trough will move over the area today and remain into Saturday night. Temperatures aloft very cold for this time of year with 500 mb temperatures dropping below -30C tonight into Saturday. Even with plenty of cloud cover and little daytime heating the very cold air aloft will create unstable conditions especially this afternoon through Saturday. Lifted indexes in the plus 2 to minus 2 range, convective temperatures both this afternoon and Saturday afternoon below the predicted high temperatures, lapse rates with the very cold air aloft in the plus 7 to 8C/km. All this adds up to showers through Saturday with a chance of afternoon and evening thunderstorms. Snow levels, already low near 4000 feet this morning, lowering to 3000 to 3500 feet tonight and Saturday. Could see a couple of inches of snow at the summit of Stevens Pass while higher up Paradise on Mount Rainier looking at 4 to 8 inches of new snow the next two days. Highs in the lower to mid 50s today and mid to upper 50s Saturday. Highs today will only be a couple of degrees warmer than record low maximums. Lows tonight in the upper 30s to mid 40s.

Upper level trough weakening Saturday night and moving out of the area Sunday. Convective activity coming to an end Saturday evening. A few breaks in the clouds cover will allow temperatures to drop into the mid 30s in the colder locations Sunday morning. Lows in the upper 30s to mid 40s for the remainder of the area.

Upper level ridge building offshore Sunday. Plenty of low level moisture over Western Washington combined with light flow in the lower levels will make it hard for the sun to break through especially in the morning. As the marine layer thins in the afternoon some sunshine will get highs into the upper 50s to mid 60s. Felton

LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/
Models in good agreement with the upper level ridge remaining in place at least through Tuesday. Differences in the model solutions beginning Wednesday with some solutions moving the ridge inland over Western Washington while other solutions keep the ridge axis offshore. Either scenario keeps the weather dry over the area. The ridge axis moving overhead would result in a little warmer days. For now with the uncertainty will keep highs just a couple of degrees above normal Wednesday and Thursday, in the mid 60s to lower 70s. Highs Monday and Tuesday in the 60s. Lows in the 40s through the period.

AVIATION
W/SW flow aloft through tonight, veering to the NW Saturday morning.
At low levels, S winds for all but the coast, where winds are W.
Speeds ranging 10-15 kts with gusts up to 25 kts. VFR conditions with areas of MVFR conditions with showers, with some recovery after 22Z allowing more widespread low-end VFR, except for those locations with lingering precipitation.

KSEA.. MVFR conditions with light rain. Some improvement expected during the afternoon. Southwesterly winds throughout the TAF period with speeds 8-12 kts this morning, becoming 10-15 kts with gusts to 25 kts this afternoon and early evening before easing tonight. For Saturday, HiRes ensembles consistently showing the development of a PSCZ Saturday afternoon with a 40-50% chance of northerly winds at the terminal by 3pm, and higher odds by 5-6PM. In addition, there is 15 to 20% chance of lightning with the convergence zone through the same period.

MARINE
Onshore flow will continue over the weekend which will allow for daily pushes through the Strait of Juan De Fuca. However, given the more southwesterly flow of winds...they may not see such a strong push today...that remains on track for Saturday though. These southwesterly winds however do look to trigger advisory level winds for the Puget Sound for much of the day today before easing by this evening. As such, an SCA has gone out with the morning forecast package.

Near-shore seas will steadily increase today, likely topping out at 7 to 9 ft. The outer waters however will see more significant increases, reaching 9 to 12 ft late tonight and persisting throughout much of Saturday. As such, have issued an SCA this morning to cover this high seas threat. Seas might be slow to regress, but they are expected to slowly ease back down to 7 to 9 ft Sunday morning.

18

HYDROLOGY
The daily hydrology discussion has ended until the start of the next rainy season; it will only be updated during this time as needed.

SEW WATCHES/WARNINGS/ADVISORIES
WA...Winter Weather Advisory until 8 AM PDT Sunday for Cascades of Pierce and Lewis Counties-Cascades of Snohomish and Northern King Counties-Cascades of Southern King County- Cascades of Whatcom and Skagit Counties-Olympics.

PZ...Small Craft Advisory until 7 PM PDT this evening for Puget Sound and Hood Canal.

Small Craft Advisory from 11 PM this evening to 11 PM PDT Saturday 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.