Marine Weather and Tide Forecast for Maple Heights-Lake Desire, WA

SHORT TERM /TODAY THROUGH MONDAY/
Satellite imagery shows broad weak upper level low off the Oregon coast. Middle and high level clouds moving over Western Washington with southerly flow aloft. Stratus along the coast last night has spread as far inland as Shelton at 3 am/10z.
Temperatures were in the mid 40s to mid 50s.

Upper level low drifting south today and tonight with the southerly flow aloft getting cut off late this afternoon. This will stop the flow of middle and high level clouds over Western Washington. Light flow in the lower levels will prevent the stratus from expanding much farther eastward but the air mass is pretty moist over the interior, dew points near 50, so we could see some shallow stratus form in place over the Central Puget Sound around sunrise. The stratus will dissipate later this morning. With plenty of sunshine in the afternoon highs warming into the mid 60s to mid 70s.

Low level flow turning offshore tonight into Sunday. Temperatures aloft continue to warm with 850 mb temps peaking around plus 16C Sunday afternoon. Sunday will be the warmest day of the year so far with highs in the mid 70s to mid 80s. Record highs are probable. Offshore flow kicking in overnight will keep Sunday morning lows in the upper 40s to mid 50s.

Low level flow turning weakly onshore Sunday night with the low level onshore flow increasing Monday. Stratus developing along the coast Monday with significant cooling, highs back into the mid 60s. For the interior the marine layer will be shallow and have a hard time getting east of the Puget Sound in the afternoon as it gets eroded by the warm air mass over the interior. Temperatures aloft cooling slightly. This combined with the weak onshore flow knocking a couple of degrees off the highs Monday compared to Sunday. Still a very warm day. Highs in the 70s and lower 80s.

The HeatRisk for the most part remains in the minor category Sunday and Monday due to the temperatures cooling off nicely in the overnight hours. Felton

LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
Upper level ridge axis dropping down from the north over Western Washington Monday night into Tuesday. Low level onshore flow increasing Monday night with stratus getting east of Puget Sound Tuesday morning. Cooler Tuesday over the interior with highs in the upper 60s to mid 70s. Coast remaining in the mid 60s.

Upper level ridge over the area weakening Wednesday, rebuilding Thursday then starts to move east Friday. Low level flow remaining light onshore. Relatively warm air aloft combined with only a shallow marine layer over the interior in the late night and morning hours will keep daytime highs above normal through the week. A little cooling Friday as the ridge starts to exit the area. Highs Wednesday and Thursday in the 60s and lower 70s, Friday in the 60s. Lows in the 40s.

AVIATION
An upper level low digging southward along the Oregon coast will produce light southwest flow aloft today. An upper level ridge will begin to rebuild into the region tonight with the flow aloft switching to light northeasterly. Light low level onshore flow will turn northerly this afternoon. Residual high and mid level moisture will thin with time today. Coastal stratus and associated MVFR/IFR ceilings will extend inland as far as Kitsap County this morning before lifting and scattering out.

KSEA...VFR with mid and high level clouds gradually thinning and clearing toward afternoon. Surface wind light and variable early will become northerly and increase to 9 to 13 knots this afternoon.

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MARINE
Thermally induced low pressure will expand northward along the coast today into Sunday with light northerly or weak offshore flow developing. The thermal trough will shift into the interior on Monday allowing onshore flow to resume and increase toward the middle of next week. Westerlies in the central and east strait will likely approach gale force Monday night or Tuesday.

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HYDROLOGY
No river flooding in the next 7 days.

SEW WATCHES/WARNINGS/ADVISORIES
WA...None.
PZ...None.