Marine Weather and Tide Forecast for Montesano, WA

SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/
An upper-ridge and thermal surface trough have worked in tandem to bring another day of well-above average temperatures. Tonight, these features are slated to gently progress east of the Cascades. This movement will be the start of a pattern change across western Washington with increasing onshore flow. As a result, conditions will begin to trend cooler but we'll see one more warm day. Overnight lows are forecast to bottom into the upper 50s to lower 60s.

As mentioned, another warm day is in the forecast across the interior on Wednesday. Minor HeatRisk is favored to become more widespread due to increased onshore flow but moderate HeatRisk will remain for the urban centers. The current Heat Advisory should be allowed to expire for coastal adjacent areas Tuesday night and the remainder of the area on Wednesday night. Onshore flow is favored to peak in intensity Wednesday evening as widespread marine air intrusion takes hold. Areas of marine stratus looks to develop as well. REFS is indicating a 30-40% chance of wind gusts greater than 35 mph across Whidbey Island during this time. HRRR probs are more bullish with 50-60% chance. Overnight lows are to bottom in the lower to upper 50s

Thursday will feel more like late June with 60s along the coast and lower 70s throughout the interior. Morning stratus will lessen in coverage but mid-high level clouds are forecast to increase ahead of an approaching frontal system. Rainfall looks to arrive along the coast Thursday evening before spreading inland overnight then transitioning to post-frontal showers.

LONG TERM /FRIDAY THROUGH TUESDAY/
As mentioned, post-frontal showers in store for Friday along with a developing convergence zone. NBM is highlighting a 20-30% chance of thunderstorms as the airmass is somewhat unstable. Cool upper level low dropping down over the area Friday night into Saturday keeping showers in the forecast. Weak upper level ridge building offshore Sunday. Weak upper level trough moving down the backside of the ridge into Western Washington Monday for a chance of showers.

High temperatures in the upper 50s to mid 60s Friday and Saturday and only in the 60s Sunday and Monday. There is a chance for record low maximum temperatures Friday and possibly Saturday.

AVIATION
Primarily VFR conditions are expected with passing mid to high clouds through the forecast period. The NBM suggests a 50-70% chance of ceilings below 3,000 ft between 12-19z Wednesday and HRRR is around 60%. Winds will generally be out of the north 5-10 knots for interior terminals and more variable in direction for the coastal terminals before a more southwesterly shift into Wednesday morning and remaining well into the day.

KSEA...VFR expected through the TAF period. Northwest winds 5-10 knots this afternoon and into the night. A return of broader onshore flow on Wednesday will shift winds to the west- southwest sometime Wednesday morning between 12-16Z. SW are in the forecast well into the day on Wednesday.

MARINE
A thermal surface trough will progress east of the Cascades tonight. Here, low-level onshore flow will begin to increase across area waters. A gale watch remains for the Central and Eastern Strait of Juan de Fuca for Wednesday night. Onshore gradients easing Thursday. Frontal system moving through the waters Friday with possible small craft advisory winds with and just behind the front. Winds easing Saturday.

Choppy seas developing over the outer coastal waters tonight with swell 7 to 10 feet with a 7 to 9 second period. As a result a SCA remains for these zones in particular. The choppy seas will continue over the outer coastal waters through Wednesday night.

FIRE WEATHER
An upper-ridge is progressing gently across the region. As a result, very warm and dry weather has lead to elevated fire weather conditions for Wednesday. Min RHs will bottom around the 20-25% range for isolated areas of the Cascade valleys.
Onshore will increase on Thursday with widespread marine air intrusion. Fire weather concerns will alleviate Thursday onward as wetting rains return Thursday night into Friday. A cooler and wetter pattern is favored into early next week.



SEW WATCHES/WARNINGS/ADVISORIES
WA...Heat Advisory until 11 PM PDT this evening for Eastern Strait of Juan de Fuca-Foothills and Valleys of Thurston and Lewis Counties-Foothills and Valleys of the North Cascades-Foothills of the Western and Southern Olympic Peninsula-Island County-Lower Chehalis River Valley- Lowlands of Lewis and Southern Thurston Counties-Lowlands of Western Skagit and Northwestern Snohomish Counties- Lowlands of Western Whatcom County-Middle Chehalis River Valley-Northern Hood Canal-Olympia and Southern Puget Sound-Port Townsend Area-San Juan County-Southern Hood Canal-Willapa and Black Hills.

Heat Advisory until 11 PM PDT Wednesday for City of Seattle- Downtown Everett / Marysville Area-Eastern Kitsap County- Eastside-Foothills and Valleys of Central King County- Foothills and Valleys of Pierce and Southern King Counties-Foothills and Valleys of Snohomish and Northern King Counties-Lowlands of Pierce and Southern King Counties-Shoreline / Lynnwood / South Everett Area.

PZ...Gale Watch from Wednesday evening through late Wednesday night for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca.

Small Craft Advisory from 6 PM this evening to 6 AM PDT Thursday 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.