Marine Weather and Tide Forecast for Willsboro, NY

NEAR TERM /THROUGH MONDAY/
As of 357 AM EDT Sunday...The end of the weekend and start of next week in the near term remains largely on the calmer side with just some mountain showers for precipitation chances. Shallow moisture this morning associated with a quasi-stationary boundary set up across Massachusetts and the Mohawk Valley in New York is slowly spreading out from the boundary axis northward. Some low clouds and patchy fog, mainly across south- central Vermont and along the Connecticut River Valley are possible before sunrise when PBL mixing helps to scour out the moisture.

A weak shortwave is expected to clip the region today to the northeast resulting in marginal instability, enough for some shower chances primarily in the Adirondacks and central Vermont. Pops are only 15-25% with weak forcing mechanisms. Behind the shortwave, drier air in the St. Lawrence Valley will begin to filter in across northern New York and much of Vermont, making for a pleasant day with light and variable winds. Temperatures will be seasonable today with highs in the low to mid 70s. Weak surface ridging from the east will begin to develop as high pressure over the Canadian Maritimes attempts to push in. This will help to draw in additional moisture beginning a trend of increasing dewpoints for the remainder of the week.

Heading into Sunday night, this increased moisture, and light winds could help develop some localized patchy fog, particularly in the Adirondacks and Northeast Kingdom where skies will be clear with decent radiational cooling. Overnight lows on Sunday will dip into the low to mid 50s, with some upper 40s in the higher terrain and NEK.

Similarly to Sunday, a weak shortwave will ride along subtle upper level ridging on Monday leading to additional chances of precipitation, primarily in the Adirondacks and central Vermont. This wave looks to be a little deeper which will lead to better rain chances on Monday than Sunday with PoPs 20-40%.
Highs on Monday will be on the increase with values in the upper 70s to near 80F.

SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/
As of 357 AM EDT Sunday...The Bermuda Ridge will be edging northward Monday night while a trough approaches out of the west. The result will be for increasing cloud cover and warming temperatures aloft.
While dry conditions will linger through the night, dew points will be rising keeping lows warmer than recent conditions generally in the upper 50s to mid 60s. Height falls ahead of the trough and impinging ridge will support increasing shower chances through the afternoon as southerly flow deepens. Temperature are strongly favored to trend warmer with highs in the upper 70s/low 80s. While a rumble of thunder cannot be completely ruled out, the primary energy with the trough will most likely pass through southern Canada.
However, the ridge placement favors a pattern where the surface boundary will linger over the North County.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
As of 357 AM EDT Sunday...Moisture and temperature advection is favored to increase further with models projecting 850mb temperatures warming around 20 C. This would lead to a marked warming trend Tuesday through Thursday with highs likely in the mid/upper 80s coupled with dew points in excess of 60 F; this supports muggy conditions and apparent temperatures around 90 F - definitely trending uncomfortable for most in the broader valleys.
With this heat, instability will be on the rise and afternoon thunderstorms should be anticipated given the proximity of a surface boundary. Wednesday, flow is projected to be more parallel to the boundary, so a mix mode of heavy rainers with a few stronger cells are possible. Model trends have shown a decreased amplitude for the Thursday trough with continued shear in the 40-50kt in the 0- 6km layer. However, some heavy rain and a few stronger thunderstorms can't be ruled out in this pattern. Friday could be the day where shear and CAPE line up better with guidance amplifying the trough enough to push a boundary through the North Country. This could allow temperatures to decrease marginally back mainly into the 70s, but has a good chance to knock dew points back into the 50s helping scour higher humidity by Saturday. Looking farther ahead, consensus points to increasing temperatures again Sunday into early next week, but trough/ridge variances are higher between models on placement of moderate amplitude trough/ridges at this time scale suggesting lower than usual reliability for the late weekend.

AVIATION /08Z SUNDAY THROUGH THURSDAY/
Through 06Z Monday...VFR conditions should prevail for most sites through the overnight period. Some patchy fog associated with moisture from a quasi-stationary boundary over Southern Vermont may reduce visibilities to IFR at RUT. Given that RUT has already seen FG, confidence is moderate to high that continued FG will continue through the first 6 hours, though not dense enough for prevailing fog. Drier air mixed down this afternoon may be able to hold off MPV/SLK/EFK from fogging in in the first 6 hours, and given satellite trends, there is lower confidence in IFR visibilities at those sites. Winds through the TAF period will remain light and variable below 5kts. Ceilings beyond 12Z will hover around 5000-10000 ft agl with some mid to upper level cumulus.

Outlook...

Monday: VFR. Slight chance SHRA.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. Chance SHRA.
Tuesday Night: Mainly VFR, with local IFR possible. Chance SHRA.
Wednesday: MVFR/IFR conditions possible. Chance SHRA, Slight chance TSRA.
Wednesday Night: Mainly VFR, with local IFR possible. Chance SHRA, Slight chance TSRA.
Thursday: Mainly MVFR, with areas IFR possible. Likely SHRA, Slight chance TSRA.

BTV WATCHES/WARNINGS/ADVISORIES
VT...None.
NY...None.