Marine Weather and Tide Forecast for Vergennes, VT

KEY MESSAGES
As of 251 AM EDT Sunday...

1. Rain associated with the remnants of Isaias will bring a some rainfall tonight with no significant impacts for our area.

2. Periods of rain Tuesday into Tuesday night before drying on Wednesday.

3. Low pressure system brings next chance for showers Friday into Friday night with showers continuing into the weekend.

DISCUSSION
As of 251 AM EDT Sunday...

KEY MESSAGE 1: The center of the low associated with the remnants of Isaias will track up into the Mid-Atlantic then track offshore before it reaches any farther north. Rainfall will spread into southern areas this evening but struggle to make it any farther north as it is running into the ~1030 mb high that is giving us the dry weekend. The 00Z guidance has trended south with the northern extent of the rain, with the global deterministic data showing the most dramatic retreat while the HRRR and global ensembles show a more subtle retreat.
Overall, areas with a 50 percent or higher chance of seeing 0.1 inches is now mostly restricted to southern Vermont, with measurable rain likely not reaching the international border in places. Forecast rain amounts range from close to a half inch in southern Windsor/Rutland counties to nothing along much of Quebec border.

KEY MESSAGE 2: A surface low will pass through from west to east Tuesday night, bringing widespread showers. While it will be quick moving and technically more northern stream and not have a strong connection to Gulf/Atlantic moisture, it will include the remnants of Tropical Storm Rachael so there will be some efficient rainfall with the former tropical moisture.
GEFS/EPS/CMCE combined probabilities of a half inch of rain range between 40-70 percent and probabilities of an inch are between 10-30 percent, so the rain would only be beneficial. The heaviest rain should fall in northern areas. Warm air aloft will remain on the backside so even though the cold front drops temperatures significantly, any upslope showers look to remain rain in the mountains. Conditions trend drier for Wednesday, but under a classic cyclonic northwest flow cold air advection regime, there will be some upslope sprinkles and showers but no widespread rain.

KEY MESSAGE 3: A dynamic low pressure system brings winds and rain to the region for Friday into Saturday. Showers will linger behind this system as upper level trough remains over the region. Still a lot of uncertainty about this system since it is six days away. Models are still not in very good agreement in this timeframe either. GFS has a deeper and stronger low while the ECMWF depicts more of an open wave as the system moves through.

AVIATION /12Z SUNDAY THROUGH THURSDAY/
Through 12Z Monday...VFR conditions are expected through 00Z Monday. Winds will increase from the south today, especially in the Champlain Valley. Some afternoon gusts 15-25 knots are expected at KBTV and KPBG. EFK and MSS should remain dry through the 24 hour TAF period. Other sites have some mention of -RA.
Best chances for precipitation will be at RUT and MPV. It's possible those will be the only 2 sites with rain. Ceilings will lower as precipitation moves in, down to MVFR in some instances.

Outlook...

Columbus Day: Mainly MVFR, with local IFR possible. NO SIG WX.
Monday Night: Mainly MVFR, with local IFR possible. Likely SHRA.
Tuesday: Mainly MVFR, with local IFR possible. Definite SHRA.
Tuesday Night: MVFR. Definite SHRA.
Wednesday: Mainly MVFR, with local VFR possible. Slight chance SHRA.
Wednesday Night: MVFR. Slight chance SHRA.
Thursday: Mainly VFR, with areas MVFR possible. NO SIG WX.

MARINE
As of 251 AM EDT Sunday...Southerly winds will continue to increase as the night goes on and sustained winds in the 20-30 KT range should prevail for much of the day. Waves will trend upward as well, reaching the 2-3 ft range in much of the broad lake. Some isolated instances of 4 ft waves are possible. Winds and waves will gradually come down tonight, with winds dropping to around and under 10 KT by tomorrow morning and decreasing to around and below a foot by then.

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