Marine Weather and Tide Forecast for Wilmington, VT

NEAR TERM /THROUGH SUNDAY/
Key Message:

- A clipper system will bring widespread light to moderate snowfall late this afternoon through Sunday. Winter Weather Advisories have been issued in the southwestern Adirondacks, western Mohawk Valley, and southern Green from 7 PM this evening through 1 PM Sunday for 3 to 7 inches of snow.

Discussion:

Cold temperatures in the 20s to low 30s and dry weather aside from a few flurries continue beneath mostly cloudy skies. A northern-stream shortwave and associated clipper low will approach into this evening, with steady light to moderate snow arriving from the west beginning late this afternoon.
Accumulating snowfall through tonight is most likely north of Interstates 88 and 90, while there is lower confidence to the south, where any accumulations will remain light, generally an inch or less. Brief periods of heavier snow rates of around 1 inch per hour are possible overnight, particularly where upslope flow reinforces large-scale isentropic ascent.

Overnight lows largely in the 20s will see light snowfall continue into Sunday morning, before the progressive clipper low exits eastward by the afternoon. Some lake-enhanced and upslope rain and snow showers may continue in western areas, with a dry break expected elsewhere through Sunday afternoon. Southwesterly flow behind the departing low will push temperatures back up toward seasonal norms, with afternoon highs reaching the upper 20s to mid 30s in high terrain and upper 30s to low 40s at lower elevations. Partly to mostly cloudy skies will persist through the period, with the highest sky cover in areas of upslope flow.

Winter Weather Advisories have been issued for the southwestern Adirondacks, western Mohawk Valley, and southern Greens from 7 PM this evening through 1 PM Sunday. Snowfall accumulations of 3 to 7 inches are expected within the Advisory area, with the highest totals at higher elevations. Lighter accumulations of 1 to 3 inches are expected elsewhere north of I-88/90, as well as across the Berkshires and higher elevations of Litchfield County. Lesser totals are expected in the eastern Catskills, Mid-Hudson Valley, and lower elevations of Litchfield County.

SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/
Key Message:

- Additional rain/snow or wintry mix expected Monday afternoon, transitioning to rain by Monday night in all but the highest elevations.

- Low confidence in accumulating sleet or freezing rain in sheltered valleys within areas of high terrain early Monday.

Discussion:

Brief shortwave ridging builds into the region from the west Sunday night with modest height rises aloft overnight yielding largely dry weather aside from a few flurries possible east of Lake Ontario. Increasing clouds are expected overnight, with more overcast conditions north of I-88/90 and clearer skies closer to the I-84 corridor. Temperatures will fall to overnight lows in the mid 20s to low 30s.

Sunday night, a southern-stream shortwave over the southern Rockies will lift northward through the Ohio Valley into Monday morning on the eastern flank of an upper-low over the Upper Midwest. Locally, isentropic lift along and ahead of a warm frontal boundary will bring light precipitation to the region from the southwest through Monday morning, with widespread coverage expected Monday evening, before becoming more showery in coverage as the best forcing for ascent exits eastward. In general, precipitation early Monday may begin as snow before warmer air arrives on southwesterly flow, yielding a transition to rain at lower elevations. Pockets of wintry mix and possible freezing rain may persist in sheltered valleys within high terrain though, resulting in the potential for light ice accumulations and associated travel hazards Monday morning.
These areas of freezing or mixed precipitation remain low confidence as changes in the onset time could also change the p-type as temperatures warm through the morning, and poorly- modeled scouring of low-level cold air within valleys also makes the duration of any freezing precipitation difficult to assess.
Precipitation may linger into Monday night, particularly in areas of upslope enhancement during westerly flow, namely the western Adirondacks and western slopes of the Berkshires and southern Greens. Snow and ice accumulations remain relatively low confidence, while total precipitation of 0.25 to 0.5 inches is expected at this point. Snow-liquid ratios will likely be below climatological values within the transitioning thermal environment, potentially yielding a few inches of wet snow accumulations in areas of high terrain.

Temperatures behind the warm front will warm to near seasonal norms in the 30s in high terrain and upper 30s to mid 40s at lower elevations. Overnight lows look to remain seasonably mild beneath continued overcast skies, only falling to the upper 20s to mid 30s across the region.

LONG TERM /TUESDAY THROUGH SATURDAY/
Key Message:

- Moderate confidence for a heavy precipitation event Tuesday night into Thursday with 1-2 inches of precipitation possible.

Discussion:

A high-amplitude, positively-tilted upper trough over central portions of the country will move eastward toward the coast Tuesday through Wednesday, becoming negatively-tilted as an upper shortwave pivots about its base late Tuesday into Tuesday night. Precipitation will spread over the region from west to east Tuesday night ahead of the approaching cold front while a surface low tracks northeastward over the eastern Great Lakes.
Southwesterly mid-level flow ahead of the front will see temperatures rise above normal locally, reaching afternoon highs Tuesday in the upper 30s to upper 40s across the region, yielding rain across the region. Through Tuesday night during ongoing precipitation, temperatures will largely remain above freezing in the 30s, allowing rain to continue aside from some rain/snow mix possible at the highest elevations of the Adirondacks by Wednesday morning. A wave developing along the front and tracking northeastward into New England, combined with potent meridional moisture advection and IVT convergence over the Northeast will result in enhanced rainfall rates through much of Wednesday, yielding a widespread 1-2 inches of rainfall across the region. Temperatures will remain mild, reaching afternoon highs in the mid 30s to low 40s in high terrain and low 40s to mid 50s at lower elevations. Overcast skies are expected through much of Wednesday.

The cold front will finally pass over the region Wednesday afternoon to evening, with potent cold advection on westerly flow developing in its wake. While precipitation will largely end behind the front, any areas of lingering showers may see a transition to snow through Wednesday night as temperatures drop to overnight lows in the 10s and 20s across the region. The colder air mass will see dry conditions return for most by Thursday, aside from reinvigorated lake-effect snows possible across the western Adirondacks and western Mohawk Valley Thursday into Friday. Seasonably cool afternoon highs in the 20s and 30s are expected each Thursday and Friday, while overnight lows dip into the single digits and teens across the region.

AVIATION /18Z SATURDAY THROUGH THURSDAY/
A band of light lake effect snow continues to impact parts of the area. Persistent light snow showers have been moving west to east, allowing for brief reductions in visibility from time to time at KALB/KPSF. This may continue for the next few hours, but should diminish by the late afternoon hours, as the lake effect activity diminishes, as the flow is disrupted. Through the late afternoon hours, flying conditions may be MVFR at most sites due to the lingering light lake effect snow and some low stratocu clouds around. KPOU should primarily remain VFR, but the other sites may vary from MVFR to VFR. South to southwest winds will be 5 to 10 kts for all sites through the late afternoon hours.

A clipper system will be moving towards the area for tonight. A period of light snow looks to spread across the region after 02z or so. KPOU may be far enough south to avoid most of it, but even there, a period of light snow is possible for a few hours around 03z to 06z or so. Within snowfall, flying conditions will be IFR due to visibility around 1-2SM. Ceilings should generally be in the 1500-3000 ft range. South to southwest winds will be around 10 kts through the overnight hours.

Steady light snow will end towards daybreak for KGFL/KPSF/KALB.
Some lingering flurries/spotty light snow showers may linger into Sunday morning, but most of the snow activity should be done. However, lingering low level moisture may keep MVFR clouds around in the morning hours, especially at KPSF. Westerly winds will be around 10-12 kts with some higher gusts possible at KALB/KPSF.

Outlook...

Sunday Night: No Operational Impact. NO SIG WX.
Monday: High Operational Impact
Definite RA
SN.
Monday Night: High Operational Impact
Likely RA
SN.
Tuesday: Moderate Operational Impact. Chance of RA.
Tuesday Night: High Operational Impact. Definite RA.
Wednesday: High Operational Impact. Definite RA.
Wednesday Night: High Operational Impact
Likely RA
SN.
Thursday: Low Operational Impact. Breezy. Slight Chance of SHSN.

ALY WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...Winter Weather Advisory from 7 PM this evening to 1 PM EST Sunday for NYZ032-033-038-082.
MA...None.
VT...Winter Weather Advisory from 7 PM this evening to 1 PM EST Sunday for VTZ013-014.