Marine Weather and Tide Forecast for Castleton-on-Hudson, NY

NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/
Key Messages:

- A single lake effect snow band off Lake Ontario extends into northern Herkimer County and Hamilton County through tonight.
Falling snow and breezy wind gusts up to 30 mph will lead to reduced visibility. Additional snowfall amounts range from 1 to 4 inches.

- Breezy tonight with wind chills falling to below zero in the higher elevations and around or just above zero in the valleys.

UPDATE
As of 920 PM EST, an upper level disturbance, seen in the latest GOES Water Vapor imagery, is slowly crossing the region. The lake effect band has started to drift southward, now across the Mohawk Valley. An abrupt wind shift to a more northwesterly direction will cause the band to continue slowly dropping southward and eventually be positioned west of our area overnight. With a continuous movement of the band, additional accumulations will be light and on the order of a coating to an inch or so. The passage of the upper disturbance has developed additional upslope snow showers for the Adirondacks and southern Greens where some light accumulations are possible throughout the night, especially the southern Greens, per area webcams. Will keep the Lake Effect Snow Warning for Northern Herkimer and Winter Weather Advisory for Hamilton going for now. Some upslope snow showers or flurries could even reach portions of the Berkshires later tonight.
Temperatures continue to slowly fall into the teens and lower 20s with a breeze making it feel even colder.

Previous Discussion: Upper system tracking through our region overnight with moisture off the Great Lakes resulting in the lake effect band continuing into northern Herkimer and Hamilton Counties. More scattered snow showers and flurries across much of the rest of the region north of the mid Hudson Valley and NW CT.

Coverage of flurries and snow showers should decrease through the night but clouds will be slow to break up. Still, some breaks in the clouds in some ares by daybreak. The lake effect snow should shift south as multibands form in northwest low level flow between midnight and daybreak.

Lows tonight in the teens with single numbers in the southern Adirondacks.

SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/
Key Messages:

- Remaining chilly and breezy Wednesday into Wednesday night.

- Upper system could bring some more scattered snow showers with light accumulations Thursday.

Generally dry weather Wednesday with flat upper ridging in our region. More clouds than sun in higher elevations and intervals of clouds and sun in the valleys. Highs Wednesday in the mid 20s to around 30 and teens to lower 20s higher elevations.

Northern stream upper energy in Canada tracks through our region Thursday with very little moisture, weak forcing and weak upper dynamics. Considerable clouds Thursday with just some scattered snow showers and flurries in some areas. Highs Thursday in the upper 20s to lower 30s with around 20 to mid 20s higher elevations.

Flat upper ridging builds in from the west and some warm advection strengthens through the day Friday. Dry weather with intervals of clouds and sun. Some high clouds in advance of the next system should spread over our region. Highs Friday in the mid to upper 30s with mid 20s to lower 30s higher elevations.

LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
Key Message:

- A slow moving cold front brings a period of rain and snow to the region Sat pm into Sun morning.

- Moderate to high confidence for below normal temps late in the weekend into early next week.

Slowly evolving upper pattern this weekend into the beginning of next week. Mean upper trough axis retrogrades west, which results in southwest upper flow. Upper energy will track through the southwest upper flow through our region Saturday into Sunday with moisture and low level jet forcing. The boundary layer winds from the southwest suggest that there will be more warming at the boundary layer than the surface. Still, there should be enough warming for snow changing to a mix of rain and snow in many areas with the best chances for more snow than rain in higher elevations.

Highs Saturday in the mid 30s to around 40 with around 30 to lower 30s higher elevations. Highs Sunday in the lower to mid 30s with around 20 to mid 20s higher terrain.

A brief brake in the precipitation potentially Sunday before another upper system tracks through the southwest flow in the Sunday night into Monday. However, the mean upper trough axis may shift east enough so that deep arctic air will spread into our region and push most precipitation south and east of our region, other than a return to more lake effect snows. Then cold and dry Tuesday.

Highs Monday around 20 to mid 20s with around 10 to mid teens higher elevations. Highs Tuesday in the mid teens to around 20 with single numbers to lower teens higher elevations.

AVIATION /02Z WEDNESDAY THROUGH SUNDAY/
Through 00z/Thu...VFR conditions should generally remain at KALB/KGFL/KPOU through the TAF period with cloud bases remaining above 3000 feet. At KPSF, upslope flow is expected to lower cigs into the MVFR range and have introduced a TEMPO group from 03-06z/Wed to address this. MVFR cigs may linger through much of the remainder of the TAF period. A brief snow shower or flurry cannot be ruled out at KPSF either between 3-12z. Vsbys could briefly lower to MVFR in these snow showers. Not enough confidence in any long period of IFR vsbys to include in the TAF at this time.

Wind speeds between 10-15 kt with gusts to 25 kt are expected through the TAF period starting from a more westerly direction this evening then shifting more northwesterly by 12z/Wed.

Outlook...

Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: No Operational Impact. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: Moderate Operational Impact
Likely RA
SN.
Saturday Night: Moderate Operational Impact
Chance of RA
SN.
Sunday: Low Operational Impact. Slight Chance of SN.

ALY WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...Lake Effect Snow Warning until 7 AM EST Wednesday for NYZ032.
Winter Weather Advisory until 7 AM EST Wednesday for NYZ033.
MA...None.
VT...None.