745 FXUS61 KALY 181153 AFDALY Area Forecast Discussion National Weather Service Albany NY 653 AM EST Thu Dec 18 2025 .WHAT HAS CHANGED... Cold frontal passage timing on Friday will be a little earlier with the strong gusty winds shifting from the south to southwest to west in late morning into the early afternoon across eastern NY and western New England with falling temps throughout the day. Precipitation will transition from rainfall to snowfall west of the Hudson River Valley in the late morning with the greatest accumulations over the southwest Adirondacks. && .KEY MESSAGES... 1. Above normal to potential record breaking temps ahead of a potent cold front will lead to a period of rain and snow melt tonight into Friday morning. 2. There is the possibility for some urban and poor drainage flooding due to the rain and snowmelt early Friday. 3. Strong gusty winds are likely tonight into Friday morning, especially for high terrain areas, which may result in downed trees and power lines. A second surge of strong winds with the cold frontal passage may lead to additional area-wide impacts. 4. Frigid conditions return Fri night thru weekend into the mid week and accumulating light snow will be possible through early next week for much of the area. && .DISCUSSION... KEY MESSAGE 1... The calm before the storm will occur today with a sfc anticyclone over NY and New England moving down stream this afternoon into tonight. A vigorous mid and upper level trough will be digging into the Upper Midwest, MS River Valley and Southeast early tonight. A strong sfc cyclone will be lifting northeast of Lake Superior into southern Ontario tonight. Meanwhile, downstream over the East Coast the mid and upper level ridging will begin to break down, as strong south to southwest flow will develop over the region. An infusion of milder air from the Deep South will surge up the Coast over the region with rising temps tonight from the 30s and lower 40s. Temps will continue to rise Fri morning into the 40s to lower to mid 50s before a sharp cold front moves through. In the deep south to southwest flow, an anomalous south to southwest low-level jet /LLJ/ increases at H925 to 40-55 KT and H850 to 50-75 KT. The latest NAEFS V-wind /southerlies/ anomalies continue to be +3 to +4 standard deviations /STDEVs/ above normal advecting moisture in from the Gulf and western Atlantic. As the isentropic lift increases ahead of the warm front, expect periods of rain to quickly develop shortly before midnight and continue overnight. The winds at the mtns and ridge tops should be very strong despite an inversion on the soundings. We continued the Wind Advisory for the region and discuss specifics below in Key Message #3. The anomalous nature of the air mass needs to be emphasized, as the record high for Albany is 54F set in 1895. We will be real close to that temp Fri morning. H850 temps will be 1 to 2 STDEVs above normal ahead of the cold front and the actual temps look to be in the +5C to +8C range by 09Z to 15Z FRI. The cold front has a strong thermal gradient with it. The theta-e difference is impressive at the sfc and h850 in the 12Z-18Z FRI time. A few thunderstorms may pop-up from Albany, the northern Taconics and the eastern Catskills south and east into the mid Hudson Valley, southern Taconics, Berkshires and NW CT. SPC continues a "General Thunderstorm" forecast and we have slight chance /15-20%/ probabilities in these areas. The instability is elevated and small but the forcing is strong with the boundary. The thunderstorm threat may need to be expanded further north through the entire area later. Initial rumbles of thunder may be ahead of the warm front, but some of the CAMs like the 3-km HRRR and 3-km NAMnest do show a strongly-forced narrow cold frontal rainband zipping across the region from west to east in the 12Z-18Z time frame (some slight timing differences). It's a high shear and low to little CAPE environment. A severe threat can not be ruled out with the impressive dynamics and shear in place. Temps will plummet across the forecast area, as colder initially polar air gushes back into the region turning the pcpn over to snow over the southwest Dacks, western Mohawk Valley and northern and eastern Catskills. A few inches will occur especially over the higher terrain by nightfall. Some totals may reach 2-4" over the western Dacks by early Sat morning. The winds ahead of the front will be south to southwest 15-30 mph with gusts 35-50 mph. The winds will shift to west at 15-30 mph with gusts 35-50 mph in the afternoon/early evening. Temps will fall into the 20s and lower 30s by the early evening. The cold advection will continue through the overnight with blustery winds with lows in the teens to lower 20s and some single digits in the Adirondack Park. Overall, the moderate to locally heavy rainfall event will produce some snowmelt with the gusty winds and warm temps, but the latest 01Z NBM still shows a 45-80% chance for 1" of rainfall for most of eastern NY and western New England by early Fri evening with the lowest chances over the western Mohawk Valley/western Dacks. Some accumulating snow on the the order of an inch or two may also occur over the southern Greens, northern Taconics and Berkshires Fri pm/early evening with coating to a few tenths in the valleys especially on the grassy surfaces. KEY MESSAGE 2... The snow melt combined with the rainfall will cause some ponding of water on roadways and some rises on rivers, creeks and brooks. The majority of the rainfall or QPF will occur Thu night into Fri in a 12 to 18-hr window. Snow depths in the south/southwest Adirondacks range from 8-20" and the southern Greens 6-16" based on the latest NOHRSC. Many valley areas have a coating to less than 5". The strong southerlies and the rainfall may melt a lot of the snow pack in the valleys causing ponding and poor drainage flooding in low-lying areas. Some melting, movement and break-up of ice may occur on rivers. Ice on the northern most basins ranges from 3" to 9" based on the NERFC guidance, which is thick for this time of year, so the ice jam threat looks somewhat low with only a brief spell of milder weather. The snowpack may ripen or compact due to absorption over the higher terrain/mtns, but the latest rainfall forecast is for 0.75"-1.25" over most of the forecast area with 1-2" over the eastern Catskills. River Flooding is not forecast, but poor drainage or urban flooding may occur in some of the valley areas. WPC has a "Marginal Risk" for excessive rainfall in their latest Fri-Fri night graphics from Albany north and east. Frigid air will sweep back in Fri night which will dry things out and freeze up any standing water. Some drains may get clogged with ice, garbage, debris or even leaves that remain from the Fall which may cause local urbanized flooding. KEY MESSAGE 3... As described earlier, the LLJ will not only advect in moisture and milder temps but also cause wind damage. H850 winds of 50-75 KT from the south to southwest may translate to the surface especially over the higher terrain over western New England, the eastern Catskills and the narrow south to north valleys merging into the Mohawk River Valley. The question remains how well the winds puncture through a duct or stable layer. It looks like the best time may be between 09Z-15Z/FRI where some of the 10-m winds on the MAVMOS for Bennington jump up to 29KT! The conceptual model with cool season CSTAR UAlbany back in 2010 for high wind and severe events fits well here, as with the warm conveyor belt we could see at least advisory level wind gusts 46-57 mph especially in the high terrain areas. We will have to monitor if an upgrade is needed to at High Wind Warning which is for wind 58 mph or greater for any of the high terrain areas. If convection occurs, then short-fuse SPSs or SVRs may be needed, and then we get into strong cold advection in the afternoon/early evening in the wake of the front. Area-wide gusts 35-55 mph will be possible, as the rapid surface pressure rises (9-12 hpa/6 hrs) will be occurring with the deepening cyclone well to the north and west over southeast Canada. It will be after dark, but strong momentum transfer from 3-5 kft AGL with the surface rapid pressure rises and cold advection may allow gusts which could bring down large tree limbs, some large trees, and power lines causing some power outages. The Wind Advisory looks good, but parts of the area may need to be expanded to a High Wind Warning later. The highest NBM 24-hr Max gust probabilities (QMD) > 50 mph for the 24-hr period ending 1 am Saturday are over the eastern Catskills, Greater Capital Region, northern Taconics and the Berkshires. The winds should begin to subside between 1 am and 7 am Sat. KEY MESSAGE 4... A frigid air mass opens the weekend with high pressure building in from the south late Fri night into Sat morning. After morning lows mainly in the teens and 20s, max temps will only recover into the mid and upper 30s in the valleys with 20s to lower 30s over the higher terrain. The mid and upper level flow becomes zonal with the next clipper arriving Sat night into Sun. The disturbance looks like it will take a more northerly track so the greatest threat for snow showers will be over the northern zones north of the Mohawk Valley and Capital Region with light accums of snow. A non-diurnal trend of temps will likely occur Sat night with temps rising from the 20s and lower 30s, but then temps will fall during the day with the cold front moving through. Highs may be near normal before tumbling. Brisk and cold conditions occur Sun pm into Sun night with lows the teens with a few single digits over the Adirondack Park and lower 20s in the mid Hudson Valley. A frigid air mass will be over the region Mon with max temps about 10 degrees or so below normal with highs in the 20s to lower 30s with some teens over the southern Greens and southwest Adirondacks. Another clipper and its warm front may bring a more widespread light accumulating snowfall late Mon night through Tue. Some impacts could occur with the potential holiday travel before Wed and Thu. Snowfall amounts may range from a half inch to two inches over most of the region with higher amounts over the southwest Dacks and southern Greens. Below normal temps continue into Christmas Day on Thu. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... Through 12z Friday...VFR conditions prevail across all TAF sites this morning as high pressure persists ahead of a potent storm system that will bring widespread rain beginning just after the end of the 12z period. While clouds will be on the increase this afternoon everywhere, ceilings will remain well within the VFR category until late this evening/early tonight when MVFR ceilings begin to develop. Some light rain showers are possible ahead of the primary rain shield, so input a PROB30 everywhere to account for these between 04-12z. Winds will be on the increase out of the south to southeast today, beginning with sustained speeds below 10 kt, but increasing to 10-15 kt with gusts up to 25 kt especially at KALB by the end of the period. Outlook... Friday Night: High Operational Impact. Very Windy With Gusts To 40 kts. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: Moderate Operational Impact. Chance of SHSN. Sunday: Low Operational Impact. Breezy. Slight Chance of SHRA...SHSN. Sunday Night: Low Operational Impact. Breezy. NO SIG WX. Monday: No Operational Impact. NO SIG WX. Monday Night: Moderate Operational Impact. Chance of SHSN. Tuesday: Moderate Operational Impact. Likely SN. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...Wind Advisory from 7 PM this evening to 1 AM EST Saturday for CTZ001-013. NY...Wind Advisory from 7 PM this evening to 1 AM EST Saturday for NYZ032-033-038>043-047>054-058>061-063>066-082>084. MA...Wind Advisory from 7 PM this evening to 1 AM EST Saturday for MAZ001-025. VT...Wind Advisory from 7 PM this evening to 1 AM EST Saturday for VTZ013>015. && $$ DISCUSSION...15 AVIATION...37