Area Forecast Discussion
Issued by NWS Albany, NY
Issued by NWS Albany, NY
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864 FXUS61 KALY 220308 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 1008 PM EST Thu Nov 21 2024 .SYNOPSIS... Low pressure will bring widespread precipitation in the form of rain and snow overnight through Friday morning. Snow will be mainly favored across the higher elevations with several inches of accumulation expected in the Catskills. Precipitation tapers to valley rain and high-elevation snow showers over the weekend, with continued cool and breezy conditions. && .NEAR TERM /THROUGH FRIDAY/... Winter Weather Advisories in effect now through 9 am Friday for the eastern Ulster and Dutchess Counties. Winter Storm Warning in effect for western Greene and western Ulster counties until 1 AM Saturday for elevations mainly above 1500 feet. Winter Weather Advisory in effect for Schoharie County until 1 AM Saturday for elevations mainly above 1000 feet. Update as of 1000 pm EST...The H500 mid-level low has moved over PA, NJ and MD, as a sfc low is near the Long Island and New England Coast. The low and mid level circulation wlll capture the sfc low and draw it over southwest New England and the lower/mid Hudson Valley 1 am to 7 am. The intensity of the pcpn increases and the rain to snow transition is likely to occur over the mid Hudson Valley/southern Taconics. The I-84 corridor looks most vulnerable for 2-3" of snowfall. We increased snow amounts to 1-4" for eastern Ulster and Dutchess Counties and with impacts near Poughkeepsie and I-84 possible. We issued a Winter Wx Advisory until 14Z/9 am Fri there. Again...we are not looking for a widespread 4", but more for the impacts with the headlines. The NYS Mesonet shows 0.8" snowfall already for the Old Forge in the western Dacks and 1.2" at Tannersville in the eastern Catskills near western Greene County. The headlines look good over eastern Catskill for warnings and Schoharie County for the advisory. The southern Adirondacks may receive 2-4" of snowfall. The southern Greens 2-4" with some localized amounts up to 6" into Friday night. Lows will be in the lower to mid 30s with some upper 20s over the higher terrain. Winds will increase from the northeast to southeast at 10-20 mph with some gusts 30-40 mph over the southern Greens. PREV DISCUSSION [403 pm EST]... As temperatures slowly fall, precipitation will begin to mix with and change to snow across the higher elevations. Mainly rain should continue across the valleys, except a rain/snow mix may begin around or shortly after midnight across the western Mohawk Valley and closer to daybreak for the Hudson Valley south of Albany. Snowfall accumulations will be dependent on surface temperatures, elevation and precipitation intensity. In addition, there remains a bit of uncertainty on where the surface low tracks overnight which would impact whether or not some southern areas become dry slotted resulting in lighter precipitation intensities. There is a signal that if the surface low does track closer to the Capital District, enough cold air and frontogenetical forcing south of the low could result in a burst of moderate snow for portions of the mid- Hudson Valley and into Litchfield County late tonight into early Friday morning, even in the lower elevations. If that occurs, a slushy coating to an inch or two of snow could occur in these areas. The heaviest snow still appears to occur across the eastern Catskills above 1500 feet where 6 or more inches is expected. As a result, these areas have been upgraded to a Winter Storm Warning. In addition, the weight of this snow could lead to some downed trees and power lines resulting in power outages. A Winter Weather Advisory remains in effect for Schoharie County for amounts of 2 to 6 inches mainly for elevations above 1000 feet. Elsewhere, snowfall amounts will generally be less than 4 inches, so no winter weather products have been issued at this time. As the low becomes vertically stacked on Friday, precipitation will begin to decrease in coverage and intensity, but some light snow accumulations will remain possible, especially across the eastern Catskills where the Winter Storm Warning is in effect. Elsewhere, some mixed rain and snow showers are expected through the afternoon but with little or no additional accumulation. Temperatures will fall into the upper 20s to upper 30s tonight rebounding to the mid-30s to mid-40s on Friday. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/... The upper-level slow will slowly pull away to the east Friday night into Saturday. Some wrap around rain and snow showers will continue during this time but any additional snow accumulations look to be on the order of a coating to an inch or two, mainly for the higher elevations. There remains some model uncertainty on if another fetch of heavier QPF advances far enough west from another developing surface low off the New England coast into western New England. If it does so, a period of moderate snow would develop across the southern Green Mountains. Will monitor trends and the progression of this system. Otherwise, the remainder of this time period will result in mostly cloudy conditions with a developing northwesterly breeze. Lows Friday night will be in the upper 20s to mid-30s with highs Saturday in the mid-30s to upper 40s. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... The extended forecast begins with a vertically stacked cyclone moving into the Canadian Maritimes. A sfc trough moving through will bring scattered rain and snow showers persisting Saturday night into Sunday from the Capital Region north and west with some light snow accums along the west facing slopes of the western Dacks and southern Greens. It will be brisk and cold with some ridging building eastward late Sunday. Lows will be in the upper 20s to lower 30s over the higher terrain Sat night with mid and upper 30s in the valleys. Sunday will feature brisk conditions with seasonable temps with 30s to lower 40s over the hills and mtns and mid 40s to around 50F in the valleys. High pressure builds in over the region Sunday night into Monday with a brief period of fair and dry weather. Decreasing clouds and light to calm winds will allow for ideal radiational cooling conditions with lows in the 20s. Mid and high clouds increase quickly Monday during the day ahead of the next warm front to the next system approaching from the Midwest and Great Lakes Region. Highs will be in the 40s to lower 50s with a few cooler readings over the mountains. The isentropic lift increases over the region Monday night for a period of showers or stratiform rainfall. The chances of precipitation have been raised into the likely (55%) to categorical range (85%) Monday night into Tuesday from the Capital Region, northern Berkshires, northern Catskills, and west of the southern Greens north and west across the forecast area. Probabilities look good for a quarter inch of rain or more from the NBM. The wave quickly moves through Tuesday. Some wet snow may mix in over the higher terrain early. Lows will be in the upper 20s to upper 30s. Max temps for Tuesday rise above normal, as the region gets in a dry slot moving into eastern NY/western New England with mid 40s to lower 50s with some cooler readings over the mountains. A weak cold front moves through Tue night with scattered rain to snow showers especially over the Adirondack Park. Temps fall back into the 20s to around 30F with the cold advection. The upper low over Quebec will continue to spin and in the the cyclonic flow, a sfc trough and short-wave will bring isolated to scattered rain and snow showers especially west of the Hudson River Valley. Temps will be seasonable. Attention shifts to a disturbance ejecting out of the TN Valley and Midwest Wed night into Thu. This storm system could bring a chance of snow/rain to region on Thanksgiving, but there are track, evolution and timing differences in the medium range guidance and ensembles for Thu into Fri. Temps look colder than normal and higher pcpn chances may be needed based on the track of the system. For now, we will have a slight to low chance of rain/snow. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... Through 00z Saturday...A complex storm system will continue to impact eastern NY and western New England with periods of rain and some mixing to snow over the higher terrain and near KPOU towards daybreak. Cigs/vsbys are mainly MVFR with some lapses to IFR noted at KPOU/KPSF. There should be a steady transition to IFR cigs and some vsbys at all the TAF sites between 03Z-09Z/FRI. Some snow may mix with the rainfall at KPOU/KPSF between 08Z-12Z/FRI. A brief period of wet snowfall may occur prior to 14Z/FRI at these sites. The stalled low pressure system will kept IFR/low MVFR cigs and occasional vsbys going through the morning with some improvement to MVFR/low VFR cigs and vsbys 19Z/FRI at all the TAF sites. VCSH and PROB30 groups were used for showers in the afternoon. The winds will be north to northeast at less than 10 KT early tonight. They will increase from the north to northeast at 10-15 KT with some gusts 20-25 KT around midnight through the early morning hours. The winds will shift to the northeast to southeast at 8-12 KT in the late morning with a few gusts close to 20 KT into the early to mid afternoon. Outlook... Friday Night: Moderate Operational Impact. Chance of SHRA. Saturday: Moderate Operational Impact. Breezy. Chance of SHRA. Saturday Night: Moderate Operational Impact. Breezy. Chance of SHRA. Sunday: Moderate Operational Impact. Windy With Gusts To 30 kts. NO SIG WX. Sunday Night: Low Operational Impact. Breezy. NO SIG WX. Monday: No Operational Impact. NO SIG WX. Monday Night: High Operational Impact. Likely SHRA. Tuesday: Moderate Operational Impact. Breezy. Chance of SHRA. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Winter Weather Advisory until 1 AM EST Saturday for NYZ047. Winter Storm Warning until 1 AM EST Saturday for NYZ058-063. Winter Weather Advisory until 9 AM EST Friday for NYZ064>066. MA...None. VT...None. && $$ SYNOPSIS...Rathbun/Wasula NEAR TERM...Rathbun/Wasula/Belkin SHORT TERM...Rathbun LONG TERM...Wasula AVIATION...Wasula