203 FXUS61 KALY 282324 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 624 PM EST Sun Jan 28 2024 .SYNOPSIS... An ongoing storm system will continue spreading rain and wet snow across the region through tonight. Most areas should see a changeover to all snow by this evening, followed by precipitation winding down overnight or early Monday morning. Moderate to heavy accumulations are expected for the high terrain of the Catskills, Berkshires and Greens. Behind this storm, colder and mainly dry weather is expected through much of the workweek. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... **WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES REMAIN IN EFFECT FOR THE EASTERN CATSKILLS, TACONICS, LITCHFIELD HILLS, BERKSHIRES, AND SOUTHERN GREENS THROUGH NOON EST MONDAY** Area of light snow with bandlets of moderate snow and some isolated pockets of heavy snow within the upper deformation of the upper system approaching the region. Snowfall rates around an inch per hour in the heavier pockets and with temperatures in the lower 30s, the snow is wet, but accumulating on all surfaces now. Based on radar and satellite loops, the heaviest snow will be this evening, then the back edge of the heaviest snow moves east and exits from west to east from midnight through Monday morning, with light snow continuing after the moderate snow exits. Some minor adjustments to temperatures and evolution of areas of light, moderate and locally heavy snow through tonight. PREVIOUS DISCUSSION: A positively-tilted southern stream upper trough continues to track eastwards across the Eastern US with a weakening surface low over the Ohio Valley being replaced by an incipient coastal low near the Delmarva Peninsula. This coastal low will continue to deepen as it tracks to the northeast, passing offshore of Cape Cod tonight and exiting eastward into Monday. Locally, a dry slot over the Mid-Hudson Valley has largely filled in again with SW-NE oriented bandlets of rain and snow tracking to the north as the coastal low develops to the south. Continued intensification of the coastal low will result in a more solid area of light rain and snow redeveloping into the evening across much of the forecast area. P-type remains very sensitive to elevation, surface temperature, and precipitation rate as all-snow persists at higher elevations while valley areas see a variable mix of rain and snow. Marginal low-level temperatures and limited prospects for diabatic cooling with dewpoints in the upper 20s to mid 30s are resulting in a very wet snow with snow to liquid ratios well below seasonal climatology, around 6-8:1 at lower elevations and closer to 10:1 in higher terrain, limiting potential accumulations. Brief heavy precipitation rates within bandlets may result in increased wet snow accumulations, but relatively warm ground temperatures may further limit potential accums within valley areas through the afternoon. As the deepening coastal low tracks eastward through the afternoon and evening, increased northerly flow will allow colder air to begin filtering into the region. Boundary layer temperatures will also finally drop to or below freezing within the larger river valleys resulting in more widespread changeover to steady light snow. Mid-level frontogenesis may briefly coincide with the dendritic growth zone from the eastern Catskills across the Capital District into the northern Berkshires and southern Vermont, resulting in a period of possible enhanced snowfall rates from roughly late this afternoon into the evening, with light snow otherwise persisting into tonight. By early Monday morning, the best synoptic forcing for ascent will exit to the east, with diminishing light snow by Monday morning. In total, wet snow accumulations of 6-10" are expected in higher terrain areas of the northeastern Catskills/Helderbergs, northern Berkshires, and southern Vermont, with 3-7" elsewhere in high terrain south of the Mohawk and east of the Hudson, and 1-4" at lower elevations and in northern zones. Temperatures will remain in the mid 20s to low 30s across the region through tonight. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... Lingering snow showers will end by midday Monday as the surface low and upper trough exit to the east, while brief upper ridging passes over the area through Tuesday night. Overcast skies will begin to give way to welcome breaks of sunshine by the Monday afternoon, while high pressure over Quebec and northern New England will result in brisk north winds, particularly along the Hudson and Champlain Valleys where gusts may exceed 20-25 mph. This northerly flow will continue to advect a much cooler and drier air mass into the region by Monday night, with afternoon highs in the upper 20s to low 30s in high terrain and 30s at lower elevations giving way to lows in the teens to low 20s by early Tuesday morning. Dry weather will continue into Tuesday with surface high pressure remaining in control and daytime highs only reaching the mid 20s to mid 30s across the region despite lighter winds. Temperatures remain cool into Tuesday night with lows in the mid teens to low 20s across the region. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... High pressure centered near or just off the New England coast combined with an upper-level low/trough and surface disturbance passing by to our south will bring continued dry weather on Wednesday with highs mainly in the 30s. From Thursday into Friday, a positively tilted northern stream trough will build across the region. A surface low will pass by to our north with a cold front crossing the region. Moisture assistance from the Great Lakes along and ahead of the front will bring our next best chance at some precipitation. Thermal profiles will generally support snow across the higher elevations and a rain/snow mix across the valleys. Currently looks to be a light precipitation event with minor snow accumulations for the higher elevations. Highs Thursday will be in the 30s to lower 40s with upper 20s to lower 40s on Friday. This trough may eventually cut off somewhere near or east of the region over the weekend. A new surface low may develop just off to our east as well. Moist, cyclonic flow over the Great Lakes could result in some lingering snow showers and flurries over the weekend, mainly on Saturday. Otherwise, it will be brisk and colder with highs both days in the 20s to lower 30s. && .AVIATION /23Z SUNDAY THROUGH FRIDAY/... All TAF sites seeing snow and predominant conditions are IFR, with periods of LIFR possible in moderate snow. Snow will become lighter after midnight but ceilings will likely be near or just above 1000 feet and visibilities around 3SM. Snow showers end around 14Z as visibilities increase to VFR but ceilings remain MVFR. Although, KPOU could become VFR after 14Z. Some lingering flurries are possible Monday afternoon in KPSF, so VCSH included there. North to northeast winds at less than 10 Kt tonight becoming north to northwest at around 10 Kt by midday Monday morning and continuing Monday afternoon. Outlook... Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: Low Operational Impact. Slight Chance of SHRA. Thursday Night: No Operational Impact. NO SIG WX. Friday: Moderate Operational Impact. Chance of SHRA...SHSN. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...Winter Weather Advisory until noon EST Monday for CTZ001. NY...Winter Weather Advisory until noon EST Monday for NYZ047-048- 054-061-063. Winter Storm Warning until noon EST Monday for NYZ051-058. MA...Winter Weather Advisory until noon EST Monday for MAZ025. Winter Storm Warning until noon EST Monday for MAZ001. VT...Winter Weather Advisory until noon EST Monday for VTZ013-015. Winter Storm Warning until noon EST Monday for VTZ014. && $$ SYNOPSIS...Picard NEAR TERM...NAS/Picard SHORT TERM...Picard LONG TERM...Rathbun AVIATION...NAS