FXUS61 KBGM 040635 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 135 AM EST Wed Dec 4 2024 .SYNOPSIS... A strong clipper system will bring increasing chances for accumulating snow Wednesday afternoon and Thursday, with colder air, gusty winds, and more lake effect snow developing in its wake. && .NEAR TERM /THROUGH TODAY/... 1 AM Update: Temperatures have continued to crater in areas with clear skies. Satellite imagery shows increasing cloud cover across the Finger Lakes, which pretty much demarks the leading edge of low level warm advection. ITH went from 12 degrees and calm at 1135 PM to 20 degrees as of 1 AM as the cloud cover overspread the area, and winds picked up from the SSE. Made some tweaks to the grids to further drop temperatures a degree or two in the mostly clear eastern half of the CWA over the next couple hours, while increasing temps from west to east through dawn. 937 PM Update: Temperatures have fallen quite a bit where skies are clear with Ithaca down to 13 degrees at the latest observation (9pm). Current values where temperatures have tanked may fall another degree or two before rising toward sunrise as weak southwesterly flow kicks in. For locations with some clouds temperatures should still fall close to a normal rate overnight. Given the amount of mixing this afternoon, dewpoints lowered quite a bit. The RGEM appears to currently have the best handle of dewpoints. Given the clouds temperatures were also raised slightly through the night. 320 PM Update... Leftover lake effect snow showers across Central NY and NE PA will continue through this evening. Localized intense snow showers may bring visibilities down to half mile, or less at times, briefly if it moves over an area. A strong low pressure system centered over the Great Lakes will begin to approach the Northeast Wednesday. Ahead of this system and the main front, gusty southerly wind gusts of 30 to 35 mph can be expected for higher elevations across Central NY and NE PA, as well as across the Finger Lakes region and the hills in Cayuga- Onondaga- Madison counties. Snow showers can also be expected to move through Central NY during the daytime hours. Orographic lift will all play a critical role with increased snowfall development in Northern Oneida County starting Wednesday, and intensifying heading into Wednesday evening and continue into the short term period. Expected snowfall for Northern Oneida County through Wednesday is 4 to 7 inches. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... 345 PM Update... With the strong low pressure system continuing it's approach, gusty southerly winds will shift westerly as the main front moves through the area Thursday morning. This will increase winds, with wind gusts expected to be up to 35 to 45 mph by Thursday morning across mainly for western portions of Central NY, the Mohawk Valley, and NE PA. With snow showers picking back up early Thursday morning, as well as some pockets of small CAPE, potential for snow squalls is possible in the early morning hours of Thursday, mainly for areas west of I-81. Confidence is low to moderate, since there isn't a strong signal for snow squall development, but will falling snow and gusty winds, visibilities could drop to half mile or less at times with any gusty snow shower that moves through. As the main passage of the front Thursday morning, lake enhancement downwind of Lake Erie will bring lake effect snowfall in Northern Oneida County. Additional snowfall, from Wednesday night through Thursday night, is expected to be 6 to 9 inches. For northern portions of Central NY, 2 to 5 inches can be expected. && .LONG TERM /FRIDAY THROUGH TUESDAY/... 1200 PM Update: With a northwesterly flow and 850mb temperatures around -14C, lake effect snow showers are expected on Friday, particularly across Central NY. Then as the wind direction shifts to more of a westerly direction, these lake effect snow showers are expected to be more concentrated towards areas along and north of the NY Thruway corridor by Friday night into Saturday. A weak clipper system may bring some additional snow showers to the area on Saturday, but it is possible that this could end up being mainly north of our area. Then weak ridging may finally bring mainly dry conditions to the area on Sunday, along with warmer temperatures. An area of low pressure passing by to our west then may bring some additional precipitation by the Monday/Tuesday timeframe. At this time, temperatures appear to be warm enough for the form of precipitation to be mainly rain from this early week system. Temperature-wise, continued below normal temperatures are expected for Friday and Saturday (highs mainly in the mid 20s to lower 30s), before a warm-up occurs starting on Sunday. Temperatures on Sunday are expected to be near-normal (highs in the mid 30s to lower 40s), before above normal temperatures are anticipated for Monday and Tuesday with highs mainly in the 40s and perhaps near 50 degrees in some of the valleys on Tuesday. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... Low level warm advection will bring some increasing cloud cover in from the west overnight, though ceilings will remain VFR. One exception is RME, where near-surface winds are from the south, resulting in upslope conditions south of the Tug Hill Plateau, and 925 mb winds are headed straight down Oneida Lake. IFR ceilings are in place, and will likely hang on until low level winds lose their lake trajectory, around 08-09Z. There's a chance though that the upslope flow alone will keep low ceilings in place, and this will be watched closely. Otherwise, VFR conditions will prevail through early afternoon across the area, as southerly flow increases. A few gusts over 20 knots are possible. A weak shortwave trough may kick off a band of snow showers or flurries in the afternoon, which will lift from SW to NE. Added some 2-3 hour TEMPO groups for minor restrictions across the NY terminals, slightly worse at SYR and RME. Snow showers will increase in coverage late in the afternoon and this evening across north-central NY. With increasing southerly flow, orographic effects will play a major role, and snow showers will be most prevalent north of the Lake Plain and Mohawk Valley, and along the northern half of the Allegheny Plateau. Downsloping may keep steadier snow just north of SYR until after 22-24Z. Further south, ITH may see light snow with MVFR conditions before sunset, and it may take until early evening for BGM and ELM. With the orographic influence, confidence in impacts from snow are highest at SYR and RME, and become progressively lower further south. Some blowing snow may impact SYR and RME in the evening and overnight hours. Outlook... Late Wednesday Night...Restrictions likely with snow showers, worst in north-central NY. Thursday...Scattered snow showers and squalls are possible in the morning as gusty west winds develop behind a cold front. Snow showers may impact areas as far south as AVP, though conditions will generally be worse further north. The snow showers will transition to lake effect snow bands by afternoon. Gusty westerly winds at 25-35 kts, and a few higher gusts will be possible at times. This will result in blowing snow in areas with snow accumulation. Friday...Scattered lake effect snow showers possible at the Central NY terminals, along with occasional restrictions. Saturday...Some additional lake effect snow showers with occasional restrictions possible in Central NY. Sunday...Mainly VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...Winter Storm Watch from this afternoon through late Thursday night for NYZ009-018-036-037-044>046. && $$ SYNOPSIS...KL NEAR TERM...KL/MPH/MWG SHORT TERM...KL LONG TERM...BJG AVIATION...JTC/MPH