087 FXUS61 KBGM 241755 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 1255 PM EST Sun Nov 24 2019 .SYNOPSIS... A coastal system will rapidly intensify this morning bringing a period of moderate, wet snow to the Catskills and Interstate 81 corridor through early afternoon. High pressure returns with dry weather and a gradual warming trend tonight through Tuesday. Next storm system arrives midweek, with periods of rain and wind, then colder with lake effect snow showers behind it for Thanksgiving. && .NEAR TERM /THROUGH TONIGHT/... 1250 PM Update...Have dropped the advisory everywhere except for Sullivan County (extending 2 hours) and Delaware and Otsego Counties where over 5 inches of snow has already fallen in some areas and continues to fall. The band of snow has weakened over the last hour, but there still remains some moderate snow falling in the advisory area. Will not be surprised if some of the higher elevations in Eastern Otsego County come out with over 7 inches of new snow when it is all said and done. 1045 AM Update...A well established heavy snow band has form from NE PA and extends to the north-northeast through Otsego County. Snowfall rates in this band are likely between 1 to 2 inches per hour. As the band slowly pivots to the east it will have its longest residence time across Otsego and Delaware Counties. Have increase forecast snow totals, with now 3 to 6 inches expected across these areas and possibly localized amounts of 7+ inches across the higher terrain. This is also a wet/sticky snow and there could be some isolated power outages due to the weight of the snow on trees. 920 AM Update...Radar is starting to fill in across the area, with heavy meso snow band now developing from Wyoming County PA northeast through Otsego County. Under this band, snowfall rates of 1 to 1.5 in/hour is likely occurring. Current forecast captures this fairly well, so will not make any adjustments to snow accumulations at this time. Will watch to see how the band evolves over the next couple of hours, still think that a 3 to 5 inch snowfall is in store for part of Otsego and Delaware counties, but if this band were to persist a bit longer, then some locations could end up with 6+ inches, especially across the higher terrain in the Catskills. Have only slightly adjusted temperatures at this time to align with current observations. Temps are highly variable at this time, with areas under the snow band right at or just below freezing and outside of the heavy snow band the temps have been above freezing. 645 AM Update...System continues to trend slightly further east with the latest hi-res near term guidance and radar trends. Adjusted PoPs, QPF and even snow amounts to better account for these trends. There will be a sharp cutoff to the accumulating snow, likely very near a line from Towanda to Binghamton, Norwich and Cooperstown. Northwest of here do not expect much if any additional accumulation. Temperatures are marginal, so steady snow is only falling when precip rates increase; otherwise it is still a mix of ptypes. This type of scenario will likely lead to narrow bands of snow accumulation, mainly over the higher terrain. Will let the winter weather advisories ride as is for now. 415 AM Update.... Complex winter storm will continue to impact the region through the early afternoon hours today. Numerous winter weather advisories are in effect for the eastern half of the forecast area. An impressive coastal low is now developing across the DELMARVA region in response to a strong upper level low working its way across SW PA at this time. Classic comma head is developing on the latest WV loop, with our area poised to be right under the favorable explosive lift zone. Cloud tops are cooling rapidly across central PA, moving north in the developing mid/upper level circulation. The surface low is forecast to deepen down to around 992mb as it passes over KACY, then 985mb near Montauk Point Long Island. The track has nudge ever so slightly to the east in the latest near term, hi-res models...however the 700mb low is still progged to track along the PA turnpike then over NYC by mid to late morning. This will put our SE zones under an area of favorable FGEN, and strong dynamic lift. This should allow for a moderate to heavy deformation band of precipitation to develop this morning...latest indications are for this band to set up south and east of about Troy PA-Owego-Marathon-Sherburne-Waterville NY. This band will be nearly stationary as it pivots this morning, with a sharp cutoff in QPF amounts NW of here. Under the area of deep moisture and lift there will be enough dynamic cooling to change the ptype to mainly wet snow. Surface temperatures will likely be near or just above freezing in the valleys, so accumulations will be very wet/slushy and cut down some in the lower elevations. Meanwhile, for the hilltops (above 1400 feet or so) expect a period of heavy snow in the advisory area and surface temperatures will likely be cold enough (30-32) to allow for more efficient accumulations, and snow ratios will be closer to 10:1. Snow rates in this developing mesoscale band could occasionally reach 1 to 1 1/2 inches per hour...mainly along and east of I-81 from Broome/Chenango counties south (including the entire I-88 corridor into Otsego county). There still remains some uncertainty in exactly where this heavy band of mixed precip/snow will set up this morning, and also the exact thermal profiles. Felt confident enough that at least several inches of snow would fall back into Chenango, Broome and Susquehanna counties to keep the winter weather advisory going here until midday. The highest snow totals from this system will likely fall over the hilltops of Susquehanna, eastern Broome, eastern Chenango, Delaware and Otsego counties...in these area (at elevations above 1400 feet) accumulations should range from 4-6 inches by the time the snow ends early this afternoon. Cannot rule out some localized amounts up to 7 inches in the highest terrain of Delaware/Otsego counties. Further northwest of the winter weather advisory zones, there will be a light lingering mix of rain, sleet, snow and perhaps a few pockets of freezing rain into the early morning hours (will cover this with and SPS and in HWO) but the precip shield should move out to the east by mid morning, leaving behind dry weather later today. The entire area dries out as the snow exits east by 2-3PM. There will actually be some partial clearing late in the day, with partly sunny skies forecast. Northwest winds increase between 10-20 mph by afternoon, with high temperatures reaching the mid 30s (east) to lower 40s (central and west). Tonight: A few flurries or sprinkles across the far north otherwise quiet and dry under mostly cloudy skies. Lows will be 30-35 as winds shift westerly and decrease under 10 mph. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... 415 AM Update... Quick passing ridge of high pressure Monday morning, will give way to southwest flow and resultant warm air advection Monday afternoon through Tuesday night. Quiet weather and moderating temperatures can be anticipated through the short term period. Shallow lake moisture will still reside roughly along and north of the New York Thruway first thing Monday morning, as flow is still light westerly before veering southwesterly. Model soundings show that there will be no ice crystals possible since the saturated layer will be minus-5 Celsius or warmer. Thus if anything at all, perhaps just a little spotty drizzle. Monday otherwise looks quiet with partial sunshine at least of Northeast PA-Catskills, and perhaps sneaking into the Southern Tier Finger Lakes in the afternoon with more clouds persisting north. Highs will be mainly in the 40s. Clouds will decrease Monday night, setting up a competition between radiational cooling yet also continued warm air advection within the column. Lows mainly in the 30s, though lower elevations of the Finger Lakes could be closer to 40. A good amount of sunshine Tuesday will help southwesterly warm air advection get better realized at the surface Tuesday with highs of mid 40s to mid 50s. Dry conditions will continue into the evening, but clouds thicken overnight ahead of the next system with lows of mid 30s to lower 40s. We may see some rain showers trying to work their way in from the west towards dawn. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... 425 AM Update... The weather turns more active for holiday travel, with a deep showery low pressure system Wednesday followed by gusty winds and colder temperatures Wednesday night through Thanksgiving including possible lake effect snow. Models have skewed just slightly further north and later in time with the passage of a deep low pressure Wednesday through Wednesday night, yet have done so in tandem and thus remain in good agreement with little change in anticipated impacts. Warm air advection ahead of the system will cause precipitation type to be developing rain Wednesday, with highs of upper 40s- mid 50s. A lower 990s surface low will then whip through the Central Great Lakes to Saint Lawrence Seaway. Strong pressure rises with steep low level lapse rates are expected late Wednesday through Wednesday night to midday Thursday with gusty winds. Gusts of 30-40 mph still appear easily attainable based on current models; we will need to monitor trends. Models have better consolidated on a window of lake enhanced/brief synoptic upslope snow southeast of Lake Ontario late Wednesday night through at least midday Thursday. We have several days to sort this out, but given the holiday travel this is worth monitoring. Chilly weather continues Friday-Saturday, but mainly dry conditions appear likely. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... MVFR to VFR for our northwest terminals this morning (KRME, KSYR, KITH and KELM). Meanwhile, rain, snow and fog are bringing LIFR conditions to KBGM and KAVP (with a few inches of slushy snow accumulations expected). The mixed precipitation will gradually taper off and move east by late morning or midday. Conditions should improve back to VFR by and after 18z just about everywhere...although some guidance shows these low CIGS holding on a few hours longer at KRME. VFR areawide late afternoon into this evening. Then some mid level clouds build in from the north, possibly becoming MVFR after about 25/06z toward KSYR and KRME. Variable winds early this morning, then shifting to a more northwesterly direction late morning and into the afternoon. Winds increase between 10-20 kts by afternoon. West winds around 10 kts overnight. Outlook... Monday through Tuesday...VFR expected. Wednesday...A system bringing rain may pass through the region with associated restrictions. Strong, gusty winds also possible. Thursday...Improvement to VFR after morning snow showers. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...Winter Weather Advisory until 3 PM EST this afternoon for NYZ046-057-062. && $$ SYNOPSIS...MJM NEAR TERM...MPK/MJM SHORT TERM...MDP LONG TERM...MDP AVIATION...MJM