737 FXUS61 KBGM 112330 AFDBGM AREA FORECAST DISCUSSION National Weather Service Binghamton NY 630 PM EST Mon Feb 11 2019 .SYNOPSIS... A Great Lakes cyclone will bring snow and mixed precipitation to NY and PA from early Tuesday morning through early Wednesday. The mixed precipitation and snow will make for difficult travel conditions. High pressure will slide across the region on Thursday, then another storm will push rain and snow toward NY and PA by Friday. && .NEAR TERM /THROUGH TUESDAY NIGHT/... With the early evening update radar and obs trends are showing the precipitation shield having a difficult time moving northeastward. It still looks like a few hours before enough saturation occurs for snow to reach the ground. As a result, snow chances were reduced in the Poconos for the remainder of the evening. 345 PM update... A winter storm warning is now in effect for the entire forecast area. 255 PM update... A complex cyclone will track into the Great Lakes and spread a mix of snow, sleet, and freezing rain across our forecast area early Tuesday morning through Tuesday night. Snow will spread into the southwestern portion of the forecast area before sunrise and increase in intensity during the morning commute. The heavier snow will then spread to the I-81 corridor in NY between 8 AM and 10 AM, and eventually work its way northward into the remainder of the forecast area. The heaviest snow will fall during the first 3-6 hours of the storm. Thereafter, a mix of sleet and freezing rain will overtake the snow and become the dominant precipitation type as warmer air aloft slides over the forecast area. Sleet and freezing rain will continue for most of Tuesday night, except over portions of the far northern forecast area where the atmosphere will remain cold enough to support snow. The wind shift late Tuesday night could provide another period of snow before the event tapers off. In total, we forecast 3 to 7 inches of snow over our PA counties, 6 to 9 inches from the Central Southern Tier and Finger Lakes eastward to the Western Catskills. Slightly higher totals are forecast over Onondaga, Madison, and Southern Oneida. Northern Oneida will see the highest snow totals with over a foot expected. Ice accumulation will range from several hundredths to 0.15 inches. 1120 AM update... Light snow ended across the region this morning. Temperatures are up to date in the new grid forecast, and we are currently examining new model data for the upcoming storm system. This morning's forecast remains in good shape. 6am update... Temperatures staying up with clouds and flurries around. Made minor adjustments. Little to no snow accumulation still. 3 AM UPDATE... A weak wave has brought mostly flurries to the area early this morning. Dry air is at the surface left by a strong ridge of high pressure in eastern NY. The highest amount and most persistent snow is the furthest from the high southwest of a line from Scranton to Elmira. Even there only around an inch expected. Flurries and light snow showers will end this morning. Some partial clearing will occur in the north this afternoon. High temperatures mostly in the low and mid 30s with light winds. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... 307 pm update... Main concerns in the short term remain focused on the potential for accumulating lake effect snow north of the Thruway Wednesday through Thursday, along with lighter snow amounts to the south and gusty west winds producing blowing snow as well. Upper level low will move from the central Great Lakes ne into srn Quebec Wednesday morning with the nose of warm air continuing to shift to the east as the cold air on the back side of the system pushes through wrn NY into central NY and ne PA. This strong cold air advection regime will allow any remaining liquid precip to change back to snow Wed morning. May see a brief period of a mix of light rain and snow over the far eastern counties early in the morning. The surface low will flatten out just north of the NY/Canada border Wed morning, and work in coordination with a surface ridge building into the srn Great Lakes to produce a predominantly westerly flow across the region. The combination of west winds and cold air advection across Lakes Ontario...850mb temps around -11 to -14 deg C...will combine with a fairly deep mixed layer...from 8-11 kft... and a low sheared deep layer...to produce favorable conditions for lake effect snow into a good portion of Oneida county. Heaviest snow will occur Wed afternoon through Wed night where as much as 10 inches is possible. Areas along and just south of the Thruway may see around 2-4 inches...including the Syracuse metro area. While even further south will likely see less than 1 inch. There will also be the threat of blowing snow during the day Wed and Wed night. Winds will increase to around 20 to 25 mph with gusts 25 to 35 mph possible. Winds this strong when combined with heavy snow to the north will produce near white-out conditions. Visibilities will likely not be as low further to the south where snow will not be as heavy. The snow will quickly taper off Thursday morning as high pressure builds in. May see a few light snow and/or rain showers Thursday afternoon as temperatures warm into the mid to upper 30s. Any additional accumulations will be light. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... 307 pm update... The next low pressure system will approach from the west Thursday night with another responsive warm nose out ahead of the system advecting in from the south over a cold near surface layer. This thermal profile will potentially set up another period of freezing rain across the region into Friday morning. At this time the precipitation amounts look to be very light. Will need to keep a close eye on this system as it evolves. There does appear to be some consensus about any wintry mix Friday morning changing to all rain through the rest of the day with the low levels warming above freezing in response to the warm air ahead of the incoming low. The arrival/timing of the cold air on the back side of the system is still quite uncertain, but it appears it will not be until after midnight with most of the rain changing back to snow by Saturday morning. May see a bit of a wintry mix through the day Saturday in ne PA and portions of the srn Catskills before a second surge of cold air arrives Sat night and Sunday sending temperatures into the teens and 20s. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... A mainly VFR cloud deck will hang over the terminals through tonight. A cyclone tracking through the Great Lakes will pull snow into our terminals toward sunrise Tuesday. Visibilities will fall to between 2SM and 5SM in light snow, before heavier snow follows a few hours afterward and knocks visibilities down to 1/2SM to 2SM. IFR ceilings are likely in heavier snow on Tuesday. A mix of sleet and freezing rain will move in southwest to northeast Tuesday afternoon and evening. IFR vsbys are likely with slowly improving ceilings. Winds will increase out of the southeast Tuesday afternoon...sustained around 10 to 15 kt with gusts 20 to 25 kt. Outlook... Tuesday night...Sleet and freezing rain likely through the night from KITH south to KAVP. Precip may remain more sleet and snow at KSYR and KRME...but cannot rule out some freezing rain mixing in at times either. Wednesday through Wednesday night...Precipitation changes back to all snow, with continued restrictions most likely across the NY terminals, even into Wednesday night. Gusty west winds. There is a chance of heavy snow and IFR or worse vsbys at KRME. Thursday through Thursday night...Mainly VFR but a chance of snow showers or wintry mix by later Thursday night. Friday and Saturday...Another low pressure system moves in with widespread restrictions and mainly rain, especially by Friday night through Saturday. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Winter Storm Warning from midnight tonight to 7 AM EST Wednesday for PAZ038>040-043-044-047-048-072. NY...Winter Storm Warning from 3 AM Tuesday to 7 AM EST Wednesday for NYZ015>017-022>025-044>046-055>057-062. Winter Storm Warning from 6 AM Tuesday to 7 AM EST Wednesday for NYZ009-018-036-037. && $$ SYNOPSIS...DJP NEAR TERM...DJP/MWG SHORT TERM...BJT LONG TERM...BJT/MWG AVIATION...BJT/DJP