269 FXUS61 KBGM 071942 AFDBGM AREA FORECAST DISCUSSION National Weather Service Binghamton NY 242 PM EST Mon Jan 7 2019 .SYNOPSIS... Overcast with brief very light snow or sleet moving through late this afternoon. A wintry mix including some freezing rain becomes more likely tonight, along with gusty winds at higher elevations. After mainly rain showers Tuesday, a cold pattern will take hold for the remainder of the week with snow showers. && .NEAR TERM /THROUGH TUESDAY/... 1130 AM Update...Near term forecast remains on track, with no major changes at this time. Clouds have quickly increased this morning, with overcast skies now across the entire CWA. A very light band of precipitation will move across the area from west to east between about 2PM in the Finger Lakes & Central Southern Tier, 5PM I-81 corridor, and 7 PM Mohawk Valley & Catskills. This will be in the form of very light snow, sleet, and perhaps a freezing rain shower. QPF Amounts will be under 0.05 through 00z tonight, resulting in just a few tenths of an inch snow and/or sleet accumulation. Winter weather advisory remains in effect for the entire forecast area this evening into tonight. For much of the area only an inch or less of snow/sleet are expected...but there still remains the potential for a light glaze of ice. Northern Oneida county still looks on track to receive 2-4 inches of snow/sleet along with a coating of ice. Southerly winds also still look strong and gusty across the hilltops of the Susquehanna region and eastern Finger Lakes. Peak gusts 40-50 mph possible in the hills south of Syracuse, Auburn and Geneva. Temperatures slowly rise overnight, reaching the freezing mark by around 4 AM across the Finger Lakes and most valleys west of I-81, then by 7AM Tuesday for most locations, except the western Catskills, NE Poconos and portions of northern Oneida County. Previous Discussion Below 410 AM Update... Main concerns are the likelihood of a light glaze of ice areawide tonight, as well as accumulating snow mainly for northern Oneida County, and gusty winds for higher elevations of Central New York. Winter Weather Advisory has been hoisted accordingly, highlighting these issues. Things are quiet for now, with high pressure drifting through the region and temperatures mostly 10 to 20 degrees, though a few spots have managed single digits and even around zero for far northern Oneida County. However, we will quickly get into a southeast to south return flow regime as the high pressure ridge departs. Strong warm air advection/isentropic lift will occur this afternoon, resulting in thickening clouds and what should be a band of reflectivity on radar as a warm frontal wave passes. Low level air will be extremely dry with dewpoints only slowly climbing out of the single digits through teens; and so while clouds thicken, actual precipitation will struggle to reach the ground. Anything that does so during the day will be either very light snow or sleet due to the amount of cool air/wet bulbing within the lowest several thousand feet. Highs for today will be in the 20s to near 30 but it will take all day to get there. The main timeframe of concern will be overnight tonight. Strong southwesterly jet will usher in deeper moisture while also surging temperatures above freezing between 900-750mb. As the warm wedge lowers a bit overnight, initial sleet-snow will begin to include some freezing rain as well. Models are in good agreement on primary precipitation wave carrying across about 10pm west to 4am east. Amounts will be light, and with much of it in the form of sleet, ice accretion is likely to be only a glaze of a trace to few hundredths of an inch. However, orographic lift and a deeper cold layer in northern Oneida County, will allow for a crusty 2-4 inches of snow in addition to the potential light glaze. The strong pressure gradient and resultant jet will cause winds to pick up considerably out of the south or south-southeast, especially at higher elevations which will not be as protected by the stable low level cold air. Higher elevations of Central New York - especially Central Southern Tier through Finger Lakes/Cortland/Cazenovia areas - will be especially prone to sustained winds exceeding 20 mph and gusts of 40-45 mph. This along with the light glaze could lead to scattered power outages from downed branches. Between 4-7 am Tuesday, the main precipitation will lift out of the region and temperatures will continue to rise above freezing for most of the area, ending the ice threat. However, higher terrain east of I-81 will as usual take the longest to get above freezing, and thus untreated surfaces could still be slick. Also, the wintry mix may persist longer in Northern Oneida County. As we carry into daytime Tuesday, we will be in between weather systems with highs eventually reaching upper 30s to mid 40s. Winds decrease and turn southwesterly, 6-12 mph. Late in the day the next low pressure system approaches from the west, bringing renewed chances of rain. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... An exiting cyclone will move into Northern New England Tuesday night into Wednesday and drag snow showers across much of the region. The most persistent snow shower activity will be downwind of Lake Ontario. Expect a few inches of new snow accumulation over the northern half of the region by Wednesday afternoon. A persistent northwest flow will set up behind the storm and generate lake effect snow showers into NY through Thursday, before tapering off Thursday night. A lack of low level moisture will cap snowfall potential during the short term period. Polar air flowing out of Canada will cause temperatures to drop below seasonal norms by Thursday. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... Northwest flow continues with just some light snow showers and flurries coming off Lake Ontario and into the terrain of the Finger Lakes and central NY. Some light activity will continue into Friday despite the ridging surface high pressure with the 850mb temps still down near -17C. Surface flow become NE into early Saturday setting up another chilly morning for Saturday with single numbers and a few below zero readings. Previous discussion below. A polar trough will remain fixed over Eastern Canada between Friday and Sunday, while a cold high pressure system builds across Lower Ontario. Weak waves in the flow might generate a few flurries or light snow showers. For the most part, it appears the weather will be quiet this weekend, with high temperatures in the teens on Friday slowly rising into the middle-20s by Sunday. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... VFR conditions are expected during the day, with wind fairly light and variable at first. Clouds will thicken and lower this afternoon, yet still VFR, and there is a small chance for brief very light snow or sleet, mainly 20-23z. However, the higher likelihood of a wintry mix will wait until late evening, arriving between 04Z-06Z and only lasting a few hours at each terminal except lingering longer for KRME. Winds will also pick up out of the southeast or south late afternoon and especially tonight, sustained 15-25 kts and gusts 25-35 kts possible. Strong 40-50 knot low level jet out of the south will cause a period of low level wind shear to materialize for all terminals tonight into early Tuesday morning. Winds then turn south- southwest and decrease mid-morning Tuesday (12 kts or less) with some moisture becoming trapped under a developing inversion. This should cause Fuel alternate to perhaps even localized IFR CIG restrictions through the morning hours at most taf sites. Outlook... Tuesday afternoon...Scattered rain showers and drizzle around. MVFR fuel alternate restrictions possible. Tuesday night through Thursday night...Restrictions in rain changing to snow showers, mainly KRME-KSYR-KITH; at times KELM- KBGM. Mainly VFR KAVP. Friday and Saturday...Mainly VFR; brief restriction/flurry possible KSYR or KITH. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Winter Weather Advisory from 10 PM this evening to 7 AM EST Tuesday for PAZ038>040-043-044-047-048-072. NY...Winter Weather Advisory from 10 PM this evening to 7 AM EST Tuesday for NYZ009-024-037-045-046-055>057-062. Winter Weather Advisory from 7 PM this evening to 7 AM EST Tuesday for NYZ015>018-022-023-025-036-044. && $$ SYNOPSIS...MDP NEAR TERM...MJM/MDP SHORT TERM...MDP LONG TERM...DGM/DJP AVIATION...MJM/MDP