596 FXUS61 KBGM 120136 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 936 PM EDT Thu Oct 11 2018 .SYNOPSIS... A cold front will continue to move through the region this evening with scattered rain showers. Much cooler weather will follow for Friday through the weekend, with the potential for frost Sunday morning. && .NEAR TERM /THROUGH FRIDAY NIGHT/... 930 pm update... The cold front and light rain showers have advanced to the far southeast. Much drier surface air has moved into Steuben County and will be across the entire area tomorrow. Temperatures are falling nicely behind the front and min temps in the 40s looks good. A weak lake response is expected with an aligned 280 low level flow off of Lake Ontario. 850mb temperatures fall below zero. Also a short wave moves through midday. Expanded the area and upped the pops slightly tonight into Friday across the thruway corridor. 330 pm update... Several key players can be seen on the mid afternoon surface analysis. The first is Tropical Storm Michael which was located over central NC. This system will continue to accelerate to the northeast, eventually moving off the Mid-Atlantic coast late tonight. A second area of low pressure was near the Ontario-Quebec border. This low will lift northward into James Bay tonight into Friday. Both low pressure systems are essentially connected by a cold front that is oriented north-south. The front, which has already made it into central NY, will progress eastward through the NY Southern Tier late this afternoon and eventually the Catskills and northeastern PA this evening. A narrow convective band associated with the front will sweep eastward through the region. Brief downpours can yield 0.25-0.50" of rain in a short period but the front is progressive enough to minimize the threat of flooding. The passage of the aforementioned cold front marks a change of seasons from almost summer-like conditions to autumn as northwest winds behind the front usher in much colder air tonight into Friday. Forecast low temperatures tonight are in mid to upper 40s while highs on Friday will only top out in the 50s. Post-frontal stratocu late tonight into tomorrow should be most persistent downwind of Lake Ontario with even lake-effect rain showers possible. A W-NW flow (near 300 deg) in the boundary layer should keep these showers focused near the I-90 corridor though some may spill downshear toward the I-88 corridor. An upper shortwave trough will move in from the west Friday night. Increasing clouds and a band of light rain is expected to overspread the area late in the evening and especially overnight. Thermal profiles may be cold enough in the boundary layer to support a period of wet snow mixing in with the rain at high elevations (near 2500 ft and higher) in the Catskills but the warm ground should preclude any snowfall accumulations. Quite a change from today! && .SHORT TERM /SATURDAY THROUGH SUNDAY/... 330 pm update... Main concerns in the short term are focused around the lake effect rain showers from the nrn Finger Lakes over to the wrn Mohawk Valley and srn Tug Hill plateau Saturday morning and early afternoon...and the potential for cold temperatures leading to frost Saturday night/Sunday morning. Upper level wave will be exiting the region to the east Saturday morning as heights rise aloft and a surface high builds east across the ern Ohio Valley region. A cooler and drier air mass will move in, and a nw wind off of Lake Ontario will induce lake effect rain showers...mainly along the Thruway and northward. There does appear to be a weak lake-to-lake connection upstream that should carry the lake showers well inland...possibly to the foothills of the nrn Catskills. The boundary layer is expected to be fairly deep...around 10k ft...with 850mb temperatures around -4C and lake temps around +14C proving very favorable for lake induced convection. There should be some mixing...albeit minor...in the BL in the late afternoon period...which will help dissipate or disorganize the rain showers. High pressure to the south moves ewd into the Mid Atlantic region Saturday night...which will shift the winds to the w/sw and move any lingering rain to the north. Drier air moves in during the overnight hours and allows much of the region to become relatively cloud free. A relatively cool air mass in place combined with strong radiational cooling and light winds will allow temperatures to fall into the mid 30s. Cannot rule out some lower 30s in the higher terrain of the Catskills. So, with much of the ground in the area still saturated from recent rainfall, and the cold temperatures, there is the potential for the first frost of the season...especially south of the Thruway where there is the best chance of clear skies. Conditions on Sunday should be quiet with high pressure shifting slowly to the east. Weak upper wave embedded in the flow may float some high clouds across the region, but otherwise quiet with highs in the lower to mid 50s. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... 3 PM update... An unsettled pattern with showers alternating with fair weather about every other day. A broad upper level trough will remain across the northeast U.S. Temperatures on the cool side with highs mostly around 50 and lows mostly around 40. Low pressure will track east across southeast PA Sunday night and Monday dragging a cold front across the area late Monday with rain showers. Minor upper level height falls will occur behind the front. A weak lake response could occur behind the front late Monday night into Tuesday morning. Another cold front goes through Wednesday with rain showers. A cold northwest flow behind the front could again set off lake effect rain showers Wednesday night and Thursday in CNY. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... 00z update... As a cold front sweeps eastward this evening, any residual restrictions at KAVP should improve to VFR by around 01-02z. Otherwise, VFR conditions will be replaced by MVFR ceilings later tonight (05-07z) at KSYR, KRME, KITH, and KBGM, as lake- effect clouds envelope parts of CNY. A few showers can't be ruled out, but light intensity/small areal coverage preclude their mention in the terminal forecasts. Friday, lingering MVFR ceilings in the morning over some of the CNY terminal sites, should improve to mostly VFR by midday/early afternoon. Surface winds will be gusty and out of the NW. The strongest gusts (near 25 kt) will be on Friday. Outlook... Friday night...A return to MVFR, perhaps IFR, is expected late, with showers moving in from the west. W-NW winds may back more out of the W-SW for a brief time. Saturday...Restrictions in rain showers possible at KSYR and KRME. Saturday night through Sunday evening...VFR. Monday and Tuesday...Additional restrictions possible in rain showers. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...BJT NEAR TERM...JRK/TAC SHORT TERM...BJT LONG TERM...TAC AVIATION...JRK/MLJ/MDP