858 FXUS61 KBGM 190758 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 358 AM EDT Fri Oct 19 2018 .SYNOPSIS... After a chilly dawn, high pressure will yield a sunny and much milder day. However, showers become likely late tonight into Saturday as a cold front sweeps through the region. This will send temperatures back below normal for the second half of the weekend, including mixed rain and snow showers from the northern tier of Pennsylvania into Central New York. && .NEAR TERM /THROUGH SATURDAY/... 345 AM Update... It is a quickly-moving pattern, and so our brief high pressure day of respite will switch to a showery cold front as we head into Saturday. With cold temperatures Thursday morning, the growing season has ended across the entire area except for Lackawanna-Luzerne which are currently under a Freeze Warning for this morning. For those NEPA counties, ideal radiational cooling conditions overnight has produced the widespread upper 20s-lower 30s now being observed, so that should do it for all Frost-Freeze products until the Spring. Despite the cold start, the surface high is in the process of shunting off the Mid-Atlantic Coast, and return flow just above the surface as well as ridging aloft is resulting in strong warm air advection. This will begin to be realized not long after dawn, as abundant sunshine helps to mix down the warm air. The rapid bounce in temperatures will bring highs into the upper 50s-lower 60s. The additional help of downsloping southwest wind could even bring a few spots into the mid 60s at lower elevations of northern Finger Lakes and perhaps Syracuse. A trio of waves, however, which will abruptly change things. The first one will zip through overnight, which will serve to moisten the atmosphere and even cause a quick batch of light rain showers to pass by, with Poconos-Catskills having the better chance for that. Rain amounts through tonight however will be under a tenth of an inch, where it occurs. Any showers will first have to overcome a good amount of dry air in the lower levels; it will be one of those nights where the radar bark is worse than the bite since much of it will be virga, especially during the first half of the night. With plenty of clouds and a continued southwest wind which actually could be somewhat stiff in higher elevations of Central NY, temperatures will only drop to mid-upper 40s for lows. The second and third waves will take the form of a pre-frontal trough and then the cold front itself, both of which will pass through Saturday with convective showers. Truth be told, in the wake of the cold front a fourth wave - the main sharp digging upper trough axis - is set to arrive Saturday night. But for Saturday itself, temperatures initially reach lower-mid 50s for Central NY and mid-upper 50s for Northeast PA, before the start of cold air advection starts to tamp temperatures down in the afternoon. With cooler air aloft outpacing lower levels, lapse rates will significantly steepen which will allow mixing down of gusty winds out of the west, veering northwest late. Peak gusts of 20-30 mph can be anticipated afternoon through evening. General rainfall totals of about one to two tenths are expected for Saturday, though some spots that end up between clusters of showers may only get a few hundredths of an inch. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... 330 pm update... Saturday night: Upper level trough axis moves overhead, with moderate cold air advection developing over Central NY and Northeast PA. WNW flow will waver a bit through the evening hours, before veering and becoming steady northwesterly overnight. This will combine with 850mb temps around -8 to -10C to develop lake effect rain/snow showers across central NY and the northern tier of PA. Could see some spotty minor snow accumulations across the higher elevations of the Susquehanna region of NY...less than 1 inch. Lows will be cold, dipping down into the upper 20s to lower 30s. Sunday: Upper level trough slowly moves off the east through the day. Could see some lingering snow showers in Central NY during the morning hours on a NNW flow. Cold air mass remains in place through the day, with high temperatures only reaching the upper 30s to mid-40s south. NW winds 8-15 mph will create wind chills in the upper 20s to 30s through the day. Sunday night: Upper level heights begin to rise, with a weak warm air advection pattern developing in the mid levels of the atmosphere. Surface high pressure system slides into the Mid- Atlantic region...with a weak warm front pushing across the northern portion of our CWA. Will see an increase in clouds along this front, with a chance for some light rain/snow showers to develop up near Syracuse/Rome. Another cold night, with lows in the mid-20s to lower 30s. && .LONG TERM /MONDAY THROUGH THURSDAY/... 345 pm update...No significant changes to the long term forecast with this update. Overall, an upper level trough looks to remain in place across the northeastern US through the middle of the week, with a series of weak disturbances rotating through the area. This weak systems will mainly act to reinforce some colder, Canadian air and bring chances for rain/snow showers mainly for our central NY zones. Monday/Monday night: Starts off mainly dry, but mostly cloudy as our area will be under a southwest flow ahead of the next approaching shortwave trough. There will be chances for rain showers across central NY, especially heading into Monday night. Temperatures aloft remain above freezing, with surface temperatures reaching 45-50 Monday afternoon...and overnight lows in the mid to upper 30s Monday night. Tuesday/Tuesday night: Upper level trough swings through our area and into New England during this time period. Moisture looks to be limited with this system, but as 850mb temps fall back to around -5C, we will likely see a lake response with scattered rain showers, mixing with snow showers overnight. Highs reach 50-55 Tuesday afternoon, with lows in the lower to mid-30s Tuesday night. Wednesday/Wednesday night: Our forecast area will be in the back side of the departing trough, under a dry NNW flow. Still can't rule out some stray lake effect showers...especially early in the day. Remaining cool, with highs in the 40s to near 50. Otherwise, becoming partly cloudy, then mostly clear by Wednesday night as a surface high builds over the region from the upper Great Lakes. With light winds, and clear skies it should still be rather chilly overnight, as lows dip into the upper 20s and lower 30s. Thursday/Thursday night: Latest guidance is in fairly good agreement that an upper level ridge and surface high pressure system will continue to slowly move into the area from the west. The 12z ECMWF is the slowest bringing these features into our area at this time...and would tend to linger some lake effect showers longer. For now, kept the forecast dry with partly sunny skies and moderating temperatures. Highs around 50, lows 30-35 Thursday night. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... 06Z Update... VFR conditions are expected through 06Z Saturday, courtesy of passing high pressure. However there will be low level wind shear to contend with this morning at KSYR-KELM-KITH-KRME, from a westerly jet of 30-35 knots not far off the ground whereas surface winds will be very light. Later this morning through afternoon, LLWS will go away as surface winds increase to 8-12 knots out of the SW with higher gusts. LLWS may actually return this evening; this time for KAVP due to WSW jet of 40 knots, and possibly other terminals. Some high thin clouds will also begin to appear well ahead of an approaching cold front this evening. While shower chances generally wait until after 06Z Saturday, KAVP could potentially get a shower just prior. Outlook... Late Friday night through Saturday...Restrictions in rain showers, especially Saturday as a cold front sweeps through. Saturday night through Sunday night...Occasional restrictions in mixed rain/snow showers, mainly NY terminals. KITH in particular, and KBGM at times, appear prone to lake effect snow restrictions Saturday night-early Sunday. Monday and Tuesday...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Freeze Warning until 8 AM EDT this morning for PAZ044-047. NY...None. && $$ SYNOPSIS...MDP NEAR TERM...MDP SHORT TERM...MLJ/MJM LONG TERM...MLJ/MJM AVIATION...MDP