080 FXUS61 KBGM 261358 AFDBGM AREA FORECAST DISCUSSION National Weather Service Binghamton NY 858 AM EST Tue Feb 26 2019 .SYNOPSIS... It will be cool today and still a bit breezy with morning snow showers southeast of Lake Ontario, tapering to flurries. A clipper system will bring a new round of snow Wednesday. Forecast amounts range widely from several inches for much of Central New York, to a few inches for the Twin Tiers, to about an inch or less for the Wyoming Valley and Poconos. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 855 AM Update The lingering band of lake effect snow has developed into a healthy snow squall and has dropped further south than expected into the Finger Lakes and the Southern Tier. This latest grid update reflects this trend as we have raised POPs and adjusted sky cover upwards in these areas. Still expecting this band to eventually diminish to multi-band flurries by early this afternoon. Otherwise, forecast remains on track. Previous discussion... 555 AM Update... Remaining Advisory for Onondaga-Madison has been dropped early, in coordination with NWS Buffalo, as lake effect continues to significantly diminish. Still dealing with last of the lake effect as of 315 AM this morning, as well as still somewhat breezy conditions today. However both snow and wind will be considerably less than Monday. Winter weather advisory will end as scheduled for Southern Oneida County at 4 AM, followed by Onondaga-Madison Counties at 7 AM. Passing shortwave followed by building high pressure, will cause the lingering band of lake effect snow to continue drifting south before diminishing to multi-band flurries. Though the inversion height has lowered to only about 7 thousand feet, all lake moisture within that layer is at dendritic growth temperatures. That lowest layer also still has decent lapse rates. Thus any cloud cover is able to continue to yield snowflakes. Eventually the dryness of the incoming air mass will win out, and indeed that transition is already underway. Some partial sunshine may be realized this afternoon. Additional snow amounts today in the snowbands will only be 1-3 inches though of very high snow- to- liquid ratios. Sustained west- northwest winds of 10-15 mph with gusts still above 25 mph at times will have no problem blowing that fluff around some more. Meanwhile, wind chills will be mostly in the single digits below or above zero this morning through midday. Actual highs will be mostly upper teens to mid 20s, though lower elevations of Northeast PA will get into upper 20s. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... 315 AM Update... A clipper system is set to swing through the region with a coating of snow Wednesday. Forecast amounts range widely from several inches north and west, to a few inches along the NY-PA border, to only about an inch south or even less. Things tonight will be rather quiet as high pressure passes. Initial relative lull in clouds will allow a window of good radiational cooling this evening, especially north of the NY Thruway where fresh snow is on the ground. Lows in the single digits to lower teens are expected, but that area along and especially north of the Thruway will probably drop below zero. Confidence is high on a clipper system to move through Wednesday with snow, yet there is still a fairly big spread in possible amounts especially in the Central portion of our area; that is, the Twin Tiers. There are a couple factors in favor of a good coating of fluffy accumulation. The warm air advection side of the clipper will have forced ascent from the right entrance region of a jet, and also a rather thick portion of the thermal profile will be at dendritic growth temperatures in the teens Celsius below zero with ample moisture. This will allow snow to develop fairly quickly mid to late morning, but after that things get more complicated. The biggest point of uncertainty is how far north the dry slot, or effectively the warm front aloft, will get. The trend in the models, and most notably the NAM, is to have a stoppage in the snow for much of the area in the afternoon before a final batch of snow as the clipper leaves in the evening. For the far northern zones, however, there is little if any gap between the front end snow and the back, and thus total snow amounts for Wednesday through Wednesday night are in the 3-5 inches range roughly north of Bath-Ithaca-Cortland-Norwich-Delhi. For the Twin Tiers to Catskills, there is a wider range of uncertainty with a forecast of 1-3 inches yet higher amounts possible if the dry slot does not make it. Meanwhile, more confidence exists for lesser amounts in the Tunkhannock-Scranton-Poconos areas and southward because of much greater exposure to the dry slot of the system. Amounts in that area will likely run only an inch or less, especially down towards Hazleton where it may turn out to be very little. As deeper moisture leaves Wednesday evening, snow winds down quickly overnight with lows of mostly teens- lower 20s, after highs of upper teens-upper 20s Wednesday. Clouds break up behind one system, while high clouds stream in well ahead of the next one on Thursday, but it will be dry thanks to passing high pressure with highs of upper 20s-mid 30s. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... 340 AM UPDATE...No major change to the long term at this time. Somewhat zonal flow has relatively weak disturbance racing eastward, with neither unseasonably cold or warm air. This will result in periods of precipitation, snow or mixed, generally light. Made some minor temporal pop and weather adjustments according to the latest model runs. Also made some minor temperature tweeks. Previous discussion below. 315 PM Update... The weather pattern overall will contain a few passing disturbances and thus multiple chances of precipitation. The next wave will actually be fairly weak while passing mainly to our south, however, at least a small chance of snow will exist into friday from the Twin Tiers southward, especially Poconos-Catskills. Some rain could mix in at lower elevations Friday. Things are more uncertain over the weekend, with an attempt at warmer air to move north only to have colder air win out in the the end. Snow-to-rain is expected Saturday, as a negatively- tilted wave of warm air advection passes, but eventually an upper trough will drop over the region. This will favor some snow showers especially off of the lakes as the weekend closes, and into early next week. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... A bit of lake effect remains at SYR bringing MVFR conditions. This will weaken in a few hours resulting in VFR to all stations under high pressure. A few gusty winds will continue as a result of mixing, but will finally weaken late in the day and overnight as the high moves overhead. Outlook... Wednesday/Wednesday night...Restrictions possible in light snow. Thursday...Primarily VFR. Thursday night through Saturday...Restrictions possible in mixed light snow/rain. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...MDP NEAR TERM...BJG/MDP SHORT TERM...MDP LONG TERM...DGM/MDP AVIATION...DGM/RRM