textproduct: Binghamton

WHAT HAS CHANGED

Didn't change snow amounts too much with Northern Oneida bordering between a low end winter storm warning and a high end winter weather advisory. Wind advisories where posted for the Finger Lakes and south into western parts of NEPA where the south winds today will lead to a few 45+ mph gusts.

KEY MESSAGES

1) A clipper system moves through today bringing a chance of mixed rain and snow, along with gusty winds, and potential afternoon snow squalls with the cold front passage. Accumulating snow will mainly affect higher elevations in the Southern Tier and areas south of it, with the Southern Tug Hill having the best chances for higher accumulation.

2) Another warmup expected late weekend as a stronger low pressure system moves into the Great Lakes region bringing another large swing in temperatures, strong winds, and potential severe thunderstorms early next week.

3) Well below average temperatures mid next week behind the departing early week low pressure system.

DISCUSSION

KEY MESSAGE 1...

A clipper system is making its way through the Great Lakes early this morning. In typical clipper fashion, most of the precipitation associated with it currently is on the warm air advection side of the storm. The clipper will begin to occlude today as it moves into the northeast with precipitation moving in from the west in the late morning into the early afternoon. There will be some warming ahead of the low so lower elevations of the Southern Tier into NEPA will see more of a rain snow mix rather than all snow but high elevations should still remain mostly snow. Across CNY into the Tug Hill closer to the low track, precipitation will be more persistent and with colder air aloft, precipitation type will remain mostly snow. Downslope winds into the Mohawk Valley and into Syracuse may raise temperatures above freezing which will make it difficult for snow to accumulate. The cold front associated with the clipper moves through this afternoon and evening and with some instability ahead of it, there is potential for a snow squall to form along it.

Upslope winds into the Tug Hill will create an area of terrain enhanced snowfall. There is still uncertainty with how much snow will fall in northern Oneida county as there will be a sharp gradient from only a slushy inch or two just north of Rome NY to up to 8 inches of snow on the Tug Hill. As of now, an advisory was kept to see how efficient the upslope snow ends up being today as there is good bust potential if the best forcing only last a few hours with the warm front passage and the snowfall rates post warm front are low. Forecast soundings also have the best lift outside of the dendritic growth zone

Wind will be a factor today in the Finger Lakes region as southerly 850 mb winds approach 50 knots and with winds aligning with terrain, there could be some local 45 to 50 mph gusts through the afternoon across the Finger Lakes so a wind advisory was issued. The wind advisory was extended through mid day Saturday as there will be another round of wind behind the low as the clipper departs. Wind advisories may need to be extended through the rest of the forecast area later today or tonight as there is a good low level jet with 850 mb winds near 50 knots with steep low level lapse rates that would help transfer some of those higher winds aloft to the surface.

KEY MESSAGE 2...

Another strong low pressure system forms in the central US this weekend with a warm front surging into the Northeast Sunday into Monday raising temperatures back to well above average. With the low deepening down into the 980s mb and potentially the high 970s mb, a strong low level jet will form in the warm sector of the low over NY and PA. Right now there is a stable layer that will prevent most of this wind from mixing down though with the south winds, the Finger Lakes could once again see some higher winds with good probabilities (>50%) of advisory level (>45mph) wind gusts.

With the warm temperatures and a strong cold front potentially moving through mid to late afternoon Monday there is potential for a line of strong showers to potentially severe thunderstorms. Shear will be very high ahead of the front, likely 60 to 80 knots of 0-6 km shear, though overall CAPE will be low, likely less than 100. Strong convergence along the front and likely quick pressure rises behind the cold front will overcome the weak instability and allow for some strong winds to mix to the surface with the line of showers/storms along the cold front.

KEY MESSAGE 3...

An anomalously cold air mass moves in behind the strong low pressure system mid next week with 850 mb temperatures back below -10C and could approach -20C for closer to Lake Ontario. This would lead to lake effect snow showers through most of the region and with strong solar heating, there will be diurnally driven convective snow showers in the afternoons of Tuesday and Wednesday. Highs will struggle to get above freezing which is pretty rare for mid to late March in the valleys at least.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

VFR conditions are expected at all terminals through this morning. The next weather system arrives this afternoon, with a mix of snow and valley rain overspreading the area. Expect MVFR to occasional IFR restrictions late in the afternoon and early evening hours for all terminals, with the lowest restrictions at the Central NY terminals. Gradual improvement is expected after 03Z Saturday, except at KRME and KSYR.

Initially light westerly winds will turn southerly later this morning, with gusts of 20-30kts possible this afternoon and tonight. There will also be a brief period of LLWS this evening at KRME, KSYR, and KBGM.

Outlook:

Saturday...Mainly VFR, although some lingering MVFR ceilings possible at KRME and KSYR in the morning.

Sunday...Brief restrictions possible in the morning with scattered snow showers; otherwise becoming mainly VFR.

Monday...Restrictions expected in rain, especially in the afternoon. Thunder possible in the afternoon.

Tuesday...Scattered snow showers with occasional restrictions possible, especially at the Central NY terminals.

BGM WATCHES/WARNINGS/ADVISORIES

PA...Wind Advisory from 2 PM this afternoon to 2 PM EDT Saturday for PAZ038-043. NY...Winter Weather Advisory from 11 AM this morning to 2 PM EDT Saturday for NYZ009. Wind Advisory from 2 PM this afternoon to 2 PM EDT Saturday for NYZ015>017-022>025.