textproduct: Binghamton

WHAT HAS CHANGED

Winter Storm Watches have been issued for portions of NE PA and the Catskills in NY. A strong coastal low, with uncertainty still remaining with its track, will develop late this weekend, tracking northeast to bring accumulating snowfall. Flood Watches remain for Steuben and Tompkins counties until this evening.

KEY MESSAGES

1) A strong coastal low will develop to our south late this weekend, tracking northeast toward the 40/70 benchmark by Monday morning. A trough of low pressure will extend northward into our region, bringing periods of snow. Portions of the area (NE PA & southern Catskills) may be more directly impacted by the coastal low, however accumulating snowfall could extend north into the Twin Tiers.

2) Watching potential for ice jams over the next few days with temperatures remaining at or above freezing. Flood Watch is in effect for Steuben and Tompkins counties until Saturday evening.

DISCUSSION

KEY MESSAGE 1...

A trough will develop over the eastern US Sunday, which will deepen and contribute to the development of a strong coastal low going into Sunday night. What well be watching for currently is the developing long wave trough starting to form in the western US, where the embedded shortwaves will play a key role in the development of the coastal low, as well as a jet streak stemming from northern Mexico adding moisture. Uncertainty lies in the phasing of the aforementioned embedded shortwaves as the main trough develops. Currently, the ECMWF shows the most pessimistic solution for snow-lovers, where delayed phasing results in the coastal low strengthening farther east and later than other deterministic counterparts (around 00z Monday). Solutions favoring higher accumulating snowfall show this phasing occurring earlier in the day Sunday, around 15z to 21z, where the coastal low strengthens quicker once heading into ocean waters. Another small factor to consider will be SLRs; this snow is expected to be on the wetter side on Sunday with temperatures hovering around freezing for the majority of places in NE PA. Heading into Sunday night, as temperatures drop, SLRs increase a little, but we also see the vertical profile align more into the DGZ, which will allow better snow accumulation overnight Sunday into early Monday morning. Even almost a day before onset time, this is a highly uncertain event with differing factors at play. Winter Storm Watches have been issued for portions of NE PA and the Catskills in effect Sunday morning through Monday evening.

KEY MESSAGE 2...

Several ice jams have been reported and noted across Steuben and Tompkins counties by EM partners, as well as observed on river gauges. With temperatures will remain at or above-freezing, this will allow the thick ice to continue breaking up and moving. Therefore, we cannot rule out additional ice jams and/or ice james producing flooding issues.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/

Widespread MVFR/Fuel Alt cigs across the region. RME continues to see light snow showers that should last off and on through the day. Cigs are expected to remain IFR until the early afternoon before briefly climbing to Fuel Alt for the afternoon and falling back to IFR through the evening and overnight hours.

MVFR/Fuel Alt cigs are expected for the rest of the terminals through the day as NW flow keeps a low stratus deck around. SYR could see an inversion set up starting in the evening, trapping moisture near the surface and bringing IFR cigs from mid evening through the overnight hours.

Snow showers from a Nor'easter are expected to move into the area late in the TAF period, impacting ELM/BGM/AVP in the late overnight hours.

Outlook...

Sunday...Coastal low could impact central NY and NE PA Sunday with restrictions from snow showers. Confidence is moderate for impacts over NEPA, with uncertainty as to how far NW the snow and IFR conditions will go.

Monday...Mainly VFR; low chance of light snow showers. Low to moderate confidence.

Tuesday...Mainly VFR. High confidence.

Wednesday...Restrictions possible as a clipper system moves through the region. Confidence is moderate.

BGM WATCHES/WARNINGS/ADVISORIES

PA...Winter Storm Watch from Sunday morning through Monday evening for PAZ039-040-043-044-047-048-072. NY...Flood Watch through this evening for NYZ022-025. Winter Storm Watch from Sunday morning through Monday evening for NYZ057-062.