ITHACA, N.Y.—A large and potent storm system is threatening major disruptions to holiday travel and outdoor activities as heavy rain, damaging winds, and dangerous wind chills bear down across the state and region.

A low pressure storm system is expected to rapidly intensify, a process known as explosive cyclogenesis or “bombogenesis,” as it crosses the Lower Great Lakes west of Ithaca and Tompkins County. This storm will be extremely powerful, with forecasted core pressure more typical to oceanic lows and hurricanes than a continental storm system. The National Weather Service Buffalo office is describing it “as a once-in-a-generation type of event.”

The northeastward track of the system, to the west of Tompkins County, means that initially Tompkins County will be in the warm sector of the low’s counterclockwise circulation as the strengthening storm approaches.

In Tompkins County, Thursday into Friday morning, an initial brief snow will quickly change over rain by early afternoon, and a moderate to heavy rainfall will continue through the overnight hours, 0.50-1.00″ before midnight and another 0.50-1.00″ after midnight. Winds will steadily pick up during the day, from SE winds 10-15 with gusts 25-30 MPH during the day, to SE winds 20-25 MPH with gusts 40-50 MPH overnight. Temperatures will continue to rise, from low 30s Thursday morning to around 40 at sunset, to near 50 by sunrise Friday.

Temperatures will begin to rapidly plunge as the cold front of the slow sweeps across the area. Temperatures will drop from near 50 at 8 a.m. to mid 30s by noon, to upper teens by 6 p.m. Remaining rain will change over to snow, but only 1-2″ is expected. However, with up to 2″ of fresh rainfall in the hours before the Arctic air arrives, a “flash freeze” event of standing water is likely. Winds will continue to gust to 45-55 MPH as temperatures plummet, and through the overnight hours. Lows will be 5-10 above, with wind chills in the -10 to -20 F range overnight Friday into Saturday.

The system begins to lift away Saturday, with gusty winds 30-40 MPH, slowly settling down Saturday night. A few snow showers are likely with partly cloudy skies and highs in the upper teens, with wind chills at or a little below zero. Saturday night will see partly cloudy skies with temperatures 5-10 above with wind chills 0 to -10 F.

With the heavy holiday travel volume and outdoor activities, precaution needs to be taken. Strong winds may cause scattered power outages and blow around unsecured objects such as outdoor decorations. Heavy rain, initial warm temperatures and blowing shore water may cause excessive runoff and localized flooding. The numerous wet surfaces will freeze rapidly Friday afternoon and along with the late wintry mix, icy roads and walkways are expected. Dangerous wind chill Friday night will cause frostbite and hypothermia if skin is exposed or underdressed individuals are outside for extended periods.

Adjust your holiday trips and outdoor plans accordingly. Travel will be difficult and dangerous in large swaths of NYS Thursday night through Saturday morning. This is a high-impact, multi-faceted winter storm with effects over a wide area. Damaging winds are expected in western New York. Lake effect will create whiteout conditions north of Buffalo and north of Syracuse Friday night, with blowing and drifting snow. Excessive rainfall and high winds will cause urban and shoreline flooding Downstate. Severe wind chills will create dangerous cold across the Southern Tier and Catskills. Blizzard conditions are impacting the Midwest and subzero temps may occur as far south as Tennessee and the Carolinas, with frost as far south as the Mexican border and Orlando.

Further updates to this complex and powerful storm system may be found at the National Weather Service Binghamton office here.

Brian Crandall

Brian Crandall reports on housing and development for the Ithaca Voice. He can be reached at bcrandall@ithacavoice.com.