ITHACA, N.Y. — A major snowstorm is expected to barrel across the region this weekend, and with it will come over a foot of snow, gusty winds and subzero temperatures.

A Winter Storm Watch has been issued for all of upstate New York, which will be directly in the path of the precipitation shield of a rapidly intensifying storm that will develop over the Ohio River Valley, cross the Appalachians and travel up the Northeast seaboard. With access to oceanic moisture and rapid strengthening, heavy snowfalls and high winds are expected, with blizzard conditions possible over an extended time period.

Latest estimates from the National Weather Service Binghamton forecast office call for an expected snowfall amount of 16 inches in Ithaca and locally higher amounts on the hills surrounding the city. Probabilitistic forecasts call for at least a 90% chance of 8 inches or more, and a 10% chance of 20 inches or more, with most areas receiving between 12 inches and 18 inches. Forecast amounts can and will vary as a result of several factors, such as how quickly the storm intensifies, the strength of the much weaker storm passing through tonight (a stronger storm tonight would draw down more cold air for later snow production), and localized bands of heavier snow embedded in the main storm.

GFS Model output for total snowfall accumulations as of 7 PM Sunday night (00z 01/21/2019). Model output courtesy of Tropicaltidbits.com.

As the storm becomes more powerful and its low pressure core strengthens, the pressure gradient will tighten and the winds will speed up. Wind gusts of 35 MPH are expected later Sunday, and higher gusts are possible. Subzero wind chills are also expected, as the powerful storms draws down frigid air from the Canadian arctic. After the snow moves out Sunday night, the extreme cold will continue, with subzero temperatures expected Sunday night, and wind chills near 20 below zero. Daytime temperatures will remain in the single digits on Monday, and temperatures of 5 to 10 degrees below zero are expected on Monday night. The week will steadily warm up from Tuesday on.

The first substantial snowbands are likely to enter the Ithaca area by 11 AM Saturday, with heavier and more persistent snows by 4 PM Saturday. Snow, heavy at times, will continue through the evening, through Saturday night, and much of the day Sunday, winding down from west to east around 5-7 PM Sunday evening. Scattered light snow showers will persist through the overnight and taper off Monday morning.

Please take all due caution. The heavy snow and high winds will create blowing snow and potentially white-out conditions, with visibility near zero. Do not drive Saturday night or Sunday if at all possible. Roads will be in poor condition, and may be closed to non-essential or non-emergency vehicles. If travel is necessary, make sure your car is equipped to handle the cold, snow and ice. Dangerously low wind chills will pose a risk of frostbite to exposed skin as well as hypothermia, so if you must be outdoors Sunday night or Monday, limit your exposure and layer and cover skin accordingly. Bring pets indoors. Power outages are possible. Make sure you are stocked to ride out the storm (as in medications, food and a heat source, beer and Netflix are optional), have an emergency kit prepared just in case, and pay attention to the National Weather Service or your news outlet of choice for weather updates.

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