ITHACA, N.Y. — A Winter Storm Warning is in effect until 5 PM tomorrow as a large and strong Nor’Easter works its way up the east coast, depositing several inches of snow across Tompkins County overnight tonight and into Monday. The remainder of the week is not much better, as generally colder-than-normal and unsettled conditions will continue until at least next weekend.

Graphic courtesy of NWS Binghamton.

Your Weekly Weather

Overall expectations for snowfall amounts have not changed significantly since yesterday’s special weather report, with 6-8″ of snow expected south and east of Ithaca, about 8″ in Ithaca itself, and 8-12″ inches in communities to the north and east, where colder air will be more persistent. The storm continues its trek northeastward along the eastern seaboard, with the edge of the precipitation shield (all snow, given the temperatures in the low 20s) currently making its way through central Pennsylvania and into the Northern Tier.

The timing, however, has sped up somewhat since yesterday morning, with the onset of significant snow now expected around 8 PM in Ithaca. It’ll be a littler earlier south and west of the city, and a little later to the north and east, given the storm system’s movement. Temperatures will warm as southerly winds channel in somewhat milder air from the Atlantic, and as it snows overnight, temperatures will warm into the mid 30s before sunrise, especially in areas south and east of Ithaca.

Generally speaking, areas north and west stay colder, with a drier, fluffier snow and higher accumulations. Ithaca’s snow will be heavier and wetter, with a lower snowfall amount overall as some rain is likely to mix in during the morning hours. Areas south and east will see less snow with more rain mixing in, including a thin layer of sleet or freezing rain. Plan accordingly, especially if you’ll be out on the roads – there’s more snow to clear to the north and west of Ithaca, but a more significant ice risk to the south and east.

The more intense snowfall will move out Monday later morning, and from afternoon onward persistent but light snow showers (and morning rain should change back over to snow by afternoon) will continue throughout the area, as there’s a lot of remnant instability and winds will have turned to the northwest and tap into Lake Ontario’s heat energy. Winds will pick up as the day goes on, and after sunset, they could really start gusting, up to 35 MPH overnight Monday, as light snow showers persist under cloudy skies. The heavy wet snow isn’t likely to blow around as much, but the snow north and west of Ithaca definitely will, so if driving in Trumansburg, Enfield, Cayuga or Schuyler Counties, take your time because blowing snow will reduce already low nighttime visibility Monday night. Temperatures will fall back from the mid 30s during the afternoon to upper teens by daybreak Tuesday.

Tuesday will be a much quieter as the Nor’Easter moves into Atlantic Canada. However, the large counterclockwise circulation will continue to influence the local atmospheric, and northwest winds will keep temperatures below normal with some scattered lake effect bands during the day, although accumulations will be less than an inch. You’d be forgiven for mistaking it for being more, as those winds will still be gusting 20-25 MPH out of the northwest during the day Tuesday and blowing that light snow around. Highs will be in low 20s with mostly cloudy skies to go with those snow showers. Tuesday night will see an early low in the late evening in the low teens with partly cloudy skies, but as winds turn to the south ahead of the next storm, it’ll warm into the mid 20s by morning Wednesday, with overcast skies and a few scattered snow showers by sunrise.

Wednesday’s storm is a weaker Alberta Clipper low that will pass to the north of Ithaca, but there will be some scattered showers during the day, starting as snow and changing over to rain shower by around noon. Ahead of the low a fair amount of milder air will be channeled into the region, and temperatures will make it into the low 40s during the day under overcast skies. Once the low passes Ithaca’s longitude around 9 PM, the cold northwesterly winds will return, and temperatures will drop overnight Wednesday into the upper teens with mostly cloudy if dry conditions.

Thursday will be cold and cloudy as northwest winds driven by an Arctic high moving into the Upper Midwest keeps temperatures frigid, with highs near 20°F and mostly cloudy skies; some light lake-enhanced snow showers are possible. Thursday night will be mostly cloudy and bitterly cold, with lows 0-5°F above, with windchills 0-5 °F below.

Friday may be a dry, partly cloudy day, but with that Arctic high, it will be a bone-chiller. Highs will only make it into the mid teens. Friday night will be quiet but dangerously cold, with lows 0-5°F above, with windchills 5-10°F below.

The weekend is looking cold but quiet, as the Arctic high moves east. Saturday will be partly cloudy with highs in the low 20s, Saturday night will be partly to mostly cloudy with lows in the low teens, and Sunday with see a few snow showers and highs near 30°F.

Graphic courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Looking into the last week of January, unfortunately the icebox-like conditions are set to continue, as a persistent jet stream trough funnels cold if dry air from polar Canada into the Eastern United States. It will be colder and drier and normal for what is climatologically the coldest part of Ithaca’s year. Further upstream, a jet stream ridge will bring warmer than normal conditions (and also drier air, as it will be advected/thermally transported from the Mexican highlands) to the Great Plains and Mountain West.

Brian Crandall

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