ITHACA, N.Y. — Throw a few more logs on the fire, because it’s going to be a chilly start to the week thanks to an Arctic high. But look on the the bright side – the weather will be sunny for much of the week, and temperatures should be well above the late January normal for the second half of the week.
Snow has become more showery this morning. However, west and northwest flow off of Lake Ontario and the Finger Lakes will keep the snow showers going into the overnight hours tonight. Here is a map of additional snow accumulations for this afternoon and tonight. #nywx #pawx pic.twitter.com/fbTPvokbqD
— NWS Binghamton (@NWSBinghamton) January 19, 2020
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It’s a rather snowy Sunday evening across Tompkins County, with a lake-enhanced snow band pushing southward into Tioga and Broome Counties, with light to briefly moderate snow in its passage. Most places received a fairly modest 1-3″ this weekend, with the local maxes of 3″ in Groton and Freeville as reported to NWS Binghamton. It’s not quite enough to bring us back to the climatological average for snowfall by this time of the month, but it does push us back above normal for the winter season to-date (for all practical purposes, being only an inch or so above normal is still considered “near normal”). It could be worse – over in Atlantic Canada, St John’s Newfoundland picked up three feet of snow and experienced 90 MPH wind gusts this weekend after a low pressure system rapidly strengthened (bombed out) over the Gulf Stream.
This week will have none of those meteorological shenanigans, but we will be starting off with snow and wintry cold. In the passage of this weekend’s storm (not the same as the Canadian one), a cold air mass fairly strong northwest wind has been able to tap into the heat energy radiated from the mostly ice-free waters of Lake Huron and Lake Ontario. This allows for the creation of channels of instability, resulting in snow bands that extend into the Southern Tier.
These bands are training, meaning that the band is redeveloping even as the snow moves southeastward; thankfully, the bands are narrow, so in general, unless a band is passing directly overhead as it undulates with the wind fetch, the snowfall will be light. Expect an additional 1-2″ by Monday morning, with a low in the low teens in Ithaca proper and along the lakeshore, and 5 to 10°F above zero in the outlying areas. With the northwesterly breeze, the wind chill will be below zero at times, so bundle up if you’ll be stepping outside tonight.
The snow bands will wind down tomorrow morning as a strong Arctic-born high approaches from the west, which will reduce the winds and cut off the snow bands’ energy supply. Clouds will progressively break down during the day, from mostly cloudy during the morning to partly cloudy by sunset. It will be cold, with highs in the upper teens to low 20s throughout Tompkins County. Monday night will be very cold but dry, with partly cloudy skies and a low around 10°F.
Tuesday will be a little warmer as the core of the high approaches and winds remain light, but a passing short wave (pulse of instability) to our north along the edges of the high pressure area will allow for some cloudiness and an isolated snow shower or two, with mostly cloudy skies otherwise. Highs Tuesday will be upper 20s. Tuesday night will be dry as the short wave moves eastward and away from the Southern Tier, and it will be partly cloudy with a low in the low to mid teens.
As the high shifts east of Ithaca’s longitude Wednesday morning, its clockwise flow will allow southerly winds to enter the region, and the temperatures will warm up accordingly. It will be partly cloudy with a high in the upper 30s. Wednesday night will keep the area dry, with partly cloudy skies and a low in the low 20s.
Thursday will be warmer still as the south-southwesterly flow is enhanced by a Gulf of Mexico low and a plume of moditure riding along the dge of the high. The rain will remain well away from Tompkins County, but the enhanced sutherly flow will allow for mostly cloudy skies and a high in the mid to upper 40s, which should decimate most of the snow pack. Thursday night will be mostly cloudy with a low in the mid 20s.
The high will remain parked in place over the eastern seaboard for Friday, so while the moisture plume will slowly work closer, there should be one more dry day in store for Tompkins County. It will be mostly cloudy with a high in the mid 40s. Friday night will see the first of the rain work in around midnight, and with temperature in the low to mid 30s, it could be a rain/snow mix. Temperatures will bottom out right around 32°F with rain and snow showers into Saturday morning.
The forecast gets a little complicated for the weekend. Some of the model runs suggest a Nor’Easter could develop, but that is far from certain at this point. It is likely that the initial low, having worked its way up the moisture plume, will transfer energy and moisture to a coastal system, but if that coastal system rapidly strengthens, it’s looking like it would do so further east, placing us outside of the precipitation shield, and limiting the flow of cold air such that most of what falls will be rain. For now, expect rain showers during the day, possible snow showers Saturday night and Sunday night, with highs in the low 40s Saturday, lows in the upper 20s Saturday night, and highs in the upper 30s for Sunday.
Looking ahead towards the end of the month, temperatures are expected to remain above normal thanks to a broad jet stream ridge, with above normal precipitation also expected, likely the result of that developing coastal storm next weekend. By the start of February, temperatures are expected to return to near-normal (colder) and drier conditions. Early projections indication a cold and dry first half of February, so you won’t be putting away the heavy coat just yet, but at least the snow shovel will get some rest.