ITHACA, N.Y. — We hope you had a chance to get out and enjoy those 60 F temperatures this past weekend, because it doesn’t look like they’ll be back anytime soon. A cooling trend will set in for the second half of the week, although it will still be above-average for this time of the year. There isn’t too much precipitation in this week’s forecast, so really, while it won’t be as warm, it won’t be too shabby for January.
Your Weekly Weather
So here’s a question that might be on your mind – how often do we make and break 60°F in the typical Ithaca winter? According to data from the Northeast Regional Climate Center based out of Ithaca, it’s about once every other year over the long-term record, which dates back to January 1893. But in practice, the answer is more nuanced. Warm weather tends to lead to more warm weather because air masses are slow-moving and persistent; likewise with cold weather and cold air masses. There are also other factors – for example, cold weather can help snowfall totals, and fresh snow helps cool off the air above it, helping to keep things cold.
One could arguably make a case that winter warm spells are becoming more frequent, though to be fair you’d want a few years of data if you wanted to make a stronger, more robust case. Lending support to the idea is an argument that appear in a weather column last month – there’s a scientific argument that as the north polar region warms faster the the mid-latitudes, the temperature gradient is decreasing and that weakens the jet stream, allowing it to meander and be more easily pushed around by storm systems. That would mean more frequent cold snaps relative to the average, but also more frequent warm spells. Anyway, the idea is still being debated in academic circles and is by no means conclusive, but it’s worth noting that these more changeable weather conditions and their causes are an active topic of meteorological research.
Turning to the weather at hand, well, the warmth of this weekend came to a swift end Sunday morning. The temperature dropped eight degrees from 7 AM to 8 AM at the airport, and 21 degrees in six hours, from 61°F to 40°F. A strong cold front is dislodging the warm air as it pushes eastward; we were fortunate enough to avoid the heavy rain at the top of the jet stream ridge over the Canadian border and Vermont, and thankfully lacked the energy that made the cold front a dangerous situation down south – with tornadoes, strong straight-line winds and rapid icing of roads, at least eleven fatalities have been reported in a swath from Texas to Alabama. In contrast, rain and winds here were fairly modest, with 0.12″ and a maximum gust of 37 MPH at the airport, with mostly cloudy skies behind the front this afternoon.
It’ll be fairly quiet for the rest of this weekend into Monday. An area of high pressure near Bermuda will direct stable, cooler air into the Southern Tier, though that cooler air will still be mild for January. Winds will calm as he head past sunset, shifting to the south as the high begins to exert greater control behind the departing cold front and its parent low. Expect mostly cloudy skies tonight and dry conditions, with a low in the upper 20s in Ithaca and along Cayuga Lake, and mid 20s in the outlying areas and higher elevations.
For Monday, expect partly to mostly cloudy skies, though there’s a small chance for an isolated shower or two north of Ithaca as a shortwave pulse of instability passes north of the region. But generally, it’ll be a quiet, dry day, with temperatures in the low 40s for highs. Monday night will be quiet and seasonably mild, with lows in the low to mid 30s and partly cloudy skies.
Tuesday will be somewhat more unsettled as a weak frontal boundary sweeps through during the afternoon, part of a low pressure area passing from the Northern Great Lakes and into Ontario. Plan for mostly cloudy skies and some scattered light rain showers during the afternoon and evening (12-6 PM). It will be seasonably mild once again, with highs in the mid to upper 40s (warmer closer to Ithaca and some southern valleys). Tuesday night will be some clearing as a weak high pressure area builds in. It will be mostly cloudy and dry with lows in the mid 30s.
Wednesday will be quiet as the high remains in place. Plan for partly cloudy skies and a high in the low 40s. Wednesday night will see clouds build back in, and potentially rain or snow showers after midnight as the next shortwave approaches, this one a little closer to us and therefore more likely to bring some notable precipitation. Temperature will drop to about 32°F by morning, and while it’s not favorable for icing, it is likely that rain showers will change over to snow showers by daybreak, and there might be a thin coating of snow as you get ready for work Thursday morning.
Thursday is likely to see the temperature slide from an early high in the upper 30s to below freezing by sunset as cold air associated with an arctic high begins to build in behind the front. Snow showers in the morning will change over to a light, occasional mix of rain and snow showers during the afternoon, and then back to all snow before dissipating completely Thursday evening as the stable air of the high builds in. Thursday night will be mostly cloudy with a low in the upper teens.
Friday is looking like the coldest day of the week, under the influence of that arctic high over the Upper Midwest. Temperatures will only get into the upper 20s with partly cloudy skies. However, a new storm system is expected to develop over Texas and Oklahoma and move northeastward during the day on Friday, and this will start to usher in somewhat milder as well as more unstable air after sunset. It’ll be mostly cloudy with some light snow showers well ahead of the system, and a low in the low 20s.
Next weekend doesn’t look good. The system will arrive for Saturday, with a mix of rain and snow likely and a high in the upper 30s. As the low moves east of us for Saturday night and Sunday, cold air will be dragged in behind its core, with snow likely Saturday night with lows in the mid 20s, and snow showers Sunday with highs in the upper 20s. It’s too early to give estimated snowfall amounts, but you’ll want to keep an eye on this system if you have weekend plans.
Looking ahead towards the end of the month, it’s looking like a broad shift towards a colder pattern will be merging as the polar vortex at the poles becomes more elongated and start to extend further into North America. A couple of the large-scale teleconnections in the Pacific and North Atlantic also support a colder pattern, though the question remains as to how intense and long-lasting will it be. IInitial long-range model runs have this carrying into the start of February, though it may perhaps weaken somewhat. A stormier pattern mid-month is expected to give way to a drier regime for last third of January as arctic highs provide stability, albeit with chilly temperatures, just in time for the climatologically coldest part of the year.