ITHACA, N.Y. — Record breaking amounts of snow. Hundreds of cancelled flights. Impassable roads. Icy mayhem. This is not us. It’s Virginia, Tennessee and North Carolina. The South. Given Tompkins County’s early winter onslaught, forgive us for not being especially sympathetic.

Things here are unusually quiet, as cold, bone-dry air has had a firm grip over the region. That pattern should largely continue through the week, with a potentially soggy warm-up in store as we approach next weekend.

Weather Recap

As said above, the start of December has been a bit colder than usual (by just 2.3 °F, so nothing to write home about), and somewhat drier than usual. The reason for this is fairly strong and persistent area of high pressure, which keeps the atmosphere fairly stable while also pumping in cold air from Canada.

The only notable inclement weather in the past few days has been lake effect snow bands, which can still arise thanks to the instability created when cold air passes over the warm lake – energy from the lake gets transferred into the atmosphere directly above, not unlike the summer pop-up thunderstorms that bubble up thanks to warm ground temperatures and cooler air aloft. However, even these are relatively weak, because the air is quite dry, and the capacity to hold moisture is limited. The clouds can billow up, but what little falling snow does develop is also liable to sublimate in the dry air. Barring the miscreant acts of humanity, the ice sculptures on the Commons should survive at least a few more days.

As we head into the next week, there will be some minor disturbances passing through the region, but overall, we’re looking to stay dry and cool – at least, for the first half of the week. Things get more interesting after that, and we’ll get to that with your weekly forecast.

Precipitation, mean sea level pressure and 1000-500 mb thickness (temperature proxy) for 8 PM Friday night. An area of low pressure to our southeast will bring warmer and more moist air into region. along with the threat of heavy rain. GFS Model output courtesy tropicaltidbits.com.

Your Weekly Weather

As of Sunday night, some clouds are starting to push back into the region from the northwest, associated with a fairly weak cold front entering into the Southern Tier from Canada. Since the frontal boundary is weak and there isn’t much moisture for it to tap into, its effects on local weather will be limited. It’ll be mostly cloudy by morning, but apart from a few flurries, don’t expect much in the way of precipitation. Temperatures tonight will bottom out in the low 20s in Ithaca and the inner suburbs, with upper teens to 20°F in the more remote and elevated areas.

Monday will be a fairly quiet December day as the cold front sinks southward. Expect mostly cloudy skies, dry conditions, and highs at or just above 32 °F. Monday night will be mostly cloudy, with calm winds, continued dry conditions, and lows in the low 20s.

Tuesday will be a bit more interesting as a shortwave atmospheric disturbances pushes into the region from the northwest, but once again, the lack of moisture will keep this from having much of an impact, though Lake Ontario will contribute some cloud cover to the forecast. Tuesday will be partly cloudy during the day, with increasing clouds in the PM hours, and a high in the mid 30s. Tuesday night will be mostly cloudy, with a few scattered snow showers, and lows in the mid 20s.

Wednesday should be another quiet, dry day, as mostly cloudy skies start to break up in the afternoon hours. Highs will be in the low 30s with a light north-northwest wind. Wednesday night will be partly cloudy with lows around 20 °F.

Thursday will be a bit milder, as the winds shift to the south and some slightly warmer air flows into the region. Temperatures will be in the mid to upper 30s with partly cloudy skies, becoming mostly cloudy late in the day. We’re seeing some very low dewpoints in the forecast models for Thursday, so break out the lip balm. Thursday night will be mostly cloudy with lows around 30 °F.

Friday through Sunday is looking to be quite the change of pace. A fairly large and strong area of low pressure will develop over Texas midweek and track northeastward through the Lower Mississippi Valley and Southern Appalachians, where it becomes deeper (stronger) and slows down. This low will pump a lot of warm, moist air into the Northeast, and depending on how dry the air overhead is and how strong the storm system is, will decide how much heavy rain we get, and how long it will last. The models have yet to converge on a consensus on rain duration and timing, so keep an eye out if rain would impact your weekend plans.

To make that extra clear – this is a rain event, not snow. Friday will be mostly cloudy to overcast with highs climbing into the mid 40s on that southerly flow, and there’s a chance of rain, but it’s just a chance for the time being. Friday night will most likely have rain as the moist flow eats away at the dry air and the rain pushes into the region, so expect a cloudy, rainy night with lows around 40 °F. Saturday will be cloudy, with rain likely, and highs in the upper 40s, and Saturday night will be rainy with lows in the mid to upper 30s. Sunday is looking a bit drier, with mostly cloudy skies, some scattered rain showers, and highs in the mid 40s.

Graphic courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Not to be the bearers of bad news (the Voice prefers to be the bearers of all news), but for those hoping for a White Christmas, the chances are looking worse by the day. With a persistent ridge in the jet stream forming over the United States (and maximum amplitude over the Eastern United States), a prolonged warm, wet spell is setting itself up in the second half of December. While we can’t totally discount the possibility of some well-time snow event, the large-scale weather conditions are not looking to be conducive for significant snowfalls over the next couple of weeks.

Brian Crandall

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