ITHACA, N.Y. — The week will start off on the warm side by late November standards, but following the passage of a storm system Wednesday night into Thursday, it’ll be as chilly as the looks your mother gives when your uncle has one too many beers and starts talking politics at the Thanksgiving dinner table. It would figure the one really iffy day of the week would be the one where most folks do their pre-holiday travels.

Precipitation, mean sea level pressure and 1000-500 mb thickness (temperature proxy) for 8 AM Thursday morning. Winds will increase rapidly as a quickly-moving low pressure area passes from west to east over our region. GFS Model output courtesy tropicaltidbits.com.

Your Weekly Weather

We’ll be starting off this week on the quiet side. The coastal storm that impacted our area is moving away and partly cloudy skies have returned to the area. This was one of those storms where, because the temperature was hovering near the freezing point, the higher elevations received a couple inches of snow especially to the south and east of Ithaca (closer to the storm), while Ithaca and Lansing received only brief periods of snow mixed with a cold rain. (What was I doing last year this time? Writing about a foot of snow that would be followed by near zero and subzero temperatures).

That should quickly melt off over the next day or so, as a ridge builds in the jet stream and funnels milder air into the Southern Tier. The low pressure will build far enough east that any cold air it funnels in behind it is likely to be out of range for Tompkins County. This results in one of those unusual cases where Albany, usually a few degrees warmer than Ithaca (and no, not because of the hot air of politicians, but because the Hudson Valley channels warmer air northward), will actually be several degrees colder this week.

For your Sunday night, things will be fairly quiet as high pressure builds in from the south. It’ll be dry, with partly cloudy skies and a low in the mid 30s. Monday will be a fairly pleasant day, a touch warmer than normal thanks to the clockwise flow of that high over the Deep South – not only does it stabilize the air, it will advect warmer air northeastward and into the Southern Tier. Expect highs to top out in the mid 40s on the hilltops, upper 40s elsewhere, and maybe 50 °F in Ithaca’s urban core, with partly cloudy skies overhead. Monday night will be partly cloudy and with that southwesterly flow continuing, lows will only fall back to the upper 30s under partly cloudy skies.

It gets a little milder for Tuesday as the southwesterly flow is enhanced by a developing low over the southern Great Plains. This will become a factor as it treks to the northeast. But for Tuesday itself, it’ll be a mild, mostly cloudy day with highs getting up into the mid 50s, the clouds due to a weak clipper low passing well to our north. However, as the Great Plains low quickly strengthens and moves closer, skies will become fully overcast Tuesday night, and the chance for rain ahead of the low will build as we get closer to daybreak Wednesday. With the cloudy skies and mild winds, temperatures will bottom out around 40 °F.

Wednesday should be warm as the counterclockwise flow of the storm system’s low pressure core drives milder winds into Tompkins County, moving into Michigan before taking on a direct eastward movement. Mid 50s is looking pretty likely. HOWEVER, this is a quickly moving storm, and its passage over us will align with part of the jet stream aloft. That will allow strong winds to work their way down to the surface. It’ll be mostly cloudy with some light rain, but as the low approaches, the winds will start to become very gusty and strong by late afternoon Wednesday – if you can leave for your travels earlier that day, then do so. These winds will continue to roar through Wednesday night after the front passes during the 6-9 PM timeframe. Ithaca will see winds of up to 40 MPH, which is definitely enough to snarl travel or make driving next to a high-profile semi truck a hair-raising experience. The hills could see winds closer to 50 MPH. These will also switch direction as the front passes, from strong southwest to strong northwest winds. Definitely use caution of on the roads Wednesday evening, because weak trees and tall trucks will be liable to break or tip in those conditions. With the passage of the cold front, lows will slip back to the upper 30s by morning.

Thanksgiving Day is not looking all that pleasant for that post-dinner walk. Winds will weaken a bit, but it will still be breezy, with 30-35 MPH gusts in the morning, and 25-30 MPH in the evening. With those strong northwest winds, temperatures will stay in the upper 30s during the day, with some snow showers in the morning (little to no accumulation expected), and mostly cloudy skies turning partly cloudy by afternoon. Winds should steadily calm down as the low moves further away Thursday night, and temperatures will bottom out in the upper 20s with partly cloudy skies.

Friday onward looks quiet. Winds will stay out of the northwest thanks to a Canadian high to the northeast of us, so while it’ll be dry, it’ll be chilly. Plan for partly cloudy skies and temperatures in the mid 30s for your Black Friday, and mostly cloudy with lows in the mid 20s Friday night. Saturday will be partly cloudy with highs in the upper 30s as the northwest winds wind down, and Sunday will be mid 40s as another storm system approaches from the west. This one could get nasty for late Monday into Tuesday, but when we’re this far out we start to get into model fantasy land, so it’s best to hold off on making any calls until next weekend.

Graphic courtesy of the NOAA Climate Prediction Center.

Extended Outlook

The medium-term outlook suggests that as we head into December, we’ll be a bit on the cool side as the jet stream ridge flattens, and a big ridge over Alaska results in lots of cold air being funneled down into the Western U.S., and to a lesser degree into the Northeast. Alaska has had a fall that’s been extremely warm by their standards, which isn’t good for sea ice and polar bears, and isn’t good for keeping us warm – the Alaskan ice and snow reinforces the cold air and keeps it up there. With these warm bubbles over Alaska and the lack of ice, the dark, still-very-cold air at the poles ends up going down the path of least resistance and slipping into whatever troughs in the mid-latitude jet stream it can find. Cooler than normal temperature and near to slightly above normal precipitation appear to be on tap for the first week of December.

Brian Crandall

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