ITHACA, N.Y. — Don’t shoot the messenger. While there is no on the ground now, an unseasonably warm and dry week ahead will turn much of it into puddles and groundwater just in time for Christmas morning. On the bright side, at least the travel shouldn’t be too difficult, and the warm trend looks to continue through New Year’s Day.

Your Weekly Weather

In a broad change of pace, the Southern Tier will be under the influence of a ridge in the jet stream for the next several days. A pair of storm systems will remain well to our north and south, with a high pressure area wedged in-between. This will provide for stable, dry air, and southwesterly flow will result in temperatures comfortable above normal, though nothing as extreme as we’ve seen with some recent Christmas holidays (no one’s going to forget flirting with 70 °F on Christmas Eve a few years ago – I was walking my dog in short sleeves that year, harboring dread because extreme abnormalities tend to beget more extreme abnormalities).

Going through the next few days, temperatures will range from a few degrees above normal to a good 15 degrees above normal, depending on the strength of southerly flow, which itself will be dependent on the location of the lows and highs with respect to Tompkins County. Temperatures got into the low to mid 40s across most of the county this Sunday, and that relatively mild air will stick around through the overnight. Expect only a few passing clouds tonight with a low in the low 30s in Ithaca and close to the lakeshore, and the upper 20s in the outlying rural areas and higher elevations.

Monday will see a generous flow of warmer air, as the high is elongated from about the Mid-Atlantic southeastward towards Bermuda. Its clockwise flow will therefore allow southwesterly flow into the Southern Tier, as well as keeping the rainmaker over the Deep South well to our south, and the Canadian clipper low will stay in Canada, riding along the edge of the jet stream ridge enhanced by the high pressure area. Some clouds will build up from that Canadian system, but it’ll still be dry and fairly pleasant. Partly cloudy skies will turn mostly cloudy by sunset with highs in the low 50s in the urban core of Ithaca and near 50 °F elsewhere. This will rapidly deplete the snow depth in most areas, so if you’re counting on that White Christmas, lower your expectations now. Monday night will see the cloudcover break down as the northern low moves away and a Canadian high builds in. This more northerly flow will drop the temperatures a little colder Monday night, to about 30 °F.

Tuesday will be cooler with that Canadian high passing to the north and pumping some cooler air down. It will still be a touch above normal for Christmas Eve, with highs in the upper 30s and partly cloudy skies. Christmas Eve night is looking dry and seasonable cold, with partly cloudy skies and lows in the mid to upper 20s.

For your Christmas Day, the Atlantic high will begin to build back in, renewing a more southerly flow while keeping things dry. Temperatures will be in the mid 40s with partly cloudy skies. Christmas Eve night will be mostly cloudy with a low in the low 30s.

Thursday will see the high pressure remain in place, retrograding a bit into the Carolinas. Highs will be in the low 40s with partly cloudy skies. Thursday night could be our first significant chance for precipitation as a pulse of instability (short wave) passed around the ridge and clips upstate New York. No expecting much precipitation if any, but it will be cloudy Thursday night with a low in the mid 30s.

Friday will be a little unsettled with that short wave passing to the north, with a few widely scattered light rain and snow showers, but otherwise mostly cloudy with a high in the mid 40s. More stable air returns for Friday night with partly cloudy skies and a low in the mid 30s.

This weekend is looking warm, with partly cloudy and highs in the mid 40s for Saturday. Rain moves in Saturday night as a storm systems passes to our west (placing up in the warm sector of the low pressure area) with a low temperature in the mid 30s, and a mostly cloudy Sunday with scattered rain showers and a high in the mid 40s.

Graphic courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Looking ahead to New Year’s, it’s looking to be on the warm side, but with above average precipitation. The jet stream ridge will remain in place as will the milder air it provides, but a steadier flow of moisture from the lower latitudes will elevate precipitation totals to modestly above normal. That’s more likely to fall as rain rather than snow, but it all depends on the timing of storm systems on any given day as we close out the decade and launch into the 2020s.

Brian Crandall

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