ITHACA, N.Y. — Normally, after Labor Day weekend, the transition to cooler conditions is as regular as the changing of leaves. However, with temperatures in the 80s and rather muggy and stormy conditions for much of the week ahead, you could be forgiven for thinking summer’s been extended. The heat looks likely to continue well into the second half of the month.

Graphic courtesy of the Northeast Regional Climate Center.

Weather Recap

With both the month of August and meteorological (June-July-August) 2021 in the record books, both will be noted locally for being warmer and wetter than what ones normally sees in Ithaca and Tompkins County. August closed with an average temperature of 70.7°F at the Northeast Regional Climate Center’s observation site on Dryden’s Game Farm Road, 3.3°F above normal and 16th warmest in the 129 years of records. Across the region, just about everyone was running above normal, and Syracuse, Buffalo and Caribou, Maine had their warmest Augusts on record.

Graphic courtesy of the Northeast Regional Climate Center.

On the precipitation side, the 6.24″ of rain received in August was also well above normal (3.77″), and the 9th wettest August recorded in Ithaca since valid records began in 1893. With the exception of Northern New England and the shores of the Great Lakes, most of the region was wetter than usual. 26 of 35 primary weather observation sites were wetter than normal, and 11 had “Top 10” wettest Augusts.

Graphic courtesy of the Northeast Regional Climate Center.

Seasonally speaking, with an average temperature of 68.7°F, this past summer clocked in at about 1.2°F above normal and at a tie for 32nd in Ithaca’s 129 years of records. This seems to be modest compared to much of the Northeast and Mid-Atlantic. 31 of 35 of the primary weather observation sites had a “Top 20” warmest summer, and 26 of 35 had a “Top 10” hottest summer. In fact, Boston had their hottest summer on record since records began at their current site in 1936, while Syracuse and Buffalo had their second-hottest summers on record. The only notable “cool spot” is Albany, which likely isn’t real. The Albany site has had an artificial cold bias because the temperature sensor hasn’t been working properly since before July 2020.

Graphic courtesy of the Northeast Regional Climate Center.

Meanwhile, the same summer period received a hefty 16.98″ of rain, making summer in the city of gorges the 6th wettest in those 129 years of record-keeping. 29 of 35 primary weather observation sites were wetter than normal, and 11 had “Top 10” wettest Augusts, with Huntington, West Virginia reporting its wettest summer on record.

This week ahead looks to be a continuation of that warm and wet weather pattern, with some potential sever weather risks, as we’ll cover below.

Your Weekly Weather

Pop-up showers and thunderstorms continue to develop across Upstate New York as a cold front that had been moving southward from a Canadian low is now stalling out, providing a channel of instability for the development of convective precipitation. Cloud cover will continue to thicken as the front slowly shuffles overhead this evening into tonight, and temperatures have topped out in the mid 70s, a few degrees cooler than initially forecast as those clouds thickened earlier than anticipated.

Graphic courtesy of NWS Binghamton

The big concern heading into tonight is a squall line currently over Michigan and moving eastward at a rapid clip. This line is expected to hold together and potentially strengthen with the help of the cold front’s instability. This will likely make it through Tompkins County and surrounding areas in the 10-11 PM timeframe, with areas west of Ithaca being a little earlier, and areas east a little later. The primary risks here are straight-line damaging winds in excess of 70 MPH and torrential downpours leading to flash flooding. Being at night time also poses an enhanced risk because it’s a lot harder to see a downed tree or a flooding roadway in the dark.

As always when severe weather is on its way, take precautions. Secure or stow away any outdoor objects that might become airborne, and avoid parking under trees. Avoid traveling late this evening if possible, and if you do have to travel, give yourself a lot of extra time and drive more slowly and carefully so you have more time to react if there is debris or flooding on the road. Those in urban areas or near streams should check to make sure nearby stormwater drains are clear and sump pumps are working. Some scattered storms are possible behind the squall line overnight, with the risk not abating until daybreak. Lows tonight will be in the low 60s.

With that cold front draped overhead from west to east and just a little to the south of Ithaca, Monday will be unsettled, though the drier, more stable air north of the frontal boundary should limit the development of showers and thunderstorms locally. Expect mostly cloudy skies, a light northwest wind, and highs in the mid 70s. A weak shortwave (pulse of instability) will ride along the front Monday night, allowing for a chance of showers overnight, though any new rainfall amounts will be light with less than one-tenth of an inch expected. It will be mostly cloudy Monday night, with lows around 60°F.

The cold front edges back to the north of Ithaca by sunrise Tuesday morning, which will make for a summer-like scenario as winds crank up from the south. As temperatures climb into the mid 80s and dewpoints into a very muggy low 70s, all that unstable air will allow mostly cloudy skies to give way to pop-up shower and thunderstorms for the afternoon and evening, some of which could be quite strong. These will die back with the loss of daytime heating Tuesday night, but with the nearly stationary front still providing some instability, showers will continue through the night Tuesday, with a very humid night in store and lows in the upper 60s.

Wednesday will be another warm and muggy day, though a more westerly breeze ahead of another storm system centered over Canada will moderate temperatures to highs around 80 °F ; it will be very muggy, however, with near-overcast skies and rounds of showers and thunderstorms throughout the day, with some risk of severe weather directly ahead of the front during the late afternoon and evening hours. The front should move through by around sunset, allowing for quieter conditions to settle in by late evening. Lows Wednesday night into Thursday will be in the low 60s.

Behind the front, the incoming air mass for Thursday is less humid and cooler, but not by much, as the high pressure system will be drawing the air in from the Carolinas and Atlantic Ocean. Dewpoints will still be on the muggy side in the mid to upper 60s, and high temperatures will make it into the upper 70s. This somewhat unstable setup will allow for some scattered convective showers and thunderstorms during the late afternoon and evening, mixed among the otherwise partly cloudy conditions – these looks to be fairly widely scattered, and by no means a washout. Thursday night will see a chance of showers early, followed by partly cloudy skies as the atmosphere settles. Lows Thursday night will be in the mid 60s.

A coastal low will develop Friday, and a few showers could make it in from the edge of its circulation during the afternoon and through the evening, though any new rainfall amounts should be modest. It will be partly cloudy with highs in the low 80s. Friday night will see a few showers, primarily south and east of Ithaca, with partly cloudy skies and lows in the mid 60s.

Next weekend is looking warm and dry as a new bubble of high pressure builds in from the southwest. Plan for partly cloudy skies both days with highs in the low 80s and lows in the low 60s.

Graphics courtesy of the NOAA Climate Prediction Center.

Extended Outlook

The unseasonable warmth is expected to continue into the end of the month as the large ridge in the jet stream persists over the central and eastern United States. This ridge will pump moist air from the Gulf of Mexico northward, allowing for wetter-than-normal conditions across the Mississippi River Valley and Great Lakes, something that the Southern Tier will be on the periphery of. Medium-range models indicate this warm setup is likely to continue into October.

Brian Crandall

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