ITHACA, N.Y. — For those who were missing the heat that was lacking from much of August (the humidity certainly wasn’t), a late-season summer swelter is on tap to ring out Labor Day Weekend and continue into mid-week. A Heat Advisory has been issued for much of the region for 12 PM to 7 PM Monday. Later in the week, a cold front will usher in more seasonable temperatures with plenty of sun for next weekend.
What a gorgeous Sunday! Clear skies and temperatures in the low to mid 80s across the area this afternoon. Enjoy!— NWS Binghamton (@NWSBinghamton) September 3, 2023
Summer's last hurrah arrives tomorrow through mid-week with muggy weather and highs in the upper 80s to lows 90s. #NYWX #PAWX pic.twitter.com/jHLQxtyBhU
Your Weekly Weather
The primary driver of our weather for the first half of the week will be a large and strong area of high pressure over the Deep South. In its clockwise flow, warm, moist air is being ushered into Upstate New York on westerly winds. This system will maintain control into Thursday night, when a low pressure storm approaches from the Western Great Lakes and begins to shunt the high out into the Atlantic as it moves east-southeast across the Eastern Great Lakes and Mid-Atlantic.
In the meanwhile, with highs in the low 90s over the next few days, dewpoints in the upper 60s and lower 70s, and ample sunshine, it will feel steamy and oppressive during the afternoon and early evening. The modest saving grace to all this is that the lower sun angle this time of the year generally means that temperatures stay at their peaks for shorter periods of time. However, high humidity slows down the air’s ability cool off, so the impact is somewhat negated.
For the rest of your Sunday night, expect a rather humid and partly cloudy overnight with lows in the upper 60s and a light south wind. Labor Day Monday will be a broiler of a day. Early cloud cover will diminish as the day progresses. With highs in the low 90s and dewpoints around 70, it will feel more like the mid to upper 90s, so stick to the shade, stay hydrated, and check on your friends and neighbors who may not have air conditioning and be more at risk of heat-related illness. Monday night will be clear, mild and humid, with lows in the upper 60s.
Tuesday is likely to be a little more humid as the high jostles slight further to the southeast. It will be sunny and temperatures will be in the low 90s again, perhaps a hair warmer than Monday, but dewpoints will be in the low 70s. This will result in the heat index reaching the upper 90s, so more Heat Advisories are likely for Tuesday. Tuesday night will be mostly clear and humid with lows in the upper 60s in Ithaca, and perhaps a degree or two cooler in the outlying areas.
Heading into Wednesday, the core of the high will still be in the same general area of the Deep South, so it’ll be another sunny, hot and humid day, with highs in the low 90s and the heat index in the mid 90s. Wednesday night will see some cloud cover build in ahead of the low to the west, but it will stay rainless, with partly cloudy skies and lows in the upper 60s.
The cloud cover will gradually increase as Thursday goes on, and as the leading edge of the low’s circulation approaches, destabilized air will result in afternoon and evening showers and thunderstorms. It will be humid with highs in the upper 80s. Thursday night will see mostly cloudy skies, with showers early, and perhaps fewer shower cells towards Friday sunrise with the passage of the low south of Tompkins County. Lows will be in the mid 60s.
Friday will see reinvigorated precip as oceanic moisture is pulled into the circulation of the low as it passes ESE through the Mid-Atlantic states. Expect scattered showers, some evening thunderstorms, mostly cloudy skies, and highs in the low 80s. Friday night will see scattered showers early with lows in the lower 60s.
The winds will turn from the southwest to the northwest for Saturday, which will bring in a cooler, less humid air mass from Canada. A few instability showers are possible as the low stalls out along the Atlantic Coast, but it will be dry for most of the day. Highs will be in the upper 70s with mostly cloudy skies. Saturday night will be partly cloudy with a chance for showers and lows in the upper 50s, and as the low slowly moves away to the east, Sunday will be dry and mostly sunny with highs in the mid 70s.
Looking into mid-September, the large-scale weather pattern calls for a pronounced ridge in the Western United States and extended through the Great Plains, but a downstream trough in the midlatitude jet stream will result in somewhat cooler than normal conditions in the Northeast and Eastern Great Lakes. with the strongest portion of the jet passing southeast from the Upper Midwest to the Southern Appalachians, precipitation will be concentrated near and along this path, while locally, further from the prevailing storm track, precipitation is expected to be near-normal.