Sunshine and afternoon temperatures in the 70s will close out the holiday weekend across the Finger Lakes and Central New York, with dry weather holding through Tuesday before rain returns around midweek.
A cool start today will give way to mostly sunny skies, according to the National Weather Service offices in Buffalo and Binghamton. Temperatures and humidity will climb ahead of a cold front expected to bring showers and a chance of thunderstorms later Wednesday into Thursday.
Sunshine follows morning fog today
High pressure settling over the region will keep Labor Day dry. After dawn temperatures in the mid-40s to lower 50s, highs will reach the lower to mid-70s across Central New York, with afternoon readings generally in the 70s across the Finger Lakes and farther west.
Clear skies overnight have allowed temperatures to fall and shallow, patchy fog to form in some valleys. Fog has already reduced visibility around Elmira and Ithaca early this morning, while Syracuse is expected to remain clear of those restrictions.
The fog should lift by midmorning as temperatures rise. Sunshine will then dominate, with only a few scattered afternoon clouds expected across Central New York. Dry air over the region will limit cloud development through the rest of the day.
Winds will remain light under the high-pressure system. On Lake Ontario and Lake Erie, the Weather Service expects little wave action today, with those relatively quiet lake conditions continuing through Tuesday.
Neither the Buffalo nor Binghamton office listed New York watches, warnings or advisories in its early Monday forecast. Buffalo also listed no marine advisories at that time.
Another cool night, then a warmer Tuesday
Temperatures will fall back into the 40s and 50s tonight. Central New York lows are expected to range from the upper 40s to mid-50s, while cooler locations farther west could drop into the mid- to upper 40s.
Some thin, high clouds will cross the region tonight as a weak disturbance passes overhead. Those clouds are not expected to prevent another round of overnight cooling in the dry air.
Valley fog will be possible again overnight into Tuesday morning. The combination of light winds and cooling temperatures will favor fog in the same sheltered areas that have seen it during the holiday weekend.
Tuesday will remain mainly dry as high pressure continues to influence the eastern Great Lakes. Afternoon temperatures will rise into the mid- to upper 70s, beginning a warming trend that will continue Wednesday.
A weak front dropping into the St. Lawrence Valley and eastern Lake Ontario region could bring additional clouds there Tuesday. An isolated shower is possible in those northern areas, but confidence is low. The broader Finger Lakes and Central New York forecast remains dry through the day.
Humidity rises before Wednesday's rain
Warmer air will move into the region ahead of the next cold front. By Wednesday, Central New York highs are expected to reach the upper 70s to lower 80s, accompanied by a noticeable increase in humidity.
Dew points will climb well into the 60s, with mid- to upper 60s possible across the eastern Great Lakes. That will give Wednesday a muggier feel than the dry conditions of Labor Day.
Low pressure is expected to travel from the northern Plains into Canada, pulling a trailing cold front toward New York. Showers may develop ahead of the front itself as smaller disturbances move through the increasingly moist air.
Rain chances will begin increasing in Central New York Wednesday afternoon, then spread across the Twin Tiers Wednesday night. Across the eastern Great Lakes, the exact arrival of showers and thunderstorms remains uncertain between Wednesday afternoon and Wednesday night.
South to southwest winds will also strengthen over Lake Ontario and Lake Erie beginning Tuesday night and continuing Wednesday. Winds and waves could reach small-craft advisory levels, although that remains a possibility for the approaching system rather than an advisory already in effect.
Wednesday night brings the best rain chance
Wednesday night currently has the highest likelihood of rain as the front moves into the region. Thunderstorms could be embedded within the showers, but the potential for stronger storms remains limited and dependent on timing.
The Buffalo office says some severe weather potential could develop if the system arrives while daytime heating has made the air sufficiently unstable. The Binghamton office also notes limited instability, keeping stronger storm chances on the lower side. A widespread severe-weather event is not established in the current forecast.
Rainfall could vary meaningfully from north to south. Binghamton's forecast guidance shows a 50% to 75% chance of more than half an inch along the New York State Thruway corridor, where conditions may provide greater support for rain as the front passes.
Farther north, toward Tug Hill, the probability of an inch is nearly 50%. The Finger Lakes and Twin Tiers may receive less than those northern areas, with a few to several tenths of an inch a reasonable expectation from Wednesday night through Thursday.
Those amounts remain forecast expectations. The front's speed and the placement of the rain will determine how much falls at any particular location.
Showers may linger Thursday
Drier weather should begin returning Thursday, but the clearing process may be uneven. Forecast models still differ on whether the front briefly slows late Wednesday night or early Thursday before another disturbance pushes it through.
If that happens, showers could linger longer across the Twin Tiers and Interstate 88 corridor, with a more persistent chance farther east toward the Catskills. Some showers may also linger in the eastern Great Lakes before drying takes hold.
Winds over the Great Lakes should gradually diminish as high pressure begins building back in Thursday. Wave action will subside more slowly, with improvement continuing into Friday.
Dry weather returns Friday
Confidence is stronger that high pressure will bring dry weather back by the end of the week. Friday will be cooler across the eastern Great Lakes, and morning fog will again be possible in parts of the region.
The high-pressure system will keep moving, allowing warmer air to begin returning by Saturday. That would start another temperature upswing after the cooler conditions behind the midweek front.
Check the latest forecast at the FingerLakes1.com Weather Center.
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