Cooler air is moving into the Finger Lakes and Central New York on Monday, bringing a breezy morning and a few spotty showers before sunshine takes over. Afternoon temperatures will stay in the 60s, a marked change from Sunday's warmer, more humid weather.
The break will be brief: Tuesday turns sunny and warmer, while a slow-moving front raises the chance of showers from Tuesday night through Thursday, according to the National Weather Service offices in Buffalo and Binghamton. Thursday currently looks like the wettest day for much of the region, though the front's exact position will determine when and where rain is most persistent.
Monday starts cool and breezy
A cold front is moving through Central New York early Monday after scattered showers crossed the region overnight. A few light showers may linger near the western Finger Lakes and the Interstate 90 corridor in the morning, including areas influenced by air moving over the warmer lakes. The showers should be widely scattered rather than a daylong rain.
Clouds may be more noticeable early in the day, especially where northwest winds carry lake moisture inland. Drier air arriving behind the front should thin those clouds by late morning or afternoon, leaving most areas partly to mostly sunny. Around Rochester and Geneva, the latest local forecasts put the best chance for a shower before about 8 a.m., with sunshine later.
The change in air mass will be easy to feel. Highs will generally reach the mid- to upper 60s in lower elevations, with lower 60s in higher terrain. The Buffalo office expects temperatures to run roughly 10 degrees cooler than Sunday across its area.
Northwest winds will add to the cooler feel, especially in open areas. The Binghamton office expects sustained winds of 8 to 15 mph with gusts of 20 to 25 mph across its region. Winds should ease toward evening as high pressure approaches.
The showers early Monday are a different system from the more organized rain chance later in the week. Once the remaining morning showers fade, high pressure is expected to keep the afternoon dry across most of the Finger Lakes and Central New York.
A chilly night, then a sunny Tuesday
Clearer skies and light winds Monday night will allow temperatures to fall quickly. Many places should drop into the 40s, with upper 30s possible in some of the colder Southern Tier valleys. The latest local forecasts show lows around 50 near Rochester and Geneva, but in the mid- to upper 40s around Ithaca and Syracuse.
Patchy valley fog may develop late Monday night and early Tuesday in the Southern Tier and parts of the Finger Lakes. Some of the coldest sheltered spots could dip into the mid-30s, but the Binghamton office says confidence in frost formation is too low to treat it as an established regional threat.
Tuesday begins cool, with any valley fog giving way to ample sunshine. High pressure will shift east and winds will turn more southerly, allowing temperatures to recover into the 70s for most communities. The latest local forecasts range from the mid-70s near Geneva and Ithaca to the upper 70s around Rochester and Syracuse.
Most of Tuesday should remain dry. A few showers cannot be ruled out farther west near the Niagara Frontier in the afternoon, but the next appreciable rain chance for the Finger Lakes and Central New York is expected to develop later as a front approaches from the Great Lakes.
Front brings a more uncertain Wednesday
Showers may begin to reach western areas Tuesday night as the front moves toward the region. The forecast is not for continuous rain everywhere: Rochester and Geneva have a chance of showers overnight, while the latest Syracuse forecast carries only a slight overnight chance and Ithaca remains mainly dry Tuesday night.
On Wednesday, the front is expected to sag south and slow down. That leaves showers possible in parts of the Finger Lakes, but Central New York may have more dry time. Rochester and Geneva have a chance of showers during the day, while Syracuse and Ithaca carry only slight chances in their current local forecasts.
Temperatures will continue to rise despite the cloud and rain uncertainty. Highs may reach the upper 70s or low 80s in Central New York and the southern Finger Lakes, while the forecast is in the mid- to upper 70s closer to Rochester and Geneva. The Binghamton office describes Wednesday's warmth as about 10 degrees above average for mid-September in its area.
The front's location is the key uncertainty. If it stalls farther north, showers could be more frequent in the Finger Lakes; if it settles farther south, a longer dry stretch is possible in some places. The front may shift back and forth, making a precise day-by-day rain line difficult to pin down this early.
Thursday has the broadest rain chance
Rain chances increase Wednesday night into Thursday as moisture gathers along the stalled front. A disturbance moving along it could bring more widespread showers and a few thunderstorms. The Binghamton office expects numerous to widespread showers Thursday; the Buffalo office also identifies late Wednesday night through Thursday as a period when broader rain could develop.
Thursday is forecast to be warm and more humid, with highs around the upper 70s to near 80 and dew points potentially rising into the upper 60s or lower 70s in Central New York. Clouds and showers should be more prevalent than on Tuesday or Wednesday. Current local forecasts put the chance of showers and thunderstorms at 70% around much of the region and 80% near Ithaca, though those probabilities do not mean rain will fall all day at every location.
No specific severe-weather threat is identified in the overnight outlooks for Thursday. The greater uncertainty is how long the front remains over the region and whether a passing wave of low pressure concentrates the rain in one corridor or spreads it more broadly. Periodic showers could continue into Thursday night before the front shifts south.
Drier Friday, with some weekend showers possible
The front is expected to move south of the region by Friday, allowing drier air to return. The current point forecasts retain a slight chance of early showers, then show at least partial sunshine later in the day. Highs should settle into the 70s, a little cooler than Thursday but still milder than Monday.
The weekend forecast is less settled between the two NWS offices. Buffalo expects high pressure to support mostly dry weather into the weekend, while Binghamton retains a chance of showers with additional fronts or disturbances nearby. Saturday carries a chance of showers in several current local forecasts, with highs generally in the upper 60s to mid-70s. Any rain chances appear more limited by Sunday, but the precise timing of those later disturbances remains uncertain.
Check the latest forecast at the FingerLakes1.com Weather Center.
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