FL1 FORECAST: Spotty showers fade today before heavier rain Thursday

Spotty showers early Wednesday will give way to a mostly dry and warm day across the Finger Lakes and Central New York, but a more organized round of rain and thunderstorms is expected Thursday.

Most of Wednesday trends dry

A band of showers moving across Central New York early Wednesday may be followed by another brief round during the morning. A few thunderstorms are also possible, mainly before midmorning in parts of the Finger Lakes, while Syracuse is more likely to remain cloudy with only a limited rain chance.

The early activity should weaken as the morning progresses. Forecasters expect the weak cold front to drift south during the afternoon, but any additional showers are likely to be isolated and their exact location remains uncertain. Most of the day should be dry.

Clouds will remain common, though breaks of sun are possible from Rochester through the Finger Lakes and into the Southern Tier. Highs will range from the mid-70s to around 80, including about 76 in Rochester, 77 in Geneva and near 79 in Ithaca and Syracuse.

Winds will turn from west or southwest toward the northwest and north behind the front. The shift will mark the arrival of slightly cooler air, but winds are not expected to become especially strong.

The front will settle near the New York-Pennsylvania line Wednesday evening, leaving an isolated shower or thunderstorm possible across the Southern Tier. Farther north, the chance for rain will begin to increase late at night as the boundary turns back north.

Overnight lows will stay mild, generally in the low to mid-60s. Rochester and Geneva are expected to fall to about 62 or 63, with similar readings around Syracuse and Ithaca.

Heavier downpours possible Thursday

Thursday will bring the most active weather of the next several days. A weak area of low pressure is expected to move along the front as it lifts north during the morning, followed by another cold front later in the day.

Showers and thunderstorms will become more numerous during the morning and afternoon. Rain chances are highest across the central and eastern Finger Lakes and Central New York, where the current forecast calls for likely showers and thunderstorms in Geneva, Ithaca and Syracuse. Rochester has a lower but still meaningful chance of rain and storms.

The atmosphere will hold unusually deep moisture for mid-September. That will allow showers and thunderstorms to produce heavy rain, even though the overall threat for severe weather remains low.

Some storms may repeatedly cross the same area if they line up with the slow-moving boundary. That could cause localized ponding in places that receive the heaviest downpours, but the corridor most likely to see that rain is still uncertain. It may remain closer to the state line or develop farther north into the Finger Lakes.

There is also a limited, conditional risk for a stronger thunderstorm in Central New York. That possibility depends on the fronts moving slowly enough for more instability to develop during the day. If the system moves through earlier, the chance for stronger storms would decrease.

Sunshine returns Friday

High pressure will bring a brief break from the unsettled pattern Thursday night through Friday night. Any lingering low clouds early Friday should give way to partly to mostly sunny skies, with no widespread rain expected.

Friday will be cooler than the previous two days. Highs will generally reach the upper 60s to low 70s, including about 69 in Rochester, 70 in Geneva and 72 in Ithaca and Syracuse.

Clearer skies and light winds Friday night will allow temperatures to drop more sharply. Lows are expected to range from the mid-40s in some sheltered parts of the Southern Tier and Central New York to around 50 near Rochester. Valley fog is likely in the Southern Tier, especially where Thursday's rain leaves the ground damp.

The colder pockets of the North Country could approach frost temperatures Friday night, but the main Finger Lakes and Central New York region is expected to remain above freezing.

Rain chances build again this weekend

Saturday should begin dry as the area of high pressure moves east. Clouds will increase, and the chance for showers will rise during the afternoon as a warm front approaches from the Ohio Valley.

Highs Saturday are expected to remain in the mid- to upper 60s, several degrees cooler than Wednesday and Thursday. Rain may arrive sooner in western sections, while much of Central New York could remain dry through at least the first half of the day.

The better chance for widespread rain will come Saturday night into Sunday morning. Current forecasts call for rain to become likely across the Finger Lakes and Central New York, with the highest probabilities centered from the Finger Lakes toward Ithaca and Syracuse.

A few thunderstorms could develop as milder, moisture-rich air moves north, though rain is expected to be the more common feature. Sunday highs should stay in the upper 60s to near 70 beneath considerable cloud cover.

Forecast confidence decreases later Sunday and into the start of next week. A frontal boundary may stall near the region while several weak systems move along it, creating the potential for repeated rounds of rain. The exact position of that boundary will determine where the steadiest and possibly heaviest rain develops, and that placement remains unresolved.

Showers may continue into Monday and Tuesday before the larger weather system moves through. Temperatures are expected to remain seasonably cool, with daytime highs mainly in the 60s and overnight lows from the upper 40s to mid-50s.