Sunshine and comfortable temperatures will settle across the Finger Lakes and Central New York on Friday after patchy morning fog clears from the valleys. High pressure will keep the region dry through tonight, with afternoon highs mainly in the low to mid-70s.
Warmer and more humid air will return Saturday before showers become more widespread Saturday night and scattered thunderstorms develop Sunday, according to the National Weather Service offices in Buffalo and Binghamton. The weekend will not be a continuous washout, but the timing and coverage of rain will vary considerably across the region.
Fog gives way to sunshine Friday
Mid- and high-level clouds will continue moving south and east early Friday, leaving mostly clear skies across much of the region. Areas of fog will be most common in the river valleys of the Southern Tier and parts of the Finger Lakes, including the Ithaca and Elmira areas, before visibility improves during the morning.
Most of the fog should lift by about 9 a.m. Sunny skies will then prevail through the afternoon, with light west to northwest winds generally staying below 10 mph.
Temperatures will reach about 72 degrees around Rochester and Syracuse, with readings near 73 in Geneva and the mid-70s around Ithaca and Elmira. Humidity will remain low enough for the afternoon to feel comfortable despite the full sunshine.
High pressure will move directly across the eastern Great Lakes and New York through Friday night. Skies should remain mostly clear, and winds will become light or calm in many locations.
That combination will allow temperatures to fall into the upper 40s and lower 50s in the colder valleys, while most communities settle into the low to mid-50s. Patchy fog may redevelop late Friday night into early Saturday, especially in the Southern Tier and other sheltered valleys.
Warmer air arrives Saturday
Saturday will begin mainly dry as high pressure moves east of the region. A developing southerly flow on the back side of the high will pull warmer and more humid air north, pushing afternoon temperatures into the upper 70s and lower 80s.
Highs are expected to reach around 80 in Geneva and Ithaca, 82 near Rochester and Syracuse, and the upper 70s around Elmira. South winds will increase to about 5 to 12 mph, with gusts near 20 mph possible in parts of the central Finger Lakes and Southern Tier.
Clouds will increase as the day continues. A few showers could reach the region during the afternoon, but much of Saturday should remain dry through at least early afternoon. The chance of rain will rise first across southern and western areas before expanding farther east and north toward evening.
An isolated thunderstorm cannot be ruled out late in the day, although the more organized period of rain is expected to wait until Saturday night. Any storm that develops could produce a brief heavy downpour as moisture increases across the region.
Rain becomes more widespread Saturday night
A warm front moving through New York will bring a broader area of showers Saturday night. Rain chances are highest across the Southern Tier, the central and eastern Finger Lakes and parts of Central New York, while coverage may be lower closer to Rochester and the Lake Ontario plain.
The exact placement of the heaviest rain remains uncertain. Forecast guidance indicates that narrow bands of heavier rain could develop closer to the track of low pressure south of New York, with the greatest potential focused toward northeastern Pennsylvania and the southern edge of the region.
Localized totals of 1 to 3 inches are possible where those narrow bands form, but that amount is not expected across the entire Finger Lakes or Central New York. The northern extent of the heavier rain remains one of the larger forecast questions heading into the weekend.
Instability will be limited Saturday night, keeping the thunderstorm chance low across most of New York. An isolated storm is more likely toward northeastern Pennsylvania and the Catskills. Overnight temperatures will remain much milder than Friday night, generally falling only into the low to mid-60s.
Scattered storms possible Sunday
A cold front will follow the warm front and cross the region late Saturday night through Sunday. Additional showers will be possible through the day, but breaks in the rain and clouds could allow temperatures to climb into the upper 70s and low 80s.
The timing of the front will shape the afternoon thunderstorm potential. If showers move out long enough for some sunshine to develop, the atmosphere could become unstable enough for scattered thunderstorms Sunday afternoon and evening.
Some storms could produce gusty winds and brief downpours, but severe storms are not expected at this time. The more humid air will also make Sunday feel noticeably different from Friday, with southwest winds ahead of the front shifting toward the west or northwest as it passes.
Rain chances may linger Sunday night, particularly if the front slows. Forecast confidence is lower on exactly how quickly showers clear the eastern Finger Lakes and Central New York, although cooler and drier air should begin spreading into the region behind the system.
Cooler weather returns Monday
Monday will bring a short break between weather systems as high pressure builds into New York. A cool northwest flow will keep afternoon highs in the upper 60s to around 70, several degrees below Sunday's readings.
A stray early shower cannot be ruled out before the weekend front fully departs, but most of Monday should be dry with increasing sunshine. The air behind the front will be dry enough to limit lake-effect cloud and shower development.
Monday night will be partly cloudy and cool, with lows mainly in the low to mid-50s. The dry stretch should continue into at least the start of Tuesday.
Midweek timing remains uncertain
Temperatures will rebound Tuesday as the high shifts east and southerly winds return. Highs are expected to range from the upper 70s around the Southern Tier to near 80 in the Finger Lakes and Syracuse area, with lower 80s possible near Rochester.
Another system approaching from the northwest could bring showers into north-central New York later Tuesday, followed by a broader chance of rain Tuesday night and Wednesday. Thunderstorms are possible where rain holds off long enough for daytime heating, but instability may be limited.
There is still substantial uncertainty over how quickly the next front moves south and whether it stalls across the region. A slower-moving boundary could prolong the rain and increase the potential for heavier amounts, while a faster passage would produce a shorter period of unsettled weather.
Check the latest forecast at the FingerLakes1.com Weather Center.
FingerLakes1.com is the region’s leading all-digital news publication. The company was founded in 1998 and has been keeping residents informed for more than two decades. Have a lead? Send it to news@fingerlakes1.com.