Heavy rain to transition to snow in Rochester region. See storm timeline

When and where will the heaviest rain hit? When will it switch to snow? A messy storm of rain, snow and wind will buffet most of New York state through Friday. Here’s a timeline of the storm forecast for our area from the National Weather Service in Buffalo.

Storm timeline for Rochester NY region

Wednesday: A flood watch remains in effect for Monroe, Genesee, Orleans, Wyoming, Livingston and Allegany counties through 2 p.m. Thursday. By 10:29 a.m., there was already more than an inch of rainfall in the Allegheny River and Upper Genesee River basins. About a half inch of rain had already fallen in the Rochester area. Flooding is possible where creeks and streams rise out of their banks or flooding could occur in poor drainage and urban areas. Also, a hazardous weather outlook is in effect through Friday.

Wednesday evening: Rain will continue periodically through 2 a.m. when there will be a mixture of rain and snow as temperatures drop. Less than a half inch of snow accumulation is expected in Rochester.

More:NY braces for incoming storm. Will it impact the Rochester region?

Thursday: The flood watch will lift, but not before most of the greater Rochester area will have received a total of an inch to an inch and a half of rainfall. Rochester will experience rain and snow showers after 1 p.m., though new snow accumulations are expected to be less than a half inch.

Thursday evening: Periods of snow as the temperature hovers around freezing, though new accumulations will be less than one inch.

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Friday: Snow will continue periodically before 2 p.m. before switching to rain and snow. New precipitation is expected to be less than a tenth of an inch.

Friday evening: Rain and snow is likely to persist before 2 a.m. before switching back to snow. Less than a tenth of an inch of new precipitation is expected.

New York state braces for spring storm

A late-season winter storm is bringing precipitation, including wet, heavy snow, and winds to large swaths of New York through Thursday evening. The storm is expected to drop up to a foot of snow in the North Country, Capital, Central, Mohawk Valley, Southern Tier and upper Mid-Hudson regions, and up to two feet in Adirondack and Catskill peaks. 

"Despite early signs of spring, we are closely monitoring a storm system that is expected to bring heavy snow, rain and gale force winds to parts of our state,” New York Gov. Kathy Hochul said in a statement on Tuesday. “It is critical that New Yorkers monitor their local forecasts and take proper precautions as the weather unfolds.” 

The heavy, wet snow could cause power outages and hazardous travel during the Wednesday and Thursday commutes in the affected areas. 

— Steve Howe covers weather, climate and lake issues for the Democrat and Chronicle and held a hummingbird in his hand when helping to band birds as a kid. Share with him at showe@gannett.com.