Steve Orr, James Goodman, and Brian Sharp

Democrat and Chronicle

Trees fell, waterways swelled and heavy thunderstorms dumped roughly an inch of rain in a span of 45 minutes on Monday evening, as the embattled Monroe County region went another round with Mother Nature.

"Things are starting to get nasty," said Hamlin Town Supervisor Eric Peters. "Right now, this situation is so fluid, things are changing moment to moment. It's been that kind of day."

The continued onslaught swamped roadways. The first tornado watch of the 2017 season in upstate New York blanketed much of the area on Monday evening. And the National Weather Service issued a flood watch for western and parts of central New York. All watches had been canceled by nightfall, but a flood warning was issued about 8:45 p.m. for Irondequoit Creek with officials expecting significant flooding in Ellison Park overnight and into Tuesday morning.

More: Will our tornado drought end this year?

An initial line of thunderstorms, packing winds of 70 mph, was at Monroe County's doorstep at 4:15 p.m. The weather service issued a severe thunderstorm warning at that time, and said downed trees and power lines and other property damage was likely. Peak winds at the airport measured 48 mph at 4:45 p.m., but damage reports of trees down in Medina, Orleans County, and Spencerport indicated gusts in the neighborhood of 60 mph, said Jon Hitchcock, meteorologist with the National Weather Service in Buffalo.

Gov. Andrew Cuomo issued a statement warning New Yorkers to beware, and utilities, including Rochester Gas and Electric Corp., said they were monitoring developments and preparing for power-restoration work.

At its peak, about 5,000 customers were without power in counties to the west and southwest of Rochester.

Monday's rains were expected to add to the woes of people who live or do business on the Lake Ontario shoreline and in low-lying areas near creeks and rivers prone to flooding. As of 6:15 p.m., the airport was reporting .8 inches of rain, Hitchcock said, with other areas measuring more than 1 inch, most of that falling in 30 to 45 minutes.

"The rain will be tapering off," he said, "so that flood risk should come down through evening hours."

But it doesn't end Monday. The National Weather Service is forecasting another significant storm Thursday through Saturday that could bring the region another 1 to 2 inches of rain. Given that the long-term average rainfall in May is 2.73 inches, the Rochester area could wind up with an entire month's worth of rain in a single week.

The entire week will be damp and blustery with below-average temperatures, more autumnal than spring-like, weather service meteorologist Jim Mitchell said.

"It's kind of like last year when we were stuck in the drought pattern," he said. "These kind of patterns feed off themselves. We’ve been wet. We’ll stay wet."

The months of March and April combined brought more than 9.5 inches of rain, making them the second-rainiest March-April period on record in Rochester. Like May, April began with a gusher of precipitation, triggering a sudden rise of the water level in Lake Ontario.

The lake is now at its highest level in 24 years. Hundreds of property owners on the shoreline have felt the effects, with increased erosion and flooding. When northeast winds pushed water onto the shoreline Sunday, waves crashed over breakwalls and into yards, basements and roadways.

Monroe County Parks Director Larry Staub said that all 21 of the parks under his supervision are open.

"Just be cautious when you go out there," said Staub.

Ontario Beach, he noted, was impacted quite a bit by Sunday's weather, with water covering parts of the beach at times and reaching the boardwalk. But the water has since receded, with 75 of about 100 yards of beach visible.

Irondequoit Creek in Ellison Park was at normal levels Monday morning.

All three county golf courses are open but only for those walking. Carts were not allowed because of the soggy weather.

Another windstorm forecast for Tuesday apparently will bring winds from the southwest and west, the weather service said Monday. That should not have a major impact on the Rochester-area shoreline, though property owners at the east end of the lake have already been alerted to looming problems there.

However, the storm system that is expected to bring heavy rain later this week could be accompanied by winds from the northeast or north, which would again pummel the shoreline here.

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