ITHACA, N.Y. — The saturated and soaking July we’ve had continues. With another long-duration moderate to heavy rain making its way into Tompkins County, the National Weather Service Binghamton forecast office has issued a Flash Flood Watch for Tompkins County and all surrounding counties through 2 AM Sunday.

A storm system working through the Ohio River Valley northeastward will usher in ample amount of moist, unstable air and widespread strong thunderstorms that will push through in waves and last for much of the day Saturday. The first wave of showers and storms will likely begin around sunrise and these waves of storms will cross the county throughout the day,before slowly weakening after sunset. Less widespread moderate to heavy rain showers will persist overnight Saturday into Sunday morning.

Graphic courtesy of NWS Binghamton.

Most of Tompkins County can expect another 1-2 inches of rain, with locally higher amounts of up to 2 inches of rain per hour possible in embedded heavy rain bands or thunderstorms. The primary concern at this time remains flash flooding as a result of so much rain being dropped upon already saturated soils, which have little capacity for further precipitation. Stormwater runoff will be quicker and more intense than would be expected otherwise. Some thunderstorms may produce damaging winds, and trees will be more vulnerable to toppling with the waterlogged soils.

Unlike a regular flood, flash floods are often more dangerous because they occur with little warning, often developing within minutes of a heavy rain. The heavy rain may be further upstream from the affected area, so do not assume that because the rain is light at your house that there is no risk. The quick nature of flash floods makes them much more powerful than regular floods, and they often become raging torrents of water, sweeping away everything in their path.

Graphic courtesy of NWS Binghamton.

For those traveling, areas between Syracuse and Cortland and parts of the Catskills in the Route 17 corridor are likely to be hardest hit. If you are out driving and come across a flooded road, do not attempt to cross it and find an alternative route. Even shallow water can damage and/or disable your vehicle, and floodwaters can rise very quickly. It only takes 6″ of fast-flowing water to wash a vehicle off a road. When traveling, give yourself extra space between other drivers and drive at a reduced speed due to the risk of hydroplaning over standing water.

Low-lying urban areas and areas with poor drainage (Fall Creek, West End, Southwest Ithaca, valley areas) will be most at risk from a flood, as well as homes and businesses adjacent to creeks and streams. Keep an eye on the television or carry your cell phone in case a flash flood warning is issued for your area, and be prepared to leave for higher ground if necessary.

Keep an eye out for flash flood warnings and further updates tomorrow morning from the National Weather Service Binghamton forecast office.

Brian Crandall

Brian Crandall reports on housing and development for the Ithaca Voice. He can be reached at bcrandall@ithacavoice.com.