ITHACA, N.Y. — The National Weather Service is advising caution if you’re in a flood prone area – there is significant risk of a flash flood event today and tonight.

Showers and thunderstorms with locally heavy rains will form and persist over the region today, lasting through the evening. With several inches of rain in the past few weeks, the soil is already saturated and it will be unable to absorb intense downpours and lead to significant runoff and flooding.

The areas that are expected to receive the heaviest rainfalls will be in the hills south and east of Ithaca, and Flash Flood Watches have already been issued for Chemung County, Tioga County and Broome County. Two to three inches will be possible in those locations, with locally higher amounts. Ithaca and communities to the north and west can expect 1 to 1.5 inches. Because these are “pop-up” convective storm cells, it is impossible to determine where exactly the heaviest downpours will be, but some areas will be at risk of significant flash flooding.

If you’re on the roads and encounter moving water of unknown depth, keep in mind the saying “turn around, don’t drown”. Six inches of fast-moving water can sweep a person off their feet. One foot of moving water can push a car off the road, and 1.5-2 feet is capable of washing away most SUVs, trucks and vans. Most flash flood fatalities occur in vehicles. Get to areas of higher ground and stay informed of weather and flooding updates through radio, internet, or whatever means you have available.

Areas most at risk for flash flooding include low-lying areas and smaller streams and creeks, where rapid runoff from fresh rain may swell and overflow their banks. Travel through and those living near streams and creeks should be mindful of potential road washouts/closures and basement flooding.

The risk of flash flooding should decrease as the region of greatest instability and heaviest rains shifts northeastward Monday night into Tuesday. Showers and thunderstorms are expected to persist through the week, though the flash flooding risk should subside. The Voice’s regular weekly weather forecast will be published later.

Brian Crandall

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