ITHACA, N.Y. — If you’ve stepped outside today, you might have noticed it feels distinctly summery. Temperatures have rapidly climbed into the upper 70s and there’s a rather muggy feeling to the air. Unfortunately, this heat and humidity is also a recipe for severe weather, and Ithaca and Tompkins County need to prepare for this evening, as short-range models increasingly suggests a widespread line of damaging thunderstorms will rake across our area.

An area of low pressure passes to our north, and in its counterclockwise flow, it has channeled warm, humid air into the Southern Tier. As the cold frontal boundary attached to that low approaches, it will destabilize the atmosphere by shunting that warm, moist air upward. Due to the heat and humidity and upper-atmospheric dynamics, there is an immense amount of energy for that destabilized environment to tap into. The result: rapidly developing and numerous damaging thunderstorms in a roughly SW-NE line across the Southern Tier, Finger Lakes and Mohawk Valley.

Graphic courtesy of NWS Binghamton.

The upper atmosphere isn’t showing much in the way of shear, so the primary risks with this event are straight-line damaging winds up to 70 MPH, damaging hail up to 1.5″ in diameter (ping-pong ball sized), flash flooding and one or two isolated tornadoes.

The highest risk will be between 5-7 PM for Ithaca and Tompkins County. Areas to the north and west will be timed a little earlier, areas south and east a little later. The line will weaken after sunset with the loss of daytime heating. A few isolated severe thunderstorms might developed ahead of the front.

As always when a line of damaging severe thunderstorms has a high chance of formation, take precaution. Large hail can damage vehicles and destroy plants, as well as pose a major risk of personal injury. Move plants and outdoor furniture inside, and park your vehicle in a sheltered area if possible. Straight line winds may cause outdoor belongings to become airborne, posing risk of injury. Move light objects inside as well. Be prepared for downed tree limbs, which may cause power outages and make road travel hazardous.

If near a creek or a low-lying area, make sure storm drains are clear and sump pumps are working properly. If water begins to rapidly pool, get to higher ground immediately. Do not attempt to drive over a road underwater, as it may be deeper than it looks, and could potentially disable a vehicle and/or sweep it off the road.

If a tornado warning is issued (generally, your cell phone or TV service will send out an emergency alert), seek shelter in a basement or interior windowless room of a sturdy building, or a ditch if no structures are nearby. Pay attention if severe thunderstorm, flash flooding or tornado warnings are issued, it means dangerous weather has developed and is moving into the area.

Further updates will be posted as they become available 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.