Severe Thunderstorm Warning: Exact Times, Impacted Counties, and Urgent Safety Tips You Need Now

Severe thunderstorm warnings have been hoisted from western Massachusetts to coastal Virginia today as a potent early-autumn cold front barrels down the Interstate 95 corridor. Meteorologists at the National Weather Service and NOAA’s Storm Prediction Center caution that the same volatile atmosphere fueling the squall line could also spin up brief tornadoes, especially near major metro areas such as New York City, Philadelphia and Washington, D.C. WHAT TO EXPECT THIS AFTERNOON AND TONIGHT • Timing: Storms will erupt in the Appalachians by early afternoon, race eastward into the I-95 urban belt for the evening commute, and reach the Atlantic before dawn Friday. • Main hazards: 60-80 mph wind gusts capable of toppling trees and power lines, penny- to quarter-size hail, cloud-to-ground lightning, and localized flash flooding where downpours “train” over the same neighborhoods. • Tornado risk: Although widespread outbreaks aren’t anticipated, any discrete cell that forms ahead of the main line could briefly rotate; SPC places more than 45 million residents under a Level 1 (marginal) tornado threat. WHY THE STORMS COULD TURN SEVERE A clash of mid-70s dew points and a fast-moving upper-level jet streak is generating pockets of energy (CAPE values near 1500 J/kg) along the boundary. As the front taps Atlantic moisture, thunderstorms will intensify rapidly, particularly where sun breaks through early cloud cover and allows additional heating. TRAVEL AND COMMUTER IMPACTS • Airports: Ground stops are possible at Newark, LaGuardia, JFK, Philadelphia International and Reagan National during peak arrival times. • Highways: Reduced visibility from torrential rain could slow traffic on I-95, I-76 and the New Jersey Turnpike; hydroplaning becomes likely when rainfall rates exceed one inch per hour. • Rail: Amtrak and regional commuter lines often impose speed restrictions when wind gusts top 60 mph; expect delays. HOW TO STAY SAFE DURING A SEVERE THUNDERSTORM WARNING • Immediately move indoors—preferably to an interior room on the lowest floor—when a warning is issued. • Avoid windows, plumbing and corded electronics; lightning can travel through wiring and pipes. • Never drive through flooded roadways; as little as 12 inches of moving water can sweep away most vehicles. • Keep multiple ways to receive alerts: NOAA Weather Radio, the FEMA app, and local TV or radio stations. LOOKING AHEAD The cold front exits the coastline before sunrise Friday, ushering in drier, less humid air for the weekend. However, residual moisture could linger over coastal New England, keeping scattered showers in the forecast through early Saturday. Behind the front, highs drop into the upper 60s to low 70s, offering a welcome taste of fall before a warming trend resumes next week. BOTTOM LINE If you live anywhere from Springfield and Hartford down to Baltimore and Norfolk, have a reliable way to get real-time updates and be prepared to act quickly. A severe thunderstorm warning means dangerous weather is imminent—take shelter the moment your phone or sirens sound.