A tornado watch is in effect from Delaware to Philadelphia to New York City to upstate New York as severe thunderstorms and torrential downpours pound the Northeast.

Thunderstorms on the Eastern seaboard have turned Tuesday into a messy travel day for tens of thousands of air travelers.

Severe thunderstorms are firing up from the Ohio Valley to the Mid-Atlantic and Northeast, including in major metropolitan areas along the Interstate 95 corridor. Some locations…