A squall line typically forms along or just ahead of a cold front and marks the boundary between air masses. Some squall lines stretch more than 1,000 miles and can travel similar distances in ...

Potent storms were hitting the northern U.S. on Monday, with a potential to turn into a derecho with hurricane-force winds. Tornados and hail could also be threats.

A squall line of severe storms blasted through the Bay Area late this afternoon — triggering a tornado warning, with confirmed damage in eastern Hernando County, and a rare flash flood warning ...

Squall lines and supercell thunderstorms are storms that have the highest chance of producing tornadoes. Kevin Deitsch, the ...

The line of storms slowly moves into central Maine midday, gaining strength and better organizing in the capital district. By mid to late-afternoon, storms impact the coastline.