Severe thunderstorms will march eastward across the northeastern United States, threatening to trigger damage and delays into Tuesday night.

An unusually strong push of dry, Canadian air will clash with high heat and humidity from the Mississippi Valley through the Ohio Valley, mid-Atlantic and into western New England.

Thunderstorms will congregate and gain strength along this dividing line on Tuesday afternoon and evening, stretching from Paducah, Kentucky, to Pittsburgh and Syracuse, New York.

Blinding downpours and winds high enough to knock down trees and power lines and toss around loose items will be the most far-reaching impact. Hail can also occur.

“A few of the strongest storms could even spin up a tornado,” AccuWeather Meteorologist Eric Leister said.

The thunderstorms will tend to move fast enough to limit the flash flood threat to localized areas. Ponding of water on roads and slight rises on small streams will be more common.

Stretches of interstates 64 70, 80, 81 87 and 90, may be slowed during busy commute times as downpours reduce visibility to near zero.

Those headed to Little League World Series games in Williamsport, Pennsylvania, should come prepared for stormy conditions and delays. Fans may need to evacuate the stands if lightning is nearby.

“Showers and thunderstorms will reach the I-95 corridor late Tuesday night; however, the risk for severe weather will be minimal as the storms lose their punch after midnight,” Leister said.

A drenching shower and a few rumbles of thunder will be more common from Washington, D.C., to Boston. Some of the showers could linger into early Wednesday and impact the morning commute.

Farther southwest along the tail end of the system, thunderstorms could turn feisty with torrential downpours, frequent lightning and gusty winds from central Arkansas westward through the Red River on Tuesday evening and overnight.

As cooler air settles into the Northeast for the remainder of the week, the threat for heavy and locally severe thunderstorms will sink southward toward southeastern Virginia and the Carolinas on Wednesday.