Weather

A large mass of cool air from Canada will be in control Tuesday from the eastern Great Lakes and the Mid-Atlantic coast to New England. This dry air is expected to dissipate by midweek.

A storm will continue moving across the Midwest. This will result in showers and thunderstorms from the upper Mississippi Valley to the lower Ohio and Tennessee valleys. Some of the storms may become severe in the afternoon and evening, with possible damaging gusts, hail, frequent lightning strikes and flash flooding. A few tornadoes could also develop across the region.

More showers and thunderstorms are in store for the Southeast, because of steamy air and a weak storm moving through the area. The storms are most likely to produce flash flooding and lightning strikes.

Most areas from the High Plains to the Rockies, the Great Basin and the Pacific Coast can expect dry weather and sunshine. As the Southwest monsoon has not yet developed, storms are unlikely to occur over much of the Rockies. A gusty wind may fan existing wildfires in the Northwest. The Pacific beaches will be cool, with morning clouds slow to burn off in some spots.

FOCUS: Heavy Thunderstorms Wednesday Afternoon

Thunderstorms are expected from the Ohio Valley to the Appalachians on Wednesday afternoon and evening. Some of the storms may be severe, with damaging winds and torrential downpours. Flash flooding may also occur.