Posted July 16, 2018 6:54 p.m. EDT
Showers and thunderstorms on Tuesday will extend from New England to the mid-Atlantic, Southeast, lower Mississippi Valley and parts of the central and southern Plains. Many of the storms will develop along the leading edge of a cooler, less humid air mass in the East. Over the central states, the rain and storms will occur along the boundary between hot and cool air. Any of the storms in the east, south and central states may cause isolated flash flooding. The greatest chance of storms with damaging gusts will be in the Northeast, along Interstate 95.
A large and expanding mass of dry air will bring sunshine, low humidity and cooler conditions to much of the Midwest. The air is expected to expand to the Northeast by midweek. Searing heat is projected to continue over much of Texas. Dust blowing thousands of miles west from the Sahara will bring a hazy sky to the region.
A few storms are expected over the Rockies and the Southwest deserts, mainly in the afternoon, as a result of the North American monsoon. Much of the West Coast can expect dry weather to continue, with the highest temperatures in the Northwest. Humid air will accompany the heat in Southern California.
Focus: Heavy Thunderstorms on Wednesday
Thunderstorms are expected across parts of the northern Plains on Wednesday as a weak storm system approaches the region. The storms may be severe from southeastern South Dakota to southeastern Nebraska, especially later in the afternoon.