Independence Day could be a volatile one across the central, southern and eastern United States as the atmosphere looks primed to produce rounds of severe thunderstorms on Tuesday, AccuWeather meteorologists warn.
By far, the greatest risk for people spending time outdoors during the holiday and days later this week will be from lightning strikes. As a general rule, experts say if distant thunder can be heard, there is a risk of a lightning strike in the vicinity.
Forecasters urge that people move indoors at the first rumble of thunder for this reason. Picnic pavilions, tents and golf carts do not offer adequate protection from a lightning strike. Standing beneath a tree or on a porch can be dangerous as well.
Storms will be active across a huge swath of the eastern and southern United States from Tuesday afternoon to Tuesday evening. This zone will include areas from near New York City to eastern Arkansas and northeastern Louisiana. Some of the thunderstorms may become severe with flooding downpours, strong wind gusts and hail.
The more robust storms will pack frequent wind gusts between 55 and 65 mph. In the strongest storms, an AccuWeather Local StormMax
gust of 80 mph is possible — winds of that magnitude are above the minimum threshold for a Category 1 hurricane (74 mph).
It is possible that thunderstorms hold off until the late-day or early-evening hours at most of the beaches – although there could be a few exceptions. This will be due to a sea breeze that sets up a few miles inland and acts as a temporary buffer to the barrier islands. When the sea breeze weakens toward evening, thunderstorms are more likely to push through off the coast.
AccuWeather meteorologists believe that most of the thunderstorms from New York City to Philadelphia and Washington, D.C., will have pushed to the east by sunset. However, light winds and lingering moisture in the air around fireworks time could lead to hazy and foggy conditions that could potentially obstruct viewing conditions.
“There will be a pool of dry air to the west that may slide in just in time to prevent fog Tuesday evening, but that is not a guarantee,” AccuWeather Senior Meteorologist Dave Dombek said.
Clouds, showers and spotty thunderstorms may persist through the evening hours in central and eastern New England as well as in areas from southeastern Virginia to portions of the Interstate 20 and 85 corridors in the Southeast.
A large area of severe weather is likely over the wide open spaces of the Plains on Tuesday afternoon and evening.
“The July Fourth holiday may be marred by severe storms erupting from the foothills of the Rockies in Colorado and southern Wyoming to much of Wisconsin and the Upper Peninsula of Michigan,” said AccuWeather Meteorologist Alex DaSilva. Denver, Minneapolis and Omaha, Nebraska, are among the major cities at risk for severe weather Tuesday afternoon and evening.
“These storms are likely to produce damaging winds, hail and torrential downpours,” said DaSilva. “Localized flash flooding is possible, as well as a few tornadoes, in the strongest storms.”
While the intensity and coverage of thunderstorms will tend to diminish and shrink on Wednesday in the Eastern states, severe weather will remain a concern for portions of the central U.S.
The risk of severe thunderstorms on Wednesday afternoon and evening will extend from the High Plains of northeastern Mexico and eastern Colorado to western Kentucky, Indiana and the western portion of the Lower Peninsula of Michigan. These storms will be capable of unleashing flooding downpours as well as frequent wind gusts between 60 and 70 mph.
The strongest storms in this zone on Wednesday may produce hail and an AccuWeather Local StormMax wind gust of 90 mph. Some of the major cities that could be affected by powerful storms at midweek include Denver, Chicago and St. Louis and Kansas City, Missouri.
On Thursday, the risk of severe weather will continue in parts of the Plains, mainly from the western parts of Nebraska, Kansas and Oklahoma to the eastern parts of New Mexico, Colorado and Wyoming.
Meanwhile, thunderstorms will not be a problem for most locations west of the Rockies to the Pacific coast through the middle of the week. However, building heat and smoke from western Canada wildfires could make for dangerous conditions to be outdoors in part of the Northwest.
Produced in association with AccuWeather
Edited by Alberto Arellano and Joseph Hammond
