Memorial Day throws heavy rain at East Coast as excessive heat scorches South

After intense and deadly storms ravaged a large swath of the central United States over the weekend, Memorial Day weather woes will continue Monday – but with the diminished threat for extreme impacts this time around.

Powerful storms and suspected tornadoes were responsible for at least 18 deaths – including four children – when severe storms hit several states including Arkansas, Texas and Oklahoma overnight Saturday into Sunday.

Images of the aftermath showed piles of rubble, damaged cars and destroyed buildings. Severe wind and rain downed trees and power lines, knocking out power for more than 600,000 people across 12 states. The storms also delayed the 108th running of the Indianapolis 500 by about four hours on Sunday afternoon.

Some relief is in store as the storm system moves east Monday, as its more violent and extreme impacts are expected to subside.

On Monday, heavy rain is expected to soak parts of the East Coast, and while the chance of tornadoes is much smaller than what unfolded over the weekend, there is still a possibility of isolated tornadoes along the Interstate 95 corridor from Newark, New Jersey, down to the Carolinas.

Some major East Coast cities also face threats from damaging winds. Meanwhile, excessive heat will bake parts of the South with possibly record-breaking high temperatures as the unofficial start of summer gets underway.

By Tuesday evening, the storm front will shift into the Eastern Seaboard, according to the National Weather Service’s Storm Prediction Center.

“The boundary will create an area of showers and severe thunderstorms over parts of eastern Missouri and the Ohio Valley,” the center said.

There is a level 3 of 5 risk of severe thunderstorms for those areas as well as the Tennessee Valley through Monday morning, with associated hazards including frequent lightning, severe thunderstorm wind gusts, hail and a few tornadoes.

“There will be an added threat of EF2 to EF5 tornadoes and hail 2 inches or greater over parts of the Lower Mississippi/Western Tennessee Valleys,” according to the Storm Prediction Center.

Areas within the Upper Mississippi Valley and Upper Great Lakes, including parts of Wisconsin, also face threats from localized flash flooding due to heavy rain through Monday morning.

Downpours will also threaten Memorial Day plans along the Mid-Atlantic and into the Northeast. There is a level 2 of 4 slight risk of excessive rainfall over those regions from Monday through Tuesday morning, with flash flooding in low-lying and urban areas possible.

High temperatures to scorch parts of the South

High temperatures and an early season heat wave are expected to make for a sweltering Memorial Day holiday across parts of the south including southern Texas, the central Gulf Coast and southern Florida.

South Texas is under an excessive heat warning through Monday evening and more heat warnings and advisories are expected to be issued across the South.

Houston; New Orleans; Miami; Mobile, Alabama; Tampa, Florida; and Charleston, South Carolina, are some areas that could experience extreme warmth on Monday.

Temperatures in some locations will be at or near-record highs, with heat index readings possibly exceeding 115 degrees, the center noted. The heat index – a measure of how the body actually feels when it’s hot out – is forecast to reach around 110 degrees on Monday in Houston and 119 degrees in Loredo, according to the city’s National Weather Service office.

Nightfall may not bring relief in some areas. Overnight low temperature are expected to be 10 to 15 degrees above normal.

Such extreme, prolonged heat raises the risk of heat illness such as heat stroke, particularly for vulnerable groups such as children, adults with underlying health conditions, pregnant women and outdoor workers.

The risks of excessive heat – the most deadly form of extreme weather – are becoming more widespread as human-driven climate change drives warming global temperatures. During the warm season last year, heat-related illnesses accounted for a 20% larger share of emergency department visits than they did in the five previous seasons.

CNN meteorologist Elliana Hebert and CNN’s Joe Sutton contributed to this report.

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