A heat wave is scorching America’s southern half as 4th of July approaches

Dangerous heat levels kicked in again Saturday for much of the southern United States as temperatures throughout the weekend were expected to reach a scorching 100 degrees Fahrenheit or even higher in several states.

Excessive heat warnings were in place for Arizona’s largest metro area, where Phoenix and surrounding communities were flirting with highs of 115 degrees Fahrenheit (46 degrees Celsius).

Meanwhile, Las Vegas got its first taste of triple digits on Friday and forecasters warned that warmer temperatures would be in store all weekend, ranging between 105 F and 120 F (41 C and 49 C) for much of the region. Clark County officials opened cooling centers for residents on Saturday.

Some cities in the southern reaches of New Mexico also were seeing triple digits. While cloud cover from isolated storms might help cool things off in the afternoon, forecasters warned that the storms would bring lightning and erratic gusts but not much rain, leading to elevated fire danger.

Josh Weiss, a meteorologist with the Weather Prediction Center in College Park, Maryland, said a ridge of high pressure that is expanding across the West and Southwest brings with it very warm to hot temperatures starting in California and expanding through the holiday and eventually into the Pacific Northwest by the middle of next week.

“We’re looking at temperatures that will be exceeding 100 degrees, maybe as high as 110 in parts of California and in the desert Southwest through the weekend and maybe even exceeding 100 degrees as it gets toward Portland, Oregon, and into the 90s into Seattle by late next week,” Weiss said.

By midafternoon Saturday, the National Weather Service had issued heat advisories or excessive heat warnings in Oregon, California, Nevada, Arizona, Texas, Louisiana, Arkansas, Mississippi, Alabama, Georgia, Tennessee and Florida.

The Weather Service says extreme heat and humidity significantly increases the potential for heat-related illnesses like heat stroke.

Weiss also said the Carolinas could be hit with intense heat through the Fourth of July.

New Orleans EMS Chief Bill Salmeron said city residents and those in town for the Essence Festival of Culture should drink double the amount of water they usually consume and avoid the sun when possible by wearing a hat and loose fitting or light-colored clothing. Several cooling centers also are open for those who might need to seek relief from the heat.

The National Weather Service in Memphis said large swaths of the mid-South could experience similar heat over the holiday. The heat index — which is what the temperature feels like to the human body when relative humidity is combined with temperature — was expected to soar to 105 F to 115 F (41 C to 46 C).

Meanwhile, in the upper Midwest and mid-Atlantic regions, Weiss said some areas were under significant wind and hail advisories.

Widespread thunderstorms and hail touched down in the St. Louis region Friday, leaving damage across several communities, KDSK-TV reported. More than 100,000 residents in Missouri and Illinois had utility service knocked out as a result.

In north Mississippi, a similar storm pushed through Panola County early Saturday.

“It moved out of the area pretty quickly though but more could form, bringing with it the potential for hail and damaging winds, later Saturday,” said National Weather Service meteorologist Andy Chiuppi.

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