Weather and Natural Disasters

As heat wave cooks eastern US, another one in store for southwest

A boy cools off at an open fire hydrant on a hot day in the Washington Heights section of New York, July 6, 2016.
Mike Segar | Reuters

As a severe heat wave suffocates much of the U.S. east of the Rocky Mountains, climate experts warned Thursday that more hot days are headed for parts of the Southwest.

Temperatures in that region already broke records in late June, and another string of exceptionally hot days are expected this weekend, according to a new report from the National Oceanographic and Atmospheric Administration.

"Right now we are looking at another heat wave, starting Friday and Saturday," for the greater Phoenix region, said Nancy Selover, State Climatologist at Arizona State University. Weather agencies are already issuing excessive heat warnings and temperatures of 112-116 degrees are expected.

This comes as a "heat dome," created by a high pressure system that traps hot air below, has already brought extremely high temperatures to much of the central U.S., as NBC News reported, and the wave is expected to reach the Northeast and Mid-Atlantic regions by the weekend. Some Midwestern cities have already felt temperatures above 100 degrees.

This year's global average temperature measurements are consistently breaking records, and if the trend continues, "2016 will be the third consecutive time we have had a record-warm year for the globe," said Jake Crouch, a climate scientist at NOAA's National Centers for Environmental Information, on a call with reporters Thursday.

Even the northerly state of Alaska has been "exceptionally warm" so far this year. The statewide temperature so far this year is 9 degrees above average, and it surpassed the previous record from 1981 by "quite a wide margin," Crouch said.

A previous severe heat wave spread across the Southwest around in mid-June. Temperatures reached 118 degrees in Phoenix, slightly below predicted temperatures, but still high enough to be some of the hottest days on record, said Selover.

High temperature records were set or tied across the Southwest, especially on June 20 and June 21. Three daily maximum temperature records were set in Flagstaff, Arizona; four in Tucson; and six in Phoenix, for example.

Temperatures in Death Valley, California, climbed to 126 degrees Fahrenheit, while the California city of Burbank climbed as high as 105 degrees.

Despite some brief snaps of torrential rain from the seasonal monsoon in Arizona and other parts of the Southwest over the last few days, Selover said, the region is already drying out again.

So far this summer the Phoenix area has had 20 days of 110 degree weather or hotter —a pproaching the record of 33 days in 2011, Selover noted.

From August to October, temperatures are expected to be above normal for the entire United States.