Heat dome shatters records across western states

After breaking numerous records in the western United States on Thursday, the season’s first major heat wave continued Friday, scorching cities from Texas to California. The hazardous heat should gradually ease this weekend but will persist in portions of Texas and Oklahoma.

While cities in the south sweltered, Spokane is ready for pleasant, summerlike weather through the weekend, with highs in the 80s with plenty of sunshine and overnight lows in the 50s. The hot spots are forecast to be Moses Lake and Lewiston at 90 degrees on Saturday.

The highs should dip back into the mid-70s next week, according to the National Weather Service.

The sprawling heat dome setting scores of records Thursday including in Sacramento, California, Phoenix and Las Vegas, which matched its earliest high of at least 110 degrees.

More than 25 million people from California’s Central Valley to Texas remain under heat alerts on Friday. The most extreme temperature forecasts triggered the highest levels of the National Weather Service’s HeatRisk forecast, which rates the danger to human health.

Officials urged people to be safe in the heat by limiting their time outdoors, staying hydrated, wearing lightweight and light-colored clothes, and never leaving children or pets unattended in vehicles.

For a second consecutive day, the heat registered at the highest level of an index that measures the influence of human-caused climate change.

Hottest spots

Forecasters predict the worst of the heat to stay centered on the Desert Southwest, California’s Central Valley, and western and southern Texas on Friday. This weekend, the heat is expected to ease in central California but persist across portions of the Desert Southwest and Texas, while briefly spreading into parts of Oklahoma.

Notable calendar-day record highs that were either broken or tied Thursday include Death Valley, California (122); Needles, California (115); Phoenix (113); Las Vegas (111); Fresno, California (107); Palmdale, California (103); Amarillo, Texas (102); Bishop, California (102); Sacramento (101); Kanab, Utah (101); Reno, Nevada (98); and Flagstaff, Arizona (91).

Here is a state-by-state roundup of forecasts and records tied or broken:

Arizona

Phoenix was forecast to reach near 110 degrees on Friday after climbing to 113 on Thursday, beating the previous calendar-day record of 111. Only slightly cooler highs of 103 to 108 are expected Saturday through Wednesday.

Temperatures in Tucson were forecast to climb to near 105 on Friday and Saturday before slightly cooler highs near 100 Sunday and Monday, then warming to near 105 again Tuesday and Wednesday.

California

Death Valley was forecast to reach 121 degrees on Friday and 118 on Saturday, short of the record high of 123 for both days, after setting a calendar-day record with a high of 122 on Thursday.

In central California, Fresno and Bakersfield are forecast to reach near 105 on Friday, registering a Level 3 out of 4 HeatRisk, before cooling off to the mid- to upper 90s this weekend. But then they could soar past 100 again by Tuesday and Wednesday.

Nevada

Temperatures in Las Vegas are forecast to reach near 110 degrees on Friday after hitting a record 111 on Thursday. Thursday’s minimum temperature of 85 was 2 degrees warmer than the previous warmest minimum for the date.

The city’s HeatRisk forecast remains at a Level 4 through Saturday, which is described as “rare and/or long-duration extreme heat with little to no overnight relief.” While cooling slightly, Las Vegas should remain several degrees hotter than normal into next week, with forecast highs of 103 to 108 Saturday through Wednesday, compared to an early-June average high in the upper 90s.

In nearby Henderson, a blacktop surface registered a temperature of 162 degrees on Thursday. “When it’s this hot outside, blacktop & sidewalks can turn into frying pans in the afternoon, which is why it is best to walk your four-legged friends in the morning hours when it is cooler,” the National Weather Service in Las Vegas said on X.

New Mexico

Albuquerque was forecast to reach a record-matching high of 100 Friday and Saturday, both days registering as a Level 3 HeatRisk, after hitting 100 for the first time this year on Thursday. That was one degree short of tying the record for the date. Daytime highs should cool off to the low 90s and upper 80s on Sunday and Monday.

Forecast highs in Roswell are near 105 degrees Friday and Saturday, right around the calendar-day records of 105 to 106, before cooling to the mid-90s on Sunday.

Oklahoma

Oklahoma City and Tulsa are forecast to reach the mid- to upper 90s on Saturday, briefly reaching a Level 3 HeatRisk, before cooler daytime highs in the upper 80s Sunday.

Texas

El Paso was forecast to reach 106 degrees on Friday and 103 on Saturday, both days registering as a Level 4 HeatRisk. Friday’s high could come close to the calendar-day record of 108. Temperatures should then top out closer to 100 Sunday through Tuesday.

Daytime highs were forecast to reach near 100 on Friday and Saturday in Amarillo, where the HeatRisk is at a Level 3. The city tied its calendar-day record of 102 on Thursday, which also stood as the record to beat for Friday. Much cooler highs in the 80s and 70s are expected Sunday through Tuesday.

Amarillo and nearby Pantex both experienced what are known as heat bursts on Thursday, when temperatures spiked approximately 10 to 15 degrees in just a few minutes as winds gusted underneath dying thunderstorms.

Heat dome moved north

The ongoing heat wave is a direct result of a high-pressure heat dome that has scorched Mexico for weeks – resulting in the country’s hottest and driest May on record – before expanding north and west into portions of the United States this week. Such heat domes suppress clouds and compress the air beneath them, causing the air to heat up.

For the second day in a row, Climate Central’s Climate Shift Index for Friday had reached a Level 5 across much of the Southwestern United States. That is the index’s highest level, indicating that human-caused climate change has made such heat five times as likely.

The Spokesman-Review contributed to this report.