June 21 (UPI) -- Las Vegas tied its record temperature of 117 degrees while under a massive heat dome over the U.S. Southwest, meteorologists said.
Dangerously high temperatures kept planes from flying in Arizona, prompted an electricity conservation alert in California and tied the record high temperature Tuesday in Las Vegas.
A "Flex Alert" issued by the California Independent System Operator asked users of air conditioners to conserve energy during the late afternoon beginning Wednesday. It noted the state's electrical grid is "under stress" and recommended that residents use fans and closed drapes to cool rooms instead of air conditioners. Electrical demand in the Cal-ISO region, which is 80 percent of the state, exceeded 44,000 megawatts on Tuesday; its record for a one-day total is 50,270 megawatts, set in 2006.
Sinking air beneath the dome of heat, coupled with low humidity, is causing temperatures to climb to 110 degrees and higher in many areas. Meteorologists regard it as a classic pre-monsoon phenomenon, indicating the heat will eventually be replaced by rain, the Weather Channel reported Tuesday. Heat alerts were issued by the National Weather Service across Arizona, western New Mexico, southern Utah, southern Nevada and portions of California.
Needles, Calif., tied its all-time official record high of 125 degrees on Tuesday. The temperature in Tucson, Ariz., was 116 degrees, one degree short of its historic record. In addition to Las Vegas, official record high temperatures were recorded in Phoenix, at 119 degrees; Yuma, Ariz., at 120 degrees; Palm Springs, Calif., at 122 degrees; Corpus Christi, Texas, at 100 degrees; Salt Lake City at 101 degrees and Denver at 99 degrees. The heat is expected to remain in the region until at least the weekend.
Dozens of flights to and from Phoenix' Sky Harbor International Airport were canceled Monday and Tuesday. Regional carrier American Eagle was particularly hard hit; its Bombardier CRJ planes can only operate in temperatures below 119 degrees. Airbus and Boeing planes have a higher tolerance for the heat, at 127 degrees and 128 degrees, respectively, to take off and land safely.
The temperature in Phoenix Wednesday is expected to reach 119 degrees. Officials have issued pleas to residents to keep pets hydrated and comfortable, and warnings of blowing dust in winds were issued throughout Arizona.