For more than a month, a blistering heat wave has scorched much of the Lower 48, reaching from the Pacific to the Atlantic and bringing triple-digit temperatures to nearly 70 million Americans. The parent “heat dome” isn’t going anywhere anytime soon, and will push the entire American continent to above-average temperatures in the coming weeks.
About 116 million Americans are included in heat advisories or excessive heat watches and warnings. That’s more than a third of the US population.
“Extreme heat can significantly increase the potential for heat-related illnesses, especially for those who work or participate in outdoor activities,” the National Weather Service warned.
Twin corridors of exceptional heat will dominate weather maps this weekend. In the desert southwest, it’s dry heat, but temperatures can still reach records. Across the South and Southeast, high temperatures will combine with strong tropical humidity, with heat indexes topping 110 degrees in spots.
The heat dome that is scorching North America is one of at least four major heat waves that have hit the Northern Hemisphere in the past week. Others helped obliterate previous records in the Atlantic Ocean, with Rome reaching a record of 109 degrees and Durban, China, setting a national record of 126 degrees. Simply put, the Earth’s temperature is warming, and significant events are already being driven into the recorded territory.
Warmth will extend inland from the Los Angeles County coast. Burbank could reach 101 degrees on Friday, just 1 degree shy of the record set in 2006. Nearby Palmdale will tie the record at 109. The city is likely to set a record high of 110 degrees on Saturday.
Las Vegas is expected to hit a daily record high of 114 degrees on Friday. It will probably hit 114 again on Saturday and tie the daily record. The city also hit 111 degrees on Thursday, marking the seventh day in a row that it has reached 110 degrees. 1961 saw a record 10 days in a row in mid-June. According to the local National Weather Service office, Friday had a 91 percent shot of reaching 110 degrees; 90 percent on Saturday, 68 percent on Sunday and 46 percent on Monday.
Phoenix is expected to hit a record high of 118 degrees on Friday, and Tucson should break records on Friday and Saturday with forecasts of 112 and 110, respectively.
In Texas, San Antonio, Corpus Christi and Houston will tie records on Friday, with each location at or above 100 degrees. Similar readings are expected to tie the records on Saturday as well.
Record temperatures are more the exception than the rule in Florida; Orlando is expected to drop 1 degree on Friday, but Miami should register a high of 97 degrees on Saturday. Heat index values, due to humidity, will hover around 105 degrees in the Gulf Coast states, but can rise to 110 degrees near the immediate coast.
Triple-digit highs could even reach the Canadian border on Sunday.
In the extended range, there are indications that a heat dome or force field of high pressure and warm, dry, sinking air will move toward New Mexico and intensify. A ridge of high pressure flattens and extends from west to east, eventually spreading over most of the country.
The National Weather Service’s Climate Prediction Center is aggressive in its forecasts, calling for above-average temperatures for nearly the entire country over the next two weeks.
Weather models agree; In fact, there’s a chance Phoenix will continue its 110-degree streak into August.
It is well established that the effects of human-induced climate change constructively overlap with natural chaos and randomness to provide heat events that increase in intensity, duration, and magnitude.