Intense heat throughout the Inland Empire is forecast to continue another week, possibly shattering temperature records before the weekend, according to the National Weather Service.
“The warming trend will continue … with high temperatures on Thursday around 10 degrees above average for the mountains and deserts, and 10 to 15 degrees above average for the coast and valleys,” the NWS said Monday. “There could be a large number of records for warmest low temperatures tied or broken on Thursday and Friday.”
A Heat Advisory remains in effect for inland valleys, including the Riverside metropolitan area, until 10 a.m. Tuesday, but an Extreme Heat Warning becomes active immediately afterward, and that will remain valid until 8 p.m. Friday. In the Coachella and Palo Verde valleys, an Extreme Heat Warning is active from Monday to Friday night.
“The Heat Risk Index is expected to peak on Thursday, with major to extreme risk for the lower deserts, valleys (and) inland Orange County,” the Weather Service stated.
The triple-digit impacts in western Riverside County have been recurring since shortly after the Fourth of July period. Daytime temps were at or slightly above 100 degrees in Riverside most of last week.
The NWS’ surface prognostication charts indicated ridges of high pressure influencing weather patterns this week, including one ridge emanating from the Pacific Ocean, where surface temperatures are almost 1.5 degrees above normal due to a strengthening El Niño.
Surface low pressure systems are also present, contributing to monsoonal activity in the lower Arizona desert. Except for a slight chance Tuesday afternoon, no thunderstorms are currently predicted this week in the inland region, meteorologists said.
In Riverside metro, daytime highs are forecast to reach 103 Monday and Tuesday, with lows generally in the mid 70s nightly. From Wednesday to Saturday, daily temps will likely peak between 105 and 110 degrees, with overnight lows close to 80.
Across the Coachella Valley, highs will top out between 112 and 116 degrees all week long, with overnight temps in the low 90s.
The Temecula Valley will labor under conditions similar to Riverside metro, with the mercury peaking in the upper 90s Monday and Tuesday, while lows will settle in the low 70s at night. From Wednesday to Saturday, temps will peak at or just above 100, with lows in the mid 70s.