SAN DIEGO -- A summer heat wave is expected to keep San Diego toasty Wednesday and again heighten wildfire risks in the mountains and deserts, but big waves and strong rip currents could stymie plans to beat the heat at the beaches.
A fifth straight day of oppressive heat combined with winds of 20 to 30 mph with gusts to 40 mph and low humidity prompted the National Weather Service to extend a previously issued red flag warning until 9 p.m. Thursday. The alert indicates imminent potential for "extreme fire behavior."
A beach hazards statement warning of rip and longshore currents, which could potentially pull swimmers out to sea, surf of 3 to 5 feet with sets to 6 feet will remain in effect this afternoon through Sunday.
On Tuesday, thermometer readings ranged from the upper 80s in the mountains to the low 90s to 105 degrees in the inland valleys to 112 and 114 in the desert towns of Borrego Springs and Ocotillo Wells. The heat also broke daily high temperature records in Alpine, where the mercury hit 105, exceeding the prior Aug. 16 high mark of 101, set in 1992, and in El Cajon and Ramona, which each topped out at 104, surpassing milestones set last year of 102 and 103, respectively.
High temperatures this afternoon are expected to range from 75 to 80 degrees along the coast, 86 to 91 inland, 88 to 93 in the western valleys, 96 to 101 near the foothills, 93 to 99 in the mountains and 109 to 114 in the deserts.
Forecasters said any fires that develop amid red flag conditions would likely spread rapidly. Outdoor burning was discouraged.
"Gusty winds, very low relative humidity and warm weather will produce critical fire weather conditions over the mountains and deserts through Thursday evening," according to the weather service. "Activities that could produce sparks, or otherwise lead to fire ignitions should be avoided."
Residents were also advised to guard against potentially serious heat- related ailments, stay hydrated, avoid unnecessary outdoor labor and check on neighbors and relatives, especially the elderly. Authorities also warned against leaving people or pets in parked cars, which can quickly become death traps in high heat.
Forecasters said the region would gradually cool throughout the remainder of the work week, and high temperatures would be close to seasonal averages by the weekend.