SAN DIEGO - A protracted hot spell combined with gusty winds and low humidity levels prompted the National Weather Service Thursday to extend a Red Flag warning for local mountain and desert locales by 24 hours, to 9 p.m. Friday.
The alert indicates imminent potential for "extreme fire behavior" and calls on the public to exercise care to avoid increasing the combustion risks.
An ongoing slow cooling trend is expected to lead to coastal and inland valley temperatures topping out in the high 70s Thursday afternoon, up to 10 degrees lower than they were Wednesday, the NWS advised.
The mercury will reach the high 80s in the western valleys, the upper 90s in the foothills, the mid-90s in the highlands and as wilting as 112 in the deserts, meteorologists predicted.
Authorities advised the public to guard against potentially serious heat-related ailments by staying hydrated; avoiding unnecessary outdoor labor; checking on neighbors and relatives, especially the elderly; and making sure to never leave children, seniors or pets in parked cars, which can quickly become death traps when temperatures are high.