Tropical Storm Flash Flood Watch in Effect

A flash flood watch remained in effect Tuesday in the Antelope Valley and the San Gabriel Mountains because of the threat of thunderstorms and the fear they might move over parts of the Southland at a languid, drenching pace.

"An influx of moisture from the remnants of former Tropical Storm Ivo will combine with light winds aloft to bring the potential for slow-moving thunderstorms across the Los Angeles County mountains and Antelope Valley, especially the eastern portions," the National Weather Service warned in an advisory.

"Excessive runoff from heavy downpours may cause rapid filling and overflowing of normally dry washes and small creeks, and low-lying areas."

The NWS warned of mud and debris flows if thunderstorms unleash rainfall on areas of the San Gabriels and the Antelope Valley denuded by wildfire, including the sites of the Powerhouse, Lake and Williams fires. The flash flood watch will remain in effect through Tuesday night.

Warm temperatures will accompany Tuesday's humid weather and partly cloudy skies, with the NWS forecasting highs  of 74 in Avalon; 77 in Newport Beach; 81 at LAX; 83 on Mount Wilson; 89 in Long Beach; 90 in Anaheim and downtown L.A.; 92 in San Gabriel; 94 in Burbank, Pasadena and Palmdale; 96 in Lancaster; 97 in Woodland Hills; and 98 in Saugus.