Flash Floodings Possible Wednesday in Inland Empire

Showers and thunderstorms will likely develop Wednesday and raise the risk of flash flooding in much of Riverside County, including the Coachella Valley, as residual moisture clashes with increasing temperatures.

A National Weather Service flash flood watch for the mountains, the Coachella Valley and the San Gorgonio Pass near Banning is set to take effect at 11 a.m. and extend until 8 p.m. The valleys around Riverside were excluded from the advisory.

Highs of 96 to 101 degrees are forecast Wednesday for the valleys of Riverside County, as are highs of 88 to 96 degrees in the mountains, 101 to 106 along the San Gorgonio Pass near Banning, and 103 to 108 degrees in the Coachella Valley. Already high temperatures are expected to push a few degrees upward as the workweek progresses.

“Residual moisture and midday heating along the higher terrain is likely to drive strong thunderstorm development,” according to the weather service. “Weak steering flow with a drift off into the deserts will increase the risk of flash flooding through evening, especially near the desert slopes of the mountains.”

Forecasters said scattered showers and thunderstorms would be possible throughout the day, but would be most widespread during the late morning and early afternoon hours, and there will be a 40 percent chance of measurable precipitation.

Forecasters said areas in and below those that have burned recently would be more susceptible to heavy runoff and debris flows should strong thunderstorms develop.

Drier air from the Southwest is expected to move through the region Thursday and Friday, bringing with it fair to hot, but dry, conditions.

--City News Service