Space Weather Prediction Center Watching Solar Storm Hitting Earth

More heavy rain was expected Saturday in the San Diego County mountains and deserts as parks officials near Borrego Springs said flash floods have washed out some roads.

Downpours from thunderstorms caused some flooding on roads in the Fish
Creek area of Anza Borrego Desert State Park. Spokewoman Sally Theriault said
park visitors were advised to stay off those washed out, muddy roads.

Meanwhile, the National Weather Service reported that the shock from Thursday's coronal mass ejection—a burst of solar wind and magnetic fields from an active region of the sun—passed the ACE spacecraft at 10:30 a.m. Pacific on Saturday.

The Space Weather Prediction Center added: "Now watch for the [coronal mass ejection] and then the imminent disturbance to the geomagnetic field. SWPC expects G1 (minor) and possibly G2 (moderate) geomagnetic storm levels over the next 36 hours."

Back on earth, a midday storm Friday dropped .92 inches of rain on Santa Ysabel, 0.82

inches in Ocotillo Wells. 0.63 inches in Ranchita and about a quarter-inch on
Mount Laguna. The storm also dropped 1.1 inches of rain in Thermal, at the
north end of Salton Sea.     

Thunderstorm clouds were expected to build up over the mountains throughout the day, and might get big enough to cause dangerous flash flooding in some areas, said National Weather Service forecaster Mike Watkins.

Residents in affected areas should be aware and monitor the forecast.

"Flash flooding is very dangerous and kills more people than anything else in
weather," Watkins said.

Residual moisture, afternoon heat and weak winds could support the storms' development this afternoon. The slow moving storms could drop very heavy rain which could lead to flash flooding on desert mountain slopes and adjacent desert areas, the weather service said.

Mud and debris flows in recently burned areas or on steep terrain could
block vehicles or make travel difficult on mountain roads, the weather service
said.

Excessive runoff from the thunderstorms could produce flooding in normally dry creeks and washes. Runoff from higher mountain slopes could lead to dangerous flash flooding far downstream from the heaviest rainfall.

The National Weather Service issued a flash flood watch, set to remain
in effect through Saturday evening, which means conditions could develop that lead to flash flooding.

—City News Service contributed to this report