SAN DIEGO (CNS) - Heavy downpours from thunderstorms could cause flash flooding in San Diego County mountains and deserts Sunday and monsoonal moisture was expected to cause hot, humid desert weather, the National Weather Service said.
Warm weather and scattered thunderstorms were expected Sunday afternoon and evening in the mountains, deserts and eastern inland valleys.
Excessive runoff from the storms could cause normally dry washes, creeks, small streams and low-lying areas to quickly fill and overflow, the NWS said.
NWS officials also reported an additional threat of rock and mud slides below steep mountain terrain and in recently burned areas. A flash flood watch will remain in effect until 7 p.m.
Monsoonal moisture to the east is expected to cause hot, humid conditions in the deserts, the NWS said. Daytime high temperatures could reach up to 118 Sunday and 116 Monday.
Hot days followed by warm, humid nights could limit the body's ability to keep cool, the NWS said. The NWS issued an excessive heat warning for the deserts to remain in effect until 10 p.m. Monday.
The warning stated hikers and campers who were unfamiliar with intense desert heat were especially susceptible to heat stroke or heat exhaustion. Pets could also be susceptible to the heat.
Those who planned to spend time outdoors should reschedule strenuous activities to early morning or evening, wear lightweight, loose fitting clothing, drink plenty of water, take advantage of shade and air conditioning and know the signs and symptoms of heat exhaustion and heat stroke.