Very Unusual, Forecaster Says : Lightning a Bolt Out of Blue for S.D.

Wednesday’s early-morning lightning show was part of an isolated thunderstorm that drifted in from the coast of Mexico, bringing clouds and a chance of showers that will linger over the county through tonight, forecasters say.

Lightning flashed and thunder boomed just after midnight Wednesday, but National City was the only spot in the county to record precipitation--0.03 of an inch--during the storm, said Robert Stitt, a National Weather Service forecaster.

Downtown San Diego has a 30% chance of rain today, Stitt said. He said Wednesday’s electrical storm was a rarity for the southwest portion of the county.

“It’s not very common. We don’t expect any more thunderstorms at Lindbergh Field, although some people may see lightning in the east and southeast areas of the county where the deserts are,” Stitt said.

Desert and mountain areas can expect widely scattered thundershowers accompanied by strong, gusty winds in the late afternoon and early evening.

The air mass is more moist than usual for July, accounting for above-normal humidity inland, Stitt said. In Kearny Mesa, Montgomery Field recorded 65% humidity Wednesday. Miramar Naval Air Station recorded 62%.

Stitt said humidity in the inland valleys usually ranges from 30% to 40% this time of year.

Patchy skies and some fog should remain over the coastal areas. Some light showers are expected to fall over the coastal strip and inland valleys today. Skies are expected to be mostly clear by Friday over the coastal strip and inland valleys.

Clouds and some light showers will block out the sunshine at beaches at least until the weekend.

Highs at the beach are predicted to range from 75 to 83 degrees. Inland valley highs are expected to range from 87 to 97 degrees with lows between 63 and 70 degrees. Along the coastal strip, highs should reach the mid-80s.