Thunderstorm Wind in San Diego County, California

A closed low over northern Baja created conditions favorable for the formation of high based convection across southern California. Thunderstorms initiated over the deserts in the afternoon and then quickly moved westward over the mountains and towards the coast. An inverted V signature was noted above the 950 mb level on the 00Z KNKX sounding that afternoon, indicative of the potential for thunderstorms to produce microbursts. Three elderly fishermen drowned after their overloaded, 12-foot motorboat capsized on Lake Henshaw while trying to outrun an approaching thunderstorm. Eyewitness accounts and observations support the idea that this thunderstorm may have produced a minor, sub-severe microburst. This was probably all that was needed to capsize the small, overloaded boat. A friend of the fishermen was the first to notice the capsized boat, however he did not actually see the boat flip over. It is still not completely known if the boat capsized before or after the thunderstorm moved across the lake.