It was another one of those rare evenings around the San Francisco Bay Area. Scattered thunderstorms had lit up the night skies around the region on Monday, August 19, 2013.
Me and my cousin Gretchen planned a mini outing down to Gilroy, CA to enjoy what's left of our summer break. Coming sunset, we noticed an isolated thunderstorm had obstructed the sunset, as well as more incoming storm clouds from the east. The sunset had added color to the anvils of the incoming storm cells. By early evening, while driving back home to San Jose along U.S. 101 north, I saw a couple lightning strikes to the left of the developing isolated t-storm (the same storm that was growing that blocked the sunset). We stopped at around Morgan Hill, CA to watch the lightning. **Mind our screaming lol we were too excited** We also saw another lightning storm coming in from the east. Then by just after 9:30 p.m., we continued the trek up 101. More distant lightning was seen.
As we arrived to San Jose, CA, we finally encountered some pockets of rainfall...our first decent rain witnessed in weeks! Despite the rain, a Red Flag Warning was in effect until 11 am PDT Tuesday for thunderstorms with dry lightning for the East Bay and Santa Cruz Mountains. Shower & thunderstorm chances was to continue at least late Tuesday morning. Gusty and erratic winds and lightning are possible through the period. T-storms may initially be dry but should become wetter with time. Stronger storms may produce abundant lightning & small hail. Dry fuels along with the potential for abundant lightning may result in new fire starts even with the wet storms.
The lightning had continued, at least just west of San Jose by the late night hours and finally diminished by after midnight or so. It was an awesome evening here, weather-wise! Slow-mo's have been added to the best lightnings :)
The culprit for all these thunderstorms was a slow-moving area of low pressure in the mid-levels of the atmosphere, detached from the jet stream. This was basically a relatively cool pocket of air aloft, enhancing instability. Together with moisture, thunderstorms had flared in the West. An estimated 14,700 lightning strikes was recorded over a four-hour period! Keep in mind, the San Francisco metro averages only two days a year with thunderstorms, so this cluster of lightning, while offshore, was quite impressive for the Bay Area.
(Filmed mostly Monday evening, August 19, 2013 around Morgan Hill and San Jose, CA)