Bay Area Lightning: Rare Storm Lights Up Sky, Sparks Power Outages & Viral Photos

Thunder rumbled awake across Northern California overnight as a sluggish tropical remnant drifted into the Central Coast, firing off hundreds of cloud-to-ground strikes that lit up skies from Santa Cruz to the East Bay, forecasters said Wednesday. The National Weather Service (NWS) confirmed the convective band first erupted near Monterey Bay around 4 a.m., then crept northward through the morning commute, tagging coastal hills with brief downpours before transitioning to “dry lightning” as surface moisture thinned. By midday, detectors had logged more than 700 strikes across the region, including pockets over San Jose’s Alum Rock foothills and the Diablo Range, where rainfall totals stayed below one-tenth of an inch. WHY THIS ROUND OF LIGHTNING MATTERS • Peak fire danger: Parched grasses left by last week’s record heat can ignite within seconds when bolts hit without soaking rain. CAL FIRE crews pre-positioned engines in Alameda and Contra Costa counties, labeling the threat “elevated” through Thursday morning. • Power disruptions: PG&E reported scattered outages in Morgan Hill and Fremont as strikes rattled distribution lines. Crews urged residents to keep phones charged and avoid downed wires. • Commuter impacts: Sudden cloudbursts sent oil-slick runoff across I-280 and Highway 17, triggering spin-outs that briefly slowed traffic; CHP warned of additional “hydro-planing bursts” through the overnight hours. WHAT TO EXPECT NEXT Meteorologists say the parent low will “pinwheel” across the Bay Area into early Thursday before weakening off the North Coast. The South Bay and interior East Bay remain the prime targets for another flare-up between 9 p.m. and 3 a.m. After that, models show a drying trend—briefly. A Pacific Northwest trough could sling a second, colder system toward the Golden Gate by Monday, again with isolated lightning potential. COUNTY-BY-COUNTY IMPACTS • Santa Clara: Best chance for additional strikes tonight; rainfall 0.05"–0.15". • Alameda/Contra Costa: Dry thunder likely; greatest wildfire ignition risk. • San Mateo/San Francisco: Fewer strikes but gusty outflow winds up to 35 mph may topple limbs on the Peninsula ridges. • North Bay: Minimal activity this round; keep watches up for Monday’s system. SAFETY AND PHOTOGRAPHY TIPS 1. Follow the 30/30 rule—if you hear thunder within 30 seconds of seeing a flash, head indoors for at least 30 minutes after the last rumble. 2. Avoid hilltops, metal fences and isolated trees; most Bay Area lightning fatalities have occurred in exposed parks and golf courses. 3. Want a dramatic shot? Use a tripod, set shutter speed to 5–15 seconds, and frame toward the southeast where cells are moving. Stay inside a vehicle or building while shooting through an open window. CLIMATE CONTEXT September lightning outbreaks are growing more common. NWS data show the Bay Area averaged 4.2 thunder-days per year in the 1990s; the 2020-2024 mean jumped to 6.7, largely driven by lingering tropical moisture and hotter inland temperatures that add instability. BOTTOM LINE Residents should keep weather alerts enabled, secure outdoor gear, and prepare for brief, intense electrical storms through Thursday morning. With fuels critically dry, even a single bolt could spark a wildfire—making vigilance as essential as rain gear in this rare Bay Area lightning show.