SAN FRANCISCO (KPIX 5) — A pool of unstable air is moving over the San Francisco Bay Area tonight, pulling in subtropical moisture and bringing in fast-moving but heavy rain showers.

More than 200 lightning strikes were reported in the Bay Area as of 11:00 p.m.

READ MORE: Big Sur Residents Told to Boil Water Due to Possible Wildfire Damage to Utility

It won’t be an all-night washout, but there is an increasing chance of scattered heavy showers and isolated thunderstorms through the morning commute on Friday.  It’s the lightning that has caught the attention of local National Weather Service meteorologists, who issued a Red Flag Warning for critical fire danger because of the lightning potential.

READ MORE: Hazardous Sneaker Waves Threaten San Francisco Beachcombers

KPIX 5 Weather Center

This is yet another not-so-normal rain chance this summer.  Typically, the Bay Area receives less than a quarter-inch of rain in June, July, and August combined.  Many areas received that in June, and it was the 6th wettest July ever (.09”) in San Francisco.  Cities that get caught under some of the heavier showers tonight may receive more than .10” by sunrise.

MORE NEWS: UPDATE: Air Attack, Calming Winds Aid Firefighters Battling Wildfire Near Big Sur; Containment Grows To 25 Percent

The low pressure area will exit to the east late Friday morning, and sunshine will likely return by Friday afternoon.