Mostly Mild, Mountain Thunder Possible

A fairly complex forecast is developing over the next 36 hours with the cool marine air playing the bigger role for most of the Bay Area. Low clouds with localized mist, or drizzle is possible near the coast and bay into Friday morning with temperatures mainly staying in the 70s to 80s inland thanks to fairly steady onshore winds. Inland valleys will still see the chance for a few 90s. This cool marine air is the epitome of what’s considered a “stable” atmosphere where cool air below and warm air above (temperature inversion) would normally not include any chance for thunder. Except in this situation where increasing mid-level moisture will increase instability especially over the higher terrain. This coupled with a small scale weather system providing some dynamic lift, maximized over the hills will warrant at least a chance for some isolated thunder over the coastal and inland mountains. Who has the best odds for this depends on who sees more available moisture aloft, right now it would appear the Central Coast and Sierra will see the bulk of it. It won’t take much however to fire off a few showers or isolated thunder when increasing moisture, increasing lift meets daytime warming to destabilize the atmosphere a little more. The window for opportunity appears to be late afternoon Friday into early Saturday morning. Christina and I will keep an eye on it for you! Enjoy your Friday! – Rob Mayeda