Up to two more inches of rain could fall in Sonoma County during the next few days, adding to an already wet week. The National Weather Service says there is also a chance of isolated lightning strikes. Since the storm moved in on Tuesday, the most rain has fallen in the North Bay’s northwest and coastal regions. There is a 20-percent chance of thunderstorms mixed in with today’s intermittent rainfall. The final wave of the storm is expected to hit from tomorrow afternoon to early Saturday.