Because of the biblical rain* predicted for tonight and tomorrow, the public school districts of San Francisco, Oakland, and Marin have all cancelled classes for Thursday. Is this just what happens when it rains for real in California? As KQED is putting it, "We're going to have to check on the last time this happened."

I want to tell everyone to settle down, it's just a few inches of rain, but yes, 4 to 5 inches of rain could spell disaster for certain areas of the Bay, and as we saw just last week with 3+ inches (on average), there was plenty of flooding.

SFUSD Superintendent Richard A. Carranza says, regarding the decision to close, "I did not arrive at this lightly." He adds, "First and foremost, we don’t want to risk having our students injured or seriously delayed transporting to and from school. In addition to student absences, the storm could result in large numbers of staff absences, which could then lead to inadequate supervision of our students. Furthermore, power outages could affect the district’s ability to feed students’ school meals, among many other operational challenges."

Clouds are ominous over San Francisco this afternoon and heavy rains have already arrived in the lower Russian River vicinity.

Brace yourselves, everybody. And try to stay dry.

Previously: 7 Reasons To Love San Francisco In The Rain

* I was employing hyperbole for the sake of web humor when I initially used that phrase, not trying to incite panic, but yes, now everyone is panicking.