It doesn't look like it now at almost 2 PM, but the National Weather Service is saying there's a 100% chance of heavy rains late tonight and on into Thursday.  Precipitation is predicted to be less than a quarter inch during that time, and it's all supposed to be gone by tomorrow afternoon.  Cold winds are also threatening, and if you're traveling, rain will keep on thru Thursday on north-facing slopes (i.e. the Grapevine).