The first rain makes the roads slippery...greasy

. First measurable rain event of the season expected late tonight
through Thursday...

A low pressure system located along 130w will develop a cut off low
off the northern California coast tonight. This system will bring
unseasonably cool and wet weather to the San Francisco and Monterey
Bay areas tonight through Thursday. Rain chances will begin late
tonight over northern California... and will increase and spread
southward on Wednesday as the low approaches the coast. The best
chance of rain is from late Wednesday afternoon through Wednesday
night. Showers are expected to linger into Thursday and possibly into
Thursday evening as well. This weather system also has the potential
of producing isolated thunderstorms across the region... particularly
on Wednesday afternoon and Wednesday evening.

Rainfall totals through Thursday morning are forecast to range
from a quarter inch to a half inch across most of the area... to as
much as three quarters of an inch in the Santa Cruz Mountains and
as much as an inch in the Santa Lucia mountains above the Big Sur
coast in Monterey County.

Motorists are urged to drive with extreme caution once rainfall
begins. This will be the first significant rainfall of the season.
Several months of dry weather has allowed a film of oil to collect on
roads. Rainfall on top of that oily layer will initially result in
slippery driving conditions and increased stopping distances.