These National Weather Service (NWS) web sites provide nationwide and Bay Area quantitative precipitation forecasts (QPF) for several time periods. Here are some key maps to watch.

NWS QPF Web Page National Maps — This link takes you to the National Maps precipitation total page. Click on the "Day 1 QPF" map and it will enlarge. Study the map to find out the NWS's 24-hour QPF for the Bay Area. 
 
NWS 24-Hour National QPF Map — This link goes directly to the Day 1 QPF map on our Rain Gauge page.
(Thumbnail of the Day 1 QPF map is shown at the right for quick reference.)

NWS Bay Area QPF Map — This link allows you to look at the SF Bay Area page for similar information using the second link.

Please note the date and time for which the map is valid (see text in lower left corner).

The notation "12Z" means "12:00 Zulu Time" or noon Greenwich Mean Time (GMT) and "00Z" means "00:00 Zulu Time" or midnight GMT. Zulu time is also called "Universal Time Coordinated" (UTC), which is also the same as GMT.

For the Bay Area:

Standard Time (Fall/Winter) — Subtract 8 hours from the UTC time 00Z = 4:00PM 12Z = 4:00AM

Daylight Savings Time (Spring/Summer)* — Subtract 7 hours from the UTC time 00Z = 5:00PM 12Z = 5:00AM.  A conversion table for the Zulu or UTC can be found at http://www.noaanews.noaa.gov/hurricanes/zulu-utc.html.

* Note: In 2007, Daylight Savings time started and ended a month earlier.