Quantitative Precipitation Forecast (QPF) is
the total rain that is forecast to fall within the time period.

The times on the maps below are based on Greenwich time.
(aka Zulu, Z, or UTC) (see below)

See also: Weather Prediction Center Interactive QPF page.
See also: NOAA QPF page.
See also: NOAA 24-hr QPF by Percentile.
See also: NOAA National Water Model Map.

Day 1 - 24-hour Cumulative Forecast Rainfall (QPF)
   Day 1 US QPF

Zulu Time Info

ZULU Time Standard
(Winter)
Daylight Savings
(Summer)
00Z 04:00 PM day before 05:00 PM day before
06Z 10:00 PM day before 11:00 PM day before
12Z 04:00 AM same day 05:00 AM same day
18Z 10:00 AM same day 11:00 AM same day
24Z 04:00 PM same day 05:00 PM same day

Day 2 - 24-hour Cumulative Forecast Rainfall (QPF)
   Day 2 US QPF

Zulu Time Info

ZULU Time Standard
(Winter)
Daylight Savings
(Summer)
00Z 04:00 PM day before 05:00 PM day before
06Z 10:00 PM day before 11:00 PM day before
12Z 04:00 AM same day 05:00 AM same day
18Z 10:00 AM same day 11:00 AM same day
24Z 04:00 PM same day 05:00 PM same day

Day 3 - 24-hour Cumulative Forecast Rainfall (QPF)
   Day 3 US QPF

Zulu Time Info

ZULU Time Standard
(Winter)
Daylight Savings
(Summer)
00Z 04:00 PM day before 05:00 PM day before
06Z 10:00 PM day before 11:00 PM day before
12Z 04:00 AM same day 05:00 AM same day
18Z 10:00 AM same day 11:00 AM same day
24Z 04:00 PM same day 05:00 PM same day

Days 4-5 - 48-hour Cumulative Forecast Rainfall (QPF)
   Days 4-5 US QPF

Zulu Time Info

ZULU Time Standard
(Winter)
Daylight Savings
(Summer)
00Z 04:00 PM day before 05:00 PM day before
06Z 10:00 PM day before 11:00 PM day before
12Z 04:00 AM same day 05:00 AM same day
18Z 10:00 AM same day 11:00 AM same day
24Z 04:00 PM same day 05:00 PM same day

Days 6-7 - 48-hour Cumulative Forecast Rainfall (QPF)
   Days 6-7 US QPF

Zulu Time Info

ZULU Time Standard
(Winter)
Daylight Savings
(Summer)
00Z 04:00 PM day before 05:00 PM day before
06Z 10:00 PM day before 11:00 PM day before
12Z 04:00 AM same day 05:00 AM same day
18Z 10:00 AM same day 11:00 AM same day
24Z 04:00 PM same day 05:00 PM same day



Multi-Day Cumulative Quantitative Precipitation Forecast

24-hour (1 Day) Cumulative Forecast Rainfall (QPF)
   US 1 Day QPF

Zulu Time Info

48-hour (2 Day) Cumulative Forecast Rainfall (QPF)
   US 2 Day QPF

Zulu Time Info

72-hour (3 Day) Cumulative Forecast Rainfall (QPF)
   US 3 Day QPF <

Zulu Time Info

120-hour (5 Day) Cumulative Forecast Rainfall (QPF)
   US 5 Day QPF

Zulu Time Info

168-hour (7 Day) Cumulative Forecast Rainfall (QPF)
   US 7 Day QPF

Zulu Time Info


    NWS Weather Prediction Center QPF source NWS Weather Prediction Center QPF sources About QPF products

-- Credits --

Images' source: National Weather Service

Page Managed by:

Hydrology Section
Contra Costa County Flood Control
  and Water Conservation District
255 Glacier Drive
Martinez, CA 94553
(925) 313-2000
floodcontrol @ pw.cccounty.us


Standard Time (Fall/Winter) - Subtract 8 hours from the UTC time (00Z = 4:00PM PST day before and 12Z = 4:00AM PST same day)

Daylight Savings Time (Spring/Summer) - Subtract 7 hours from the UTC time (00Z = 5:00PM PST day before and 12Z = 5:00AM PST same day).

Reading Time for the QPF Maps ( top)

Please note the date and time for which the maps are valid (see text in lower left corner text block on maps).

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 PST day before and 12Z = 4:00AM PST same day

Daylight Savings Time (Spring/Summer):* Subtract 7 hours from the UTC time 00Z = 5:00PM PST day before and 12Z = 5:00AM PST same day. A conversion table for the Zulu or UTC can be found at Zulu Time Table.

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