CNRFC/HPC Quantitative Precipitation Forecasts (QPF)

QPF forecasts are issued several times daily by the Hydrometeorological Prediction Center. QPF represents the total amount of liquid precipitation (in inches) expected during a specified period, typically 6 or 24 hours, at any point or basin in the forecast area. The river forecast models at the CNRFC use 6-hour QPF/QPE. QPE, or Quantitative Precipitation Estimate, represents the total amount of liquid equivalent precipitation (in inches) that has been observed during the specified period at a point or basin. HPC QPF guidance is reviewed by HAS meteorologists at the CNRFC and modified when appropriate.

The CNRFC uses 5 days of forecast precipitation and temperature in our 5-day river guidance products.  The same information is reflected in the Significant Flood Outlook product.

CNRFC Text Hydrometeorological Products

A discussion of the latest meteorological and hydrological conditions across portions of southern Oregon, California, and Nevada issued by the Hydrologist and HAS Meteorologist on-duty. This product is issued once per day during the winter operational season (October 15 through April 15) around 9:30 AM PST.

CNRFC Hydrometeorological Discussion - [Alternate Link]

The graphics below display 6-hour and 24-hour QPF for the next 3 days for the CNRFC area of responsibility and for the Weather Service Forecast Office (WFO) Hydrologic Service Areas (HSA). In most cases, this QPF is converted to basin Mean Areal Precipitation (MAP) and serves as input to our NWSRFS hydrologic models.

QPF images are issued daily at 8:00 AM. During CNRFC winter operations (Oct 15 - Apr 15), images are updated again at 1:30 PM daily with additional issuances as needed during extended hours of operation.

Please Note: The areas outlined in black delineate the areal coverage of the larger fire complexes that burned in 2007 or 2008.

Beginning June 20, 2007, Day 1 CNRFC QPF verification maps encompassing the entire CNRFC area will be available for retrieval. The 24-hour period runs from 4 AM to 4 AM during PST and 5 AM to 5 AM during PDT. Data for the previous day are made available approximately after 8:30 AM PST (9:30 AM PDT). From the interface below, select the ending date for the desired image.

National Precipitation Verification - the National Precipitation Verification Unit (NPVU) provides precipitation verification statistics for the conterminous United States. Graphical continuous and categorical verification statistics are provided for each River Forecast Center area of responsibillity, and includes monthly and seasonal verification of 6-hourly QPF for day 1, and 24-hour verification for days 1, 2, and 3 at 4 km and 32 km grid resolution. The NPVU also provides an archive of observed precipitation for each RFC area in graphic image format (GIF).

The Hydrometeorological Prediction Center (HPC) provides basic hydrometeorological analysis and forecasts for National Weather Service Field Offices and the entire meteorological community at the national scale. HPC meteorologists serve as experts in quantitative precipitation forecasting and numerical model interpretation. Products provided by the HPC include surface analyses, outlooks for heavy rain and snow, as well as guidance weather forecasts through five days. Below are links to HPC's national QPF guidance.

HPC QPF Discussions

Quantitative Precipitation Forecast Discussion (QPFPFD)
Excessive Rainfall Discussion (QPFERD)
Heavy Snow Discussion (QPFHSD)