Hourly/6-hourly Precipitation Analysis at NCEP/EMC

Stage II: NCEP National Multi-sensor Hourly Precipitation Analysis
Generated at NCEP, from hourly radar precipitation estimates and from hourly gauge reports. Generated at ~35 minutes after the top of the hour, and again at T+6h and T+18h. No manual QC.

Stage IV: Mosaicked from the regional multi-sensor analyses generated by the RFCs
Mosaicked into a national product at NCEP, from the regional hourly/6-hourly multi-sensor (radar+gauges) precipitation analyses produced by the 12 River Forecast Centers (RFCs) over CONUS. Some manual QC done at the RFCs. Mosaic done at NCEP within an hour of receiving any new hourly/6-hourly data from one or more RFC.

Precipitation RTMA

Precipitation URMA

Questions and Answers

Stage II/IV Comparisons(left panel is Stage II):


Planned Upgrade: early Jan 2016
  1. Stage IV mosaicking:
    • For grid points inside of an RFC's domain, if input from that RFC is late or missing, we will no longer use neighboring RFCs' data to fill in.
    • Areas outside of the RFC domains (except for Gulf of Mexico and the Atlantic) are set as no data/missing
    • Areas in the Gulf of Mexico and off the Atlantic Coast are filled in with data from the RFCs, as before
    • WGRFC domain expanded to part of Mexico
    • Coverage for the Great Lakes will come from specific RFCs assigned to the Lakes (currently it is the average of coverage from all neighboring RFCs)
    • For hourly Stage IV, CNRFC input is excluded (as is NWRFC, which does not provide hourly input)
  2. Stage II: gross error check of gauges (reports tossed above limit) increased from 1"/hr to 5"/hr
  3. Precipitation RTMA: Stage IV hourly is used as primary input for RTMA, supplemented by Stage II hourly

New RFC domain mask

Additional notes/examples about this upgrade

Parallel run output:
NCO parallel runs, 30 Oct 2015 -

YLin parallel runs, 12 Aug - 6 Nov 2015

NOTICE NOTICE NOTICE ftp://ftp.ncep.noaa.gov changed to http://nomads.ncep.noaa.gov!!!
On August 18, 2015, server ftp://ftp.ncep.noaa.gov (aka ftp://ftpprd.ncep.noaa.gov) will be replaced by http://nomads.ncep.noaa.gov. If you have been accessing the Stage II/IV data at ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/hourly/prod/, please change the path in your script to http://nomads.ncep.noaa.gov/pub/data/nccf/com/hourly/prod/ NOW (the NOMADS server is running now, you don't have to wait until 18 Aug). For additional information about this change, please see http://www.nws.noaa.gov/os/notification/tin15-21ftpprd_end.htm.


NCEP/EMC Mesoscale Modeling Branch