National Stage IV QPE Product

What is the NCEP Stage IV analysis?

Mosaicked into a national product at NCEP, from the regional hourly/6-hourly multi-sensor (radar+gauges) precipitation analyses (MPEs) produced by the 12 River Forecast Centers over CONUS. Some manual QC done at the RFCs.

The Stage II/IV job is run at 33min past the top of each hour. Hourly Stage IV is re-made hourly (if there is new input) for the first 23 hours after valid time, then again at 1/3/5/7 days after valid time. The 6-hourly Stage IV is re-made hourly (if there is new 6h input) for 42 hours after valid time; the four 6-hourlies covering a 12Z-12Z 24h period are also re-made on a fixed schedule, regardless of input, at 1/3/5/7 days after the ending 12Z (i.e. at the 12:33Z run); at which time the corresponding 24h totals are also re-made. The current day's 24h totals are made at 15:33/21:33/23:33Z run cycles. (Note: after 2 May 2017, the current day's 24h totals will be made hourly, at 12:33/13:33...,23:33Z).

History:

• 6 Jan 2016:
  • 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 (previously it was 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)
• 14 Apr 2015: Stage IV look-back period extended to 7 days.
• 28 Jan 2014: Stage IV 6-hourly began to be used for precipitation URMA
• ... (more complete history to be filled in later)
• 11 May 2004: grid number changed from 240 to 255; correction to grid coordinates
• 1 Oct 2002: Stage IV processing became operational. Grid number in Grib header changed from '255' to '240' (it's the same grid, only the grid number was updated)
• 8 May 2002: started timelier processing, mosaic now done within one hour of receiving any new data, i.e., program is run once an hour; for any 1-hour/6-hour period, if there have been new MPE data arriving from at least one RFC, the mosaic for that time period (1-hour/6-hour) is performed, either for the first time, or re-done
• 1 Jan 2002: stage IV data began to be archived at NCAR
• 1 Dec 2001: began routine generation of the NCEP Stage IV analysis

References

What is available in Stage IV:

Analysis on the 4km HRAP grid: ST4.yyyymmddhh.xxh.Z, where xx (=01,06 or 24) is the accumulation period and yyyymmddhh is the ending time of the accumulation period.

• Hourly analysis: from the hourly MPEs sent by the RFCs
• 6-hourly analysis: from the 6-hourly MPEs sent by the RFCs
• 24-hour (12Z-12Z) analysis: summed up from the 6-hourly Stage IV

Images (left panel is Stage II):

• Snapshot from T-12h (T is current time)
• 12h loop from T-12h
• 24h loops (there is a 2-day lag in image production)
• 24h accumulation (12Z-12Z) comparison: Go to the model daily precipitation verification page. Select a day, go to the bottom of that day's page, where the Stage II/IV analysis are compared to the 1/8-degree daily precipitation analysis (produced by CPC, based on the 7,000-8,000 daily gauge reports)

Where to get NCEP Stage IV:

• Past 10 days' data on line
• Daily tar file for the past few months (see caveat)
• Tape archive at NCAR, from 1 Jan 2002
• Which one should I use?

Log of problem hours
Timeliness of the data, daily logs of regional MPE arrival times
Grid information
Questions and Answers
Links to NCEP Stage II and other precipitation products

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Various regional MPE links:

Individual RFCs:

Sub-center ID	RFC	Name	Location
105	SJU	Puerto Rico	San Juan, PR
150	ABRFC	Arkansas-Red Basin	Tulsa, OK
151	APRFC	Alaska-Pacific	Anchorage, AK
152	CBRFC	Colorado Basin	Salt Lake City, UT
153	CNRFC	California Nevada	Sacramento, CA
154	LMRFC	Lower Mississippi	Slidell, LA
155	MARFC	Middle Atlantic	State College, PA
156	MBRFC	Missouri Basin	Pleasant Hill, MO
157	NCRFC	North Central	Chanhassen, MN
158	NERFC	Northeast	Taunton, MA
159	NWRFC	Northwest	Portland, OR
160	OHRFC	Ohio	Wilmington, OH
161	SERFC	Southeast	Peachtree City, GA
162	WGRFC	West Gulf	Fort Worth, TX