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. Mosaic done at NCEP within an hour of receiving any new hourly/6-hourly data from one or more RFC.

History:

• 6 Oct 2006: one-week on-line rotating archive discontinued
• 22 Feb 2006: intent to discontinue the one-week on-line rotating archive sent to existing users (those who had left their email address in anonymous FTP) and posted on line
• 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 24 hours 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

---

Various regional MPE links:

Individual RFCs over ConUS:

Sub-center ID	RFC	Name	Location
150	ABRFC	Arkansas-Red Basin	Tulsa, OK
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