NCEP Stage II Multi-Sensor Precipitation Analysis

Old vs. New Comparison

 

On 10 Jul 2001, the NCEP Stage II (aka Stage IV) hourly precipitation analysis became operational. The old Stage II analysis continued on to provide users with a transition period, and was discontinued on 31 Jul 2002. The new Stage II replaced the old in the long-term archive on 1 Jan 2002.

 

Major differences between the old and the new Stage II analyses are listed below:

 

  1. Data Availability:

 

 

Old Analysis

New Analysis

Produced During

1 May 1996 31 Jul 2002

10 Jul 2001-

1-week Archive

N/A

ftpprd.ncep.noaa.gov:

/pub/gcp/precip/stage2/yyyymmdd

6-month Archive

 

N/A

ftpprd.ncep.noaa.gov:

/pub/gcp/precip/mpe.arch/stage2/

Long-term Archive

May 1996 Dec 2001

Jan 2002 -

http://www.joss.ucar.edu/cgi-bin//codiac/dss?21.006

 

 

  1. Grids for the 4km analyses:

 

 

Old Analysis

New Analysis

Projection

Polar stereographic

Dimension

1160 x 880

1121 x 881

Lower left point

(1,1) = (22.7736N,120.376W)

(1,1) = (23,117N,119.023W)

Upper left point

(1,880) = (52.613N,136.394W)

(1,881) = ( 53.509,134.039W)

Lower right point

(1160,1) = (19.810N,80.802W)

(1121,1) = ( 19.805, 80.750W)

Upper right point

(1160,880) = (45.619N,60.079W)

(1121,881) = ( 45.619, 59.959W)

Pole Point

(I,J) = (441,1601)

(I,J)=(400.5,1600.5)

y-axis

Parallel to 105W

Resolution

4.7625 km at 60N

 

  1. Grids for the 15km analyses (simply a 3x3 mapping from the 4km grid).

 

 

Old Analysis

New Analysis

Dimension

386 x 293

373 x 293

Lower left point

(1,1) = (22.813N,120.351W)

(1,1) = (23,156N,118.996W)

Upper left point

(1,293) = (52.564N,136.264W)

(1,293) = ( 53.421,133.876W)

Lower right point

(386,1) = (19.876N,80.877W)

(373,1) = ( 19.870, 80.825W)

Upper right point

(386,293) = (45.646N,60.277W)

(373,293) = ( 45.618, 60.197W)

Pole Point

(I,J) = (147.323,534)

(I,J)=(133.81,533.83)

y-axis

Parallel to 105W

Resolution

14.2875 km at 60N

 

  1. Naming convention (date stamp in italics denotes the ending time of the accumulation period). 15km files are not saved in the long-term archive.

 

 

Old Analysis

New Analysis

4km multi-sensor :

USAmlmmddyyhh.Grb.Z (1-week)

mul4.yyyymmdd.hh.Z (longer term)

ST2mlyyyymmddhh.Grb.Z

4km radar-only:

hdpmmdd.Grbhh.Z (1-week)

rad4.yyyymmdd.hh.Z (longer term)

ST2rdyyyymmddhh.Grb.Z

4km gage-only:

USAggmmddyyhh.Grb.Z (1-week)

gag4.yyyymmdd.hh.Z (longer term)

ST2ggyyyymmddhh.Grb.Z

4km gage-adjusted radar-only:

USAunmmddyyhh.Grb.Z (1-week)

ubr4.yyyymmdd.hh.Z (longer term)

ST2unyyyymmddhh.Grb.Z

4km xxh accum:

(xx=06,24)

1-week:

USAml.yymmddhh.xxh.Z

hdp.yymmddhh.xxh.Z

USAgg.yymmddhh.xxh.Z

USAun.yymmddhh.xxh.Z

Longer Term:

mul4.yyyymmdd.hh.xxh.Z

rad4.yyyymmdd.hh.xxh.Z

gag4.yyyymmdd.hh.xxh.Z

ubr4.yyyymmdd.hh.xxh.Z

ST2mlyyyymmddhh.xxh.Z

ST2rdyyyymmddhh.xxh.Z

ST2ggyyyymmddhh.xxh.Z

ST2unyyyymmddhh.xxh.Z

15km multi-sensor:

multi15.mmddhh.Z (1-week only)

multi15.yyyymmddhh.Z

15km radar-only :

rad15.mmddhh.Z (1-week only)

rad15.yyyymmddhh.Z

15km gage-only:

gage15.mmddhh.Z (1-week only)

gage15.yyyymmddhh.Z

15km gage-adjusted

radar-only

radunb15.mmddhh.Z (1-week only)

radunb15.yyyymmddhh.Z

15km xxh accum

(xx=06,24)

multi15.yymmddhh.xxh.Z

rad15.yymmddhh.xxh.Z

gage15.yymmddhh.xxh.Z

radunb15.yymmddhh.xxh.Z

multi15.yyyymmddhh.xxh.Z

rad15.yyyymmddhh.xxh.Z

gage15.yyyymmddhh.xxh.Z

radunb15.yyyymmddhh.xxh.Z

 

  1. Old vs. new grid (grid domain is within the red rectangle):