NOUS41 KWBC 191219 CCA

PNSWSH

 

Technical Implementation Notice 14-04, Corrected

National Weather Service Headquarters Washington DC

815 AM EDT Wed Mar 19 2014

 

To:       Subscribers:

          -Family of Services

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network

          -NOAAPORT

          Other NWS Partners, Users and Employees

 

From:     Tim McClung

          Chief, Science Plans Branch

          Office of Science and Technology

 

Subject:  Corrected: Addition of GEFS/NAEFS Bias-Corrected

          Products and Downscaled Products for Alaska and CONUS:

          Effective March 27, 2014

 

Corrected an error in the WMO headers provided: the third digit

(A1) in the WMO header should be A, not E.  Also amended to

change the effective date from March 18 to March 27, 2014.

 

Effective on or about Thursday, March 27, 2014, beginning with

the 1200 Universal Coordinated Time (UTC) run, the National

Centers for Environmental Prediction (NCEP) will upgrade the

Global Ensemble Forecast System (GEFS) and the North American

Ensemble Forecast System (NAEFS). The upgrade will include:

 

- Adding variables to bias-corrected products globally and

  downscaled probabilistic products for CONUS and Alaska from

  the Global Ensemble Forecast System (GEFS) and the North

  American Ensemble Forecast System (NAEFS)

 

- New product generation of calibrated CONUS precipitation

 

- Consolidation of the "early" and "late" runs of the NAEFS 

  jobs into one operational run. Today, NCEP disseminates 

  "early" NAEFS output files that only contain output from the

  GEFS members, followed 2 hours later by a re-dissemination

  of these same NAEFS files now populated with the combined

  GEFS and CMC output. With this upgrade, the files will be

  posted only one time, roughly 20 minutes after the current

  early delivery time, but they will be these final GEFS/CMC

  combined output products.

 

In addition, on or about Wednesday, April 9, 2014, beginning

with the 1200 UTC run, NCEP will begin disseminating total

precipitation and 2 meter bias-corrected temperature grids from

the individual members of the GEFS ensemble forecast. This

product will be sent on NOAAPORT and the Satellite Broadcast

Network (SBN) to support the Eastern Region River Forecast

Centers (RFCs) Ensemble River Forecast System, also known as

Model Ensemble River Forecasts (MMEFS)

 

http://www.erh.noaa.gov/mmefs/index.php

 

There will be no change to the current GEFS and NAEFS output

file names. NCEP will only be modifying the output variables

from the NCEP GEFS and the NAEFS.

 

More information about the GEFS and NAEFS upgrade is available

on the NCEP server at:

 

http://www.emc.ncep.noaa.gov/gmb/yzhu/html/imp/201204_imp.html

 

All filenames given below can be located on the NCEP server via

the following URLs (yyyymmdd is the year, month, and day):

 

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.yyyymmdd

 

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/gens/prod/naefs.yyyymmdd

 

http://www.ftp.ncep.noaa.gov/data/nccf/com/gens/prod/gefs.yyyymmdd

 

http://www.ftp.ncep.noaa.gov/data/nccf/com/gens/prod/naefs.yyymmdd

 

Addition of New Variables:

 

## is the number of the ensemble member

CC is the cycle

FFF is the forecast hour

 

1. Adding the following two bias-corrected elements:

 

     2-meter relative humidity

     2-meter dew point temperature

 

Ensemble products with the two new variables listed include:

 

     NCEP bias-corrected GEFS forecast for each member

          GEFS filenames pgrb2a_bc/gep##

     NCEP bias-corrected GFS forecast

          GEFS filenames pgrb2a_bc/gegfs

     10% probability forecast

          GEFS filenames pgrb2a_bc/ge10pt

          NAEFS filenames pgrb2a_bc/naefs_ge10pt

     50% probability forecast

          GEFS filenames pgrb2a_bc/ge50pt

          NAEFS filenames pgrb2a_bc/naefs_ge50pt

     90% probability forecast

          GEFS filenames pgrb2a_bc/ge90pt

          NAEFS filenames pgrb2a_bc/naefs_ge90pt

     Ensemble mean forecast 

          GEFS filenames pgrb2a_bc/geavg

          NAEFS filenames pgrb2a_bc/naefs_geavg

     Ensemble mode forecast 

          GEFS filenames pgrb2a_bc/gemode

          NAEFS filenames pgrb2a_bc/naefs_gemode

     Ensemble spread forecast

          GEFS filenames pgrb2a_bc/gespr

          NAEFS filenames pgrb2a_bc/naefs_gespr

 

2. Adding the following six new variables for CONUS products:

 

     2-meter maximum temperature

     2-meter minimum temperature

     2-meter relative humidity

     2-meter dew point temperature

     10-meter wind speed

     10-meter wind direction

 

Ensemble products with the six new variables listed include:

 

     10% probability forecast

          GEFS filenames ndgd_gb2/ge10pt.tCCz.ndgd_conus

          NAEFS filenames ndgd_gb2/naefs_ge10pt.tCCz.ndgd_conus

     50% probability forecast

          GEFS filenames ndgd_gb2/ge50pt.tCCz.ndgd_conus

          NAEFS filenames ndgd_gb2/naefs_ge50pt.tCCz.ndgd_conus

     90% probability forecast

          GEFS filenames ndgd_gb2/ge90pt.tCCz.ndgd_conus

          NAEFS filenames ndgd_gb2/naefs_ge90pt.tCCz.ndgd_conus

     Ensemble mean forecast

          GEFS filenames ndgd_gb2/geavg.tCCz.ndgd_conus

          NAEFS filenames ndgd_gb2/naefs_geavg.tCCz.ndgd_conus

     Ensemble mode forecast 

          GEFS filenames ndgd_gb2/gemode.tCCz.ndgd_conus

          NAEFS filenames ndgd_gb2/naefs_gemode.tCCz.ndgd_conus

     Ensemble spread forecast

          GEFS filenames ndgd_gb2/gespr.tCCz.ndgd_conus

          NAEFS filenames ndgd_gb2/naefs_gespr.tCCz.ndgd_conus

 

3. Adding the following two new variables for Alaska products:

 

     2-meter relative humidity

     2-meter dew point temperature

 

Ensemble products with the two new variables listed include:

 

     10% probability forecast

          GEFS filenames ndgd_gb2/ge10pt.tCCz.ndgd_alaska

          NAEFS filenames ndgd_gb2/naefs_ge10pt.tCCz.ndgd_alaska

     50% probability forecast

          GEFS filenames ndgd_gb2/ge50pt.tCCz.ndgd_alaska

          NAEFS filenames ndgd_gb2/naefs_ge50pt.tCCz.ndgd_alaska

     90% probability forecast

          GEFS filenames ndgd_gb2/ge90pt.tCCz.ndgd_alaska

          NAEFS filenames ndgd_gb2/naefs_ge90pt.tCCz.ndgd_alaska

     Ensemble mean forecast 

          GEFS filenames ndgd_gb2/geavg.tCCz.ndgd_alaska

          NAEFS filenames ndgd_gb2/naefs_geavg.tCCz.ndgd_alaska

     Ensemble mode forecast 

          GEFS filenames ndgd_gb2/gemode.tCCz.ndgd_alaska

          NAEFS filenames ndgd_gb2/naefs_gemode.tCCz.ndgd_alaska

     Ensemble spread forecast

          GEFS filenames ndgd_gb2/gespr.tCCz.ndgd_alaska

          NAEFS filenames ndgd_gb2/naefs_gespr.tCCz.ndgd_alaska

 

New Products Available: there will be one file per forecast hour

that contains all forecasts for all ensemble members:

 

1. 1.0 degree GEFS bias-corrected 6-hourly precipitation

projections for forecast hours 00 through 384

      NCEP bias-corrected GFS Quantitative Precipitation

      Forecast (QPF) and NCEP bias-corrected GEFS QPF for each

      member

          GEFS filenames prcp_gb2/geprcp.tCCz.pgrb2_bc_06h

      NCEP bias-corrected GEFS Probabilistic QPF (PQPF) for 14

      thresholds

          GEFS filenames prcp_gb2/gepqpf.tCCz.pgrb2_bc_06h 

 

2. 5.0 km NDGD grid GEFS 6-hourly precipitation projections for

forecast hours 00 through 384

      NCEP downscaled GFS Quantitative Precipitation Forecast

      (QPF) and NCEP downscaled GEFS QPF for each member

          GEFS filenames

          ndgd_prcp_gb2/geprcp.tCCz.ndgd_conus_06h

NCEP downscaled GEFS PQPF for 14 thresholds

          GEFS filenames

          ndgd_prcp_gb2/gepqpf.tCCz.ndgd_conus_06h

 

Directory Changes:

 

To maintain consistency, NCEP will move the existing GEFS 24-

hour accumulated PQPF files into the new prcp_gb2 directory:

 

     prcp/gepqpf.tCCz.pgrb2_24hfFFF will now be found in

     prcp_gb2/

 

New Products Available on NOAAPORT and SBN:

 

The GEFS products being added will be on a Global

Latitude/Longitude grid with 1.0 degree resolution. Forecast

cycles are 4 times daily (00Z, 06Z, 12Z and 18Z), with forecast

projections at 6-hourly increments from 00 through 180 hours for

each 20 members and the control. The total volume throughput

will be 252MB/day. The data will be transmitted in GRIB2 with

the following WMO header format:

 

T1T2A1A2ii cccc where

   - If T1=L

     Then A2 is: A=00, B=06, C=12, D=18, E=24, F=30, G=36, H=42,

     I=48, J=60, K=72, L=84, M=96, N=108, O=120, P=132, Q=144,

     R=156, S=168, T=180

   - If T1=M

     Then A2 is: M=54, N=66, T=78, U=90, V=102, W=114, Z=126,

     Z=138, Z=150, Z=162, Z=174

   - T2 specifies the parameters as follows

E = Total precipitation (APCP) 

T = Temperature 2 m above ground (TMP)

   - A1 = A Grid ID #3 (Global Lat/Lon 1 degree resolution)

   - ii specifies the levels as follows: 98 = surface of Earth

   - cccc = KWBK

 

1. Bias-corrected 2 meter temperature headers:

     [LM]TE[A-WZ]98 KWBK

 

2. 6 hour accumulating total precipitation headers:

     [LM]EE[A-WZ]98 KWBK

 

NCEP will offer a consistent parallel feed of both GEFS and

NAEFS data via the following URLs:

 

http://www.ftp.ncep.noaa.gov/data/nccf/com/gens/para

 

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/gens/para

 

NCEP encourages all users to ensure their decoders are flexible

and are able to adequately handle changes in content order,

changes in the scaling factor component within the product

definition section (PDS) of the GRIB files, and also any volume

changes which may be forthcoming. These elements may change with

future NCEP model implementations. NCEP will make every attempt

to alert users to these changes prior to any implementations.

 

For questions regarding these changes, please contact:

 

     Yuejian Zhu

     NCEP/EMC Global Modeling Branch

     College Park, Maryland

     Phone: 301-683-3709

     Email: Yuejian.Zhu@noaa.gov

 

For questions regarding the dataflow aspects of these data sets,

please contact:

 

     Rebecca Cosgrove

     NCEP/NCO Dataflow Team

     College Park, Maryland

     Phone:  301-683-0567

     Email:  ncep.list.pmb-dataflow@noaa.gov

 

NWS National Technical Implementation Notices are online at:

 

     http://www.weather.gov/os/notif.htm

 

$$