-------- Original Message --------
177
NOUS41 KWBC 071933
PNSWSH
Technical Implementation Notice 10-50, Amended
National Weather Service Headquarters Washington DC
233 PM EST Fri Jan 7 2011
To: Subscribers:
-Family of Services
-NOAA Weather Wire Service
-Emergency Managers Weather Information Network
-NOAAPORT
Other NWS Partners, Users and Employees
From: Timothy McClung
Chief, Science Plans Branch
Office of Science and Technology
Subject: Amended: Changes to the North American Ensemble
Forecasting System (NAEFS): Effective January 18, 2011
Amended to postpone the effective date from January 11th to
January 18th to allow for sufficient evaluation.
Effective Tuesday, January 18, 2011, beginning with the 1200
Coordinated Universal Time (UTC) run, the National Centers for
Environmental Prediction (NCEP) will make modifications to the
North American Ensemble Forecasting System (NAEFS). The current
NAEFS output is derived by combining the NCEP Global Ensemble
Forecast System (GEFS) and the Canadian Meteorological Centers
GEFS. Starting January 18, the global ensemble system run by the
Fleet Numerical Meteorology and Oceanography Center (FNMOC) will
also be included in the NAEFS.
The NAEFS output is disseminated only via the NCEP server.
Products are available for http and ftp download at the
following URLs:
http://www.ftp.ncep.noaa.gov/data/nccf/com/gens/prod/
and
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/gens/prod/
In addition to including the FNMOC data in the NAEFS ensemble
calculations, NCEP will also be modifying the output available
from the NCEP GEFS, CMC GEFS, and the NAEFS. These
modifications include:
Adding the following 13 bias-corrected elements to the NCEP
GEFS and NAEFS output for all probabilistic products:
10 hPa(mb) geopotential height
10 hPa(mb) temperature
10 hPa(mb) u component of wind
10 hPa(mb) v component of wind
50 hPa(mb) geopotential height
50 hPa(mb) temperature
50 hPa(mb) u component of wind
50 hPa(mb) v component of wind
100 hPa(mb) geopotential height
100 hPa(mb) temperature
100 hPa(mb) u component of wind
100 hPa(mb) v component of wind
850 hPa(mb) vertical velocity
The directory location of the raw CMC GEFS data will be
changed. Starting on January 18, the GRIB2 output for the
individual member and ensemble means and spreads will be online
in the following directories, where YYYYMMDD is the date and CC
is the model cycle:
http://www.ftp.ncep.noaa.gov/data/nccf/com/gens/prod/cmce.YYYYMM
DD/CC/pgrb2a
and
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/gens/prod/cmce.YYYYMMD
D/CC/pgrb2a/
In addition, the following 28 variables will be added to the CMC
output:
10 hPa(mb) geopotential height
10 hPa(mb) temperature
10 hPa(mb) relative humidity
10 hPa(mb) u component of wind
10 hPa(mb) v component of wind
50 hPa(mb) geopotential height
50 hPa(mb) temperature
50 hPa(mb) relative humidity
50 hPa(mb) u component of wind
50 hPa(mb) v component of wind
100 hPa(mb) geopotential height
100 hPa(mb) temperature
100 hPa(mb) relative humidity
100 hPa(mb) u component of wind
100 hPa(mb) v component of wind
850 hPa(mb) vertical velocity
Convective inhibition (CIN 180-0 hPa)
Latent heat net flux
Sensible heat net flux
Downward shortwave radiation flux at surface
Downward longwave radiation flux at surface
Upward shortwave radiation flux at surface
Upward longwave radiation flux at surface
Upward longwave radiation flux at top of atmosphere
Volumetric soil moisture (0-10cm)
Water equivalent of accumulated snow depth
Snow depth (surface)
Soil temperature (0-10cm down)
Data delivery timing is not expected to be impacted by the
implementation. There will only be a minor increase in the data
volumes of existing files due to the addition of new variables.
A sample dataset for this NAEFS implementation is available at:
ftp://ftp.emc.ncep.noaa.gov/gc_wmb/yzhu/1q2011
Specific information regarding the NAEFS and scientific
implementation is online at:
http://www.emc.ncep.noaa.gov/gmb/yzhu/html/imp/201012_imp.html
By early December, once the model is running in parallel on the
NCEP Central Computing System, a consistent parallel feed of
data will be available on the NCEP server. The parallel data
will be available via the following URLs:
http://www.ftp.ncep.noaa.gov/data/nccf/com/gens/para
and
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/gens/para
NCEP urges all users to ensure their decoders can handle changes
in content order, changes in the scaling factor component within
the product definition section (PDS) of the GRIB files, and
volume changes. These elements may change with future NCEP model
implementations. NCEP will make every attempt to alert users to
these changes before implementation.
For questions regarding these changes, please contact:
Yuejian Zhu
NCEP/Global Modeling Branch
Camp Springs, Maryland
301-763-8000 X 7052
Yuejian.Zhu@xxxxxxxx
For questions regarding the dataflow aspects of these datasets,
please contact:
Rebecca Cosgrove
NCEP/NCO Dataflow Team
Camp Springs, Maryland 20746
301-763-8000 X 7198
ncep.pmb.dataflow@xxxxxxxx
NWS National Technical Implementation Notices are online at:
http://www.nws.noaa.gov/os/notif.htm
$$