NOUS41
KWBC 161344 AAB
PNSWSH
Technical
Implementation Notice 10-55, Amended
National
Weather Service Headquarters
840 AM EST Wed Feb 16 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: Climate Forecast System (CFS) Changes:
Effective Date Postponed until late March
Amended
to postpone the implementation from February 22, 2011, to allow for further
evaluation. NCEP is targeting the last
week in March for implementation of CFS Version 2. A follow-up Technical
Implementation Notice will be issued announcing the exact date.
Effective
around the end of March 2011, beginning with the 1200
Coordinated
Universal Time (UTC) run on the day of implementation, the National Centers for
Environmental Prediction (NCEP) will upgrade the CFS. All components of the
CFS--the atmospheric model, ocean model, land-surface model, and data
assimilation--will be upgraded as part of this change.
Users
must upgrade their process of obtaining CFS data as there will be major changes
in content, format, volume of data, and data dissemination source with this
upgrade.
NCEP
will continue to run the current version of the CFS
A
3-layer interactive global sea ice model, as well as a global
land
data assimilation will be introduced to the CFS. The resolution of the
atmospheric forecast model will be increased from T62 (210 km) to T126 (100
km). The ocean forecast model will be upgraded from the limited area GFDL MOM3
to the global MOM4. The horizontal resolution will increase from 0.33 degree to
0.25 degree from 10 North to 10 South latitudes. Northwards and southwards to
the poles, the resolution will increase from land
model. For more details on the upgrades to the forecast model and products,
please check the CFS website at:
http://cfs.ncep.noaa.gov/cfsv2.info
The
data assimilation for the Climate Forecast Model will also be upgraded. The
resolution of the Atmospheric Climate Data Assimilation Version 2 (CDAS2) will
be upgraded from T62
http://cfs.ncep.noaa.gov/cfsv2.info
There
will be significant additions to parameters in the pressure grib (PGRB), flux files (FLX) and ocean (OCN) files. In addition, there will be a
new file that contains parameters on isentropic surfaces (IPV).
Due to
the increases in resolution, there will be significant changes to the format,
content and sizes of all these files. The horizontal resolution of PGRB files
will increase from 2.5 x 2.5 degree to 1 x 1 degree and the number of pressure
levels will increase from 17 to 37. The size of the flux file will increase
from the Gaussian grid for T62 (192X94) to that for T126 (384X190). The ocean
file will increase from 2.5 x 2.5 degree to 0.5 x 0.5 degree. The new
isentropic file will have a resolution of 1 x 1 degree. There will also be an
increase in the temporal resolution of the output forecast data, from 12-hourly
to
6-hourly.
For more detailed information about changes/additions to these files, please
check the CFS website at:
http://cfs.ncep.noaa.gov/cfsv2.info
Another
significant change will be the discontinuance of all seasonal products, both
for the real time forecasts and climatologies. Only monthly
mean products will be disseminated.
A set
of test data is available at the CFS website at:
http://cfs.ncep.noaa.gov/cfsv2.info
The
current CFS output is disseminated via both the NWS FTP server and the NCEP
server. With this upgrade, there will no longer be CFS output
disseminated from the NWS FTP server at:
ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/
in the MT.cfs_MR.clim or MT.cfs_MR.fcst directories. All CFS output, along with the climatologies,
will be made available only on the NCEP server and NOMADS. Beginning on
February 22, 2011, CFS output from the current day will be available via http
and ftp at:
http://www.ftp.ncep.noaa.gov/data/nccf/com/cfs/prod
and
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/cfs/prod
CFS
output from the previous 7 days will be available
http://nomads.ncep.noaa.gov/pub/data/nccf/com/cfs
Data
delivery timing of the CFS will be changed by this implementation. The
new CFS will run longer than the current CFS, and therefore disseminate the
products at a later time.
A
consistent parallel feed of data has been available on the NCEP server since
late December 2010, at the following URL:
http://www.ftp.ncep.noaa.gov/data/nccf/com/cfs/para/
and
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/cfs/para/
NCEP
encourages all users to ensure their decoders are flexible and are able to
adequately handling changes in content, changes in the scaling factor component
within the product definition section (PDS) of the GRIB files, and any volume
changes which may occur.
If you
have any questions concerning these changes, please contact:
Suranjana Saha
NCEP/Global
Climate and Weather Modeling Branch
301-763-8000
X 7236
or
Shrinivas Moorthi
NCEP/Global
Climate and Weather Modeling Branch
301-763-8000
X 7233
NWS
National Technical Implementation Notices are online at:
http://www.nws.noaa.gov/os/notif.htm
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