[nws-changes] 20100913: GEFS/NAEFS products for Alaska

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: [nws-changes] 20100913: GEFS/NAEFS products for Alaska
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Mon, 13 Sep 2010 07:12:50 -0600

055
NOUS41 KWBC 101831
PNSWSH

Technical Implementation Notice 10-45
National Weather Service Headquarters Washington DC
230 PM EDT Fri Sep 10 2010

To:       Subscribers:
          -Family of Services
          -NOAA Weather Wire Service
          -Emergency Managers Weather Information Network
          -NOAAPORT
          Other NWS Partners...Users and Employees

From:     Tim McClung
          Science Plans Branch Chief
          Office of Science and Technology

Subject:  Addition of GEFS/NAEFS Products for Alaska:
          Effective November 30, 2010

Effective November 30, 2010, beginning with the 1200 Coordinated
Universal Time (UTC) run, the National Centers for Environmental
Prediction (NCEP) will generate downscaled probabilistic
products for Alaska from the Global Ensemble Forecast System
(GEFS) and the North American Ensemble Forecast System (NAEFS).
There will be no change to the GEFS and NAEFS models.  This
implementation is only to create new output products for Alaska.
These new products will be disseminated on the NCEP server via
http and ftp.

The following describes the new Alaskan products:

1. Geographic coverage is the 6km NDFD grid (grid 198),
   which covers all of Alaska
2. Products will be in GRIB2 format
3. Output produced four times per day (0000, 0600, 1200,
   and 1800 UTC)
4. Output available every 6 hours out to 384 hours
5. Output available for eight variables:
     surface pressure
     2-meter temperature
     2-meter maximum temperature
     2-meter minimum temperature
     10-meter u-wind
     10-meter v-wind
     10-meter wind speed
     10-meter wind direction
6. Ensemble products for each of the 8 variables listed above
include:
     10% probability forecast (filename ge10pt)
     50% probability forecast (filename ge50pt)
     90% probability forecast (filename ge90pt)
     Ensemble mean forecast   (filename geavg)
     Ensemble mode forecast   (filename gemode)
     Ensemble spread forecast (filename gesprd)

Test data is currently available at:

ftp://ftp.emc.ncep.noaa.gov/gc_wmb/yzhu/alaska_q4fy2010/

Specific information regarding the GEFS/NAEFS model and
associated products can be found at:

http://www.emc.ncep.noaa.gov/gmb/yzhu/html/imp/201004_imp.html

A consistent parallel feed of data will become available on the
NCEP server once the model is running in parallel on the NCEP
Central Computing System by mid-October.  The parallel data will
be available 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

The products will be available in the ndgd_gb2 directories under
gefs and naefs. The files will have alaska in the filename.
After the implementation, the operational products will be
available on the same server but the URLs above will end in
prod rather than 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...Global Modeling Branch
Camp Springs, Maryland
Phone: 301-763-8000 X 7052
Email:Yuejian.Zhu@xxxxxxxx

For questions regarding the dataflow aspects of these data
sets... please contact:

     Rebecca Cosgrove
     NCEP/NCO Dataflow Team
     Camp Springs, Maryland 20746
     Phone:  301-763-8000 X 7198
     Email:ncep.list.pmb-dataflow@xxxxxxxx

NWS National Technical Implementation Notices are online at:

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

$$
NNNN