NOUS41 KWBC 181849 AAB

PNSWSH

 

Technical Implementation Notice 13-27, Amended

National Weather Service Headquarters Washington DC

150 PM EST Mon Nov 18 2013

 

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: Upgrade the Real-Time Ocean Forecast System

         Effective December 10, 2013

 

Amended to change the implementation date for all changes in this

notification to December 10, 2013

 

On or about Tuesday December 10, 2013, the National Centers for

Environmental Prediction’s (NCEP) Real-Time Ocean Forecast System

(RTOFS) products being disseminated to the NCEP servers will be

changing. The resolution of the existing grids will change, and

new GRIB2 output files will be added. In addition, NCEP will

disseminate the new GRIB2 RTOFS files on NOAAPORT.

 

The changes will replace the low (10 level depths) vertical

resolution regional Network Common Data Form (NetCDF) files with

high (40 level depths) vertical resolution regional NetCDF files.

 

The data volume difference will be an increase of 64 GB per day.

 

Low vertical resolution files will no longer be available:

 

       rtofs_glo_3dz_?FFF_6hrly_reg#.nc

 

High vertical resolution will now be available:

 

       rtofs_glo_3dz_?FFF_6hrly_hvr_reg#.nc

 

--Where ? is either "n" for nowcast or "f" for forecast

--FFF is the nowcast hour 006 to 048 or forecast hour from

  006 to 192

--# is the region number, 1-3

 

NetCDF RTOFS products are disseminated at the following

locations:

 

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/rtofs/prod/rtofs.YYYYMMDD

http://www.ftp.ncep.noaa.gov/data/nccf/com/rtofs/prod/rtofs.YYYYMMDD

and

http://nomads.ncep.noaa.gov

 

New surface regional GRIB2 files will be available for the

following sub-regions:

 

Region                  Lat          Lon             Resolution      

Filename

=================================================================

 

Alaska                  40-84.7    140-244.7        0.3 X  0.3  

rtofs_glo.t00z.fFFF_alaska_std.grb2

 

Arctic                  60-79.92   160-235.92      0.08 X  0.08        

rtofs_glo.t00z.fFFF_arctic_std.grb2

 

Bering                  40-67.12   155-210.92      0.08 X  0.08        

rtofs_glo.t00z.fFFF_bering_std.grb2

 

Guam                    0-29.92    130-179.92      0.08 X  0.08        

rtofs_glo.t00z.fFFF_guam_std.grb2

 

Gulf of Alaska          0-62       195-236           0.5 X 0.5             

rtofs_glo.t00z.fFFF_gulf_alaska_std.grb2

 

Honolulu                0-39.92    180-229.92       0.08 X  0.08         

rtofs_glo.t00z.fFFF_honolulu_std.grb2

 

Hudson-Baffin           45-77.5    252-333         0.25  X 0.25         

rtofs_glo.t00z.fFFF_hudson_baffin_std.grb2

 

Samoa                   -30- -0.08  170-214.72      0.08 X  0.08        

rtofs_glo.t00z.fFFF_samoa_std..grb2

 

Trop Pac                -40-39      130-249            1 X 1                   

rtofs_glo.t00z.fFFF_trop_paci_lowres_std.grb2

 

West Atlantic           10-44.72    260-305.92      0.08 X 0.08         

rtofs_glo.t00z.fFFF_west_atl_std.grb2

 

West CONUS              10-59.92    210-259.92      0.08 X 0.08         

rtofs_glo.t00z.fFFF_west_conus_std.grb2

 

where FFF is forecast hour 024 to 144.  The forecast hours start

from 01 to 72 at 1-hour intervals, and from 75 to 144 at 3-hourly

intervals

 

The WMO header template T1 T2 A1 A2 ii cccc will be as follows

for the products on NOAAPORT:

 

T1 = E - oceanographic in the NWS AWIPS system

 

T2 specifies the parameters:

     H - Sea Surface Height Relative to Geoid (SSHG)

     S - Salinity (SALTY)

     T - Water Temperature (T)

     U - U-Component of Current (UOGRD)

     V - V-Component of Current (VOGRD)

     U - Barotropic U Velocity (UBARO)

     V - Barotropic V Velocity (VBARO)

 

A1 specifies the grid:

     A - Alaska 0.3 km grid

     B - Bering 0.08 km grid

     C - Western CONUS 0.08 km grid

     D - Arctic 0.08 km grid

     G - Guam 0.08 km grid

     I - Gulf of Alaska 0.5 km grid

     K - Western Atlantic 0.08 km grid

     H - Honolulu 0.08 km grid

     S - Samoa 0.08 km grid

     T - Tropical Pacific 1.0 km grid

     J - Hudson-Baffin 0.25 degree grid

 

A2 specifies the forecast hours:

     B = 01, 02, 03

     C = 04, 05, 06

     D = 07, 08, 09

     E = 10, 11, 12

     F = 13, 14, 15

     G = 16, 17, 18

     H = 19, 20, 21, 22, 23

     I = 24, 25, 26, 27, 28, 29

     J = 30, 31, 32, 33, 34, 35

     K = 36, 37, 38, 39, 40, 41

     L = 42, 43, 44, 45, 46, 47

     M = 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59

     N = 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71

     O = 72, 75, 78, 81

     P = 84, 87, 90, 93

     Q = 96, 99, 102, 105, 108, 111, 114, 117

     R = 120, 123, 126, 129

     S = 132, 135, 138, 141

     T = 144

 

ii = 01 - Depth Below Sea Level

 

cccc = KWBW, where ‘W’ is Real-Time Ocean Forecast System

 

Follow the link below for examples of the WMO headers and the

GRIB2 data with filenames like:

 

wmo_grib2_rtofs_glo.t00z.(n|f)FFF_region_std 

(where FFF is forecast hour)

 

and

 

grib2_rtofs_glo.t00z.(n|f)FFF_region_std 

(where FFF is forecast hour)

 

http://www.nco.ncep.noaa.gov/pmb/codes/rtofs_wmo_headers_regions/

 

The new products will be delivered over NOAAPORT and to the NCEP

servers. The increase in data volume for the new GRIB2 regions

will be around 2.0 GB per day.

 

The RTOFS model runs once a day in three steps occurring at 00Z,

06Z and 12Z. The daily run has 2 days of nowcast and 8 days of

forecasts. For more information on the RTOFS Global model please

visit:

 

http://polar.ncep.noaa.gov/global

 

See ON-388 Appendix A for WMO headers with NCEP GRIB information

here:

 

http://www.nco.ncep.noaa.gov/pmb/docs/on388/appendixa.html

 

NCEP would encourage all users to ensure their decoders are

flexible and are able to adequately handle changes in content,

parameter fields changing order, changes in the scaling factor

component within the Product Definition Section of the GRIB files

and 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 the scientific content of the modeling

system please contact:

 

  Avichal Mehra

  NCEP/EMC

  College Park, MD

  Email: avichal.mehra@noaa.gov

 

For questions regarding the dataflow aspects of these data sets

please contact:

 

  NCEP/NCO Dataflow Team

  College Park, MD

  Phone: 301-683-0567

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

 

National NWS Technical Implementation Notices are online at:

 

  http://www.nws.noaa.gov/om/notif.htm

 

$$