NOUS41 KWBC 161925


Technical Implementation Notice 12-57

National Weather Service Headquarters, Washington, DC

225 PM EST Fri Nov 16 2012

To:†††††† Subscribers:

††††††††† -Family of Services

††††††††† -NOAA Weather Wire Service

††††††††† -Emergency Managers Weather Information Network

††††††††† -NOAAPORT

††††††††† Other NWS Partners, Users and Employees

From:†††† John Derber

††††††††† Acting Chief, Global Climate and Weather

††††††††† Modeling Branch

†††††††† NCEP/Environmental Modeling Center

Subject:Termination of NCEPís Legacy Global Data

††††††††† Assimilation System: Effective January 08, 2013

Effective Tuesday, January 8, 2013, with the 1200 Universal

Coordinated Time (UTC) cycle, the National Centers for

Environmental Prediction (NCEP) will stop running the legacy

Global Data Assimilation System (GDAS2) and discontinue all

associated output products.This change does not impact any

output from the existing higher-resolution Global Data

Assimilation System (GDAS1).

A Public Information Statement was issued on September 27, 2012,

requesting comments on the proposed termination of the GDAS2.

Based on responses received, NWS will terminate the GDAS2 and all

associated output products on January 8, 2013.

The GDAS2 are legacy products with a horizontal resolution of

triangular truncation T62 (about 208 km on 28 sigma layers),

which is much less than the resolution of the current Global

Forecast System (GFS), and the current GDAS1 system. As outlined

in the PNS referenced above, corresponding products are available

from the higher-resolution GDAS1 for all GDAS2 products to be

discontinued. The GDAS2 products were not created independently

from the GDAS1 products and were interpolated fields from the

higher resolution products.

The GDAS2 output is only disseminated via the NCEP FTP server. No

GDAS2 products are sent on NOAAPORT. The exact filenames being

removed, along with the corresponding replacement GDAS1

filenames, are outlined in the PNS referenced above.

If you have questions about this termination, please contact:

†† John Derber

†† NWS/NCEP Environmental Modeling Center

†† College Park, MD





†† Rebecca Cosgrove

†† NWS/NCEP Central Operations

†† College Park, MD


National Public Information Statements are online at: