[nws-changes] 20091106: [Fwd: [NCEP.List.ModelEvalInfo] GFS General Evaluation]

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: [nws-changes] 20091106: [Fwd: [NCEP.List.ModelEvalInfo] GFS General Evaluation]
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Fri, 06 Nov 2009 07:10:32 -0700

FYI--

-------- Original Message --------

NCEP Model Evaluation Subscribers,


     The Environmental Modeling Center (EMC) has proposed an upgrade to
the Global Forecast System (GFS).

The model changes include:
1. Assimilation of new observation data sources, including
        Tropical storm pseudo sea-level pressure obs

        RARS 1B data
        EUMETSAT-9 atmospheric motion vectors
2. Implementing improved techniques in the GSI analysis, including
        Use of uniform thinning mesh for brightness temperature data
        Improvements to assimilation of GPS RO data (QC, retune obs             
        errors)
        Addition of dry mass pressure constant
        Update of background error covariance
        Merging of GMAO and EMC codes
3. Improvements to the Global Forecast Model, including
        Restructuring of the Global Model code
        Code unification between GFS and GEFS
        Consolidation of Global Post codes used in GFS and GDAS
        Upgrade to ESMF 3.1.0rp2
        Modification of low cloud definition
        Output additional parameters for TIGGE and ICAO
        Introduction of more accurate algorithm for several diagnostic          
        variables
        Output additional hourly files to 12 hrs for RTMA Guam
        Output additional 3-hourly files to 60 hrs for GOCART

*Near real time parallel data*
Beginning Friday, November 6, 2009, a consistent parallel feed of data
will be available at:

FTP:
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/gfs/para
<ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/gfs/para>

HTTP:
http://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/para
<http://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/para>


We will make the model output available for 30 days starting Friday, 6
November so that end-users of the GFS data can verify that no unforeseen
changes have been introduced.

Any comments on this proposed change will be appreciated. Any feedback
you wish to provide during the evaluation period should be emailed to
NCEP.List.ModelEvalFeedback@xxxxxxxx prior to 7 December, 2009.  Please
note the quick turn around time on this evaluation.  We are briefing Dr.
Uccellini on 14 December, 2009 and are aiming for implementation of the
GFS upgrade on 15 December, 2009.  We ask that those of you who choose
to participate in the evaluation please prepare your evaluation packages
as early as possible in order for us to meet our briefing and
implementation dates.

The Environmental Modeling Center, EMC, has a publicly available website
which can provide users with more information concerning the GFS:
http://www.emc.ncep.noaa.gov/gmb/treadon/experiments/pru12a/vsdb/



Thanks

Chris Caruso Magee