[conduit] [Fwd: [NCEP.List.ModelEvalInfo] Proposed NAM upgrade]

Hello CONDUIT users,

This information might be of interest to you.

-------- Original Message --------
Subject:        [NCEP.List.ModelEvalInfo] Proposed NAM upgrade
Date:   Tue, 12 Feb 2008 15:54:19 -0500
From:   John Ward <john.ward@xxxxxxxx>
Reply-To:       NCEP.List.ModelEvalFeedback@xxxxxxxx
Organization:   NCEP/NCO/Production Management Branch
To:     NCEP.List.ModelEvalInfo@xxxxxxxx

NCEP Model Evaluation Subscribers,

   The Environmental Modeling Center (EMC) has proposed an upgrade to
the North American Mesoscale (NAM) system.  The proposed upgrade includes:

Model Changes

1. Enlarge the computational domain of the NAM by ~ 18%, (North West to
cover Alaska & East to cover incoming flight paths to Mia for AWC).
2. Two minor changes will be made to the WRF-NMM model radiation
3. Changes will be made to the WRF-NMM orography and land-sea mask,
including a more realistic depiction of the Great Salt Lake and the
channel islands, smoother NAM surface heights and removal of spurious
elevated water points.
4. During the NDAS forecast the 12-26 hour precipitation from the 00Z
NAM will be used to fill in for the CONUS-based stage II/IV analysis as
a driver for NDAS soil moisture outside of the CONUS.
5. The new unified Land-Surface physics model will be used.
6. A modified horizontal advection algorithm for cloud water, specific
humidly, and turbulent kinetic energy will be used.
7. The WRF-NMM Model dynamics will be modified to include effects of
gravity wave drag and mountain blocking.

Analysis changes

1. Assimilation of new observation and new observation types, including
AIRS, GOES 1x1 radiances, and Surface mesonet data.
2. Revised background error covariance to improve the analysis fit to

Near Real-Time Parallel Data

Data is available to external users on the NCEP ftp server:

Any comments on this proposed change will be appreciate.  Because of the
increase in domain size, external customers are encouraged to download
test data to verify that there will be no impact on your current
operations.  Any feedback you wish to provide during the evaluation
period should be emailed to NCEP.List.ModelEvalFeedback@xxxxxxxxx



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