NCEP Modeling Synergy Meeting
Highlights: September 24, 2007
This meeting
was led by Michael Brennan and attended by Brent Gordon, Keith Brill, Mark
Iredell, Mary Hart, Hendrik Tolman, Ed Danaher, and Bill Bua. Steve Silberberg
of AWC, Steve Weiss of SPC, Brian Moore of AFWA, and Stephen Jascourt of
UCAR/COMET attended by remote teleconference.
1. NCO
Brent Gordon outlined the following implementations
planned by NCO:
FY07
·
The GFS Unified
Post will be implemented on 25 September.
1st
Quarter of FY08
·
Implementation
of the new multi-grid wave model for the NOAA Wavewatch III has been pushed
back to FY08 to improve product delivery times
o
The upgrade will
continue to run in parallel with a potential implementation date of 20 November
if a 30-day parallel test is needed. An earlier implementation is possible if a
shorter parallel testing period is required.
o
Hendrik Tolman
reported that the new wave model will run concurrently with the GFS, using GFS
data as they become available. This will result in wave model output being made
available 15 minutes earlier
·
In early
December, NAEFS combined NCEP and CMC ensemble output will be produced
operationally for the first time, initially twice a day after receipt of CMC
ensemble output. The NAEFS output will consist of 35 bias-corrected parameters.
Once CMC begins running their ensemble four times per day, the NAEFS output
frequency will increase accordingly. This upgrade will also include:
o
A downscaling
vector for variables included in the RTMA over the CONUS to 5-km grid
spacing.
o
Merged GFS and
ensemble bias-corrected output, resulting in more weight being placed on the
operational GFS during the first three days of the forecast period when it
performs best. After three days, the
ensemble will be weighted more heavily.
o
This package
will go into parallel processing on 25 October for evaluation by the
operational centers.
·
An upgrade to
the CFS/GODAS (Global Ocean Data Assimilation System) will introduce two new
members and use 1-day old initial conditions instead of 8-day old initial
conditions for the model run. Also, deep water data assimilation in the GODAS
will be improved.
·
A minor upgrade
to the GSI is planned to incorporate JMA winds and SBUV ozone data. No
evaluation period will be undertaken for this change.
·
Expansion of the
SREF domain to include
·
Production of
downscaled NWP grids (DNG) through F84 from the
·
RTMA over
·
Implementations
tentatively planned for the 2nd quarter of FY08 include
o
Improvements to
the Great Lakes Wave Model (see section 2e below for more details)
o
NAM GSI upgrade
o
Ensemble for the
2008
o
Production of
DNG and RTMA for
A detailed list of upgrades and implementations can
be found here.
2. NOTES
FROM EMC
2a. Global Climate and Weather Modeling Branch
Mark Iredell provided additional detail on a major
GFS upgrade planned beyond the 1st quarter of FY08, including
potential physics upgrades to the GFS (radiation) and changes to the GSI to use
first-order time optimization (a step toward using 4DVAR) and variational
quality control in the GSI.
2b. Mesoscale Modeling Branch
No representative present.
2c. Global Ensemble Prediction System
No representative present.
2d.
No representative present.
2e. Marine Modeling and Analysis Branch
Hendrik Tolman provided more information on the Great
Lakes Wave Model upgrade scheduled for the 2nd quarter of FY08. This
upgrade will use new software and provide additional output (e.g., wind wave
and swell) but will not include major changes to the model itself. The use of downscaled winds and improvements
to the transition between the land and water PBL structure will be tested and
possibly included in this upgrade. Downscaling is needed to correct a slow bias
in GFS wind speeds extending up to 50 km offshore.
Code will also be prepared for a second setup of the Great Lakes Wave Model to
use NDFD winds as input, but an implementation of this has not yet been scheduled.
3. Feedback
from operational centers
AWC
Steve Silberberg reported that AWC will request a
crisis change to the GFS Unified Post related to the output of the model
freezing level. The new post is currently configured to search for the highest
freezing level from the top of the model (0.01 hPa for the GFS), and AWC is
concerned that episodes of stratospheric warming could result in the
development of a stratospheric freezing level that would be identified by the
post as the “freezing level” in model output.
AWC will request that the post be modified to search for the freezing
level beginning from the model level nearest to 300 hPa and working downward.
Steve also mentioned that AWC and SPC are responding
to interest from the FAA in additional radiosondes launches to improve traffic
flow management due to weather impacts.
4. The next synergy meeting will be held Monday, 29 October
2007, at 12 pm EDT in Room 209 at EMC, with remote conference capability.