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.

 

1^st 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 Alaska

·        Production of downscaled NWP grids (DNG) through F84 from the NAM for the CONUS and Alaska

·        RTMA over Alaska will be implemented in time for OB8.2 or 8.3 of AWIPS

·        Implementations tentatively planned for the 2^nd 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 Beijing Olympics

o       Production of DNG and RTMA for Hawaii and Puerto Rico

 

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 1^st 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. Short Range Ensemble Forecast System

 

No representative present.

 

2e. Marine Modeling and Analysis Branch

 

Hendrik Tolman provided more information on the Great Lakes Wave Model upgrade scheduled for the 2^nd 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.