NCEP Modeling Synergy Meeting Highlights: October 29, 2007


This meeting was led by Michael Brennan and attended by Joey Carr, Keith Brill, Mark Iredell, Mary Hart, Geoff DiMego, Joe Sienkiewicz, Ed Danaher, Zoltan Toth, Dave Plummer, and Vera Gerald. Steve Weiss and David Bright of SPC attended by remote teleconference.


1. NCO


Joey Carr outlined the following implementations planned by NCO:

1st Quarter of FY08


        A NAM-post upgrade is scheduled for 6 November

        Implementation of the new multi-grid wave model for the NOAA Wavewatch III is scheduled for 27 November

        A minor GSI upgrade is scheduled for 27 November

        A NAEFS upgrade is scheduled for 4 December

        A SREF upgrade is scheduled for 11 December

        A Climate Forecast System (CFS) upgrade is schedule for 18 December


2nd Quarter of FY08


        NAM Upgrade

        Great Lakes wave model

        RTMA for Alaska first or second week in January

        5-km NAM downscaled NWP grids (DNG)


More details on these implementations can be found below in the respective EMC branch sections. A detailed list of all upcoming upgrades and implementations can be found here.




2a. Global Climate and Weather Modeling Branch


Mark Iredell detailed the following upcoming global branch implementations:

  • A minor upgrade to the GSI scheduled for 27 November will to incorporate format changes for JMA winds and SBUV ozone data. No evaluation period will be undertaken for this change.
  • The upgrade to the CFS/GODAS (Global Ocean Data Assimilation System) scheduled for 18 December will introduce two new members and use 1-day old initial conditions instead of 8-day old initial conditions for the model run. This will improve model performance in the short range (3-6 weeks). Also, deep water data assimilation in the GODAS will be improved.
  • A patch for the GFS post to address the calculation of the freezing level and the production of simulated GOES products will be coming in the next 2 to 3 weeks for evaluation.


2b. Mesoscale Modeling Branch


Geoff DiMego reported that the NAM post upgrade scheduled for 6 November will include the production of satellite lookalike data for N-AWIPS, the production of new NAM tiles for Alaska, and script changes to improve production time.


Other upcoming MMB implementations include a NAM upgrade that will begin to run in parallel in December or January. This upgrade will include:


  • An increase in the domain size by 18% (in the north, west, and east directions)
  • An upgrade in the i,j,k WRF-NMM code
  • Introduction of gravity-wave drag and mountain blocking
  • A unified LSM (NOAH)
  • GSI upgrade to increase the resolution of GOES field-of-view data and the inclusion of some mesonet data
  • A slight modification of the positive definite advection scheme


Another upcoming project is the reinstatement of Fire Weather runs in 2008 based on a request from OCWWS. These WRF runs will cover 26 predefined 8-km domains, similar to the Fire Weather runs from the Eta. A new capability with WRF is the ability to nest down to 2.67-km grid spacing near the fire center within each of the 8-km domains.


A future upgrade will be development of downscaled NWP grids (DNG) from the NAM and the implementation of the RTMA for Hawaii and Puerto Rico. DNG grids for the GFS will need to be implemented before the RTMA can be run over Guam.


2c. Global Ensemble Prediction System


Zoltan Toth discussed the upcoming NAEFS implementation scheduled for 4 December. The upgrade will include the production of combined NCEP and CMC ensemble 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:


        A downscaling vector for 2-m temperature, 10-m wind (u and v components) and surface pressure the CONUS on the 5-km NDFD grid spacing.

        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.

        Output of the ensemble mean, the 10th, 50th (median), and 90th percentile probabilities of the ensemble, the mode, the spread, and climate anomalies compared to NCEP/NCAR reanalysis.

        This package is currently in parallel processing through 23 November and datasets are currently available on NCOSRV and through ftpprd.


2d. Short Range Ensemble Forecast System


Geoff DiMego reported on the SREF upgrade scheduled for 11 December. This upgrade will include bias corrected output and an increase in the size of the RSM domain. These parallel datasets are currently available on NCOSRV and through ftpprd. After the implementation, SREF products in AWIPS will eventually transition to the bias corrected products.


2e. Marine Modeling and Analysis Branch


Vera Gerald reported that the Great Lakes wave model code will be delivered to NCO on 18 December with a scheduled implementation for March 2008. 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 NAM wind speeds extending up to 50 km offshore.

Upgrades to the wave model ensemble are schedule for implementation in June 2008, including:


  • An increase from 10 to 20 members
  • Increase in lead time to 7-8 days
  • Initial condition perturbations for swell
  • Bias corrected winds for oceanic forcing


3. Feedback from operational centers




David Bright of SPC asked for information on the parameter identifications for new aviation products in the SREF. Geoff DiMego and Joey Carr replied that the issue could be related to the use of different GEMPAK tables for conversion from grib format.


A summary of the parameters and units from various GEMPAK tables can be found at:


4. The next Synergy Meeting will be held Monday, 26 November 2007, at 12:00 pm EST in Room 209 at EMC, with remote conference capability.