GEMPAK Status Report

Steve Chiswell
April 26, 2005

Purpose of GEMPAK status report

The activities carried out toward GEMPAK development and support fulfill the following endeavors as described in the Unidata 2008 NSF proposal:


GEMPAK Downloads
  5.6.L 5.6.M 5.7.1 5.7.2 5.7.3 5.7.4 5.8.1
Source Code 158 114 167 416 106 361 160
Linux Binary 233 260 159 661 395 630 273
FreeBSD Binary 29 42 9 23 34 105 5
Solaris Sparc Binary 26 23 10 34 19 29 4
Solaris x86 Binary 4 10 3 24 2 14 8

Current Status

GEMPAK 5.8.2 release in progress

GEMPAK 5.8.2 adds ensemble creation using sets of grid files. This release adds the ability to specify sets of grid files to be processed in ensemble calculations. Currently, ensemble means are computed. Additional ensemble functions will be added in future releases. Ensemble calculations can use grids on different navigations, expanding the functionality of the general grid library rewrite first introduced in version 5.8.1.

Time binning of observational data has been added to NMAP2. Time binning allows observations to be combined from different times into NMAP frames for display. This capability is especially useful for observations that are not concentrated at nominal observation times.

Watch Outline Update (WOU) and Watch County Notification (WCN) displays now support county fill in addition to outline. Status update displays have been enhanced to allow the option of only displaying the most recent status line via the WTCH attributes.

A stand-alone GRIB2 decoder NAGRIB2 has been added to the core development. The ability to pack and store data in GRIB2 format within GEMPAK grid files will be added in a future release.

GEMPAK 5.8.1 release

GEMPAK 5.8.1 will add internal grid interpolation to facilitate computations involving grids of different navigations. A general grid library rewrite has been done to improve time handling.

Unidata additions include improved GRIB2 handling for products available in the DVB-S NWSTG channel, updated tables, and NMAP2 modifications to allow parameter and tilt selection for Level II radar data within NMAP2.

GEMPAK 5.7.4 release

GEMPAK 5.7.4 added QuikSCAT wind plotting from BUFR products available via Unidata IDD.

Garp model data access was rewritten to take advantage of GEMPAK's template functions, which now allows access to gridded data in multiple directories, as was possible in all other GEMPAK programs previously. As a result, the distributed configuration files for GEMPAK will now store different models in unique directories, and can take advantage of file storage by forecast hour making access to increased number of grid times/levels/parameters possible and allowing easier configuration for local scouring.

NWX tables were updated for new Communication Identifiers as a result of NWS implementation of phased CID changes.

GEMPAK application training workshop

The Unidata applications training workshop for GEMPAK was conducted October 20-22, 2004. This year there were 30 registrants for the GEMPAK workshop (space was available for 16 participants; though, due to registration for multiple workshops, 14 were able to be accepted for GEMPAK). The workshops were webcast in real-time. Most segments were archived (about 3 hours of the GEMPAK workshop were lost).

GEMPAK 5.7.3 release

GEMPAK 5.7.3 adds loop capability to NSHARP, NIDS alphanumeric overlay capability, 16 loop/briefing frames and improved range/interval time selection for NMAP2.

GEMPAK 5.7.2 release

GEMPAK 5.7.2 contains many updates to NMAP2 including improved map database selection, time interval and range selection, and the addition of a GUI for Advanced Objective Dvorak Technique. Additional changes include updates to several decoders, and algorithms for model precipitation accumulation time periods.

Unidata enhancements to this release include the ability to display Level II nexrad data in the bzip2 compressed format, eliminating the need to uncompress the data when received by the LDM.

GEMPAK 5.7.1 release

Beginning with GEMPAK 5.7.1, NCEP will employ a new version numbering method based on quarterly releases as described in the GEMPAK 5.7.1 release notes. Unidata releases generally follow 1 to 3 months after receiving the NCEP release depending on the details of the release and UPC development of additional features.

Radar mosaics for GIS

Iowa State is actively using GEMPAK radar mosaics with their mesonet products in GIS applications. To facilitate this process, I developed the GEMPAK program NEX2IMG to generate composite images which can be used with a file to provide GIS navigation information. Daryl Herzmann has put together a How-To document to help other sites set up their own radar mapservers.

Previous developments

  • See October 2004 status report for past information.

    Web pages and documentation for GEMPAK 5.6 have been updated.

    Ongoing Additions

    COMET case studies available via CODIAC

    COMET case studies are compatible with the GEMPAK/NAWIPS environment, and are being made available via the CODIAC system.

    GEMPAK workshop and tutorial online

    All the handouts/displays for the GEMPAK workshop are been made available through the GEMPAK web page tutorial. Included in the presentation are numerous sample exercises and output samples. This format of presentation allows workshop participants to be able to review or utilize any of the material at their home institution. The tutorial is updated as new features dictate.