GEMPAK Status Report

Steve Chiswell
March 2, 2007

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 by Version
  5.6.L 5.6.M 5.7.1 5.7.2 5.7.3 5.7.4 5.8.1 5.8.2a 5.8.3a 5.8.4 5.9.1 5.9.2 5.9.3 5.9.4 5.10.1
Source Code 158 114 171 445 108 393 252 301 318 139 687 609 534 1034 76
Linux Binary 233 260 159 661 395 649 427 529 311 117 679 582 612 1126 54
Linux64 Binary                           336 8
FreeBSD Binary 29 42 9 23 34 105 8 21 17 4 35 12 31 22 2
Solaris Sparc Binary 26 23 10 34 19 29 21 14 16 1 27 29 10 13 1
Solaris x86 Binary 4 10 3 24 2 14 21 7 9 5 21 2 18 27 3
MAC OSX Binary               45 33 5 120 24 153 39 9


Current Status

Site visit to St. Louis University

Dr. Chuck Graves will host a GEMPAK and IDV site visit to SLU March 19-21, 2007. The proposed schudule provides for direct interaction with undergraduate and graduate classes, one-on-one time with individual students as well as site administrators, a departmental presentation on Unidata activities, and attending the student AMS meeting.

GEMPAK 5.10.2 release

NCEP developers have provided notification for retirement of five legacy GEMPAK GD programs. They are: GDCNTR, GDSTREAM, GDWIND, GDMAP and GDPLOT. The functionality of each of these programs is fully incorporated into GDPLOT2. In addition, GDPLOT2 provides additional capabilities beyond the capabilities provided by these individual programs. Minimal changes are needed to go from the legacy program parameter settings to GDPLOT2 parameter settings. The last release to support these programs will be 5.11.2 (February, 2008).

Additions include:

  • NMAP2 now supports multiple, simultaneous locator displays
  • Added support for new mesocyclone detection algorithm NEXRAD products
  • Contour label formating
  • Updated to latest version of Advanced Dvorak Technique (ADT) v7.2 for tropical cyclone evaluation.

GEMPAK 5.10.1 release

The maximum grid size supported by N-AWIPS grid programs has been increased from 750,000 to 1,000,000 points. In addition, the grid size limit has been completely eliminated in the following programs: NAGRIB, NAGRIB2, GDGRIB and GDGRIB2. The programs NAGRIB and GDGRIB were converted from FORTRAN to C to eliminate the restriction. In addition, in preparation for completely eliminating the grid size restriction, the programs GDDIAG and GDLIST were converted to C. Larger grids may be subsampled in area or grid stride for use in GEMPAK.

Other additions include:

  • New 2007 daytime savings rules
  • Addition of text strings in contours
  • Two new ensemble functions based on a univariate cumulative probability under a piecewise linear probability density function (PDF).

GEMPAK 5.9.4 release

NCEP is developing XML/XSLT infrastructure within GEMPAK as part of the creation of products by NMAP2. Future development will include a migration of the current table structure from column based formats to XML, which will remove legacy issues regarding metadata and precision, as well as increase the utility of these tables with other packages.

GEMPAK 5.9.4 introduces a rewrite of the core GEMPAK grid diagnostics library routines in C. This initial phase is a straight translation of routines from Fortran to C, which will be followed by implementation of dynamic memory allocation, thereby facilitating the use of GEMPAK with increasingly large data sets.

An overarching goal in the GEMPAK library rewrite is to separate the library routines from the underlying data files and formats. This will facilitate the use of GEMPAK routines in the next generation AWIPS development. A primary benefit of this work will be the ability to support a wider range of data sets, including remote access.

GEMPAK application training workshop

The Unidata applications training workshop for GEMPAK was conducted October 25-27, 2006. Attendees of the GEMPAK workshop traveled from Korea, Mali, Burkina Faso, Brazil, and Canada in addition to domestic institutions.

GEMPAK 5.9.3 release

New layer based grid diagnostics have been added which allow computation of quantities over a number of levels, on a max/min level within a layer, or on an isosurface.

GRIB2 decoding has been revised to allow the packed grid to be stored directly into the decoded GEMPAK grid file, thereby increasing the efficiency of the decoder and greatly decreasing CPU usage.

New time matching rules have been added which allow templates to configure how time is used to find a matching dataset.

Previous developments

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.

  • See August 2006 status report for past information.

    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 documentation for the GEMPAK workshop is made available through the GEMPAK 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.