hurdec

Sections

• NAME
• SYNOPSIS
• PARAMETERS
• DESCRIPTION
• EXAMPLES
• FILES
• SEE ALSO

NAME

hurdec - Tropical advisory decoder

SYNOPSIS

hurdec [parameters...] filename

PARAMETERS

DESCRIPTION

The hurdec program parses tropical advisory products in order to generate a wide range of data files containing information on specific hurricanes. The input to the program is raw tropical data file from the TPC (Tropical Prediction Center) and the Joint Typhoon Warning Center (JTWC) which can contain any number of products. To simplify the process, it is highly recommended to save the hurricane products (WTxx) in a separate file type as specified by the trp_dat file name tag.

The program parses three types of TPC products:

• ADVISORY -- including intermediates and specials and gets wind speed, pressure and location info.
• FORECAST/ADVISORY -- these are more regularly formatted and are used to get location, speed and pressure and saves the general information on hurricane for later insertion into the storm.html file.
• DISCUSSION -- it parses the forecast track information from this product and saves the track lines for insertion into the storm.html file.
• WARNING - Issued by the JTWC and contains tropical storm and typhoon advisories for the western Pacific.

The output of the program is the following set of files for each active storm:

• track.dat - text based track file including forecasted track. This is intended for general use and printing.

  Date: 24 AUG-04 SEP 1996
  Hurricane FRAN
  ADV  LAT   LON     TIME    WIND  PR  STAT
   1  14.40  -25.10 24/03Z   30  1007 TROPICAL DEPRESSION
   2  14.80  -26.70 24/09Z   30  1007 TROPICAL DEPRESSION
   3  14.50  -29.20 24/15Z   30  1007 TROPICAL DEPRESSION
  ...
  41A  25.70  -73.10 04/00Z  100   963 HURRICANE-3
  +12  26.10  -74.50 04/06Z   95     - HURRICANE-2
  +24  27.40  -76.40 04/18Z  100     - HURRICANE-3
  +36  29.00  -78.10 05/06Z  105     - HURRICANE-3
  +48  30.90  -79.80 05/18Z  110     - HURRICANE-3
  +72  35.00  -83.00 06/18Z   40     - TROPICAL STORM
  

• track.raw - this is very similar to the track.dat file but it is formatted as a WXP RAW file for use with mapplt to create tracking charts.
• track.dom - the domain for the entire storm track used by mapplt to plot tracking chart. This calculates the range of lat and lon and adds 5 degrees in order to create a plot domain that fully encompasses the entire track. The output is a full WXP plot domain specification that can be used by a program like mapplt to create a tracking chart:
  
  mapplt -pd=fi:track.dom track.raw-LINE
  
  Example file contents:
  
  ll,24.70,-54.05,25,17,2.83,2.83
  
• last.dom - last position of storm used by xsat for satellite plots. The file is a full WXP plot domain specification so it can be used by xsat directly:
  
  xsat ... -pd=fi:last.dom
  
• storm.html - full HTML file for that storm, uses image.list file to insert image snapshots of storm, also inserts segments of latest TPC advisories as described above.
• image.list - this file is a list of images that have been saved for viewing. This file is NOT created by hurricane but is used by the program to create links in the storm.html file. The file is a list of image file names along with a description:

  170903i.gif Infrared image of storm east of Bahamas (17Z Sep 03)

• storm.line - single line status listing for storm. Example:

  Hurricane FRAN    24 AUG-04 SEP 100 963 3
  

The program puts these files in directories sorted by storm, region and year. The above files are put in the directories for each storm. The directory structure looks like:

The regions include:

• atlantic - Atlantic storms
• e_pacific - Eastern Pacific
• c_pacific - Central Pacific
• w_pacific - Western Pacific

Finally, the program produces a listing file which is put in each year directory:

• storm.list - list of currently active storm, used for plotting all the data.  

This file is only a list of those storms that were active within the period parsed. This list can be used to determine which storms need to be updated on a regular basis. Also, this list can be parsed and new storms added to an overall names file which has all the named storms for a particular year.

Automating the Hurricane Processing

The hurricane program will process each storm that has advisories in the raw tropical files that are in the range specified by num_hour resource. When reprocessing the data, hurdec reads in the track.dat file for every storm that it sees in the raw files to obtain any older advisory information, adding the new advisories onto the end of the file.

There are a couple of scripts that go with the hurdec program. The first is hur_update which runs all the tasks to generate images and HTML pages based on the information generated by hurricane. This script should be run in cron once every 2-4 hours or roughly 10-15 minutes after each advisory in order to get the latest advisories. The script does the following tasks:

1. it runs hurricane to process all the latest hurricane information.
2. it uses the storm.list file to generate a list of the currently active storms. It updates a names file with each new storm.
3. it generates satellite images for each active storm using xsat with the last.dom file. The visible file is sat_vis.gif and the IR file is sat_ir.gif. It also generates a small IR image named sat_ir_s.gif for inclusion into the storm.html file.
4. it generates full Atlantic visible, IR and water vapor images on the same projection as the yearly tracking chart.
5. it runs the hur_plt script.
   1. generates a yearly tracking chart based on the names in the names file. When a new storm develops, the hur_update will add its name to this file. You can delete names out of this file when depressions become tropical storms.
   2. generates storm based tracking charts using mapplt and the track.dom file.
   3. it generates small track charts for inclusion into the storm.html file.
6. it runs hur_html_setup which is a Perl script that generates a large HTML file for each region and year named index.html.
   1. it inserts each of the storm.line files for a general storm summary
   2. it generates a HTML table using all the storm.html files generated by the hurricane program.

When all this is completed, there is an up to date HTML hurricane page with all the tracking charts updated and current satellite images.

EXAMPLES

• hurricane -cu=la -nh=-6
  This updates the hurricane files for the last 6 hours. This should be run from cron either by invoking the hurdec program or the hur_update script.

FILES

SEE ALSO

Last updated October 2013