Input format
Input formatTC-Pairs input data format
As mentioned previously, the input to TC-Pairs is two ATCF format files, in addition to the distance_to_land.nc file generated with the TC-Dland tool. The ATCF file format is a comma-separated ASCII file containing the following fields:
| Basin | basin | |
| CY | annual cyclone number (1-99) | |
| YYYYMMDDHH | Date - Time - Group | |
| TECHNUM/MIN | Objective sorting technique number, minutes in Best Track | |
| TECH | acronym for each objective technique | |
| TAU | forecast period | |
| LatN/S | Latitude for the date time group | |
| LonE/W | Longitude for date time group | |
| VMAX | Maximum sustained wind speed | |
| MSLP | Minimum sea level pressure | |
| TY | Highest level of tropical cyclone development | |
| RAD | wind intensity for the radii at 34, 50, 64 kts | |
| WINDCODE | radius code | |
| RAD1 | full circle radius of wind intensity, 1st quadrant wind intensity | |
| RAD2 | radius of 2nd quadrant wind intensity | |
| RAD3 | radius of 3rd quadrant wind intensity | |
| RAD4 | radius of 4th quadrant wind intensity | |
| ... |
These are the first 17 columns in the ATCF file format. MET-TC requires the input file has all 17 comma-separated columns present (although valid data is not required). For a full list of the columns as well as greater detail on the file format, see: http://www.nrlmry.navy.mil/atcf_web/docs/database/new/abdeck.txt
Model data must be run through a vortex tracking algorithm prior to becoming input for MET-TC. Running a vortex tracker is outside the scope of this tutorial, however a freely available and supported vortex tracking software is available at:https://dtcenter.org/community-code/gfdl-vortex-tracker/download
If users choose to use operational model data for input to MET-TC, all U.S. operational model output in ATCF format can be found at: ftp://ftp.nhc.noaa.gov/atcf/archive. Finally, the most common use of MET-TC is to use the best track analysis (used as observations) to generate pairs between the model forecast and the observations. Best track analyses can be found at the same link as the operational model output.
Open files aal112017.dat (model data) and bal112017.dat (BEST track). Take a look at the columns and gain familiarity with ATCF format. These files are input ATCF files for TC-Pairs.
In addition to the files above, data from five total storms over hurricane seasons 2011-2012 in the AL basin will be used to run TC-Pairs. Rather than running a single storm, these storms were chosen to provide a larger sample size to provide more robust statistics.
- aal092011: Irene
- aal182011: Rina
- aal052012: Ernesto
- aal092012: Isaac
- aal182012: Sandy