MET Online Tutorial for METv8.0 | TC-Pairs > Output

The output of the TC-Pairs tool is simply an ASCII file ending with the .tcst suffix. Open up the $MET_TUTORIAL_DATA/output/tc_pairs/tc_pairs_sandy.tcst output file using the text editor of your choice and note the following:

• The file contains a table which summarizes the ADeck and BDeck pairs.
• Browse the header row and note the data types. For a complete description of the contents, see section 19.2.3 of the MET Users Guide.
• The header columns contain the model name, storm identification, and timing information.
• There is one output line for each track point but the points are grouped together sequentially into tracks.
• Scroll over to the LINE_TYPE column which is set to TCMPR for Tropical-Cyclone Matched Pairs. Additional line types will be added in future releases when support for new data types are added.
• Scroll over to the TOTAL column which lists the total number of track points and the INDEX column which counts from 1 up to TOTAL.
• Scroll over to the LEVEL and WATCH_WARN columns which indicate the storm intensity and hurricane watches or warnings in effect at that time.
• Scroll over to the ALAT, ALON, BLAT, and BLON columns which indicate the ADeck and BDeck storm locations. Notice that some values contain NA. By default, TC-Pairs writes all ADeck and BDeck track points, regardless of whether the same time exists in the other track. This behavior is configurable, as we'll see below.
• Scorll over to the TK_ERR column. This is the distance in nautical miles between the ADeck and BDeck locations. The X_ERR and Y_ERR columns decompose the difference into East-West and North-South components. The ALTK_ERR and CRTRK_ERR columns decompose the difference into track-relative components.
• The AMAX_WIND and BMAX_WIND columns indicate the ADeck and BDeck maximum wind speeds in knots and are used to determine storm intensity.
• There are many additional columns for the 34, 50, and 64 knot radius winds broken down by quadrant and several other summary columns. These columns are only populated when the input ATCF files contain that data.

Since the lines of data in these ASCII files are so long, we strongly recommend configuring your text editor to NOT use dynamic word wrapping. The files will be much easier to read that way.

Match Points

As mentioned above, TC-Pairs by default writes every track point regardless of whether that time is present in the other track. This is the behavior when the match_points configuration entry is set to FALSE. Let's try switching that option and rerunning TC-Pairs:

• Open up the $MET_TUTORIAL_DATA/config/TCPairsConfig configuraiton file for editing and set:

• Save and close that file and rerun TC-Pairs:

• Open up the output $MET_TUTORIAL_DATA/output/tc_pairs/tc_pairs_sandy.tcst file and inspect the ALAT, ALON, BLAT, and BLON columns. The NA values should be gone. Also note that the TOTAL number of pairs for each track has decreased.