Tropical Depression 18W

Passive Microwave (PMW) Intensity Information
Advanced Dvorak Technique (ADT)
Version 8.2.1
 

         Overpass     Inten           Ring    Ring          Wind           Forecast        Final        Target  
       Date    Time   Score  Meaning   Pct    Diam  BTdiff   Est   Sat    Lat    Lon    Lat    Lon    Lat    Lon              
     20170831 200309   -1.9      N/A  11.0% 144.43    1.92  25.0 SSMI15  19.1 -118.7   19.1 -118.7   19.4 -119.1 Analysis Plot     
     20170831 221800 -930.0      N/A   N/A     N/A    0.00  25.0 SSMI17  19.3 -118.6   19.3 -118.6   19.3 -117.9 Analysis Plot     
     20170831 225300 -930.0      N/A   N/A     N/A    0.00  25.0 SSMI18  19.3 -118.5   19.3 -118.5   20.0 -118.8 Analysis Plot     
     20170901 062259 -930.0      N/A   N/A     N/A    0.00  30.0    GMI  20.0 -118.0   20.0 -118.0   20.7 -118.7 Analysis Plot     
     20170901 080251   -3.5      N/A   N/A   77.77    3.51  30.0 SSMI15  19.9 -118.0   19.9 -118.0   21.0 -118.4 Analysis Plot     
     20170901 084500   -0.0      N/A   N/A     N/A    0.00  30.0 SSMI16  20.6 -118.3   20.6 -118.3   20.6 -118.3 Analysis Plot     
     20170901 100800   -3.0      N/A  27.4% 111.10    2.96  30.0 SSMI18  20.8 -118.2   20.8 -118.2   21.0 -118.5 Analysis Plot     
     20170901 194139 -930.0      N/A   N/A     N/A    0.00  35.0    GMI  21.5 -117.9   21.5 -117.9   21.6 -117.6 Analysis Plot     
     20170901 195501   -1.7      N/A  12.3% 111.10    1.68  35.0 SSMI15  21.5 -118.0   21.5 -118.0   21.4 -117.7 Analysis Plot     
     20170901 224000   -1.8      N/A  27.4% 166.65    1.83  35.0 SSMI18  21.7 -117.8   21.7 -117.8   21.4 -117.3 Analysis Plot     
     20170902 083200   -1.5      N/A  15.1% 122.21    1.45  40.0 SSMI16  21.4 -117.3   21.4 -117.3   21.5 -117.1 Analysis Plot     
     20170902 095700   -1.4      N/A  16.4% 144.43    1.44  40.0 SSMI18  21.5 -117.2   21.5 -117.2   21.8 -117.0 Analysis Plot     
     20170902 110000 -930.0      N/A   N/A     N/A    0.00  40.0 SSMI17  21.6 -117.2   21.6 -117.2   22.1 -116.8 Analysis Plot     
     20170902 191353 -930.0      N/A   N/A     N/A    0.00  45.0 SSMI15  21.9 -116.9   21.9 -116.9   21.6 -117.8 Analysis Plot     
     20170902 213800   -1.3      N/A  46.6%  77.77    1.33  45.0 SSMI16  21.9 -116.8   21.9 -116.8   21.8 -116.4 Analysis Plot     
     20170902 222800   -2.0      N/A  16.4% 111.10    1.95  45.0 SSMI18  22.1 -116.8   22.1 -116.8   22.2 -116.8 Analysis Plot     
     20170903 080900 -930.0      N/A   N/A     N/A    0.00  45.0 SSMI16  22.3 -116.4   22.3 -116.4   23.1 -115.9 Analysis Plot     
     20170903 213500   -0.9      N/A   N/A  222.20     .91  30.0 SSMI16  23.2 -115.5   23.2 -115.5   23.7 -115.5 Analysis Plot     
     20170903 231600 -930.0      N/A   N/A     N/A    0.00  30.0 SSMI17  23.5 -115.2   23.5 -115.2   24.2 -115.3 Analysis Plot     
     20170904 052053   -1.1      N/A   4.1% 244.42    1.05  30.0    GMI  23.9 -114.8   23.9 -114.8   24.1 -114.1 Analysis Plot     
     20170904 103300   -0.0      N/A   N/A     N/A    0.00  30.0 SSMI17  24.1 -114.6   24.1 -114.6   24.4 -114.9 Analysis Plot
 
 
Legend:

  - Date/Time are determined from PMW imagery at Forecast (initial guess) Lat/Lon position.

  - Positive/Negative Latitude = North/South Hemisphere; Longitude = Western/Eastern Hemisphere.

  - "Ring Diam" value indicates the estimated surface eyewall diameter in km (the MI eyewall edge diameter minus 10 km).

  - "Ring Pct" is the percentage of the "ring" (eyewall inner boundary) that is 1) colder than the "hot spot" (warmest eye pixel) in the eye by 20K, or 2) the percentage that is a) colder than 232K and b) colder than the "hot spot" by 10K, whichever is greater.
  - Values are red if Ring % <= 65, yellow/brown if Ring % <= 85 and green if Ring % > 85.

  - "Tb diff" is the difference between the "hot spot" (warmest eye pixel) and the warmest pixel on the eyewall.

  - Intensity score are listed as negative, and not used, when the JTWC or NHC estimated Vmax is <55 kts in order to rule out weak but highly symmetric TCs.

  - Error messages in intensity scores: -920 is used when the hottest pixel in the eye is <200K, to prevent false positives; -930 means <85% of eyewall has observations/data.