Tropical Depression 18W

Passive Microwave (PMW) Intensity Information
Advanced Dvorak Technique (ADT)
Version 8.1.5
 

         Overpass     Inten           Ring    Ring          Wind           Forecast        Final        Target  
       Date    Time   Score  Meaning   Pct    Diam  BTdiff   Est   Sat    Lat    Lon    Lat    Lon    Lat    Lon              
     20130918 101600   -0.4      N/A   5.5% 288.86     .38  25.0 SSMI17  16.5 -109.8   16.5 -109.8   16.3 -109.6 Analysis Plot     
     20130918 124800 -930.0      N/A   N/A  333.30    5.30  25.0 SSMI18  16.5 -109.4   16.5 -109.4   15.9 -109.4 Analysis Plot     
     20130918 214200 -930.0      N/A   N/A  333.30    3.08  25.0 SSMI16  16.2 -107.5   16.2 -107.5   15.9 -107.4 Analysis Plot     
     20130918 225100 -930.0      N/A   N/A  333.30    3.62  25.0 SSMI17  16.1 -107.3   16.1 -107.3   15.7 -106.7 Analysis Plot     
     20130919 012300 -930.0      N/A   N/A  333.30    1.51  25.0 SSMI18  16.0 -106.8   16.0 -106.8   15.8 -106.2 Analysis Plot     
     20130919 035642 -930.0      N/A   N/A  322.19    9.87  25.0   TRMM  16.0 -106.6   16.0 -106.6   15.6 -106.4 Analysis Plot     
     20130919 094957   -2.1      N/A   N/A  222.20    2.15  25.0 SSMI15  15.8 -105.8   15.8 -105.8   15.2 -105.7 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.