Tropical Depression 21L

Passive Microwave (PMW) Intensity Information
Hurricane Intensity Estimation (HIE) Algorithm
Version 9.0


         Overpass     Inten           Ring    Ring          Wind           Forecast        Final        Target  
       Date    Time   Score  Meaning   Pct    Diam  BTdiff   Est   Sat    Lat    Lon    Lat    Lon    Lat    Lon              
     20200914 165105   -4.0      N/A   5.5% 222.20    4.04  40.0    GMI  18.9   28.6   18.9   28.6   18.6   28.8 Analysis Plot     
     20200914 182322   -0.5      N/A   N/A  222.20     .50  40.0 SSMI16  19.0   28.7   19.0   28.7   18.4   28.8 Analysis Plot     
     20200915 041227 -930.0      N/A   N/A     N/A    0.00  45.0  AMSR2  19.7   30.1   19.7   30.1   20.2   30.0 Analysis Plot     
     20200915 060200   -5.3      N/A  11.0% 144.43    5.33  45.0 SSMI15  19.9   30.3   19.9   30.3   20.4   29.9 Analysis Plot     
     20200915 080555   -4.4      N/A   9.6% 222.20    4.45  45.0 SSMI16  19.9   30.4   19.9   30.4   20.1   30.3 Analysis Plot     
     20200915 150614 -930.0      N/A   N/A     N/A    0.00  45.0  AMSR2  20.6   31.0   20.6   31.0   20.6   31.0 Analysis Plot     
     20200915 181013   -4.7      N/A   6.8% 211.09    4.72  45.0 SSMI16  20.8   31.3   20.8   31.3   20.6   31.4 Analysis Plot     
     20200916 032240  -13.3      N/A  12.3% 155.54   13.32  45.0    GMI  21.6   33.2   21.6   33.2   21.5   33.1 Analysis Plot     
     20200916 075249   -6.0      N/A   N/A  222.20    6.01  45.0 SSMI16  21.8   33.7   21.8   33.7   21.5   33.5 Analysis Plot     
     20200916 164148  -12.8      N/A   5.5% 177.76   12.82  35.0    GMI  21.5   34.9   21.5   34.9   21.3   34.8 Analysis Plot     
     20200916 175705 -930.0      N/A   N/A     N/A    0.00  35.0 SSMI16  21.5   35.0   21.5   35.0   21.3   35.0 Analysis Plot     
     20200916 191114   -2.9      N/A  13.7% 144.43    2.94  35.0 SSMI18  21.6   35.2   21.6   35.2   21.4   34.6 Analysis Plot     
     20200917 035904   -5.7      N/A   4.1% 222.20    5.73  35.0  AMSR2  21.6   36.0   21.6   36.0   21.8   36.3 Analysis Plot     
     20200917 073944 -930.0      N/A   N/A     N/A    0.00  35.0 SSMI16  21.6   36.3   21.6   36.3   21.7   36.5 Analysis Plot     
     20200917 074825 -930.0      N/A   N/A     N/A    0.00  35.0 SSMI15  21.6   37.2   21.6   37.2   22.2   36.8 Analysis Plot     
     20200917 085817   -3.2      N/A   N/A   66.66    3.17  35.0 SSMI18  21.9   36.5   21.9   36.5   22.0   36.8 Analysis Plot     
     20200917 190312   -2.0      N/A   N/A   66.66    1.95  30.0 SSMI18  21.3   38.7   21.3   38.7   21.2   38.8 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.