Tropical Depression 21N_04

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              
     20210925 065746   -3.4      N/A  79.5%  22.22    3.40  30.0  AMSR2  18.3  -88.4   18.3  -88.4   18.3  -88.9 Analysis Plot     
     20210925 111648    N/A      N/A   N/A     N/A     N/A  30.0 SSMI16  18.3  -87.7   18.3  -87.7   18.2  -88.4 Analysis Plot     
     20210925 124305 -930.0      N/A   N/A     N/A    0.00   0.0 SSMI17  18.2  -87.5   18.2  -87.5   19.1  -88.6 Analysis Plot     
     20210926 001459 -930.0      N/A   N/A     N/A    0.00  35.0 SSMI18  18.2  -86.6   18.2  -86.6   19.2  -87.3 Analysis Plot     
     20210926 003237   -2.9      N/A  20.6% 133.32    2.87  35.0 SSMI16  18.2  -86.5   18.2  -86.5   19.1  -86.9 Analysis Plot     
     20210926 021002  -25.2      N/A 100.0%  33.33   10.23  35.0 SSMI17  18.2  -86.3   18.2  -86.3   18.3  -85.6 Analysis Plot     
     20210926 073912   -2.6      N/A  38.4% 122.21    2.56  45.0  AMSR2  18.3  -85.5   18.3  -85.5   18.6  -84.8 Analysis Plot     
     20210926 104431    N/A      N/A   N/A     N/A     N/A  45.0 SSMI18  18.3  -85.3   18.3  -85.3   18.0  -84.4 Analysis Plot     
     20210926 110356    N/A      N/A   N/A     N/A     N/A  45.0 SSMI16  18.3  -85.2   18.3  -85.2   18.2  -84.4 Analysis Plot     
     20210926 122952 -930.0      N/A   N/A     N/A    0.00  45.0 SSMI17  18.3  -85.1   18.3  -85.1   18.0  -84.4 Analysis Plot     
     20210926 195125   -1.9      N/A  28.8%  33.33    1.93  35.0  AMSR2  18.3  -82.8   18.0  -83.3   18.0  -83.3 Analysis Plot     
     20210927 000111   -2.4      N/A  50.7% 177.76    2.43  35.0 SSMI18  18.3  -82.4   18.0  -82.5   18.0  -82.5 Analysis Plot     
     20210927 002306   -4.5      N/A  46.6% 188.87    4.51  35.0 SSMI16  18.3  -82.3   18.3  -82.3   18.1  -82.5 Analysis Plot     
     20210927 020053 -930.0      N/A   N/A     N/A    0.00  35.0 SSMI17  18.3  -82.1   17.8  -82.3   17.8  -82.3 Analysis Plot     
     20210927 082325 -930.0      N/A   N/A     N/A    0.00  30.0  AMSR2  18.3  -81.8   18.3  -81.8   18.2  -81.2 Analysis Plot     
     20210927 105039 -930.0      N/A   N/A     N/A    0.00  30.0 SSMI16  18.3  -81.4   18.3  -81.4   18.5  -81.1 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.