Tropical Depression 21W

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              
     20201024 080423   -3.3      N/A  17.8% 199.98    3.33  30.0 SSMI16  13.3 -129.7   13.3 -129.7   13.3 -129.6 Analysis Plot     
     20201024 093539   -2.6      N/A  27.4% 166.65    2.59  30.0 SSMI18  13.3 -129.5   13.3 -129.5   13.3 -129.6 Analysis Plot     
     20201024 194020   -3.6      N/A  38.4%  99.99    3.60  35.0 SSMI15  13.5 -127.5   13.5 -127.5   13.4 -127.2 Analysis Plot     
     20201024 212251   -5.8      N/A  15.1%  99.99    5.79  35.0 SSMI18  13.5 -127.2   13.4 -127.0   13.4 -127.0 Analysis Plot     
     20201024 213141   -4.6      N/A  15.1%  99.99    4.59  35.0 SSMI16  13.5 -127.2   13.3 -126.9   13.3 -126.9 Analysis Plot     
     20201025 075123   47.2  >65 kts 100.0%  66.66   32.22  55.0 SSMI16  13.4 -124.7   13.3 -124.5   13.3 -124.5 Analysis Plot     
     20201025 184056   85.5  >85 kts 100.0%  44.44   70.49  65.0    GMI  13.5 -121.3   13.2 -121.7   13.2 -121.7 Analysis Plot     
     20201025 211911   66.7  >85 kts 100.0%  44.44   51.67  75.0 SSMI16  13.2 -121.2   13.2 -121.4   13.2 -121.4 Analysis Plot     
     20201026 091022   52.1  >65 kts 100.0% 111.10   37.13  80.0 SSMI18  13.6 -118.4   13.1 -118.4   13.1 -118.4 Analysis Plot     
     20201026 094719    2.7      N/A  42.5% 122.21    2.70  80.0 SSMI15  13.5 -118.6   13.3 -118.5   13.3 -118.5 Analysis Plot     
     20201026 211241   45.6  >65 kts 100.0%  88.88   30.61  90.0 SSMI15  13.3 -115.3   13.3 -115.6   13.3 -115.6 Analysis Plot     
     20201026 223007   18.4      N/A  60.3%  99.99   18.44  90.0 SSMI18  13.3 -115.1   13.4 -115.4   13.4 -115.4 Analysis Plot     
     20201027 090704   11.5      N/A  42.5%  66.66   11.50 110.0 SSMI16  13.6 -113.0   13.4 -112.8   13.4 -112.8 Analysis Plot     
     20201027 221659    5.1      N/A  11.0% 188.87    5.06 100.0 SSMI18  14.4 -110.5   14.7 -110.9   14.7 -110.9 Analysis Plot     
     20201027 222543    4.8      N/A  21.9% 177.76    4.80 100.0 SSMI16  14.4 -110.5   14.8 -110.6   14.8 -110.6 Analysis Plot     
     20201028 055601    5.3      N/A  12.3% 155.54    5.31  90.0    GMI  15.3 -108.5   15.8 -108.9   15.8 -108.9 Analysis Plot     
     20201028 085353    N/A      N/A   N/A     N/A     N/A  70.0 SSMI16  15.5 -108.0   15.5 -108.0   15.1 -107.1 Analysis Plot     
     20201028 104552    N/A      N/A   N/A     N/A     N/A  70.0 SSMI15  15.5 -107.9   15.5 -107.9   15.1 -107.0 Analysis Plot     
     20201028 191105 -930.0      N/A   N/A     N/A    0.00  70.0    GMI  16.0 -105.5   16.0 -105.5   16.5 -105.6 Analysis Plot     
     20201028 222110 -930.0      N/A   N/A     N/A    0.00  70.0 SSMI16  16.1 -105.0   16.1 -105.0   15.8 -105.9 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.