Tropical Depression 18W

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              
     20210906 084001   -2.7      N/A  41.1%  44.44    2.74  30.0 SSMI16  11.0 -127.0   11.0 -127.0   10.8 -126.5 Analysis Plot     
     20210906 095615   -8.6      N/A  79.5%  33.33    8.62  50.0 SSMI18  10.9 -126.7   10.9 -126.7   10.8 -126.5 Analysis Plot     
     20210906 115431  -43.0      N/A 100.0%  33.33   27.96  50.0 SSMI17  11.1 -126.5   11.1 -126.5   11.0 -126.2 Analysis Plot     
     20210906 213348    2.8      N/A   1.4%  44.44    2.85  60.0 SSMI18  11.7 -124.6   11.7 -124.6   11.6 -124.4 Analysis Plot     
     20210906 215532    4.9      N/A  20.5%  44.44    4.92  60.0 SSMI16  11.7 -124.6   11.7 -124.6   11.7 -124.4 Analysis Plot     
     20210906 233050    N/A      N/A   N/A     N/A     N/A  60.0 SSMI17  11.8 -124.4   11.8 -124.4   12.0 -124.3 Analysis Plot     
     20210907 052757   19.8      N/A  61.6%  55.55   19.80  55.0  AMSR2  12.2 -123.8   12.2 -123.4   12.2 -123.4 Analysis Plot     
     20210907 081537    7.1      N/A  38.4%  55.55    7.15  55.0 SSMI16  12.4 -123.6   12.4 -123.6   12.4 -123.4 Analysis Plot     
     20210907 094330   -1.1      N/A  20.5%  66.66    1.10  45.0 SSMI18  12.7 -123.0   12.7 -123.0   12.3 -123.3 Analysis Plot     
     20210907 174217    6.1      N/A  64.4%  66.66    6.12  55.0  AMSR2  13.3 -122.0   13.3 -122.2   13.3 -122.2 Analysis Plot     
     20210907 214248    6.6      N/A  35.6%  44.44    6.63  55.0 SSMI16  13.5 -121.7   13.5 -121.8   13.5 -121.8 Analysis Plot     
     20210907 231816   33.9  >65 kts  95.9%  33.33   18.86  55.0 SSMI17  13.6 -121.6   13.6 -121.6   13.6 -121.6 Analysis Plot     
     20210908 210814 -930.0      N/A   N/A     N/A    0.00  50.0 SSMI18  15.8 -118.7   15.8 -118.7   15.1 -118.9 Analysis Plot     
     20210908 213024 -930.0      N/A   N/A     N/A    0.00  50.0 SSMI16  15.8 -118.6   15.8 -118.6   15.8 -118.4 Analysis Plot     
     20210909 051656  -35.9      N/A 100.0%  11.11   20.86  50.0  AMSR2  16.0 -117.3   16.0 -117.3   15.8 -117.0 Analysis Plot     
     20210909 111414   -1.8      N/A   6.8% 177.76    1.82  50.0 SSMI17  16.0 -116.4   16.0 -116.4   15.2 -116.0 Analysis Plot     
     20210910 003335    N/A      N/A   N/A     N/A     N/A  45.0 SSMI17  16.0 -112.9   16.0 -112.9   15.8 -112.8 Analysis Plot     
     20210910 055937   -7.4      N/A  58.9%  22.22    7.37  45.0  AMSR2  15.8 -111.9   15.8 -111.9   15.8 -111.8 Analysis Plot     
     20210910 090511    N/A      N/A   N/A     N/A     N/A  40.0 SSMI18  15.6 -111.8   15.6 -111.8   15.5 -112.2 Analysis Plot     
     20210910 092824   -0.2      N/A  17.8%  33.33     .15  40.0 SSMI16  15.6 -111.8   15.6 -111.8   15.5 -112.1 Analysis Plot     
     20210910 110044   -1.5      N/A   6.8% 122.21    1.49  40.0 SSMI17  15.6 -111.6   15.6 -111.6   15.6 -112.2 Analysis Plot     
     20210910 181237   -2.6      N/A   6.8%  33.33    2.61  45.0  AMSR2  15.7 -110.8   15.7 -110.8   15.7 -110.8 Analysis Plot     
     20210910 222429   -0.1      N/A  20.5% 144.43     .14  45.0 SSMI18  15.7 -110.6   15.7 -110.6   15.9 -109.6 Analysis Plot     
     20210910 224607   -1.5      N/A  20.5%  66.66    1.50  45.0 SSMI16  15.7 -110.5   15.7 -110.5   15.8 -109.7 Analysis Plot     
     20210911 002005   -0.8      N/A  75.3%  55.55     .84  45.0 SSMI17  15.7 -110.4   15.7 -110.4   15.2 -109.5 Analysis Plot     
     20210911 085224   -4.8      N/A   N/A  211.09    4.79  50.0 SSMI18  15.6 -109.4   15.6 -109.4   15.8 -109.5 Analysis Plot     
     20210911 091534   -4.3      N/A   6.8% 188.87    4.33  50.0 SSMI16  15.6 -109.4   15.6 -109.4   15.7 -109.5 Analysis Plot     
     20210911 185703 -930.0      N/A   N/A     N/A    0.00  40.0  AMSR2  15.2 -109.1   15.2 -109.1   15.8 -108.2 Analysis Plot     
     20210911 221218   -2.8      N/A  12.3% 122.21    2.79  40.0 SSMI18  15.2 -109.1   15.2 -109.1   15.7 -109.3 Analysis Plot     
     20210912 000600    N/A      N/A   N/A     N/A     N/A  40.0 SSMI17  15.2 -109.1   15.2 -109.1   15.3 -108.5 Analysis Plot     
     20210912 054752   -4.5      N/A   N/A  111.10    4.46  30.0  AMSR2  15.6 -109.1   15.6 -109.1   15.2 -109.4 Analysis Plot     
     20210912 180113   -2.8      N/A   N/A   44.44    2.82  25.0  AMSR2  15.4 -109.1   15.4 -109.1   15.5 -109.3 Analysis Plot     
     20210912 221916   -1.6      N/A   N/A   88.88    1.58  25.0 SSMI16  15.6 -108.8   15.6 -108.8   15.7 -108.8 Analysis Plot     
     20210913 063052 -930.0      N/A   N/A     N/A    0.00  25.0  AMSR2  16.1 -108.0   16.1 -108.0   15.8 -107.7 Analysis Plot     
     20210913 120150   -2.1      N/A   N/A   44.44    2.11  25.0 SSMI17  16.3 -107.5   16.3 -107.5   16.0 -107.5 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.