Tropical Depression 31W

Passive Microwave (PMW) Intensity Information
Advanced Dvorak Technique
Version 9.1


       --Overpass--              --ARCHER--   Ring  Ring            Eye              BT   -Forecast-  
       Date    Time      Sat     Lat    Lon   Diam   Pct  TbDiff   Score  Meaning   Vmax  Lat    Lon                 
     20251101 162920     AMSR2   10.8  136.3    46   72%    8.03   -8.03      N/A   35.0  10.6  136.1 Analysis Plot     
     20251101 192451  SSMISF18   10.7  135.3   N/A   N/A     N/A     N/A      N/A   40.0  10.7  135.9 Analysis Plot     
     20251101 203650  SSMISF17   10.0  136.5   N/A   N/A     N/A     N/A      N/A   40.0  10.7  135.6 Analysis Plot     
     20251101 214016  SSMISF16   11.1  136.6   N/A   N/A     N/A     N/A      N/A   40.0  10.8  135.4 Analysis Plot     
     20251102 045741     AMSR2   11.3  133.3    57   33%    8.51   -8.51      N/A   45.0  10.8  133.9 Analysis Plot     
     20251102 114316       GMI   11.4  131.6   N/A   N/A     N/A     N/A      N/A   50.0  11.3  132.0 Analysis Plot     
     20251102 114326       GMI   11.0  132.5   N/A   N/A     N/A     N/A      N/A   50.0  11.3  131.9 Analysis Plot     
     20251102 171225     AMSR2   10.9  129.8    79   58%    9.85    9.85      N/A   55.0  11.3  130.1 Analysis Plot     
     20251102 231631       GMI   10.4  128.9    57   43%   11.61   11.61      N/A   60.0  10.8  128.8 Analysis Plot     
     20251103 080138  SSMISF18   10.6  127.4   N/A   N/A     N/A     N/A      N/A   80.0  10.4  127.1 Analysis Plot     
     20251103 101617  SSMISF16   10.7  126.5    12  100%   21.91   36.91  >65 kts   80.0  10.4  126.5 Analysis Plot     
     20251104 100343  SSMISF16   10.8  119.4   N/A   N/A     N/A     N/A      N/A   70.0  10.6  121.0 Analysis Plot     
     20251104 115407       GMI   11.1  120.9   112   47%    0.11    0.11      N/A   70.0  10.6  120.8 Analysis Plot     
     20251104 202310  SSMISF18   10.9  119.6    79  100%   39.06   54.06  >65 kts   70.0  11.1  119.3 Analysis Plot     
     20251104 232739       GMI   11.3  119.1    68  100%   34.84   49.84  >65 kts   70.0  11.3  119.0 Analysis Plot     
     20251105 052810     AMSR2   11.7  117.6    23   61%   12.19   12.19      N/A   75.0  11.8  117.8 Analysis Plot     
     20251105 174331     AMSR2   13.1  114.5    34  100%   63.96   78.96  >85 kts  100.0  13.0  114.0 Analysis Plot     
     20251105 230054  SSMISF17   12.9  112.6    23  100%   55.09   70.09  >85 kts  100.0  13.6  112.9 Analysis Plot     
     20251106 061149     AMSR2   13.3  110.7    23   26%   18.91   18.91      N/A  110.0  13.7  110.3 Analysis Plot     
     20251106 120606       GMI   13.9  109.4    90   31%    5.14    5.14      N/A  110.0  13.9  109.2 Analysis Plot     
     20251106 182545     AMSR2   14.6  107.6   N/A   N/A     N/A     N/A      N/A   80.0  14.4  107.2 Analysis Plot     
     20251106 213704  SSMISF18   14.6  106.8   N/A   N/A     N/A     N/A      N/A   80.0  14.6  106.6 Analysis Plot     
     20251106 233741       GMI   14.5  106.4   N/A   N/A     N/A     N/A      N/A   80.0  14.7  106.5 Analysis Plot     
     20251106 235311  SSMISF16   14.5  106.4   N/A   N/A     N/A     N/A      N/A   80.0  14.8  106.2 Analysis Plot

Legend

  - Overpass Date/Time are determined from satellite overpass of targeted TC (position determined from Best Track Lat/Lon position). Date is YYYYMMDD and time in HHMMSS (UTC).

  - Forecast (Best Track) and ARCHER positions (deg) of the TC center at overpass day/time. Positive/Negative: Latitude = North/South Hemisphere; Longitude = Eastern/Western Hemisphere.

  - BT Vmax is the concurrent ATCF Best Track (BT) wind speed intensity estimate (Vmax) value from either NOAA/National Hurricane Center (NHC) (North Atlantic and Northeast Pacific), NOAA/Central Pacific Hurricane Center (CPHC) (North-central Pacific) or Joint Typhoon Warning Center (JTWC) (Northwest Pacific, Indian Ocean, or Southwest Pacific).

  - Sat is the satellite descriptor providing the overpass. Currently the satellites used are the DMSP/SSMIS-16/17/18, GPM/GMI, and GCOM/AMSR2.

  - Ring Diam (km) indicates the estimated surface eyewall diameter if one is analyzed in the PMW imagery. The value listed is the average PMW-estimated inner eyewall edge diameter minus 10 km for eyewall slope. N/A indicates no appreciable eyewall is analyzed.

  - Ring Pct is the percentage of the analyzed "ring" (eyewall inner boundary) that is 1) colder than the eye Tb (the "hot spot" -- warmest eye pixel) by at least 20K, or 2) that is colder than 232K and colder than the eye Tb by 10K, whichever is greater. Values are red if Ring % ≤65,yellow/brown if Ring % ≤85 and green if Ring % >85. N/A indicates no appreciable eyewall is analyzed. A value over 85% is used in the intensity score by adding 15 points to it.

  - TbDiff is the difference between the warmest eye pixel and the warmest pixel on the eyewall. This value is used in the Intensity Score. N/A indicates no appreciable eyewall is analyzed.

  - Eye Score values are based on the strength and organization of the convective/eyewall signatures in the PMW imagery, and based on the ARCHER center location. They normally range from 0 to 100 with empirically-determined thresholds related to intensity (Vmax) in the "Meaning" column (≥20 suggests ≥65kts; ≥60 suggests ≥85kts). Scores are listed as negative, and not used by the ADT, when the NHC, CPHC, or JTWC Best Track Vmax is <55 kts in order to filter out occasional "false eye" cases. A value of -920 is used when the warmest eye pixel is <200K to prevent false positives; -930 means edge of overpass and <85% of eyewall is captured and therefore can't fully be analyzed.