Tropical Depression 21P

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                 
     20250224 220423       GMI  -16.3  170.1   N/A   N/A     N/A     N/A      N/A   40.0 -16.7  170.7 Analysis Plot     
     20250225 023356     AMSR2  -16.5  171.0   N/A   N/A     N/A     N/A      N/A   45.0 -17.1  171.0 Analysis Plot     
     20250225 065122  SSMISF16  -17.1  171.0    79   40%    4.36    4.36      N/A   60.0 -17.3  171.1 Analysis Plot     
     20250225 132754     AMSR2  -18.1  171.4    34   40%   13.61   13.61      N/A   65.0 -18.3  171.3 Analysis Plot     
     20250225 185908  SSMISF17  -18.8  171.3   N/A   N/A     N/A     N/A      N/A   65.0 -18.8  171.5 Analysis Plot     
     20250225 212258       GMI  -18.5  170.9   N/A   N/A     N/A     N/A      N/A   55.0 -19.0  171.5 Analysis Plot     
     20250226 073211  SSMISF17  -20.0  172.3   N/A   N/A     N/A     N/A      N/A   55.0 -20.5  170.6 Analysis Plot     
     20250226 164610  SSMISF18  -22.0  172.5   N/A   N/A     N/A     N/A      N/A   50.0 -21.4  170.8 Analysis Plot     
     20250226 184507  SSMISF17  -22.2  172.6   N/A   N/A     N/A     N/A      N/A   50.0 -21.6  170.9 Analysis Plot     
     20250227 022004     AMSR2  -22.0  171.0   N/A   N/A     N/A     N/A      N/A   45.0 -22.1  171.2 Analysis Plot     
     20250227 051755  SSMISF18  -22.9  171.1   N/A   N/A     N/A     N/A      N/A   45.0 -22.3  171.4 Analysis Plot     
     20250227 071631  SSMISF17  -23.1  172.9   N/A   N/A     N/A     N/A      N/A   45.0 -22.4  171.4 Analysis Plot     
     20250227 080859       GMI  -22.2  171.0   N/A   N/A     N/A     N/A      N/A   45.0 -22.5  171.5 Analysis Plot     
     20250227 163220  SSMISF18  -23.4  173.4   N/A   N/A     N/A     N/A      N/A   45.0 -23.1  172.4 Analysis Plot     
     20250227 183117  SSMISF17  -24.8  173.4   N/A   N/A     N/A     N/A      N/A   45.0 -23.1  172.5 Analysis Plot     
     20250227 213517       GMI  -22.0  173.9   N/A   N/A     N/A     N/A      N/A   40.0 -23.2  172.6 Analysis Plot     
     20250228 050310  SSMISF18  -23.4  172.5   N/A   N/A     N/A     N/A      N/A   40.0 -23.0  172.9 Analysis Plot     
     20250228 070200  SSMISF17  -23.0  172.8   N/A   N/A     N/A     N/A      N/A   40.0 -23.0  172.9 Analysis Plot     
     20250228 072613       GMI  -22.9  172.6   N/A   N/A     N/A     N/A      N/A   40.0 -23.0  172.9 Analysis Plot     
     20250228 135832     AMSR2  -23.0  173.1   N/A   N/A     N/A     N/A      N/A   40.0 -23.1  173.2 Analysis Plot     
     20250228 161812  SSMISF18  -23.1  173.3   257   N/A    2.70   -2.70      N/A   40.0 -23.2  173.3 Analysis Plot     
     20250228 181706  SSMISF17  -23.2  173.4   301   N/A    1.47   -1.47      N/A   30.0 -23.2  173.4 Analysis Plot     
     20250228 190553  SSMISF16  -23.1  173.5   N/A   N/A     N/A     N/A      N/A   30.0 -23.1  173.5 Analysis Plot     
     20250228 205149       GMI  -22.9  173.4   N/A   N/A     N/A     N/A      N/A   30.0 -23.1  173.5 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.