Tropical Depression 04W

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                 
     20230714 200154  SSMISF18   17.8  117.7   235   19%    1.46   -1.46      N/A   30.0  17.7  117.8 Analysis Plot     
     20230714 215513  SSMISF16   17.7  117.2   157    3%    0.72   -0.72      N/A   30.0  17.8  117.7 Analysis Plot     
     20230714 221402  SSMISF17   18.7  118.0   N/A   N/A     N/A     N/A      N/A   30.0  17.8  117.7 Analysis Plot     
     20230715 031403       GMI   18.4  118.4   N/A   N/A     N/A     N/A      N/A   35.0  18.3  116.8 Analysis Plot     
     20230715 050644     AMSR2   18.3  118.0   N/A   N/A     N/A     N/A      N/A   35.0  18.5  116.6 Analysis Plot     
     20230715 090818  SSMISF16   18.7  117.4   101   14%    0.83   -0.83      N/A   35.0  18.2  117.7 Analysis Plot     
     20230715 163048       GMI   19.1  116.7   N/A   N/A     N/A     N/A      N/A   40.0  18.7  117.1 Analysis Plot     
     20230715 194944  SSMISF18   18.7  116.3   N/A   N/A     N/A     N/A      N/A   45.0  18.8  116.6 Analysis Plot     
     20230715 214156  SSMISF16   18.7  116.1   135   31%    0.57   -0.57      N/A   45.0  18.9  116.3 Analysis Plot     
     20230716 054839     AMSR2   19.0  115.7    57   25%    6.13    6.13      N/A   55.0  19.4  115.4 Analysis Plot     
     20230716 105400  SSMISF17   19.6  115.1    57    3%    6.59    6.59      N/A   55.0  19.6  115.1 Analysis Plot     
     20230716 175936     AMSR2   19.9  113.6   168  100%   23.29   38.29  >65 kts   65.0  20.0  113.6 Analysis Plot     
     20230716 232644  SSMISF17   19.9  113.3   101   22%   22.89   22.89  >65 kts   65.0  19.9  113.2 Analysis Plot     
     20230717 030116       GMI   20.6  112.4   N/A   N/A     N/A     N/A      N/A   70.0  20.3  112.6 Analysis Plot     
     20230717 083033  SSMISF18   21.2  111.5    79  100%   30.32   45.32  >65 kts   70.0  21.0  111.7 Analysis Plot     
     20230717 104029  SSMISF17   21.3  111.0    57   58%   26.92   26.92  >65 kts   65.0  21.3  110.6 Analysis Plot     
     20230717 161927       GMI   21.4  110.3   N/A   N/A     N/A     N/A      N/A   65.0  21.4  110.3 Analysis Plot     
     20230717 184215     AMSR2   21.9  110.0   N/A   N/A     N/A     N/A      N/A   70.0  21.5  109.0 Analysis Plot     
     20230717 210231  SSMISF18   21.6  109.1   N/A   N/A     N/A     N/A      N/A   70.0  21.5  108.8 Analysis Plot     
     20230717 225648  SSMISF16   22.0  109.1    23   N/A    5.52    5.52      N/A   70.0  21.6  108.5 Analysis Plot     
     20230717 231227  SSMISF17   22.0  108.7    23   N/A    4.87    4.87      N/A   70.0  21.6  108.4 Analysis Plot     
     20230718 053843     AMSR2   22.1  107.6   N/A   N/A     N/A     N/A      N/A   60.0  22.1  107.7 Analysis Plot     
     20230718 081753  SSMISF18   22.4  107.3    23   N/A    4.27   -4.27      N/A   50.0  22.2  107.5 Analysis Plot     
     20230718 101111  SSMISF16   22.3  107.2   N/A   N/A     N/A     N/A      N/A   50.0  22.3  107.2 Analysis Plot     
     20230718 102831  SSMISF17   22.4  107.0   N/A   N/A     N/A     N/A      N/A   50.0  22.4  107.1 Analysis Plot     
     20230718 204935  SSMISF18   22.9  105.4   N/A   N/A     N/A     N/A      N/A   30.0  22.8  105.3 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.