Tropical Storm 23S

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                 
     20240501 102522     AMSR2   -8.8   45.0    90   10%    6.84   -6.84      N/A   35.0  -8.6   45.0 Analysis Plot     
     20240501 133026  SSMISF18   -9.3   43.9   N/A   N/A     N/A     N/A      N/A   35.0  -8.6   45.0 Analysis Plot     
     20240501 153007  SSMISF16   -8.8   45.1    68   17%    9.72   -9.72      N/A   35.0  -8.6   45.0 Analysis Plot     
     20240502 003706  SSMISF18   -9.3   44.1    68   26%    4.94   -4.94      N/A   35.0  -8.9   44.7 Analysis Plot     
     20240502 023655  SSMISF16   -9.2   44.0    68   44%    4.88   -4.88      N/A   35.0  -9.1   44.5 Analysis Plot     
     20240502 110902     AMSR2   -8.9   44.3   N/A   N/A     N/A     N/A      N/A   45.0  -9.1   44.0 Analysis Plot     
     20240502 131549  SSMISF18   -8.8   43.9    90   60%   20.28  -20.28      N/A   50.0  -8.7   44.0 Analysis Plot     
     20240502 150530  SSMISF17   -8.8   43.8    57   33%   20.63  -20.63      N/A   50.0  -8.7   44.0 Analysis Plot     
     20240502 151534  SSMISF16   -8.9   44.0    46   36%   22.30  -22.30      N/A   50.0  -8.7   44.0 Analysis Plot     
     20240502 201653       GMI   -8.9   43.7    46  100%   31.51   46.51  >65 kts   55.0  -8.6   43.7 Analysis Plot     
     20240503 002450  SSMISF18   -8.7   43.0   N/A   N/A     N/A     N/A      N/A   75.0  -8.4   43.4 Analysis Plot     
     20240503 075128       GMI   -8.4   42.4    34   64%    9.79    9.79      N/A   80.0  -8.6   42.5 Analysis Plot     
     20240503 130247  SSMISF18   -8.2   41.7    12  100%   20.46   35.46  >65 kts   80.0  -8.1   41.8 Analysis Plot     
     20240503 150238  SSMISF16   -8.3   41.1   N/A   N/A     N/A     N/A      N/A   75.0  -8.1   41.7 Analysis Plot     
     20240504 033926  SSMISF17   -8.0   39.9   N/A   N/A     N/A     N/A      N/A   55.0  -7.7   40.3 Analysis Plot     
     20240504 105630     AMSR2   -7.9   38.4   N/A   N/A     N/A     N/A      N/A   55.0  -7.3   39.7 Analysis Plot     
     20240504 125052  SSMISF18   -6.1   39.3   N/A   N/A     N/A     N/A      N/A   40.0  -7.2   39.6 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.