Tropical Storm 31P

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                 
     20260405 121031       GMI  -14.9  172.3    23   67%    5.80   -5.80      N/A   50.0 -14.7  172.1 Analysis Plot     
     20260405 195012  SSMISF16  -15.3  172.9    12  100%   15.34   30.34  >65 kts   75.0 -15.7  173.0 Analysis Plot     
     20260406 112757       GMI  -16.5  173.9    68   99%   18.46   33.46  >65 kts   90.0 -16.6  174.0 Analysis Plot     
     20260406 134411     AMSR2  -17.0  173.9    57  100%   33.42   48.42  >65 kts   95.0 -16.9  174.2 Analysis Plot     
     20260406 193617  SSMISF16  -17.6  174.6    34   51%   20.60   20.60  >65 kts   95.0 -17.7  174.8 Analysis Plot     
     20260407 045721  SSMISF18  -18.7  175.4   201   69%   19.13   19.13      N/A  100.0 -19.0  175.3 Analysis Plot     
     20260407 104529       GMI  -19.8  176.2    34   57%    0.19    0.19      N/A  100.0 -20.0  175.8 Analysis Plot     
     20260407 161038  SSMISF18  -21.0  176.4    68  100%   25.83   40.83  >65 kts   95.0 -20.9  176.5 Analysis Plot     
     20260408 001042       GMI  -23.0  177.6   N/A   N/A     N/A     N/A      N/A   90.0 -22.1  177.6 Analysis Plot     
     20260408 044155  SSMISF18  -22.9  177.7   223   19%    7.35    7.35      N/A   80.0 -23.1  177.9 Analysis Plot     
     20260408 100306       GMI  -24.1  178.5   N/A   N/A     N/A     N/A      N/A   75.0 -24.1  177.9 Analysis Plot     
     20260408 133356     AMSR2  -26.1  179.2   N/A   N/A     N/A     N/A      N/A   65.0 -24.9  178.2 Analysis Plot     
     20260408 155732  SSMISF18  -25.2  178.3   279   N/A    4.83    4.83      N/A   65.0 -25.2  178.3 Analysis Plot     
     20260408 233007       GMI  -25.8  178.8   N/A   N/A     N/A     N/A      N/A   60.0 -26.0  178.7 Analysis Plot     
     20260409 073904  SSMISF16  -27.0  179.1   N/A   N/A     N/A     N/A      N/A   55.0 -27.1  179.0 Analysis Plot     
     20260409 154413  SSMISF18  -28.0  179.3    90   18%    1.73    1.73      N/A   55.0 -27.9  179.1 Analysis Plot     
     20260409 181512  SSMISF17  -28.8  179.3   135   17%    0.82    0.82      N/A   55.0 -28.1  179.1 Analysis Plot     
     20260409 185655  SSMISF16  -28.5  179.0    90    7%    2.20    2.20      N/A   55.0 -28.4  179.1 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.