Tropical Depression 01W

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                 
     20230419 144721       GMI    6.1  157.8    57    3%    0.10   -0.10      N/A   25.0   5.1  158.2 Analysis Plot     
     20230419 165916  SSMISF18    6.0  157.7   N/A   N/A     N/A     N/A      N/A   25.0   5.6  158.0 Analysis Plot     
     20230419 185535  SSMISF16    5.7  156.0   N/A   N/A     N/A     N/A      N/A   30.0   5.9  157.6 Analysis Plot     
     20230419 195058  SSMISF17    6.1  158.3   157   33%    0.48   -0.48      N/A   30.0   6.0  157.6 Analysis Plot     
     20230420 021743       GMI    8.5  157.7    23   19%    2.48   -2.48      N/A   35.0   8.2  157.8 Analysis Plot     
     20230420 054626  SSMISF18   10.6  156.1   N/A   N/A     N/A     N/A      N/A   35.0   9.2  156.9 Analysis Plot     
     20230420 184153  SSMISF16   10.7  155.5   168   14%    1.49   -1.49      N/A   45.0  10.3  155.7 Analysis Plot     
     20230420 193734  SSMISF17    9.6  156.1    34   53%    0.97   -0.97      N/A   45.0  10.0  155.9 Analysis Plot     
     20230421 030641     AMSR2    9.8  155.7    34    7%    2.37   -2.37      N/A   45.0  10.2  156.0 Analysis Plot     
     20230421 053315  SSMISF18   10.3  155.9    23   22%    0.48   -0.48      N/A   45.0  10.3  155.9 Analysis Plot     
     20230421 143751       GMI   11.4  155.2   N/A   N/A     N/A     N/A      N/A   45.0  10.5  155.9 Analysis Plot     
     20230421 181226  SSMISF18   10.5  155.1    57   N/A    2.18   -2.18      N/A   45.0  10.6  155.6 Analysis Plot     
     20230422 020417       GMI   10.4  154.7   N/A   N/A     N/A     N/A      N/A   45.0  10.6  154.8 Analysis Plot     
     20230422 052032  SSMISF18   10.5  154.1   N/A   N/A     N/A     N/A      N/A   45.0  10.7  154.4 Analysis Plot     
     20230422 071813  SSMISF16   10.6  153.3    12   N/A    1.09   -1.09      N/A   45.0  10.4  153.1 Analysis Plot     
     20230422 081216  SSMISF17   10.4  153.1   101   N/A    1.93   -1.93      N/A   45.0  10.4  153.1 Analysis Plot     
     20230422 175824  SSMISF18    9.6  152.6   N/A   N/A     N/A     N/A      N/A   20.0  10.5  152.5 Analysis Plot     
     20230422 205056  SSMISF17   11.0  152.4   N/A   N/A     N/A     N/A      N/A   20.0  10.6  152.1 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.