*          ATLANTIC TC GENESIS INDEX           *
                      *                GFS VERSION                   *
                      *           AL172020 09/19/20 18 UTC           *

TIME (hr)           0     6    12    18    24    36    48    60    72    84    96   108   120
Prob of Genesis                                       40%                                 55%

LAT  (deg N)     36.0  35.9  35.8  35.6  35.5  35.5  36.3  37.0  36.8  36.3  35.8  35.3  34.6
LON  (deg W)     29.7  29.4  29.4  29.6  29.6  28.4  25.7  22.9  19.8  16.4  13.8  12.5  12.1
DTL  (km)        1813  1784  1779  1786  1782  1683  1481  1218   958   674   461   379   363
TRACK SOURCE     AP01  AP01  AP01  AP01  AP01  AP01  AP01  AP01  AP01  AP01  AP01  AP01  AP01

TCGI  0-48h Genesis Forecast:   40% is  1.3 times the sample mean (  30%)
TCGI 0-120h Genesis Forecast:   55% is  1.3 times the sample mean (  43%)

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INDIVIDUAL PREDICTOR CONTRIBUTIONS TO PROBABILITY OF GENESIS 

               *******  48-HR ******   ******* 120-HR ******
                   AVG   TCGI   CONT       AVG   TCGI   CONT
DIVERGENCE        -1.0    0.2   5.1%       1.0    0.7   7.2%
VORTICITY          1.7    4.0  15.5%       1.4    3.2  25.9%
VERTICAL SHEAR    16.3   10.2  17.9%      18.4   15.3  18.8%
RH                73.1   54.2  -0.1%      70.9   55.3   1.1%
GOES              29.1    0.0   0.0%      29.3    0.0   0.0%
DVORAK             0.8    0.5   1.8%       0.8    0.5   1.7%

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PREDICTOR DEFINITIONS (Averaged Over 500 km Radius)

GENESIS CLIM   = Climatological Prob (%) of Genesis (Source: NHC-TAFB Invest Database) 
DIVERGENCE     = GFS 850 hPa Horizontal Divergence (x10-7 s-1)
VORTICITY      = GFS 850 hPa Vorticity (x10-6 s-1)
VERTICAL SHEAR = GFS 200-850 hPa Vertical Shear (kt)
RH             = GFS 600-850 hPa Relative Humidity (%)
GOES           = GOES Water Vapor Pixels Colder than -40C (%)
DVORAK         = Dvorak T-number, source: TAFB

Version 3.0, July 2018