* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL122017 09/05/17 00 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 58% 88% LAT (deg N) 11.6 12.0 12.4 12.5 12.7 13.3 13.8 14.3 15.4 16.8 18.2 19.9 22.0 LON (deg W) 36.1 37.0 38.1 39.1 40.1 42.7 45.3 47.9 50.6 53.3 55.4 57.0 58.4 DTL (km) 1668 1688 1710 1627 1553 1395 1261 1149 1140 1065 1019 930 865 TRACK SOURCE AVNO AVNO AVNO AVNO AVNO AVNO AVNO AVNO AVNO AVNO AVNO AVNO AVNO TCGI 0-48h Genesis Forecast: 58% is 2.0 times the sample mean ( 29%) TCGI 0-120h Genesis Forecast: 88% is 1.8 times the sample mean ( 48%) --------------------------------------------------------------------------------------------- CONTRIBUTIONS (CONT) OF CLIMATOLOGY AND INDIVIDUAL PREDICTORS TO TCGI PROBABILITY ******* 48-HR ****** ******* 120-HR ****** AVG TCGI CONT AVG TCGI CONT GENESIS CLIM 28.5% 48.4% DIVERGENCE -1.4 -3.0 7.9% -1.4 -3.6 14.1% VORTICITY 1.7 2.4 4.6% 1.4 2.8 15.5% VERTICAL SHEAR 16.3 6.8 10.3% 18.4 11.7 6.0% RH 73.1 81.7 0.0% 70.9 78.4 -0.3% GOES 29.1 53.6 2.6% 29.3 53.6 1.4% DVORAK 0.8 1.0 3.8% 0.8 1.0 2.9% --------------------------------------------------------------------------------------------- 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 = TAFB Dvorak T-number Version 2.0, August 2017