* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL902021 08/31/21 18 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 100% 100% LAT (deg N) 10.5 10.8 11.2 12.0 12.3 12.3 13.4 14.6 16.8 18.3 20.1 21.4 23.0 LON (deg W) 21.2 23.0 24.2 26.0 27.8 30.3 31.9 33.8 35.8 37.7 39.8 41.7 43.0 DTL (km) 515 692 812 970 1146 1410 1559 1752 1969 2167 2176 2167 2247 TRACK SOURCE AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 TCGI 0-48h Genesis Forecast: 100% is 3.3 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 100% is 2.3 times the sample mean ( 43%) --------------------------------------------------------------------------------------------- INDIVIDUAL PREDICTOR CONTRIBUTIONS TO PROBABILITY OF GENESIS ******* 48-HR ****** ******* 120-HR ****** AVG TCGI CONT AVG TCGI CONT DIVERGENCE -1.0 -4.7 20.7% 1.0 -4.0 21.6% VORTICITY 1.7 5.2 28.9% 1.4 5.6 40.8% VERTICAL SHEAR 16.3 4.0 31.2% 18.4 5.2 23.7% RH 73.1 87.7 -0.2% 70.9 83.4 2.0% GOES 29.1 50.6 3.6% 29.3 50.6 1.7% DVORAK 0.8 1.5 15.7% 0.8 1.5 10.1% --------------------------------------------------------------------------------------------- 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