* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL902021 08/31/21 06 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 76% 100% LAT (deg N) 9.5 10.6 11.5 10.7 11.3 11.0 11.4 12.8 15.1 18.0 20.7 23.5 26.7 LON (deg W) 16.6 17.1 18.9 20.9 22.6 26.8 26.9 28.2 30.7 33.8 35.3 36.7 36.6 DTL (km) 226 180 241 476 638 1092 1085 1175 1417 1773 1900 2035 2061 TRACK SOURCE AP02 AP02 AP02 AP02 AP02 AP02 AP02 AP02 AP02 AP02 AP02 AP02 AP02 TCGI 0-48h Genesis Forecast: 76% is 2.5 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 -2.9 14.5% 1.0 -2.7 20.9% VORTICITY 1.7 4.3 22.5% 1.4 4.9 42.6% VERTICAL SHEAR 16.3 14.6 21.4% 18.4 16.8 20.7% RH 73.1 88.8 -0.1% 70.9 84.6 2.2% GOES 29.1 45.7 3.0% 29.3 45.7 1.8% DVORAK 0.8 1.5 14.4% 0.8 1.5 11.9% --------------------------------------------------------------------------------------------- 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 = Dvorak T-number, source: TAFB Version 3.0, July 2018