* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL902021 09/29/21 06 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 80% 90% LAT (deg N) 8.2 7.6 8.7 9.1 9.4 10.4 10.9 11.4 12.5 14.1 16.2 18.8 22.0 LON (deg W) 21.7 22.9 23.3 24.5 25.3 27.4 30.0 32.3 35.1 37.6 40.1 41.9 42.2 DTL (km) 696 840 809 908 978 1172 1421 1645 1795 1863 1822 1922 2193 TRACK SOURCE AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 TCGI 0-48h Genesis Forecast: 80% is 2.7 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 90% is 2.1 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 -5.6 21.8% 1.0 -3.7 24.6% VORTICITY 1.7 3.4 19.1% 1.4 3.2 30.1% VERTICAL SHEAR 16.3 9.2 25.8% 18.4 15.3 21.9% RH 73.1 78.1 -0.3% 70.9 75.6 3.8% GOES 29.1 77.2 5.2% 29.3 77.2 3.0% DVORAK 0.8 1.0 8.6% 0.8 1.0 7.0% --------------------------------------------------------------------------------------------- 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