* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL922021 08/07/21 00 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 35% 64% LAT (deg N) 10.5 11.4 12.3 13.0 13.3 13.9 14.5 14.9 15.1 15.8 16.8 18.8 19.9 LON (deg W) 25.1 25.3 26.3 27.4 28.4 30.4 32.2 34.3 36.4 38.6 41.2 44.3 47.1 DTL (km) 923 924 990 1086 1186 1392 1580 1804 2029 1903 1798 1775 1746 TRACK SOURCE AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 AP26 TCGI 0-48h Genesis Forecast: 35% is 1.2 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 64% is 1.5 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 -0.3 5.6% 1.0 0.1 9.9% VORTICITY 1.7 3.3 12.2% 1.4 2.7 25.0% VERTICAL SHEAR 16.3 14.1 14.7% 18.4 11.3 22.9% RH 73.1 80.9 -0.2% 70.9 72.7 3.6% GOES 29.1 31.8 1.4% 29.3 31.8 1.2% DVORAK 0.8 0.5 1.6% 0.8 0.5 1.9% --------------------------------------------------------------------------------------------- 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