* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL982020 08/18/20 12 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 49% 75% LAT (deg N) 12.0 12.2 12.4 12.6 13.0 13.9 15.1 16.1 17.0 17.9 18.5 19.3 20.2 LON (deg W) 37.3 38.5 39.7 40.9 42.1 45.1 48.6 52.2 55.6 59.0 62.6 66.3 69.8 DTL (km) 1682 1662 1567 1479 1415 1284 1196 1118 902 709 327 88 56 TRACK SOURCE AEMI AEMI AEMI AEMI AEMI AEMI AEMI AEMI AEMI AEMI AEMI AEMI AEMI TCGI 0-48h Genesis Forecast: 49% is 1.6 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 75% is 1.8 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 -3.7 12.8% 1.0 -1.7 16.9% VORTICITY 1.7 2.6 11.8% 1.4 2.8 26.7% VERTICAL SHEAR 16.3 6.4 20.9% 18.4 10.4 24.2% RH 73.1 77.1 -0.2% 70.9 74.5 3.9% GOES 29.1 38.6 2.0% 29.3 38.6 1.5% DVORAK 0.8 0.5 1.9% 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