* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL982020 08/18/20 00 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 44% 68% LAT (deg N) 11.2 11.5 11.7 11.9 12.1 12.7 12.9 13.3 14.0 14.5 15.5 16.2 16.5 LON (deg W) 35.3 36.2 37.4 38.6 39.8 42.9 45.9 48.6 51.5 54.0 56.8 61.3 65.7 DTL (km) 1651 1654 1647 1635 1539 1330 1143 1016 962 863 692 521 168 TRACK SOURCE AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 TCGI 0-48h Genesis Forecast: 44% is 1.5 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 68% is 1.6 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 -2.8 11.1% 1.0 -1.5 15.7% VORTICITY 1.7 1.8 9.3% 1.4 2.3 22.0% VERTICAL SHEAR 16.3 9.2 19.5% 18.4 11.4 23.1% RH 73.1 78.7 -0.2% 70.9 75.4 3.7% GOES 29.1 46.8 2.4% 29.3 46.8 1.7% 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