* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL922020 09/05/20 18 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 70% 91% LAT (deg N) 17.7 17.3 17.6 17.7 17.6 17.1 16.7 17.0 18.0 18.2 18.8 18.9 18.9 LON (deg W) 34.8 36.9 38.2 39.5 40.7 41.7 42.3 42.0 43.7 45.5 47.9 50.1 52.3 DTL (km) 1873 2090 2074 1990 1901 1791 1716 1762 1736 1653 1599 1476 1297 TRACK SOURCE AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 TCGI 0-48h Genesis Forecast: 70% is 2.3 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 91% 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 -0.9 9.2% 1.0 -0.5 13.0% VORTICITY 1.7 3.7 19.0% 1.4 3.8 35.2% VERTICAL SHEAR 16.3 5.8 26.2% 18.4 8.1 26.3% RH 73.1 73.2 -0.2% 70.9 70.4 3.5% GOES 29.1 33.1 2.1% 29.3 33.1 1.3% DVORAK 0.8 1.5 13.8% 0.8 1.5 12.1% --------------------------------------------------------------------------------------------- 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