* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL982020 09/17/20 18 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 11% 15% LAT (deg N) 12.7 13.1 13.7 14.5 15.3 17.1 19.0 19.6 19.0 18.1 17.7 17.8 18.8 LON (deg W) 26.0 27.6 29.5 31.5 33.4 36.6 39.4 41.9 44.1 45.6 46.2 46.1 45.4 DTL (km) 945 1108 1296 1501 1702 2060 2108 1990 1802 1634 1564 1583 1720 TRACK SOURCE TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TCGI 0-48h Genesis Forecast: 11% is 0.4 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 15% is 0.3 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 2.2% 1.0 -0.2 4.0% VORTICITY 1.7 0.6 1.7% 1.4 0.0 2.1% VERTICAL SHEAR 16.3 21.5 4.5% 18.4 24.9 5.3% RH 73.1 66.1 0.0% 70.9 59.3 0.6% GOES 29.1 15.8 0.3% 29.3 15.8 0.2% DVORAK 0.8 1.0 2.2% 0.8 1.0 2.3% --------------------------------------------------------------------------------------------- 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