* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL982020 09/18/20 12 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 42% 42% LAT (deg N) 12.1 12.7 13.4 13.7 14.1 15.2 16.6 17.5 18.0 17.3 18.9 22.3 25.5 LON (deg W) 31.4 32.8 34.4 35.8 37.2 39.9 42.4 45.6 47.9 49.4 50.8 50.0 51.5 DTL (km) 1531 1667 1827 1902 1898 1756 1700 1580 1519 1382 1417 1690 1670 TRACK SOURCE AP06 AP06 AP06 AP06 AP06 AP06 AP06 AP06 AP06 AP06 AP06 TABM TABM TCGI 0-48h Genesis Forecast: 42% is 1.4 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 42% is 1.0 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 0.2 5.2% 1.0 0.4 7.0% VORTICITY 1.7 1.7 8.6% 1.4 1.3 11.3% VERTICAL SHEAR 16.3 16.0 15.4% 18.4 23.6 12.1% RH 73.1 69.6 -0.2% 70.9 62.0 1.6% GOES 29.1 35.4 1.7% 29.3 35.4 1.0% DVORAK 0.8 1.5 10.8% 0.8 1.5 8.7% --------------------------------------------------------------------------------------------- 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