* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL982020 09/17/20 06 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 35% 63% LAT (deg N) 9.9 10.0 10.3 10.4 10.7 11.3 11.8 12.7 14.2 14.8 14.2 15.5 17.3 LON (deg W) 25.7 26.7 28.0 29.2 30.9 33.4 36.5 38.8 41.7 43.9 45.0 45.9 46.4 DTL (km) 1003 1106 1238 1359 1522 1739 1678 1666 1541 1443 1316 1374 1519 TRACK SOURCE AP07 AP07 AP07 AP07 AP07 AP07 AP07 AP07 AP07 AP07 AP07 AP07 AP07 TCGI 0-48h Genesis Forecast: 35% is 1.2 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 63% is 1.5 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 -1.6 7.6% 1.0 -0.6 12.4% VORTICITY 1.7 2.0 8.5% 1.4 2.1 20.1% VERTICAL SHEAR 16.3 17.8 12.9% 18.4 15.8 20.1% RH 73.1 77.5 -0.2% 70.9 69.4 3.1% GOES 29.1 13.6 0.6% 29.3 13.6 0.5% DVORAK 0.8 1.0 5.6% 0.8 1.0 6.5% --------------------------------------------------------------------------------------------- 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