* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL972020 09/13/20 18 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 8% 13% LAT (deg N) 18.9 19.0 19.1 19.2 19.3 19.7 21.4 23.7 25.8 27.3 29.1 30.5 31.4 LON (deg W) 26.2 27.3 28.2 28.9 29.3 30.0 30.1 29.7 29.5 30.0 30.5 30.2 28.1 DTL (km) 992 1101 1188 1253 1297 1358 1356 1324 1342 1445 1563 1601 1457 TRACK SOURCE TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TCGI 0-48h Genesis Forecast: 8% is 0.3 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 13% 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 -0.2 2.1% 1.0 0.3 3.3% VORTICITY 1.7 1.2 2.4% 1.4 0.1 2.2% VERTICAL SHEAR 16.3 42.7 0.6% 18.4 32.7 3.7% RH 73.1 59.4 0.0% 70.9 55.4 0.4% GOES 29.1 61.5 1.1% 29.3 61.5 0.8% 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