* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL972020 09/13/20 00 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 13% 15% LAT (deg N) 17.9 18.5 18.9 19.0 19.0 18.6 18.4 18.7 19.7 20.7 21.3 21.9 22.5 LON (deg W) 23.8 25.5 27.2 28.7 30.1 32.2 33.2 33.6 33.3 32.7 32.3 32.2 32.1 DTL (km) 754 934 1089 1245 1388 1615 1721 1749 1708 1630 1582 1577 1560 TRACK SOURCE TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TCGI 0-48h Genesis Forecast: 13% is 0.4 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 15% is 0.4 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 -3.0 4.7% 1.0 -2.2 6.4% VORTICITY 1.7 1.4 3.2% 1.4 0.5 3.1% VERTICAL SHEAR 16.3 37.0 2.0% 18.4 39.8 2.2% RH 73.1 66.0 -0.1% 70.9 63.1 0.8% GOES 29.1 37.6 0.8% 29.3 37.6 0.5% DVORAK 0.8 1.0 2.7% 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