* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL912020 09/04/20 12 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 23% 65% LAT (deg N) 10.8 10.6 10.4 10.3 10.4 10.9 12.1 13.1 14.8 14.7 14.9 14.9 14.7 LON (deg W) 39.3 39.9 40.5 41.2 41.7 41.5 40.0 37.4 36.2 38.2 40.6 42.6 44.1 DTL (km) 1500 1438 1370 1299 1260 1310 1521 1801 2008 1853 1679 1535 1425 TRACK SOURCE AP17 AP17 AP17 AP17 AP17 AP17 AP17 AP17 TABM TABM TABM TABM TABM TCGI 0-48h Genesis Forecast: 23% is 0.8 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 65% 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 -2.7 7.0% 1.0 -1.5 15.8% VORTICITY 1.7 1.6 5.4% 1.4 2.3 22.2% VERTICAL SHEAR 16.3 19.2 9.1% 18.4 14.6 21.0% RH 73.1 74.0 -0.1% 70.9 72.8 3.6% GOES 29.1 19.5 0.6% 29.3 19.5 0.7% DVORAK 0.8 0.5 1.2% 0.8 0.5 1.9% --------------------------------------------------------------------------------------------- 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