* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL912020 09/04/20 00 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 25% 67% LAT (deg N) 11.3 11.1 10.6 10.5 10.3 10.6 11.1 11.7 12.4 12.6 13.2 13.2 13.2 LON (deg W) 36.4 37.2 38.2 38.4 38.8 39.3 39.0 37.6 35.1 33.6 33.3 33.4 36.8 DTL (km) 1627 1586 1513 1499 1472 1480 1545 1643 1784 1755 1712 1723 1823 TRACK SOURCE AP11 AP11 AP11 AP11 AP11 AP11 AP11 AP11 AP11 AP11 AP11 AP11 AP11 TCGI 0-48h Genesis Forecast: 25% is 0.8 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 67% is 1.6 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 -2.1 6.6% 1.0 -2.4 18.8% VORTICITY 1.7 1.5 5.4% 1.4 1.7 17.9% VERTICAL SHEAR 16.3 23.7 8.0% 18.4 17.4 19.5% RH 73.1 73.6 -0.1% 70.9 75.9 3.6% GOES 29.1 12.1 0.4% 29.3 12.1 0.4% DVORAK 0.8 1.0 4.4% 0.8 1.0 6.7% --------------------------------------------------------------------------------------------- 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