* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL902021 09/29/21 00 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 86% 86% LAT (deg N) 6.7 6.6 7.5 8.1 8.7 9.9 11.0 11.2 12.3 13.6 16.4 18.5 19.9 LON (deg W) 21.8 21.8 21.8 23.0 23.7 25.6 28.2 30.6 33.0 35.3 37.4 38.6 40.0 DTL (km) 820 829 756 816 848 993 1233 1473 1697 1905 2043 2120 2145 TRACK SOURCE AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 TCGI 0-48h Genesis Forecast: 86% is 2.9 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 86% is 2.0 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 -8.7 30.8% 1.0 -4.6 28.0% VORTICITY 1.7 3.2 19.2% 1.4 2.9 27.8% VERTICAL SHEAR 16.3 7.9 27.7% 18.4 16.7 21.1% RH 73.1 80.0 -0.3% 70.9 75.3 3.9% GOES 29.1 90.9 6.4% 29.3 90.9 3.5% DVORAK 0.8 0.5 2.6% 0.8 0.5 2.0% --------------------------------------------------------------------------------------------- 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