* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL912021 09/30/21 00 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 11% 15% LAT (deg N) 5.6 5.6 5.8 6.2 6.4 6.5 6.7 7.1 7.5 8.0 8.6 9.6 10.7 LON (deg W) 33.4 33.4 34.4 35.2 37.0 36.9 37.2 38.1 39.0 40.0 41.0 41.7 41.8 DTL (km) 1194 1194 1149 1143 1085 1099 1114 1126 1159 1182 1205 1215 1270 TRACK SOURCE AP27 AP27 AP27 AP27 AP27 AP27 TABM TABM TABM TABM TABM TABM TABM TCGI 0-48h Genesis Forecast: 11% is 0.4 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 15% 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 0.4 1.8% 1.0 0.5 3.0% VORTICITY 1.7 0.6 1.8% 1.4 0.0 2.0% VERTICAL SHEAR 16.3 9.8 6.9% 18.4 12.1 7.9% RH 73.1 67.7 -0.1% 70.9 62.2 0.8% GOES 29.1 20.3 0.4% 29.3 20.3 0.3% DVORAK 0.8 0.5 0.7% 0.8 0.5 0.7% --------------------------------------------------------------------------------------------- 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