* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL972021 06/29/21 18 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 49% 76% LAT (deg N) 8.1 8.0 8.3 8.3 8.3 8.7 9.7 10.7 12.2 13.7 14.8 15.3 15.8 LON (deg W) 36.0 37.3 39.5 41.0 42.4 45.7 49.7 54.9 60.7 66.7 72.9 78.1 82.0 DTL (km) 1300 1247 1242 1171 1073 799 608 532 158 332 286 280 156 TRACK SOURCE AP23 AP23 AP23 AP23 AP23 AP23 AP23 AP23 AP23 AP23 AP23 AP23 AP23 TCGI 0-48h Genesis Forecast: 49% is 1.6 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 76% is 1.8 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 10.8% 1.0 -1.2 15.2% VORTICITY 1.7 2.9 12.8% 1.4 2.7 25.4% VERTICAL SHEAR 16.3 12.7 17.5% 18.4 9.9 24.6% RH 73.1 84.7 -0.1% 70.9 79.9 3.0% GOES 29.1 26.5 1.3% 29.3 26.5 1.0% DVORAK 0.8 1.0 6.5% 0.8 1.0 6.8% --------------------------------------------------------------------------------------------- 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