* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL972021 06/30/21 00 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 45% 70% LAT (deg N) 8.2 8.3 8.4 8.4 9.0 9.6 10.9 12.2 13.7 14.9 15.3 14.8 15.6 LON (deg W) 37.0 38.8 40.8 42.3 44.3 49.3 54.0 59.3 64.7 69.8 74.4 78.7 81.5 DTL (km) 1277 1251 1190 1088 938 624 574 241 341 311 306 350 194 TRACK SOURCE AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 AP12 TCGI 0-48h Genesis Forecast: 45% is 1.5 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 70% 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 -1.0 7.4% 1.0 -0.1 11.1% VORTICITY 1.7 3.0 12.7% 1.4 2.7 25.3% VERTICAL SHEAR 16.3 12.0 17.3% 18.4 13.9 21.7% RH 73.1 82.2 -0.2% 70.9 75.2 3.7% GOES 29.1 29.8 1.5% 29.3 29.8 1.1% DVORAK 0.8 1.0 6.3% 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