* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL962021 08/15/21 18 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 23% 28% LAT (deg N) 34.9 34.1 33.5 32.7 32.2 32.0 31.9 32.2 32.6 32.7 33.7 34.8 34.5 LON (deg W) 62.8 62.8 62.8 62.6 62.8 63.2 64.6 65.7 67.1 67.8 67.9 67.1 66.9 DTL (km) 983 1070 1130 1215 1252 1239 1120 1012 873 808 761 803 827 TRACK SOURCE AP21 AP21 AP21 AP21 AP21 AP21 AP21 AP21 AP21 AP21 AP21 AP21 TABM TCGI 0-48h Genesis Forecast: 23% is 0.8 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 28% is 0.7 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 0.2 3.4% 1.0 0.2 5.5% VORTICITY 1.7 0.7 3.4% 1.4 0.6 5.8% VERTICAL SHEAR 16.3 10.5 12.1% 18.4 15.1 12.0% RH 73.1 61.1 -0.1% 70.9 59.6 1.0% GOES 29.1 6.9 0.2% 29.3 6.9 0.1% DVORAK 0.8 1.0 4.2% 0.8 1.0 3.8% --------------------------------------------------------------------------------------------- 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