* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL902021 05/20/21 18 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 29% 47% LAT (deg N) 35.0 35.6 34.8 33.6 33.0 33.4 33.9 33.9 34.4 34.9 35.9 39.2 40.4 LON (deg W) 55.1 57.4 60.0 61.4 61.9 62.6 63.9 63.5 61.3 58.3 53.5 50.1 49.7 DTL (km) 1246 1114 1076 1156 1208 1150 1037 1057 1074 1139 1200 865 755 TRACK SOURCE AP07 AP07 AP07 AP07 AP07 AP07 AP07 AP07 AP07 AP07 AP07 TABM TABM TCGI 0-48h Genesis Forecast: 29% is 1.0 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 47% is 1.1 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 4.7% 1.0 0.3 7.8% VORTICITY 1.7 5.0 15.0% 1.4 3.6 25.9% VERTICAL SHEAR 16.3 29.8 6.6% 18.4 31.2 9.5% RH 73.1 63.6 -0.1% 70.9 59.5 1.5% GOES 29.1 38.7 1.5% 29.3 38.7 1.2% DVORAK 0.8 0.5 1.4% 0.8 0.5 1.6% --------------------------------------------------------------------------------------------- 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