* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL982021 09/21/21 12 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 38% 38% LAT (deg N) 9.3 8.5 8.2 7.9 7.7 6.9 6.5 7.0 8.5 10.0 11.8 13.8 15.5 LON (deg W) 27.2 28.7 29.5 30.4 31.1 32.5 34.0 35.9 38.3 41.1 44.5 48.0 51.2 DTL (km) 1180 1364 1463 1556 1510 1377 1241 1194 1277 1288 1145 1091 1133 TRACK SOURCE AP23 AP23 TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TCGI 0-48h Genesis Forecast: 38% is 1.3 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 38% is 0.9 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 0.3 4.7% 1.0 1.0 5.4% VORTICITY 1.7 1.4 7.0% 1.4 0.3 6.0% VERTICAL SHEAR 16.3 14.8 15.1% 18.4 18.1 14.5% RH 73.1 81.4 -0.2% 70.9 73.1 2.8% GOES 29.1 24.6 1.1% 29.3 24.6 0.7% DVORAK 0.8 1.5 10.2% 0.8 1.5 8.6% --------------------------------------------------------------------------------------------- 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