* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL982021 09/21/21 00 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 80% 97% LAT (deg N) 6.6 6.4 6.6 6.9 7.1 6.9 7.6 9.6 11.1 12.5 13.3 14.1 14.9 LON (deg W) 24.2 24.7 25.7 27.6 28.9 31.0 32.1 34.1 36.6 38.6 40.5 41.9 42.9 DTL (km) 1022 1079 1157 1321 1441 1430 1459 1535 1600 1671 1563 1519 1519 TRACK SOURCE AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 TCGI 0-48h Genesis Forecast: 80% is 2.7 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 97% is 2.3 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 -4.3 18.6% 1.0 -3.2 23.2% VORTICITY 1.7 2.2 13.8% 1.4 2.5 24.8% VERTICAL SHEAR 16.3 12.3 23.6% 18.4 7.4 27.0% RH 73.1 86.1 -0.2% 70.9 79.0 3.3% GOES 29.1 44.6 3.0% 29.3 44.6 1.7% DVORAK 0.8 2.0 20.9% 0.8 2.0 17.2% --------------------------------------------------------------------------------------------- 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