* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL952021 09/19/21 00 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 66% 77% LAT (deg N) 15.6 16.3 17.1 17.8 18.1 18.9 20.1 20.9 22.2 22.8 23.9 25.9 28.2 LON (deg W) 53.6 54.1 55.2 56.4 57.4 59.9 61.3 63.3 64.8 66.5 66.6 67.1 66.6 DTL (km) 961 963 938 922 876 614 503 382 429 477 577 746 1002 TRACK SOURCE AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 AP15 TCGI 0-48h Genesis Forecast: 66% is 2.2 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 77% is 1.8 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 -0.9 8.9% 1.0 -0.9 13.9% VORTICITY 1.7 2.4 13.2% 1.4 2.0 20.6% VERTICAL SHEAR 16.3 18.7 17.3% 18.4 21.9 17.4% RH 73.1 66.0 -0.2% 70.9 63.4 2.4% GOES 29.1 38.9 2.4% 29.3 38.9 1.5% DVORAK 0.8 2.5 24.5% 0.8 2.5 21.6% --------------------------------------------------------------------------------------------- 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