* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL982021 08/25/21 00 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 43% 45% LAT (deg N) 9.9 10.4 11.0 11.6 12.4 13.9 14.9 15.8 16.7 17.7 18.9 19.9 20.5 LON (deg W) 29.4 30.5 31.5 32.5 33.5 35.0 36.2 37.1 38.1 39.4 40.9 42.5 44.2 DTL (km) 1397 1492 1574 1661 1748 1886 2008 2023 2011 1997 1999 1982 1943 TRACK SOURCE AVNI AVNI AVNI AVNI AVNI AVNI AVNI AVNI AVNI AVNI AVNI AVNI AVNI TCGI 0-48h Genesis Forecast: 43% is 1.4 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 45% 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 0.6 4.7% 1.0 0.8 6.2% VORTICITY 1.7 2.3 10.7% 1.4 1.5 13.5% VERTICAL SHEAR 16.3 7.2 20.3% 18.4 15.1 16.8% RH 73.1 80.1 -0.2% 70.9 73.5 3.0% GOES 29.1 26.0 1.3% 29.3 26.0 0.8% DVORAK 0.8 1.0 6.5% 0.8 1.0 5.3% --------------------------------------------------------------------------------------------- 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 2.1, February 2018