* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL972021 08/27/21 06 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 40% 40% LAT (deg N) 32.1 32.3 32.7 33.0 33.7 35.0 36.5 37.6 37.6 37.1 36.5 36.1 35.6 LON (deg W) 53.4 52.8 52.1 51.5 50.9 49.4 47.5 46.0 44.0 41.5 38.9 35.7 31.9 DTL (km) 1605 1600 1558 1528 1456 1336 1225 1163 1258 1432 1636 1868 1977 TRACK SOURCE AVNI AVNI AVNI AVNI AVNI AVNI AVNI TABM TABM TABM TABM TABM TABM TCGI 0-48h Genesis Forecast: 40% is 1.3 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 40% 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 -0.8 6.8% 1.0 0.0 8.4% VORTICITY 1.7 1.0 5.9% 1.4 1.3 11.6% VERTICAL SHEAR 16.3 14.0 15.9% 18.4 31.2 9.0% RH 73.1 61.3 -0.1% 70.9 58.7 1.3% GOES 29.1 13.3 0.6% 29.3 13.3 0.4% DVORAK 0.8 1.5 10.5% 0.8 1.5 9.0% --------------------------------------------------------------------------------------------- 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