* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL972021 08/27/21 18 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 26% 35% LAT (deg N) 33.2 33.1 33.4 33.8 34.5 36.1 37.7 39.2 40.8 42.8 45.8 50.0 53.1 LON (deg W) 52.0 51.4 50.6 49.9 48.8 46.1 43.0 39.8 37.1 34.9 33.5 32.8 31.9 DTL (km) 1503 1518 1493 1458 1403 1314 1300 1365 1441 1500 1484 1471 1447 TRACK SOURCE AVNI AVNI AVNI AVNI AVNI AVNI AVNI AVNI AVNI AVNI AVNI AVNI TABM TCGI 0-48h Genesis Forecast: 26% is 0.9 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 35% is 0.8 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 -0.2 4.4% 1.0 -0.6 8.3% VORTICITY 1.7 0.6 3.7% 1.4 1.1 8.9% VERTICAL SHEAR 16.3 19.3 10.0% 18.4 30.5 7.9% RH 73.1 64.0 -0.1% 70.9 64.6 1.7% GOES 29.1 13.6 0.5% 29.3 13.6 0.3% DVORAK 0.8 1.5 7.9% 0.8 1.5 7.6% --------------------------------------------------------------------------------------------- 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 2.1, February 2018