* 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 29% 29% LAT (deg N) 33.7 33.7 34.2 33.8 33.8 34.0 34.5 35.4 36.6 38.1 39.9 41.7 42.6 LON (deg W) 51.3 51.1 50.1 50.1 50.1 49.5 48.1 45.3 40.9 35.9 30.8 25.5 20.7 DTL (km) 1452 1454 1411 1455 1459 1439 1422 1418 1506 1700 1836 1354 945 TRACK SOURCE AP04 AP04 AP04 AP04 TABM TABM TABM TABM TABM TABM TABM TABM TABM TCGI 0-48h Genesis Forecast: 29% is 1.0 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 29% is 0.7 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 -0.1 4.5% 1.0 0.0 7.2% VORTICITY 1.7 0.8 4.2% 1.4 0.5 6.6% VERTICAL SHEAR 16.3 17.8 11.3% 18.4 35.9 6.1% RH 73.1 54.7 0.0% 70.9 53.8 0.7% GOES 29.1 13.6 0.5% 29.3 13.6 0.4% DVORAK 0.8 1.5 8.5% 0.8 1.5 8.0% --------------------------------------------------------------------------------------------- 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 3.0, July 2018