* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL972021 08/26/21 06 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 27% 31% LAT (deg N) 27.2 27.7 28.8 29.8 30.3 30.9 31.0 30.7 29.6 28.0 26.8 26.2 26.3 LON (deg W) 57.7 58.8 60.0 59.1 59.0 59.2 59.0 57.5 55.6 54.5 53.9 53.3 52.2 DTL (km) 1284 1259 1297 1437 1487 1509 1501 1587 1617 1575 1533 1547 1650 TRACK SOURCE AP25 AP25 AP25 AP25 TABM TABM TABM TABM TABM TABM TABM TABM TABM TCGI 0-48h Genesis Forecast: 27% is 0.9 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 31% 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 -0.2 4.4% 1.0 -0.1 6.6% VORTICITY 1.7 0.1 2.5% 1.4 0.4 5.3% VERTICAL SHEAR 16.3 6.4 14.9% 18.4 12.1 13.8% RH 73.1 55.1 0.0% 70.9 55.7 0.8% GOES 29.1 9.1 0.3% 29.3 9.1 0.2% DVORAK 0.8 1.0 4.7% 0.8 1.0 4.1% --------------------------------------------------------------------------------------------- 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