* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL922020 07/27/20 06 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 61% 93% LAT (deg N) 11.5 12.0 12.8 13.1 13.3 13.0 13.5 14.5 15.1 16.1 17.1 19.0 20.6 LON (deg W) 41.1 42.1 43.2 45.3 47.5 52.6 56.4 59.7 62.8 65.9 68.7 71.2 73.5 DTL (km) 1385 1337 1317 1201 1074 825 582 434 461 211 111 -78 83 TRACK SOURCE AP04 AP04 AP04 AP04 AP04 AP04 AP04 AP04 AP04 AP04 AP04 AP04 AP04 TCGI 0-48h Genesis Forecast: 61% is 2.0 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 93% is 2.2 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 -2.8 12.6% 1.0 -2.0 18.5% VORTICITY 1.7 4.1 19.1% 1.4 4.1 36.8% VERTICAL SHEAR 16.3 11.4 20.8% 18.4 9.2 25.7% RH 73.1 80.1 -0.2% 70.9 75.4 3.9% GOES 29.1 14.5 0.8% 29.3 14.5 0.6% DVORAK 0.8 1.0 7.4% 0.8 1.0 7.0% --------------------------------------------------------------------------------------------- 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