* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL912020 09/04/20 12 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 26% 68% LAT (deg N) 10.7 10.6 10.6 10.7 11.1 12.2 14.0 15.0 16.1 17.4 18.9 18.3 18.6 LON (deg W) 38.7 39.0 39.1 39.3 39.3 38.1 36.0 33.8 35.6 38.4 41.0 46.6 48.3 DTL (km) 1518 1494 1490 1490 1523 1691 1929 1750 1943 2043 1992 1609 1561 TRACK SOURCE AP13 AP13 AP13 AP13 AP13 AP13 AP13 AP13 AP13 AP13 AP13 AP13 AP13 TCGI 0-48h Genesis Forecast: 26% is 0.9 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 68% is 1.6 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 -3.3 8.5% 1.0 -2.5 19.4% VORTICITY 1.7 1.7 6.2% 1.4 2.3 22.2% VERTICAL SHEAR 16.3 20.4 9.5% 18.4 15.5 20.7% RH 73.1 76.3 -0.1% 70.9 77.0 3.4% GOES 29.1 19.5 0.7% 29.3 19.5 0.7% DVORAK 0.8 0.5 1.3% 0.8 0.5 1.9% --------------------------------------------------------------------------------------------- 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