* 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 37% 51% LAT (deg N) 32.7 32.8 32.9 33.0 33.4 35.0 37.4 39.7 42.1 44.7 47.3 50.4 55.2 LON (deg W) 52.7 52.3 52.0 51.3 50.5 48.6 45.1 40.8 37.1 35.4 34.2 35.1 36.8 DTL (km) 1556 1546 1536 1530 1494 1354 1226 1264 1369 1379 1397 1307 1261 TRACK SOURCE AP19 AP19 AP19 AP19 AP19 AP19 AP19 AP19 AP19 AP19 AP19 AP19 AP19 TCGI 0-48h Genesis Forecast: 37% is 1.2 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 51% is 1.2 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 -0.6 6.1% 1.0 -0.7 11.2% VORTICITY 1.7 1.4 6.8% 1.4 1.7 15.4% VERTICAL SHEAR 16.3 17.6 13.5% 18.4 26.2 12.4% RH 73.1 57.7 -0.1% 70.9 58.0 1.4% GOES 29.1 13.6 0.6% 29.3 13.6 0.4% DVORAK 0.8 1.5 10.0% 0.8 1.5 9.8% --------------------------------------------------------------------------------------------- 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