* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL972021 08/27/21 12 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 38% 38% LAT (deg N) 32.3 32.8 32.9 33.3 33.8 34.5 36.3 38.7 40.6 42.2 43.8 45.9 51.1 LON (deg W) 53.2 52.4 51.7 51.1 50.0 48.4 44.9 41.1 38.8 36.7 35.0 34.5 36.7 DTL (km) 1592 1545 1538 1498 1457 1412 1342 1323 1334 1393 1446 1406 1200 TRACK SOURCE AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 AP28 TCGI 0-48h Genesis Forecast: 38% is 1.3 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 38% is 0.9 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 6.3% 1.0 -0.8 9.8% VORTICITY 1.7 1.0 5.8% 1.4 1.4 11.6% VERTICAL SHEAR 16.3 14.1 15.5% 18.4 35.4 6.7% RH 73.1 58.1 -0.1% 70.9 58.7 1.3% GOES 29.1 12.3 0.6% 29.3 12.3 0.3% DVORAK 0.8 1.5 10.3% 0.8 1.5 8.5% --------------------------------------------------------------------------------------------- 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