* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL902021 05/20/21 12 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 19% 59% LAT (deg N) 34.4 35.2 36.2 35.8 34.3 32.6 33.4 34.1 34.4 35.2 36.1 37.4 38.9 LON (deg W) 53.9 54.9 56.9 59.6 61.5 61.5 62.4 62.1 60.8 57.4 53.2 47.4 43.0 DTL (km) 1352 1233 1063 993 1079 1260 1154 1085 1089 1155 1177 1135 1196 TRACK SOURCE AP20 AP20 AP20 AP20 AP20 AP20 AP20 AP20 AP20 AP20 AP20 AP20 TABM TCGI 0-48h Genesis Forecast: 19% is 0.6 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 59% is 1.4 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 -1.9 5.2% 1.0 -0.4 11.2% VORTICITY 1.7 3.8 8.9% 1.4 3.3 27.7% VERTICAL SHEAR 16.3 35.8 3.1% 18.4 23.8 15.0% RH 73.1 64.4 -0.1% 70.9 61.1 1.9% GOES 29.1 42.1 1.2% 29.3 42.1 1.5% DVORAK 0.8 0.5 1.0% 0.8 0.5 1.8% --------------------------------------------------------------------------------------------- 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