176 WTNT41 KNHC 311437 TCDAT1 Potential Tropical Cyclone Six Discussion Number 5 NWS National Hurricane Center Miami FL AL062018 1100 AM AST Fri Aug 31 2018 The circulation is better defined this morning, but the associated convection is rather weak. In fact, Dvorak numbers have not changed overall, and do not support classifying the system as a tropical cyclone yet. It seems like both NHC and the global models predicted the development of a cyclone too soon. Nevertheless, the environmental conditions are favorable for both genesis and strengthening, and a tropical depression or a storm is expected to form later today or Saturday. The shear does not appear to be a problem at this time, but the cyclone should be moving over marginal SSTs, limiting the amount of intensification. The HWRF model changed its tune to a more reasonable one, and it now shows more modest strengthening. The NHC forecast is similar to the previous one, and continues to be very close to the intensity consensus. The disturbance is moving toward the west-northwest or 285 degrees at about 11 kt. The subtropical high should continue to steer the system toward the west-northwest with some increase in forward speed for the next 2 to 3 days. After that time, a weakness in the ridge will induce a more northwestward track over the open Atlantic Ocean. This is supported by the track guidance which continues to be in very good agreement for the next 3 days. Thereafter, the guidance envelope widens and becomes bounded by the westernmost ECMWF and the easternmost GFS models decreasing the confidence in the track forecast. FORECAST POSITIONS AND MAX WINDS INIT 31/1500Z 13.7N 22.7W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 01/0000Z 14.1N 24.5W 35 KT 40 MPH...TROPICAL STORM 24H 01/1200Z 14.8N 27.0W 40 KT 45 MPH 36H 02/0000Z 15.5N 29.5W 45 KT 50 MPH 48H 02/1200Z 16.2N 32.1W 50 KT 60 MPH 72H 03/1200Z 17.5N 37.5W 55 KT 65 MPH 96H 04/1200Z 19.5N 42.0W 60 KT 70 MPH 120H 05/1200Z 22.0N 45.5W 65 KT 75 MPH $$ Forecaster Avila