000 WTPZ44 KNHC 301437 TCDEP4 Potential Tropical Cyclone Fourteen-E Discussion Number 4 NWS National Hurricane Center Miami FL EP142017 900 AM MDT Wed Aug 30 2017 The potential tropical cyclone has not become any better organized overnight, though available data indicate that the pressures continue to fall and that the winds have increased to 30 kt. It appears that there are two centers in the broad circulation, and the NHC position uses a mean center. Only slow strengthening is forecast today due to the disorganized surface circulation, but a more significant intensification could start tomorrow. If the circulation consolidates, the upper-level winds and water temperatures are very conducive to strengthening. The NHC forecast is similar to the previous one, just a bit above the model consensus. Because the system is forecast to be approaching hurricane strength as it nears Baja California Sur, the hurricane watch is maintained. Later in the forecast period, the cyclone should weaken while it traverses either land or the cooler waters west of the Baja peninsula. As before, with the lack of a definite center the initial motion is quite uncertain, with the current estimate at 335/8 kt. For the next couple of days, the system/tropical cyclone is expected to move slowly north-northwestward on the eastern end of a broad mid-level cyclonic gyre. In 3-5 days the motion should bend toward the northwest and west-northwest due to a mid-level ridge to the north. Model guidance has shifted a bit to the east today, and the official forecast is adjusted in that direction. A tropical storm watch has been issued for the west coast of Mexico due to the changes in the forecast. Since the disturbance still lacks a well-defined center and there is considerable spread in the model guidance, this official track forecast has greater-than-usual uncertainty. It is also important to note that very heavy rain causing life-threatening flash floods and mudslides is possible over portions of western Mexico and Baja California Sur. Regardless of exactly how strong the cyclone becomes, this is expected to be a significant hazard. FORECAST POSITIONS AND MAX WINDS INIT 30/1500Z 19.3N 108.6W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 31/0000Z 20.4N 109.2W 35 KT 40 MPH...TROPICAL STORM 24H 31/1200Z 21.4N 109.6W 40 KT 45 MPH 36H 01/0000Z 22.3N 109.9W 50 KT 60 MPH 48H 01/1200Z 23.4N 110.4W 55 KT 65 MPH 72H 02/1200Z 25.4N 112.3W 45 KT 50 MPH 96H 03/1200Z 27.5N 115.0W 35 KT 40 MPH 120H 04/1200Z 28.5N 118.5W 25 KT 30 MPH $$ Forecaster Blake