Important Tropical Events Could Affect U.S. In Early October

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GFS and ECM indicate hurricane risk for the U.S. in early October. One system approaches the East Coast another is in the eastern Gulf of Mexico arriving from the western Caribbean Sea.

Fig. 1: ECMWF 240-hour forecast of two significant tropical cyclones in the North Atlantic basin tracking westward.

Fig. 2: GFS 348-hour forecast of a significant eastern Gulf of Mexico tropical cyclone.

Fig. 3: Morning weather satellite view of the North Atlantic basin.

Discussion: Due to upper shear, former tropical storm(s) Peter and Rose have weakened and will continue to encounter upper shear leading to dissipation by early weekend. Tropical Depression 18 is expected to become a major hurricane by early next week as a slow-mover reaching the central North Atlantic tropics by early Monday. The remains of Odette linger in the north-central North Atlantic basin and will loop south and west over the next 5 days. NOAA/NHC indicates a >50% risk of a regenerating subtropical storm over the next several days.

The concern in the morning outlook is the longer-range forecast. In early October, the major hurricane reaching the central North Atlantic tropics early next week continues a slow west-northwest trek and could be in the Bahamas, possibly as a major hurricane in 10 days and heading for the Southeast U.S. or Florida Coast according to ECMWF. The same model indicates another tropical cyclone likely to follow a similar path.

Meanwhile, in the 11-15-day forecast, the GFS generates a western Caribbean hurricane which turns north into the northeast Gulf of Mexico and likely to turn north and northeast impacting the Southeast/East U.S.

The U.S. is quiet right now regarding tropical cyclone issues but a more active and concerning regime appears ahead for early October.