"Potential Tropical Cyclone 9 could become a landfalling major hurricane for the Florida Gulf Coast on Thursday."
"Tropical Storm Warning flags are flying for western Cuba and Mexico’s Yucatan Peninsula as a large area of disturbed weather in the western Caribbean heads toward the Gulf of Mexico and an expected landfall in western Florida on Thursday under the name Helene. Originally labeled Invest 97L, the disturbance was re-christened Potential Tropical Cyclone 9, or PTC 9, by the National Hurricane Center, or NHC, at 11 a.m. EDT Monday. The PTC designation is used for systems that could bring tropical storm or hurricane conditions to land areas within 48 hours but that are not yet tropical cyclones.
At 11 a.m. EDT Monday, PTC 9 was located 130 miles south-southwest of Grand Cayman Island, moving north at 6 mph (9.7 kmh), with top sustained winds of 30 mph (48 kmh) and a central pressure of 1004 mb. Satellite imagery and Cayman Islands radar showed that PTC 9 had a large area of heavy thunderstorms with plenty of rotation, which were steadily growing more organized and bringing heavy rains to the Cayman Islands and portions of Cuba. Conditions were favorable for development, with near-record ocean temperatures near 30.5 degrees Celsius (87°F), moderate wind shear of 10-20 knots, and a very moist atmosphere (a midlevel relative humidity of 75%).
PTC 9 will initially be steered northwestward into the Yucatan Channel by a high pressure system to its north, then mostly to the north once it enters the Gulf of Mexico as the high pressure system moves to its northeast, and a trough of low pressure digs in to its northwest. As usual for a system that is in the developing stages, there is considerable track uncertainty (Fig. 1). The locations of a potential U.S. landfall are almost entirely in Florida, though, from the western panhandle to Tampa. The latest 12Z Monday forecast from the GFS model (see Tweet below) shows PTC 9 coming uncomfortably close to the heavily populated Tampa Bay area."
Jeff Masters and Bob Henson report for Yale Climate Connections September 23, 2024,
SEE ALSO:
"John Rapidly Strengthens Into A Hurricane Off Southern Mexico’s Pacific Coast" (AP)
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