Current Snapshot

The Pacific Disaster Center’s (PDC Global) Friday, September 27, 2024, Tropical Cyclone Activity Report for the Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico

CURRENT TROPICAL CYCLONES:

Post-Tropical Cyclone 09L (Helene)…located about 115 miles east-northeast of Paducah, Kentucky

Tropical Cyclone 10L (Isaac)…located about 890 miles west of the Azores

Tropical Cyclone 11L (Joyce)…located about 1205 miles east of the northern Leeward Islands

Tropical Cyclone 09L (Helene)

CATASTROPHIC, HISTORIC FLOODING CONTINUES OVER PORTIONS OF THE SOUTHERN APPALACHIANS

According to the NHC Advisory number 19

The post-tropical cyclone is moving toward the west-southwest near 8
mph (13 km/h), as a slowdown in the forward speed has already begun. The system is forecast to stall over the Tennessee Valley late tonight and through the weekend.

Maximum sustained winds are near 30 mph (45 km/h) with higher gusts.
Continued weakening is expected during the next couple of days.

HAZARDS AFFECTING LAND

RAINFALL: Over portions of the Central and Southern Appalachians, Helene is expected to produce additional rainfall amounts of 3 to 6 inches leading to total rain accumulations of 6 to 12 inches, with isolated totals around 20 inches. This rainfall will result in catastrophic and potentially life-threatening flash and urban flooding, along with significant and record river flooding. Numerous significant landslides are expected in steep terrain across the Southern Appalachians.

STORM SURGE: Water levels will continue to recede along the Florida
Gulf Coast and portions of the southeast U.S. coast throughout the day.

WIND: Tropical storm conditions are occurring along much of the South Carolina coast, and these conditions will continue for the next several hours. Strong, damaging winds, especially in gusts, will also continue as far inland as the higher terrain of the southern Appalachians.

SURF: Swells generated by Helene will affect the coasts of Georgia and the Carolinas during the next day or so. These swells are likely to cause life-threatening surf and rip current conditions.

TORNADOES: Tornadoes are possible today across eastern South Carolina, central and eastern North Carolina, and southern Virginia.

Tropical Cyclone 10L (Issac)

ISAAC CONTINUES TO STRENGTHEN

According to the NHC Advisory number 9

Isaac is moving toward the east-northeast near 16 mph (26 km/h). A gradual turn to the northeast is expected with a slight decrease in forward speed over the next day or so. The northeastward motion should then continue through Monday.

Maximum sustained winds are near 90 mph (150 km/h) with higher gusts. Little change in strength is expected through Saturday morning, followed by gradual weakening through early next week. Isaac is expected to be a post-tropical cyclone on Monday.

Hurricane-force winds extend outward up to 30 miles (45 km) from the
center and tropical-storm-force winds extend outward up to 150 miles
(240 km).

HAZARDS AFFECTING LAND

SURF: Swells generated by Isaac and a large wind fetch from a deep layer trough could spread into the Azores by this weekend. These swells are likely to cause life-threatening surf and rip current conditions.

Tropical Cyclone 11L (Joyce)

JOYCE HOLDING STEADY IN INTENSITY

According to the NHC Advisory number 3

Joyce is moving toward the west-northwest near 12 mph (19 km/h), and
general motion with a decrease in forward speed is expected through early Sunday. A slow turn toward the northwest and north is forecast later on Sunday and Monday.

Satellite-derived wind data indicate that maximum sustained winds remain near 50 mph (85 km/h) with higher gusts. Little change in strength is expected through Saturday. Weakening is forecast to begin by Sunday, and Joyce could degenerate into a remnant low by late Monday.

Tropical-storm-force winds extend outward up to 105 miles (165 km) from the center.

>>> Western Caribbean and Gulf of Mexico:

An area of low pressure could form over the western Caribbean Sea by
the early part of next week. Environmental conditions are expected
to be conducive for additional development thereafter while the system moves generally northwestward, and a tropical depression could form by the middle of next week as the system enters the Gulf of Mexico.

* Formation chance through 48 hours…low…near 0 percent
* Formation chance through 7 days…medium…40 percent

>>> Eastern and and Central Tropical Atlantic:

A broad and elongated area of low pressure, associated with a tropical wave, is producing limited shower activity near and to the west of the Cabo Verde Islands. Environmental conditions appear conducive for gradual development of this system, and a tropical depression could form next week while moving toward the west and then northwest at about 10 mph across the eastern and central tropical Atlantic.

* Formation chance through 48 hours…low…10 percent
* Formation chance through 7 days…medium…50 percent