Hurricane Helene Intensifies to Category 4

From the National Hurricane Center: Hurricane HELENE: Intermediate Advisory Number 14A. Issued at 800 PM EDT Thu Sep 26 2024

Hurricane Helene is traveling across the Gulf of Mexico in the Big Bend area, where the Florida Panhandle meets the Florida Peninsula. It is fairly shallow water, as these things go, and it tends to be very warm water in late summer. Ideal for intensifying all kinds of tropical cyclones.

And Hurricane Helene is intensifying. As of the 9PM EDT update (O1:00 Zulu) the minimum central pressure of the storm had fallen to 941 millibars.

At 800 PM EDT (0000 UTC), the eye of Hurricane Helene was located near latitude 28.7 North, longitude 84.3 West. Helene is moving toward the north-northeast near 23 mph (37 km/h). A continued fast motion to the north-northeast is expected through landfall in the Florida Big Bend in a few hours. After landfall, Helene is expected to turn northwestward and slow down over the Tennessee Valley on Friday and Saturday.

Maximum sustained winds are near 130 mph (215 km/h) with higher gusts. Helene is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some additional strengthening is possible before the center reaches the coast in a few hours. Weakening is expected after Helene moves inland, but the fast forward speed will allow strong, damaging winds, especially in gusts, to penetrate well inland across the southeastern United States, including over the higher terrain of the southern Appalachians.

A recent category 4 hurricane you may remember, is Hurricane Harvey, that made landfall in Texas in 2017.

Sustained winds and storm surge do a lot of damage in a category 4 hurricane. This is defined as a hurricane in which sustained winds are 58–70 m/s, 113–136 knots, 209–251 km/h or 130–156 mph. Gusts may be higher. Sometimes MUCH higher. And this doesn't include the possible formation of tornadoes, a possible side effect of hurricanes.