Hurricane Helene has rapidly intensified into a large Class 4 storm, with hurricane-force winds extending as much as 60 miles outward from the attention. Forecasters warn that Helene — which has wind speeds of close to 120 miles per hour — may very well be lethal for these residing in coastal Florida, the place it’s anticipated to make landfall this night.
The Nationwide Hurricane Heart predicts storm surge as excessive as 20 ft in some elements of Florida’s Large Bend, a area between the panhandle and the peninsula. Storm surge, which describes an increase in sea degree, is probably the most harmful a part of tropical storms and has a lethal monitor report: In 2022, storm surge killed greater than 40 individuals throughout Hurricane Ian. The storm can also be anticipated to inundate inland areas throughout a lot of the southeastern US with rain, dumping a foot or extra in elements of southern Appalachia.
“This rainfall will possible end in catastrophic and doubtlessly life-threatening flash and concrete flooding,” the Nationwide Hurricane Heart stated early Thursday afternoon.
Helene may additionally disrupt a part of the epic monarch butterfly migration, which generally passes via the Large Bend’s St. Marks Nationwide Wildlife Refuge in early October.
Helene is the eighth named storm in what has up to now amounted to a considerably puzzling hurricane season. It began with a bang — June’s Hurricane Beryl turned the earliest Class 5 storm on report — after which a lot of August and September was unexpectedly quiet.
Many meteorologists, although, have been warning to not be fooled by this late-summer lull.
“Having multi-week intervals of quiet after which multi-week intervals of exercise could be very regular all through a hurricane season,” Brian McNoldy, a climatologist on the College of Miami, instructed me earlier this month. “I undoubtedly wouldn’t learn an excessive amount of into it.”
Plus, McNoldy stated, the ocean within the Gulf of Mexico has been — and nonetheless is — exceptionally scorching, and scorching water fuels hurricanes. Ocean warmth content material, a measure of how a lot warmth power the ocean shops, is at a report excessive for this time of 12 months.
Check out the chart beneath. The pink line is 2024 and the blue line is the common during the last decade.
This report ocean warmth is a transparent motive why Hurricane Helene — which has been touring via the Gulf on its method to Florida — has intensified so rapidly. Put merely, hotter water evaporates extra readily, and rising columns of heat, moist air from that evaporation are finally what drive hurricanes and their fast intensification.
“The sea floor temperature and the ocean warmth content material are each report excessive within the Gulf,” McNoldy, who produced the chart above, instructed me. “That warmth on the floor and accessible via a depth will give Helene all of the gas it must quickly intensify at this time and into tomorrow.”
The report Gulf temperatures are only one sign of a extra widespread bout of warming throughout the North Atlantic that ramped up final 12 months.
It’s not completely clear what’s inflicting this warming, although scientists suspect a mixture of things together with local weather change — which raises the baseline ocean temperature — in addition to lingering results of El Niño, pure local weather variability, and maybe even a volcanic eruption.
“That is out of bounds from the sorts of variability that we’ve seen in [at least] the final 75 years or so,” Ben Kirtman, director of the Cooperative Institute for Marine and Atmospheric Research, a joint initiative of the College of Miami and the Nationwide Oceanic and Atmospheric Administration (NOAA), instructed Vox in August. “That may be scary stuff.”
Replace, September 26, 6:50 pm ET: This story, initially printed September 25, has been up to date with new info as Hurricane Helene approaches the Florida coast.
