As Hurricane Helene intensifies in the Gulf of Mexico, its storm surge has the potential to be quite large, with 4- to 8-foot surges possible from Englewood north though Tampa Bay, and up to 15 feet in and around where Helene makes landfall.

Such large geographical area of surge has the potential for severe damage and  for loss of life.  Please heed evacuation messages in your specific community and leave if alerted to. Scores of Floridians died in the Hurricane Ian storm surge just two years ago. Be smart!

Winds will be increasing tonight and reach gale force (39-54 miles per hour) before midnight. Then, a long period of gale-force wind—extending more than 24 hours—is likely. Peak winds will likely be Thursday afternoon, with hurricane-force gusts (74 miles per hour and above) from Sarasota northward. 

At first, the winds will blow from land to the Gulf, but after Helene's eye passes, on Thursday late afternoon, expect strong onshore winds and high storm surge  potential with saltwater flooding along the coastlines. Wet ground from our region's previous record rainfall will mean trees may fall more easily as wind gusts occur.

The storm continues to strengthen. Located in the western part of the Yucatan Straits, between Cuba and Cozumel, Helene is a very large storm covering a lot of area—like Hurricane Debby, but much more powerful. It is in a bad location for Florida, and I expect it to rapidly intensify today and tonight into a major hurricane before it hits land on Florida’s west coast on Thursday in the Florida Big Bend area. Warnings for tropical storm or hurricane winds, associated storm surges and flooding rains, are in effect for 61 counties, including Sarasota and Manatee.

Here is the latest cone (above). Remember that the cone shows the range of possibilities for where the center, or eye, of Helene will pass. Life threatening impacts can and are forecast to occur well outside the cone especially on the east and northeast side of this storm. 

Helene will likely be in the Category 3 range, and possibly a Category 4, when it strikes. Low wind shear has allowed the storm to organize, despite its large size, in such a way that it has an impressive eye stacked perfectly in vertical extent, making it an efficient, angular, momentum machine. Combined with record-high water temperatures in the Gulf of Mexico, it's in a perfect situation for rapid intensification, which is or will be underway soon.  Below are recent satellite and radar images.

Heavy rains are likely, and could set off another round of freshwater flooding inland, as the ground is still quite wet from the unnamed June 11 storm (which produced the heaviest hourly rain in an estimated 1,000 years in Sarasota), followed by a 200-year rain event over a much larger area during Hurricane Debby. A record 50 inches of rain fell in Sarasota from June through August.

Although I expect about 5 inches of rainfall, on average, from Helene, the storm's spiral bands may set up some other storms and could result in localized rainfall that's double that total. We need to be ready for that—and the potential for a few tornadoes, too, which are becoming more common in tropical storms and hurricanes in our climate-warmed world. 

Helene is now bigger than 90 percent of all the storms that have ever been recorded south of 20°N of the equator (which marks a parallel that runs across the globe and through parts of Africa, Asia, the Indian Ocean, Pacific Ocean and North America). This is why the storm could have serious impacts well away from its eye. Since the storm will be moving north-northeast from its present point at an increasingly forward speed, the northeast quadrant of the storm will likely be the most intense.

Because the Gulf Coast has become such a big target for hurricanes and major hurricanes (Category 3 or higher) in the past five or six years, the economic and medical toll on residents is growing.

The Climate Adaptation Center's fourth annual Florida Climate Conference, on Nov. 14-15, focuses on climate and human health, and how we can prepare in advance for the heath impacts of our heating climate. For more information, click here. 

In the meantime, stay safe, know your evacuation zone and where to take shelter if needed, and follow local government and media for important updates.