Four early signs a storm will strengthen, found in 1,510 radar scans
How do forecasters know when a hurricane is about to rapidly strengthen
Researchers at the University of Miami Rosenstiel School, working with NOAA, used 1,510 Hurricane Hunter radar analyses from 1997 through 2024 to identify four features that appear about a day before a tilted storm straightens up and intensifies, which could give the Gulf coast and inland areas like
Photo: Miguel Á. Padriñán / Pexels
We are a few hours from the Gulf here, close enough that a storm getting stronger overnight changes what people in Columbus and Eufaula do the next morning. The hardest thing for forecasters to call is exactly that: the disorganized, unimpressive storm that suddenly gets its act together. New work out of Miami has found four things that show up about a day before it happens.
The research was led by scientists at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science, working with NOAA's Atlantic Oceanographic and Meteorological Laboratory. They leaned on a remarkable pile of data: 1,510 radar analyses collected by NOAA Hurricane Hunter aircraft flying into storms across 28 seasons, from 1997 through 2024. The archive, called TC-RADAR, was built by the study's lead author, Michael S. Fischer, and his colleagues.
Here is the idea at the heart of it. A tropical cyclone is not a flat pinwheel; it is a column of spinning air miles deep. When strong winds high up push the top of that column away from the bottom, the storm is leaning, and a leaning storm mostly cannot intensify. As Fischer put it, a tropical cyclone has to stand up straight before it can intensify. Meteorologists call that lean the tilt, and the change in wind with height that causes it is called vertical wind shear.
So the researchers compared the storms that eventually straightened up with the ones that stayed leaning. Four features separated them. First, a compact, tightly wound circulation down near the ocean surface. Second, a tilt pointed in a favorable direction relative to the shear. Third, stronger rising air and heavier rain close to that low-level center. Fourth, a helpful neighborhood: warm water, a moist atmosphere, and relatively weak winds through the middle levels.
The part that changes things is the timing. Fischer said the storms that aligned already looked different about a day beforehand, with stronger, tighter circulations near the surface and more widespread, vigorous thunderstorms lifting air near that center. The team also suspects those thunderstorms are not just evidence that a storm is organizing. They may be part of what hauls the leaning column upright.
For us, the value is in hours. Rapid strengthening is the scenario that leaves coastal communities and emergency managers almost no time to act, and everything that moves inland to Phenix City, Auburn and Cusseta starts with decisions made on the coast the day before. An extra day of warning is extra time for evacuation calls and for the rest of us to fill the tank and move the lawn furniture.
None of this is aimed at anything on the map right now. The Hurricane Center's Tuesday afternoon outlook has advisories out on Fay, a downgraded tropical depression several hundred miles southwest of the Azores, and it is watching a tropical wave due to move off the coast of west Africa. Upper-level winds there are not especially favorable, though slow development is possible as it drifts northwest across the far eastern Atlantic. That is the Cabo Verde neighborhood, a long way from the Gulf of America, and the outlook says nothing about this part of the country.
Still, it is October that tends to concentrate the mind around here. Worth knowing that the people flying into these storms have gotten better at spotting the ones about to stand up.
Slight Chance Showers And Thunderstorms then Partly Cloudy
WED
90°
69°
20%
Mostly Sunny then Slight Chance Showers And Thunderstorms
THU
83°
62°
4%
Partly Sunny
FRI
83°
59°
0%
Sunny
SAT
84°
58°
0%
Mostly Sunny
SUN
87°
59°
2%
Mostly Sunny
MON
88°
61°
8%
Mostly Sunny
Written by the CNAW 2 weather desk from CNAW 2 weather desk data. Last updated September 22, 2026 at 8:31 PM Eastern. Covering Columbus and Phenix City, Auburn–Opelika, LaGrange, Eufaula and the rest of the 19-county CNAW viewing area.
