Tropical Storm Helene — or Hurricane Helene, depending on when you read this — may have seemed like it popped up from nowhere this week. Warnings have been issued for residents along Florida's Gulf Coast with projections from the National Hurricane Center it could be a Category 3 storm when it reaches land in the next 24-48 hours.
So perhaps you're wondering how forecasters seem so certain it will grow so quickly and move so fast.
The answer? Balloons. Lots and lots of weather balloons made with specialty polymer films attached to high-end equipment to track storm conditions. Accompanied, of course, by the expertise from meteorologists who can interpret data sent from the balloons.
Technically, equipment is called a radiosonde and consists of a "small, expendable instrument package suspended below a weather balloon," the NHC says. As the balloon rises, sensors note the atmospheric temperature, pressure and relative humidity. They can ascend more than 115,000 feet.
They are deployed twice a day, every day of the year. With Helene developing, the New York Times reports, National Weather Service locations along the Gulf Coast are sending extra balloons aloft.
The NWS has been using weather balloons since the 1930s.
"While there are several new and improved tools used to enhance storm forecasts, weather balloons prevail as one of the longest running and most dependable tools deployed by meteorologists," NWS said.