Never-Ending Tropical Storm Nadine Spins in the Atlantic

By Andrew Freedman

Tropical Storm Nadine just won’t give up. The storm has been spinning in the eastern Atlantic Ocean in varying stages of intensity, since September 11. Since then, it has been classified at various times as a tropical depression, a tropical storm, a hurricane, a tropical storm again, a subtropical storm, and now is back to tropical storm status.

A NASA satellite image of Tropical Storm Nadine in the eastern Atlantic.
Click on the image for a larger version. Credit: NASA.

Despite being around for about two weeks, the storm has managed to avoid making landfall anywhere. But it has certainly annoyed residents and tourists on the Azores Islands, since it has drifted close enough to bring blustery conditions, rain showers, and high surf. In fact, some computer models show the storm making another close pass with these islands early next week, and continuing to exist as a tropical storm, with sustained winds of between 39 and 74 mph, right on through the first week of October, which would put the storm among the longest-lasting tropical cyclones on record.

The modern title-holder is Hurricane Ginger in 1971, which lasted for 27 days, according to the National Hurricane Center’s FAQ. Nadine will more likely rival 1969’s Hurricane Inga, Hurricane Kyle in 2002, and Hurricanes Carrie and Inez. Those storms lasted from between 20.25 to 24.75 days.

To put this into perspective, the average named Atlantic storm lasts about six days.

Satellite loop of Super Typhoon Jelawat. Credit: NOAA's National Hurricane Center.

Nadine has been too far out to sea to be routinely investigated by the U.S. Air Force’s Hurricane Hunters or by NOAA researchers, but it has been a boon for NASA, which has been flying Global Hawk drones above Nadine on missions that have lasted as long as 26 hours. Taking off from Wallops Island, Va., the drones have flown clear across the Atlantic, and then flown zig-zagging, “lawn mower patterns” at altitudes of up to 65,000 feet – far higher than commercial airliners fly — above the storm.

Scott Braun, the principal investigator for NASA’s Hurricane and Severe Storm Sentinal (HS3) mission, said the fifth flight into Nadine was underway Wednesday, and it’s “probably also our last unless it does something really interesting next week (assuming that it is still around).”

Braun’s team has been able to collect valuable data as Nadine has undergone various transitions. However, it hasn’t been the ideal storm for collecting data sets on what makes hurricanes rapidly intensify, Braun said

“…We have captured this storm at so many stages (very early formation, transition to hurricane, back to tropical storm, to post-tropical, and back to tropical) and it will tell us a lot about each of these stages. However, it won't be ideal for addressing our science goals as far as larger changes in intensity are concerned,” Braun said via email. “So we would really have liked to have gotten a stronger storm for at least a flight or two. But you have to take what nature gives you. Luckily, we have two more years, so we should have no trouble collecting the data that we ideally would like to have.”

Photo taken from NASA's Global Hawk drone as it flew towards T.S. Nadine on September 26.
Click on the image for a larger version. Credit: NASA.

The HS3 project is designed to help answer lingering questions on tropical cyclone intensity changes. Although hurricane track forecasts have improved greatly during the past two decades, intensity forecast accuracy has languished.

While Nadine continues to defy the odds in the eastern Atlantic, the Pacific Ocean is playing host to a far fiercer storm, Category 5 Super Typhoon Jelawat. Like Super Typhoon Senba, Jelawat is expected to come close to or over the island of Okinawa, before turning northeastward and striking Japan in a weakened state. Fortunately for Okinawa, it is not expected to retain its “Super” status, with forecasts calling for it to be only a Category 1 or 2 storm at that time.