NASA's Global Hawk flew five science missions into Tropical Storm/Hurricane Nadine, plus the transit flight circling around the east side of Hurricane Leslie. This is a composite of the ground tracks of the transit flight to NASA Wallops plus the five science flights. TD means Tropical Depression; TS means Tropical Storm. Credit: NASA

NASA's Hurricane and Severe Storm Sentinel or HS3 scientists had a fascinating tropical cyclone to study in long-lived Hurricane Nadine. NASA's Global Hawk aircraft has investigated Nadine five times during the storm's lifetime.

NASA's Global Hawk also circled around the eastern side of Hurricane Leslie when it initially flew from NASA's Dryden Research Flight Center, Edwards Air Force Base, Calif. to the HS3 base at NASA's Wallops Flight Facility, Wallops Island, Va. on Sept. 6-7, 2012.

Nadine has been a great tropical cyclone to study because it has lived so long and has strengthened to hurricane status a couple of times, and then weakened back into a tropical storm. Hurricane Nadine is an anomaly because it has been tracking through the North Atlantic since Sept. 11, when it developed as the fourteenth tropical system of the hurricane season.

Longest-lived Tropical Cyclones

As of Oct. 2, Nadine has been alive in the north Atlantic for 21 days. According to NOAA, in the Atlantic Ocean, Hurricane Ginger lasted 28 days in 1971. The Pacific Ocean holds the record, though as Hurricane/Typhoon John lasted 31 days. John was "born" in the Eastern North Pacific, crossed the International Dateline and moved through the Western North Pacific over 31 days during August and September 1994. Nadine, however, is in the top 50 longest-lasting tropical cyclones in either ocean basin.

First Flight into Nadine

On Sept. 11, as part of NASA's HS3 mission, the Global Hawk aircraft took off from NASA Wallops at 7:06 a.m. EDT and headed for Tropical Depression 14, which at the time of take-off, was still a developing low pressure area called System 91L.

At 11 a.m. EDT that day, Tropical Depression 14 was located near 16.3 North latitude and 43.1 West longitude, about 1,210 miles (1,950 km) east of the Lesser Antilles. The depression had maximum sustained winds near 35 mph. It was moving to the west near 10 mph (17 kmh) and had a minimum central pressure of 1006 millibars.

NASA's Global Hawk landed back at Wallops Flight Facility, Wallops Island, Va., on Sept. 12 after spending 11 hours gathering data in the storm, which had strengthened into Tropical Storm Nadine during the early morning hours of Sept. 12.

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NASA's HS3 mission thoroughly investigates long-lived Hurricane Nadine