Tropical Storm Lee

Tropical Storm Lee

One week after Hurricane Irene battered the East Coast of the United States with damaging winds and flooding rain, a less-touted, plodding storm system soaked the eastern half of the country with more rain than its predecessor, and over a wider area. Tropical Storm Lee had a short official life as a named storm, but its effects lasted nearly a week.

Officially declared a tropical storm late on September 2, Lee reached its peak sustained winds of 57 miles (92 kilometers) per hour—well below hurricane force—on September 3 before making landfall on the Gulf Coast. By September 5, the storm was no longer a tropical depression, yet it was only beginning its march from Louisiana to soggy New England and the Mid-Atlantic.

The satellite image above shows the remnants of Lee and several other weather systems mashed together in the eastern U.S. at 14:02 Universal Time (10:02 a.m. Eastern Daylight Time) on September 7, 2011. Hurricane Katia whirls well out in the Atlantic Ocean, but plays a key role in stalling the storms over land.

Click on the animation (also linked below the image) to follow the progress of the weather systems from 13:02 Universal Time (9:02 a.m. EDT) on September 2 through 11:32 UTC (7:32 a.m. EDT) on September 9, 2011. The still image and the animation were built from images acquired every 5–15 minutes by the GOES-East satellite.

As Lee moved north and east, it merged with a stalled frontal system. Meanwhile, Hurricane Katia was pushing north and west over the Atlantic, and blocking Lee from quickly moving east and offshore. The two storms aligned to pull copious amounts of moisture from the Gulf of Mexico and the Atlantic. A meteorologist with the National Weather Service in Binghamton, New York, summed it up this way on September 7:

{There is a] bad combo of ingredients in place to continue very heavy rainfall. A closed upper low continues to spin over the Ohio Valley, with a deep southerly fetch along the eastern seaboard, only adding to the moisture in place from the remains of Tropical Storm Lee. Water vapor loops show tropical moisture from distant Hurricane Katia getting steered all the way into the rain area.

Weekly rainfall totals topped 10 inches (25 centimeter) in cities and towns across eight states; another dozen states saw 6 to 10 inches. Jackson, Mississippi, received 11.68 inches of rain in just 24 hours. Elizabethtown, Pennsylvania, recorded 15.37 inches for the week—more than three months worth of rain. Locations across Vermont, New York, New Jersey, Maryland, and Connecticut absorbed 6 to 10 inches of rain just days after receiving as much from Hurricane Irene.

Image and animation courtesy NASA/NOAA GOES Project Science Team. Caption by Mike Carlowicz.

References & Resources