December 14, 2013 - Tropical Cyclone Helen

Tropical Cyclone Helen

On November 21 at 07:55 UTC (2:55 a.m. EDT) the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Aqua satellite flew over Tropical Cyclone Helen and captured a true-color image of the storm approaching India. The stormís northwestern quadrant had already spread over eastern India, bringing heavy rain, but the strongest thunderstorms still remained offshore. Helen's western cloud cover extended from Kolkata south to Chennai at the time.

About 7 hours after this image was captured, at 1500 UTC (10 a.m. EST) Tropical Cyclone Helen was located about 569.6 miles (916.7 km) southwest of Calcutta, India, near 16.1 north and 83.0 east. Helen was moving a little faster than the previous day, now at 4.6 mph (7.4 km/h) to the northwest. Helen's maximum sustained winds peaked at 63.2 mph (101.9 km/h) and tropical storm force winds extend out 74.8 miles (120.4 km) from the center. Helen was also creating maximum wave heights of up to 20 feet (6.0 m), and causing rough seas along the southwestern coast of India.

By 0900 UTC (4:00 a.m. EST) on November 22, Helen made landfall near Machillipatnam, Andhra Pradesh. Maximum sustained winds were near 40 mph (62 km/h) at the time of landfall. At that time, Helen was located near 16.2 north latitude and 81.0 east longitude, about 222 miles (357 km) north-northeast of Chennai, India. Helen was moving to the west at 8.0 mph (12.9 km/h) near Tenali while heading further inland. Just before landfall, the stormís convection sheared to the north, weakening the storm. Once over land, Cyclone Helen deteriorated rapidly.

The Joint Typhoon Warning Center issued their final bulletin on Cyclone Helen on November 22 at 0900 UTC (4:00 a.m. EST). Although it was not a large storm, Helen uprooted trees and downed electrical lines. The most extensive damage was to crops, especially coconut, paddy and banana. Damage estimates to Krishna, and West and East Godavari districts in Andhra Pradesh have been as high as $262 million US Dollars.

Image Facts
Satellite: Terra
Date Acquired: 11/21/2013
Resolutions: 1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC