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Tropical Depression 03B (Northern Indian Ocean)
11.20.12
 
MODIS image captured on Nov. 17 when Tropical Depression 03B was forming in the Bay of Bengal. › View larger image
This image from the MODIS instrument aboard NASA's Aqua satellite was captured on Nov. 17 at 0710 UTC (2:10 a.m. EDT) when Tropical Depression 03B was forming in the Bay of Bengal.
Credit: NASA Goddard MODIS Rapid Response Team
Tropical Depression 03B Continues to Stretch, Weaken

Tropical Depression 03B's remnants continue to linger in the Bay of Bengal, but dry air and wind shear continue to batter the storm and elongate it. The remnants are expected to bring rainfall to the southern coast of Andhra Pradesh and northern coast of Tamil Nadu on Nov. 21 and 22.

NASA's Aqua satellite captured a visible image of 03B when it was forming on Nov. 17, when its clouds covered the northern part of the Bay of Bengal. On Nov. 17 at 0710 UTC (2:10 a.m. EDT), Tropical Depression 03B was forming when the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Aqua satellite captured a visible image of the storm. The image showed good circulation and bands of thunderstorms wrapping into the center from the southern and northeastern quadrants. The tropical cyclone would later strengthen into a tropical storm.

By Nov. 20, wind shear continued to elongate 03B from southwest to northeast. It was located near 15.3 north latitude and 86.0 east longitude, about 360 miles east-northeast of Chennai, India.

The Regional Specialised Meteorological Centre (RSMC) in New Delhi, India issues local advisories on tropical cyclones affecting India. In the bulletin from Nov. 20, RSMC noted "The well-marked low pressure area over west central Bay of Bengal persists over the same region at 0830 hours IST [Nov. 20]." RSMC expects the remnants of Tropical Cyclone 03B to weaken while moving west-southwestwards toward southern coast of Andhra Pradesh and northern coast of Tamil Nadu over the next two days.

RSMC noted that moderate rainfall, with isolated areas of heavy rainfall can be expected over southern coastal Andhra Pradesh, northern coastal Tamilnadu and Puducherry on Wed. Nov. 21 and then over southern coastal Andhra Pradesh, Rayalaseema, Puducherry and north Tamil Nadu on Nov. 22.

The Joint Typhoon Warning Center noted that the likelihood that 03B could reform into a tropical cyclone is low.

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center




Nov. 19, 2012 This composite image uses METEO-7 data with rainfall data from NASA's TRMM satellite. › View larger image
This composite image uses METEO-7 data with rainfall data from NASA's TRMM satellite. The image from Nov. 18 at 1551 UTC (10:51 a.m. EDT) showed the center of then Tropical Storm 03B over the Bay of Bengal and the fringes of its northern clouds over eastern India and western Bangladesh.
Credit: NRL/JTWC/NASA/ESA
Wind Shear and Dry Air Squashing Indian Ocean's Tropical Depression 03B

The third tropical cyclone to form in the Northern Indian Ocean had a short life as satellite data indicates wind shear and dry air are bringing about its demise after two days.

Tropical Depression 03B was born on Nov. 18 over the open waters of the Bay of Bengal. It briefly reached tropical storm status when it's maximum sustained winds peaked at 35 knots (40.2 mph/64.8 kph). Then wind shear increased and dry air moved in, weakening it back to depression status.

In a composite image created by the Naval Research Laboratory and Joint Typhoon Warning Center, METEO-7 data was coupled with rainfall data from NASA's Tropical Rainfall Measuring Mission (TRMM) satellite. The image from Nov. 18 at 1551 UTC (10:51 a.m. EDT) showed the center of then Tropical Storm 03B over the Bay of Bengal and the fringes of its northern clouds over eastern India and western Bangladesh. Rainfall was light to moderate, and over open ocean waters.

The last bulletin on the system was issued at 0300 UTC on Nov. 19 (10 p.m. EDT, Nov. 18). At that time, Tropical Depression 03B had maximum sustained winds near 30 knots (34.5 mph/55.5 kph). At that time it was centered near 15.2 north latitude and 86.5 east longitude, about 395 nautical miles east-northeast of Chennai, India, and it was moving to the southwest near 2 knots (2.7 mph/3.7 kph).

At 11 a.m. EDT (1600 UTC) on Nov. 19, the center of Tropical Depression 03B (TD03B) was located about 275 nautical miles (316.5 miles/509.3 km) south-southeast of Visakhapatnam in the open waters of the Bay of Bengal. Visakhapatnam is a port city located on India's southeastern coast and is the second-largest city in the state of Andhra Pradesh.

Despite its center being over open waters, TD03B's clouds extended over eastern India and over southwestern Bangladesh. The depression's heaviest rainfall was occurring in a band of thunderstorms located east of the center of circulation. The center of circulation appeared to devoid of any precipitation.

Satellite data from the Advanced Microwave Sounding Unit on NOAA's polar orbiting satellites revealed that dry air was wrapping around Tropical Depression 03B. TD03B was also elongating as a result of high vertical wind shear. Whenever a tropical cyclone elongates and cannot keep a rounded circulation, it begins weakening.

The Joint Typhoon Warning Center expects that the combination of dry air moving into the system coupled with the strong wind shear will dissipate TD03B over open ocean waters in the next couple of days.

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center