Tag Archives: IO98

Tropical Cyclone 03A Forms South of Pakistan

Tropical Cyclone 03A formed over the Arabian Sea south of Pakistan on Thursday night. At 5:00 a.m. EDT on Friday the center of Tropical Cyclone 03A was located at latitude 21.8°N and longitude 56.6°E which put it about 225 miles (370 km) south-southwest of Karachi, Pakistan. The tropical cyclone was moving toward the west at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1003 mb.

The circulation around a low pressure system over the Arabian Sea south of Pakistan strengthened on Thursday night and the Joint Typhoon Warning Center designated the system as Tropical Cyclone 03A. The distribution of thunderstorms around Tropical Cyclone 03A was asymmetrical. Thunderstorms were occurring in bands in the western half of the tropical cyclone. Bands in the eastern half of the circulation consisted primarily of showers and lower clouds. An upper level ridge over Southwest Asia was producing easterly winds that were blowing toward the top of the tropical cyclone’s circulation. Those winds were causing vertical wind shear and the shear was contributing to the asymmetrical distribution of thunderstorms. Winds to tropical storm force extended out 115 miles (185 km) from the center of circulation.

Tropical Cyclone 03A will move through an environment that is somewhat favorable for intensification during the next 24 hours. The tropical cyclone will move over water where the Sea Surface Temperatures are near 28˚C. The upper level ridge over Southwest Asia will continue to cause vertical wind shear. There is also drier air over Southwestern Asia. Tropical Cyclone 03A could strengthen during the next 24 hours if the wind shear does not increase.

Tropical Cyclone 03A will move south of a high pressure system over Southwest Asia. The high pressure system will steer the tropical cyclone toward the west-northwest during the next 24 hours. On its anticipated track Tropical Cyclone 03A will move a little closer to Pakistan.

Tropical Depression Forms East of Sri Lanka

A Tropical Depression (also designated as Invest 98B) formed over the southern Bay of Bengal east of Sri Lanka on Monday. At 10:00 p.m. EST on Monday the center of a tropical depression was located at latitude 6.7°N and longitude 86.3°E which put it about 295 miles (475 km) east of Pottuvil, Sri Lanka. It was moving toward the west at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h). The minimum surface pressure was 1004 mb.

A low level center of circulation developed in an area of thunderstorms over the southern Bay of Bengal east of Sri Lanka on Monday. The circulation around the tropical depression was still organizing on Monday night. More thunderstorms were developing near the low level center. Bands of showers and thunderstorms were forming outside the center of circulation. Storms near the center started to generate upper level divergence which pumped mass away to the north and west of the tropical depression.

The tropical depression will move through a region somewhat favorable for intensification during the next 24 hours. The depression will move over water where the Sea Surface Temperature is near 29°C. It will move under the western end of an upper level ridge centered over Southeast Asia. The ridge will produce easterly winds which will blow toward the top of the depression. Those winds will cause moderate vertical wind shear. The shear will inhibit intensification, but it probably will not be strong enough to prevent the tropical depression from intensifying.

The tropical depression will move south of a high pressure system over India and the Bay of Bengal. The high will steer the depression toward the west during the next several days. On its anticipated track the tropical depression will approach Sri Lanka in about 36 hours. It will drop heavy rain over parts of Sri Lanka and flash floods could occur.

Tropical Cyclone Forms Over Northern Bay of Bengal

A tropical cyclone formed over the northern Bay of Bengal on Thursday.  At 11:00 a.m. EDT on Thursday the center of the tropical cyclone was located at latitude 20.0°N and longitude 86.5°E which put it about 25 miles (40 km) south-southwest of Paradip, India.  The cyclone was moving toward the north-northeast at 18 m.p.h. (30 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 999 mb.

A center of low pressure developed within a broader area of showers and thunderstorms over the northern Bay of Bengal on Thursday.  A wide band of showers and thunderstorms wrapped around the eastern side of the circulation.  The center of circulation was west of that primary rainband.  Additional bands of showers and thunderstorms formed in other parts of the circulation.  The circulation exhibited enough organization and characteristics to be classified as a tropical cyclone.  The Indian Meteorological Department was giving the the system a classification of depression.

The tropical cyclone is being steered north by a ridge of high pressure to its east.  On its anticipated track the tropical cyclone with make landfall on the coast of the northern Bay of Bengal within 12 hours.  Although the tropical cyclone is moving over water where the Sea Surface Temperature is near 31°C and there is not much vertical wind shear, it does not have much time to intensify before the center moves inland.  The tropical cyclone could strenthen a little more prior to landfall.  It will bring a storm surge of several feet (one to two meters) to the coast along the northern Bay of Bengal.  The tropical cyclone will also drop locally heavy rain and flooding could occur in some parts of India and Bangladesh.