Tag Archives: Bay of Bengal

Tropical Depression Forms Near Southern Tip of Sri Lanka

A tropical depression formed near the southern tip of Sri Lanka on Wednesday.  At 7:00 a.m. EST on Wednesday the center of Tropical Depression 96S was located at latitude 6.2°N and longitude 80.0°E which put it about 20 miles (30 km) northwest of Galle, Sri Lanka.  It was moving toward the west-southwest at 4 m.p.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 center of circulation formed within a cluster of thunderstorms also designated as Invest 91B and the Indian Meteorological Department classified the system as a Depression.  The circulation in the tropical depression was still organizing.  A large, primary rainband wrapped around the southern and western sides of the center of circulation.  Additional bands of showers and strong thunderstorms were forming in the western half of the circulation.  Bands of showers and isolated thunderstorms were developing in the eastern half of the circulation.  Thunderstorms in the primary rainband were generating upper level divergence which was pumping away mass to the west of the depression.

The depression will move through an environment favorable for intensification during the next several days.  It will move over water where the Sea Surface Temperature is near 29°C.  An upper level ridge over India is generating easterly winds which are blowing toward the top of the circulation.  Those winds are causing moderate vertical wind shear which is probably the reason why most of the stronger thunderstorms are occurring in the western half of the depression.  The vertical wind shear will inhibit intensification, but it is not likely to prevent strengthening.  The depression is likely to intensify into a stronger tropical cyclone during the next several days.

The ridge over India is steering the tropical depression toward the west-southwest.  The ridge is forecast to steer the depression in a generally westerly direction during the next several days.  On its anticipated track the depression will move away from Sri Lanka and the center will pass south of India.  The depression could cause locally heavy rain and flash floods in parts of Sri Lanka and southern India.

Tropical Depression Forms Over Bay of Bengal

A tropical depression formed over the Bay of Bengal on Wednesday.  At 10:00 a.m. EST on Wednesday the center of the tropical depression was located at latitude 16.2°N and longitude 83.3°E which put it about 105 miles (170 km) south of Visakhapatnam, India.  The depression was moving toward the north-northeast at 9 m.p.h. (15 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 1003 mb.

A low level center of circulation developed on the southwestern edge of a cluster of showers and thunderstorms over the Bay of Bengal and the Indian Meteorological Department classified the system as a depression.  The circulation is not particularly well organized.  As noted above, the low level center is on the southwestern side of showers and thunderstorms.  Several bands of showers and storms formed northeast of the center.  There were not many thunderstorms near the center of circulation.  There were bands of showers and lower clouds in the western half of the circulation.  An upper level trough over India is producing southwesterly winds which are blowing over the top of the depression.  Those winds are causing moderate vertical wind shear, which is tilting the upper part of the depression to the northeast of the low level center of circulation.  The depression also appears to be pulling drier air from India around the western side of the circulation.  The combination of wind shear and drier air is probably responsible for the asymmetrical distribution of thunderstorms.

The depression will move through an environment that is marginally favorable for intensification.  It will move over water there the Sea Surface Temperature is near 28.5°C.  So, there is enough energy in the upper ocean to support intensification.  However, the upper level trough over India will continue to cause moderate vertical wind shear, which will inhibit the consolidation of the low level circulation.  The depression is also likely to continue to draw in drier air from over India into the western part of the circulation.  The depression could strengthen, but it could also weaken if the upper level winds get stronger.

The trough over India is steering the depression slowly toward the north-northeast and that general motion is expected to continue.  On its anticipated track the depression is expected to move toward the northern Bay of Bengal during the next several days.  The depression could make landfall over northeastern India or Bangladesh later this week.

The primary risk from the depression will be locally heavy rain, which could cause flash floods in parts of eastern India and Bangladesh.  The wind will push water toward the north coast of the Bay of Bengal and the depression could cause a storm surge of several feet (approximately one meter).

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.

Stronger Tropical Cyclone Mora Near Landfall in Bangladesh

A stronger Tropical Cyclone Mora neared landfall between Cox’s Bazar and Chittagong, Bangladesh.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Mora was located at latitude 21.8°N and longitude 91.9°E which put it about 90 miles (145 km) south of Chittagong, Bangladesh.  Mora was moving toward the north at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 974 mb.  Tropical Cyclone Mora was the equivalent of a hurricane/typhoon.

The inner core of Tropical Cyclone Mora organized quickly on Monday.  The primary rainband wrapped entirely around the center of circulation and an eye formed.  Additional bands of showers and thunderstorms were revolving around the core Tropical Cyclone Mora.  Thunderstorms near the core of Mora generated strong upper level divergence which pumped out mass and allowed the surface pressure to decrease.  The decrease of pressure caused the surface winds to increase to hurricane/typhoon intensity.  Winds to hurricane/typhoon strength extended out about 25 miles (40 km) from the center.  Winds to tropical storm force extended out about 150 miles (240 km) from the center.  The strongest winds were occurring in the eyewall and over the Bay of Bengal.

Tropical Cyclone Mora is moving around the western end of a subtropical ridge.  The ridge is steering Mora toward the north and that general motion is expected to continue for another 12 to 18 hours.  On its anticipated track the center of Tropical Cyclone Mora will move near the coast of Bangladesh between Cox’s Bazar and Chittagong.  The center is likely to make landfall near Chittagong during the next few hours.

The recent intensification of Tropical Cyclone Mora has made it a more dangerous storm.  The increased wind speed will increase the potential for wind damage.  In addition, stronger winds will increase the height of the storm surge along the coast.  A storm surge of 6 to 9 feet (2 to 3 meters) will be possible along the coast between Cox’s Bazar and Chittagong.  The increase in organization of the core has also created the potential for heavier rain and greater fresh water flooding of rivers and streams.

Tropical Cyclone Mora will start to weaken after the center makes landfall.  However, it will continue to generate areas of heavy rain while it moves inland over Bangladesh and northeastern India.

 

Tropical Cyclone 02B Forms Over the Bay of Bengal

A surface circulation formed over the Bay of Bengal on Saturday and the system was designated Tropical Cyclone 02B.  At 8:00 p.m. EDT on Saturday the center of Tropical Cyclone 02B was located at latitude 14.2°N and longitude 88.9°E which put it about 640 miles (1030 km) south-southwest of Chittagong, Bangladesh.  The tropical cyclone was moving toward the north-northeast at 4 m.p.h. (6 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 998 mb.

A low level center of circulation consolidated over the Bay of Bengal on Saturday.  The distribution of thunderstorms was asymmetrical.  Most of the thunderstorms in the inner part of the circulation developed west of the center.  There were some thunderstorms in outer bands northeast of the center, but there were few thunderstorms closer to the core of the circulation in the eastern half of the tropical cyclone.  The thunderstorms west of the center were producing upper level divergence which was pumping away mass to the west of the tropical cyclone.

Tropical Cyclone 02B will be moving through an environment that will be favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge east of the tropical cyclone is generating southeasterly winds which are blowing toward the top of the circulation.  Those winds are creating moderate vertical wind shear and the shear may be the reason why the thunderstorms were developing west of the center.  The shear will be strong enough to slow intensification, but it will not prevent intensification.  Tropical Cyclone 02B will intensify during the next two days and it could become the equivalent of a hurricane/typhoon.

A subtropical ridge located east of Tropical Cyclone 02B is steering it slowly toward the north-northeast.  A general north-northeasterly motion is expected to continue during the next several days.  On its anticipated track the center of Tropical Cyclone 02B could approach the coast of Bangladesh and northwestern Burma in about 48 hours.  Tropical Cyclone 02B could be the equivalent of a hurricane/typhoon by that time.  It could bring gusty winds and locally heavy rain when it makes landfall.  Heavy rain could cause fresh water flooding of rivers.  In addition the winds on the eastern side of Tropical Cyclone 02B will push water in the Bay of Bengal toward the coast.  A serious storm surge could occur along the coast east and near where the center makes landfall.

Possible Tropical Cyclone Developing Over Bay of Bengal

Satellite imagery indicates that a possible tropical cyclone may be developing over the Bay of Bengal.  Thunderstorms have increased and the system has been designated as Invest 94B.  At 8:00 p.m. EDT on Thursday the center of Invest 94B was located at latitude 11.8°N and longitude 88.7°E which put it about 575 miles (930 km) east of Chennai, India.  The invest was not moving much.  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1002 mb.

A circulation began to consolidate in an area of thunderstorms over the Bay of Bengal on Thursday.  Many more thunderstorms formed in the western half of the circulation.  Although there was still not a well defined center of circulation, some curved bands began to form.  A broad cyclonic circulation began to rotate counterclockwise.

Invest 94B was organizing in area that was favorable for further intensification.  It was moving over water where the Sea Surface Temperature was near 30°C.  An upper level ridge centered to the east of the invest was generating easterly winds that were blowing toward the top of the circulation.  The winds were producing some vertical wind shear and the shear may have contributed to the asymmetrical distribution of thunderstorms.  The shear could slow the development, but it is probably not strong enough to prevent the formation of a tropical cyclone.

Invest 94B did not move much during Thursday.  The is some uncertainty about the future track of the system.  Some numerical models are forecasting that the subtropical ridge to the east of Invest 94B will steer it toward the northern Bay of Bengal.

 

Tropical Cyclone Maarutha Strengthens Over Bay of Bengal

Tropical Cyclone Maarutha strengthened over the Bay of Bengal on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Maarutha was located at latitude 15.8°N and longitude 91.7°E which put it about 350 miles (565 km) southwest of Sandoway, Burma.  Maarutha was moving toward the northeast at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 993 mb.

A primary rainband wrapped around the western side of the center of circulation.  The band was broken on the eastern side of the center.  Additional bands of showers and thunderstorms were revolving around the northern and eastern periphery of the circulation.  Thunderstorms in the primary rainband were generating upper level divergence which was pumping mass out to the northeast of the circulation.

Tropical Cyclone Maarutha will be moving through an environment that will be moderately favorable for intensification during the next 12-24 hours.  Maarutha will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge east of Maarutha is producing southwesterly winds which are blowing toward the top of the tropical cyclone.  Those winds are causing moderate vertical wind shear which will inhibit intensification.  Despite the vertical wind shear Tropical Cyclone Maarutha could intensify further before it makes landfall in Burma in 18 to 24 hours.

A subtropical ridge east of Maarutha is steering the tropical cyclone toward the northeast and that general motion is expected to continue for the next several days.  On its anticipated track Tropical Cyclone Maarutha will make landfall in Burma between Sittwe and Bassein near Sandoway.

Tropical Cyclone Maarutha will bring gusty winds and locally heavy rain to Burma when it makes landfall.  Some storm surge is likely south of where the center makes landfall and the wind blows the water toward the coast.

Tropical Cyclone Vardah Reorganizes Over the Arabian Sea

After moving across southern India and weakening Tropical Cyclone Vardah began to reorganize over the eastern Arabian Sea on Thursday.  At 7:00 p.m. EST on Thursday the center of Tropical Cyclone Vardah was located near latitude 11.0°N and longitude 68.0°E which put it about 1140 miles (1840 km) east of Baargaal, Somalia.  Vardah was moving toward the west at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 25 m.p.h. (40 km/h) and there were wind gusts to 35 m.p.h. (55 km/h).  The minimum surface pressure was 1007 mb.

Tropical Cyclone Vardah retained a well organized low level circulation as it moved across southern India and into the eastern Arabian Sea.  However, almost all of the showers and thunderstorms dissipated as the cyclone crossed over land.  A few showers and thunderstorms began to redevelop about 24 hours ago.  There are now several rainbands that are spiraling around the circulation and stronger thunderstorms are forming in some of those bands.  The thunderstorms are beginning to produce upper level divergence.

Tropical Cyclone Vardah will be moving through an environment that is favorable for intensification.  Vardah will be moving over water where the Sea Surface Temperature is near 28°C.  The upper level winds are weak and there is not much vertical wind shear.  Tropical Cyclone Vardah should continue to redevelop during the next 24 hours.

A subtropical ridge to the north of Vardah has been steering the tropical cyclone toward the west and that general motion is expected to continue.  On its anticipated track Tropical Cyclone Vardah will move across the Arabian Sea toward eastern Africa during the next several days.

Tropical Cyclone Vardah Nearing Landfall in India

Tropical Cyclone Vardah moved steadily toward a landfall near Chennai India on Sunday.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Vardah was located at latitude 13.2°N and longitude 81.1°E which put it about 60 miles (105 km) east of Chennai, India.  Vardah was moving toward the west at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (170 km/h).  The minimum surface pressure was 967 mb.

The Indian Meteorological Department’s radar at Chennai shows that Tropical Cyclone Vardah is very well organized and symmetrical.  There is a circular eye surrounded by a ring of strong thunderstorms.  The strongest storms are west and south of the eye, and the ring is thinner east of the eye.  There are multiple bands of thunderstorms and the heaviest thunderstorms in those bands are also in the western half of the circulation.  The thunderstorms are generating strong upper level divergence which is pumping out mass to the west and north of the tropical cyclone.

Tropical Cyclone Vardah is moving over water where the Sea Surface Temperature is near 29°C.  The energy from the ocean will keep Vardah from weakening before it makes landfall.  Tropical Cyclone Vardah will weaken steadily once it begins to move over southern India.

A subtropical ridge north of Vardah is steering the tropical cyclone toward the west and that general motion is expected to continue.  On its anticipated track Tropical Cyclone Vardah will make landfall near Chennai, India in a few hours.  Vardah will continue to move west across southern India after it moves inland.

Tropical Cyclone Vardah will bring strong winds and heavy rain to the area around Chennai.  The Hurricane Intensity Index (HII) is 12.7.  The Hurricane Size Index (HSI) is 11.3 and the Hurricane Wind Intensity Size Index (HWISI) is 24.0.  Those indices indicate that Tropical Cyclone Vardah is capable of causing regional minor wind damage when it makes landafall.

Vardah will also generate a storm surge along portion of the coast north of Chennai where the wind will blow the water toward the coast.  Vardah will produce locally heavy rain over Tamil Nadu, Andhra Pradesh and Karnataka.  The heavy rain could produce floods and mudslides.

Tropical Cyclone Vardah Reaches Hurricane Intensity

Tropical Cyclone Vardah intensified into the equivalent of a hurricane on Saturday as it moved across the Bay of Bengal toward India.  At 4:00 p.m. EST on Saturday the center of Tropical Cyclone Vardah was located at latitude 13.0°N and longitude 84.8°E which put it about 290 miles (470 km) east of Chennai, India.  Vardah was moving toward the west at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 974 mb.

The circulation of Tropical Cyclone Vardah is well organized, but the distribution of thunderstorms is asymmetrical.  There is a broken ring of thunderstorms around the center of circulation.  Outside of that ring most of the thunderstorms are forming in the western half of the circulation.  It appears that an upper level ridge to the north of Vardah is producing easterly winds which are causing moderate vertical wind shear.  The wind shear seems to be the primary cause of the asymmetry of the convection.  The thunderstorms are generating upper level divergence which is pumping out mass to the west of the cyclone.

The environment around Tropical Cyclone Vardah is marginal for further intensification.  Vardah is moving over water where the Sea Surface Temperature is near 29°C.  However, the moderate vertical wind shear may be strong enough to inhibit further intensification.  There are some indications that the upper level winds may be getting stronger and the shear could increase.  If the shear increases, then Tropical Cyclone Vardah could start to weaken even though it is over warm water.

The same ridge that is causing the wind shear is also steering Tropical Cyclone Vardah toward the west and that general motion is expected to continue.  On its anticipated track Tropical Cyclone Vardah could make landfall near Chennai, India in about 36 hours.  Tropical Cyclone Vardah will bring gusty winds and locally heavy rain to portions of southern India.  The heavy rain could cause flooding and mudslides.  Vardah will also cause a storm surge along the coast near and to the north of where the center makes landfall.