Category Archives: Indian Ocean

Tropical Cyclone Nisagra Makes Landfall South of Mumbai

Tropical Cyclone Nisarga made landfall south of Mumbai, India on Wednesday.  At 5:00 a.m. EDT on Wednesday the center of Tropical Cyclone Nisarga was located at latitude 18.3°N and longitude 73.3°E which put it about 80 miles (130 km) south of Mumbai, India.  Nisarga was moving toward the northeast at 12 m.p.h. (19 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. (165 km/h).  The minimum surface pressure was 973 mb.

Tropical Cyclone Nisarga rapidly intensified into the equivalent of a hurricane/typhoon on Tuesday night before it made landfall on the west coast of India.  An eye with a diameter of 40 miles (65 km) formed at the center of Nisarga.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Winds to hurricane/typhoon force extended out 30 miles (50 km) from the center of Tropical Cyclone Nisarga at the time of landfall.  Winds to tropical storm force extended out 100 miles (160 km) from the center.

Tropical Cyclone Nisarga brought winds to hurricane/typhoon force to a portion of the west coast of India south of Mumbai.  Those winds would have pushed water toward the coast.  The would have generated a storms surge of 3 to 6 feet (1 to 2 meters) near where the center of Nisarga made landfall.  Tropical Cyclone Nisarga will drop heavy rain over parts of Maharashtra.  Heavy rain could cause flash floods in some locations.

Strengthening Tropical Cyclone Nisarga Nears Mumbai

Strengthening Tropical Cyclone Nisarga neared  Mumbai, India on Tuesday night.  At 11:00 p.m. EDT on Tuesday the center of Tropical Cyclone Nisarga was located at latitude 17.6°N and longitude 72.4°E which put it about 140 miles (225 km) south-southwest of Mumbai, India.  Nisarga was moving toward the northeast at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 985 mb.

Tropical Cyclone Nisarga strengthened quickly on Tuesday night as it moved closer to the west coast of India.  An eye with a diameter of 40 miles (65 km) formed at the center of circulation.  A ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Nisarga.  Storms near the core were generating upper level divergence which was pumping mass away to the east of the tropical cyclone.  Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

Tropical Cyclone Nisarga will move around the western end of a high pressure system over India.  The high will steer Nisarga toward the northeast during the next 24 hours.  On its anticipated track the center of Tropical Cyclone Nisarga will make landfall on the west coast of India south of Mumbai in a few hours.

Tropical Cyclone Nisarga will continue to intensify until it makes landfall.  Nisarga will move over water where the Sea Surface Temperature is near 31°C.  It will move under the western part of an upper level ridge centered over India.  The ridge will produce southerly winds which will blow toward the top of Nisarga.  Those winds will cause some vertical wind shear, but the shear will not be great enough to prevent intensification.  Tropical Cyclone Nisarga is likely to strengthen into the equivalent of a hurricane/typhoon before it makes landfall.

Tropical Cyclone Nisarga will bring strong winds to the west coast of India.  Those winds will push water toward the coast and they could cause a storm surge of 3 to 6 feet (1 to 2 meters) near Mumbai and near where the center makes landfall.  Nisarga will also drop heavy rain over parts of Maharashtra.  Locally heavy rain could cause flash floods in some locations.

Tropical Cyclone Nisarga Develops West of India

Tropical Cyclone Nisarga developed west of India on Tuesday.  At 5:00 a.m. EDT on Tuesday the center of Tropical Cyclone Nisarga was located at latitude 16.0° and longitude 71.2°E which put it about 225 miles (365 km) south-southwest of Mumbai, India.  Nisarga was moving toward the north 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 1000 mb.

The circulation around a low pressure system over the Arabian Sea west of India strengthened on Tuesday and the India Meteorological Department designated the system as Tropical Cyclone Nisarga.  More thunderstorms developed near the center of Nisarga.  Numerous bands of showers and thunderstorms were revolving around the center of circulation.  The strongest rainbands were in the western half of the tropical cyclone.  Storms near the center of circulation generated upper level divergence which pumped mass away from the tropical cyclone.

Tropical Cyclone Nisarga will move through an environment favorable for intensification during the next 24 hours.  Nisarga will move over water where the Sea Surface Temperature is near 31°C.  It will move under the western side of an upper level ridge centered over India.  The ridge will produce southerly winds which will blow toward the top of the circulation.  Those winds will produce some vertical wind shear, but the shear will not be strong enough to prevent the intensification of Tropical Cyclone Nisagra.  Nisagra could strengthen into the equivalent of a hurricane/typhoon.

Tropical Cyclone Nisarga will move around the western end of a high pressure system over India.  The high will steer Nisarga toward the north during the next 12 hours.  Nisarga will move more toward the north-northeast when it moves around the northwestern part of the high pressure system.  On its anticipated track Tropical Cyclone Nisarga could approach Mumbai in about 24 hours.  Nisarga could be the equivalent of a hurricane/typhoon when it approaches Mumbai.

Tropical Cyclone Nisarga will bring gusty winds and locally heavy rain to Mumbai on Wednesday.  Nisarga could also cause a storm surge of  3 to 6 feet (1 to 2 meters) in the area around Mumbai where the wind blows the water toward the coast.  Tropical Cyclone Nisarga will drop locally heavy rain over parts of Maharashtra and southern Gujarat.  Heavy rain could cause flash floods in some locations,

Tropical Depression Forms Near Western Oman

A Tropical Depression formed over the Arabian Sea near the coast of western Oman on Friday.  At 2:00 p.m. EDT on Friday the center of the tropical depression was located at latitude 16.8°N and longitude 54.2°E which put it about 10 miles (15 km) southeast of Salalah, Oman.  The depression was moving toward the west-northwest at 2 m.p.h. (3 km/h).  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 1004 mb.

More thunderstorms developed near the center of a small low pressure system near the coast of western Oman on Friday and the India Meteorological Department classified the system as a depression.  Thunderstorms were forming near the center of the depression.  Bands of showers and thunderstorms were revolving around the center of circulation.  Storms near the center were generating upper level divergence which was pumping mass away from the depression in all directions.

The tropical depression will move through an environment favorable for intensification if the center remains over water.  It will move over water where the Sea Surface Temperature is near 31°C.  The depression will be under an upper level ridge where the winds are weak.  There will be little vertical wind shear and the upper level ridge will enhance upper level divergence.  If the center of the tropical depression remains over the Arabian Sea, then it is likely to strengthen into the equivalent of a tropical storm during the next 24 to 48 hours.  If the center of circulation moves inland over western Oman and eastern Yemen, then intensification becomes much less likely.

The tropical depression will move under the upper level ridge and the steering winds will be very weak.  The depression is forecast to drift very slowly toward the west during the next several days,  The center of the depression could remain just off the coast or it could move slowly inland.  The slow movement of the depression will allow it to drop locally heavy rain over parts of western Oman and eastern Yemen.  The heavy rain could very likely cause flash floods in some locations.

Tropical Cyclone Mangga Brings Wind and Rain to Cocos Island

Tropical Cyclone Mangga brought wind and rain to Cocos Island on Friday.  At 11:00 p.m. EDT on Friday the center of Tropical Cyclone Mangga was located at latitude 16.3°S and longitude 97.6°E which put it about 270 miles (435 km) south of Cocos Island.  Mangga was moving toward the southeast at 21 m.p.h. (34 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 996 mb.

The center of Tropical Cyclone Mangga passed southwest of Cocos Island on Friday.  The circulation around Mangga was fairly large.  Winds to tropical storm force extended out 150 miles (240 km) to the northeast of the center of circulation.  A weather station on Cocos Island reported a sustained wind speed of 27 m.p.h. (43 km/h) and a wind gust of 38 m.p.h. (61 km/h).  The station measured 1.25 inches (32 mm) of rain during the passage of Tropical Cyclone Mangga.

The circulation around Tropical Cyclone Mangga did not appear to be well organized.  There were not a lot of thunderstorms near the center or circulation.  Bands near the center consisted primarily of showers and lower clouds.  Thunderstorms were occurring to the southeast of the low level center of circulation.  The thunderstorms appeared to be associated with a circulation in the middle and upper troposphere.  Those thunderstorms were generating upper level divergence which was pumping mass away to the southeast of Tropical Cyclone Mangga.

Tropical Cyclone Mangga will move through an environment only marginally favorable for intensification.  Mangga will move over water where the Sea Surface Temperature is near 27°C.  However, an upper level ridge northwest of Australia and an upper level trough west of Australia will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause strong vertical wind shear.  The shear is likely to be strong enough to prevent intensification of the current low level center of Tropical Cyclone Mangga.  It is possible that the circulation in the middle and upper troposphere could cause a new low level center to form.  If a new center forms where the thunderstorms and upper level divergence are occurring, then some intensification might be possible.

Tropical Cyclone Mangga will move around the southwestern part of a high pressure system centered over Australia.  The high will steer Mangga quickly toward the southeast.  On its anticipated track the center of Tropical Cyclone Mangga could reach the coast of Western Australia in less than 36 hours.  Mangga could produce winds to tropical storm force along the coast of Western Australia.

Tropical Cyclone Mangga Develops Northwest of Cocos Islands

Tropical Cyclone Mangga developed over the South Indian Ocean northwest of the Cocos Islands on Thursday.  At 11:00 a.m. EDT on Thursday the center of Tropical Cyclone Mangaa was located at latitude 9.4°S and longitude 93.1°E which put it about 320 miles (515 km) northwest of Cocos Island.  Mangga was moving toward the south-southeast at 7 m.p.h. (12 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 996 mb.

The Australian Bureau of Meteorology issued a Warning for the Cocos Islands.

Tropical Cyclone Mangga developed within a trough of low pressure that extended from southwest of Indonesia to western Australia.  The trough had persisted for several days and a center of low pressure gradually formed northwest of the Cocos Islands during the past 24 hours.  The Australian Bureau of Meteorology designated the system as Tropical Cyclone Mangga on Thursday.

The circulation around Tropical Cyclone Mangga was still in the process of organizing.  The strongest thunderstorms were in a band on the western side of the circulation.  Bands on the eastern side of the circulation consisted primarily of showers and lower clouds.  More thunderstorms began to develop near the center of circulation on Thursday.  Storms developing near the center started to generate upper level divergence which was pumping mass away to the west of the tropical cyclone.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Mangga.

Tropical Cyclone Mangga will move through an environment somewhat favorable for intensification during the next 24 to 36 hours.  Mannga will move over water where the Sea Surface temperature is near 27°C.  It will move under the northwestern part of an upper level ridge centered over Indonesia.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will produce moderate vertical wind shear.  The wind shear may be the reason why the bands on the eastern side of Tropical Cyclone Mangga are weaker.  The shear will also inhibit intensification, but it will probably not be strong enough to prevent Manga from strengthening during the next 24 hours.

Tropical Cyclone Mangga will move around the western end of a high pressure system centered north of Australia.  The high will steer Mangga toward the southeast during the next few days.  On its anticipated track Tropical Cyclone Mangga will pass near the Cocos Islands in about 24 hours.  Manga will bring gusty winds and locally heavy rain to those islands.

Tropical Cyclone Amphan Makes Landfall Near Kolkata

The center of Tropical Cyclone Amphan made landfall on the north coast of the Bay of Bengal near Kolkata, India on Wednesday.  At 11:00 a.m. EDT on Wednesday the center of Tropical Cyclone Amphan was located at latitude 22.7°N and longitude 88.4°E which put it about 30 miles (50 km) south-southwest of Kolkata, India.  Amphan was moving toward the north-northeast at 19 m.p.h. (30 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. (165 km/h).  The minimum surface pressure was 979 mb.

The center of Tropical Cyclone Amphan made landfall near Haldia, India which is a little to the south-southwest of Kolkata on Wednesday.  The maximum sustained wind speed in Amphan at the time of landfall was 100 m.p.h. (160 km/h).  Tropical Cyclone Amphan weakened after the center moved over land.  Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of circulation.  Winds to tropical storm force extended out 160 miles (260 km) to the southeast of the center.  The stronger winds were occurring near the center of circulation and over the northern Bay of Bengal.

When Tropical Cyclone Amphan approached the coast, the heaviest rain occurred in bands in the western side of Amphan.  Heavy rain fell over parts of northern Odisha and West Bengal.  After the center of Amphan made landfall and the tropical cyclone moved inland, the heaviest rain fell in bands in the northeastern part of the circulation.  Heavy rain was falling over parts of Bangladesh.

Strong southerly winds blowing toward the north coast of the Bay of Bengal pushed water toward Bangladesh and the coast of India south of Kolkata.  The coast around the northern Bay of Bengal is very vulnerable to storm surges caused by tropical cyclones.  Tropical Cyclone Amphan likely caused a significant storm surge along that coast.

Tropical Cyclone Amphan will move around the northwestern part of a high pressure system over Southeast Asia.  The high will steer Amphan toward the north-northeast.  On its anticipated track the center of Tropical Cyclone Amphan will move across western Bangladesh and northeastern India.  The circulation around Amphan will continue to weaken as the system moves farther inland.  Tropical Cyclone Amphan will continue to drop locally heavy rain over Bangladesh and northeastern India.  Heavy rain could cause flash floods to occur in some locations.

Large Dangerous Tropical Cyclone Amphan Nears Kolkata and Bangladesh

Large dangerous Tropical Cyclone Amphan neared Kolkata, India and Bangladesh late on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Cyclone Amphan was located at latitude 18.8°N and longitude 87.0°E which put it about 310 miles (505 km) south-southwest of Kolkata, India.  Amphan was moving toward the north at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 951 mb.

Tropical Cyclone Amphan was the equivalent of a major hurricane as it neared Kolkata, India and the coast of Bangladesh on Tuesday.  An eyewall replacement cycle caused the circulation around Amphan to expand in size.  Some satellite images showed evidence of the remnants of the original small inner eye inside the larger second eye.  The larger eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Amphan.

Tropical Cyclone Aphan had a large circulation that covered much of the northern Bay of Bengal.  Winds to hurricane/typhoon force extended out 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out 230 miles (370 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Amphan was 20.6.  The Hurricane Size Index (HSI) was 20.8 and the Hurricane Wind Intensity Size Index (HWISI) was 41.4.  Amphan was capable of causing major damage.

Tropical Cyclone Amphan will move through an environment capable of supporting a large powerful tropical cyclone during the next 12 to 18 hours.  Amphan will move over water where the Sea Surface Temperature is near 30°C.  It will move under the western side of an upper level ridge.  The upper level winds will be weak and there will be little vertical wind shear.  The circulation around Tropical Cyclone Amphan could start to pull in some drier air that is over eastern India when it get closer to the coast.  Amphan will remain a large dangerous tropical cyclone until it makes landfall on the north coast of the Bay of Bengal.

Tropical Cyclone Amphan will move around the western end of a high pressure system over Southeast Asia.  The high will steer Amphan toward the north-northeast during the next 36 hours.  On its anticipated track the center of Tropical Cyclone Amphan will pass near Puri, India in about 12 hours.  The center of Amphan could make landfall south of Kolkata near Haldia, India in about 18 hours.  Tropical Cyclone Amphan could cause major damage.  The wind will blow water toward the coast around the northern Bay of Bengal.  Amphan could generate a storms surge of up to 12 to 15 feet (3 to 4 meters) along past of the Bangladesh coast.  Tropical Cyclone Amphan will also drop heavy rain over parts of northeastern India and Bangladesh when it moves inland.  The heavy rain is likely to cause floods in some locations.

 

Tropical Cyclone Amphan Intensifies Into Equivalent of Cat. 5 Hurricane

Tropical Cyclone Amphan intensified into equivalent of a Category 5 hurricane on the Saffir-Simpson Scale over the Bay of Bengal on Monday.  At 5:00 a.m. EDT on Monday the center of Tropical Cyclone Amphan was located at latitude 13.9°N and longitude 86.5°E which put it about 635 miles (1025 km) south-southwest of Kolkata, India.  Amphan was moving toward the north at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h).  The minimum surface pressure was 909 mb.

The circulation around Tropical Cyclone Amphan appeared to develop a concentric eyewall structure on Monday.  The inner end of a rainband wrapped around the original small eye and eyewall.  The inner eye had a diameter of 10 miles (16 km).  A ring of strong thunderstorms surrounded the inner eye and the strongest winds were occurring in that ring of storms.  An outer eyewall with a diameter of 50 mile (80 km) surrounded the inner eye.    Bands of showers and thunderstorms were revolving around the concentric eyewalls.  Storms in the core of Amphan were generating strong upper level divergence which was pumping mass away from the tropical cyclone in all directions.

Tropical Cyclone Amphan had a large circulation.  Winds to hurricane/typhoon force extended out 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out 200 miles (325 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Amphan was 35.0.  The Hurricane Size Index (HSI) was 16.5 and the Hurricane Wind Intensity Size Index (HWISI0 was 51.5.  Tropical Cyclone Amphan was capable of causing catastrophic damage.

Tropical Cyclone Amphan will move through an environment very favorable for a strong tropical cyclone during the next 36 hours.  Amphan will move over water where the Sea Surface Temperature is near 31°C.  It will move under an upper level ridge where the upper level winds are weak.  There will be little vertical wind shear.  The eyewall replacement cycle will stop the intensification of Tropical Cyclone Amphan.  Amphan will weaken, at least temporarily, when the inner eyewall dissipates.  When that occurs the strongest winds will be occurring in the outer eyewall.  The eyewall replacement cycle could cause the circulation to increase in size.

Tropical Cyclone Amphan will move around the western end of a high pressure system over Southeast Asia.  The high will steer Amphan toward the north-northeast.  On its anticipate track the center of Tropical Cyclone Amphan will approach the coast around the northern Bay of Bengal in 36 hours.  Amphan will be a large dangerous tropical cyclone when it approaches the coast.  Tropical Cyclone Amphan will generate a significant storm surge along the coast of Bangladesh.  Amphan will cause major wind damage.  It will drop locally heavy rain over northeast India and Bangladesh.  Freshwater flooding will occur.

Tropical Cyclone Amphan Rapidly Intensifies Into Equivalent of Major Hurricane

Tropical Cyclone Amphan rapidly intensified into the equivalent of a major hurricane over the Bay of Bengal on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Tropical Cyclone Amphan was located at latitude 13.3°N and longitude 86.4°E which put it about 675 miles (1090 km) south-southwest of Kolkata, India.  Amphan was moving toward the north at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h).  The minimum surface pressure was 919 mb.

Tropical Cyclone Amphan rapidly intensified into a large powerful tropical cyclone on Sunday night.  A small circular eye was at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Amphan.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone in all directions.

The circulation around Tropical Cyclone Amphan grew in size on Sunday.  Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out 210 miles (335 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Amphan was 31.6.  The Hurricane Size Index was 16.8 and the Hurricane Wind Intensity Size Index (HWISI) was 48.4.  Tropical Cyclone Amphan was capable of causing widespread significant damage.

Tropical Cyclone Amphan will remain in an environment capable of supporting a strong tropical cyclone during the next 36 to 48 hours.  Amphan will move over water where the Sea Surface Temperature is near 31°C.  It will move under an upper level ridge.  The upper level wind will be weak and there will be little vertical wind shear.  The ridge will actually enhance the upper level divergence.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Tropical Cyclone Amphan to weaken.  Tropical Cyclone Amphan is likely to remain a large, powerful tropical cyclone during the next 48 hours.

Tropical Cyclone Amphan will move around the western end of a high pressure system over Southeast Asia.  The high will steer Amphan toward the north.  On its anticipated track Tropical Cyclone Amphan could approach the coast of Bangladesh in 48 hours.  Amphan is could still be the equivalent of a major hurricane when it reaches Bangladesh.  Tropical Cyclone Amphan could generate a significant storm surge at the coast.  Amphan will cause major wind damage and heavy rain could cause freshwater flooding.