Tag Archives: Pakistan

Powerful Tropical Cyclone Ockhi Churns West of India

Powerful Tropical Cyclone Ockhi churned over the Arabian Sea west of India on Saturday night.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Ockhi was located at latitude 12.1°N and longitude 69.1°E which put it about 535 miles (860 km) south-southwest of Mumbai, India.  Ockhi was moving toward the northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 963 mb.

Tropical Cyclone Ockhi intensified again on Saturday and it was the equivalent of a strong Category 2 hurricane on the Saffir-Simpson Scale.  There was an elliptical eye at the center of circulation.  A ring of strong thunderstorms surrounded the eye, but there was a weaker area in the eastern side of the ring.  Bands of showers and thunderstorms were revolving around the core of the circulation.  The storms around the center of circulation were generating strong upper level divergence which was pumping mass away to the northeast of Tropical Cyclone Ockhi.  Winds to hurricane/typhoon force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 160 miles (260 km) from the center.

Tropical Cyclone Ockhi has been moving through an environment favorable for intensification, but it will move into a less favorable environment on Sunday.  Ockhi will continue to move over water where the Sea Surface Temperature is near 29°C.  So, there will be enough energy in the upper ocean to support a strong tropical cyclone.  Tropical Cyclone Ockhi could intensify a little more during the next 12 hours.  However, an upper level trough over Saudi Arabia will approach Ockhi from the west.  Southwesterly winds ahead of the trough will increase the vertical wind shear over Tropical Cyclone Ockhi and the increased shear is likely to cause the tropical cyclone to start to weaken later on Sunday.

Tropical Cyclone Ockhi is moving around the western end of a ridge centered over the Bay of Bengal.  The ridge is steering Ockhi toward the northwest.  Tropical Cyclone Ockhi will turn more toward the north on Sunday when it moves around the western end of the ridge.  The upper level trough approaching Ockhi from Saudi Arabia will steer the tropical cyclone toward the northeast in about 24 hours.  On its anticipated track the center of Tropical Cyclone Ockhi will approach the west coast of India north of Mumbai in about 60 hours.

Tropical Cyclone Ockhi Strengthens to Hurricane Equivalent

Tropical Cyclone Ockhi strengthened to the equivalent of a hurricane/typhoon on Friday as it moved over the Arabian Sea west of India.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Ockhi was located at latitude 9.4°N and longitude 71.7°E which put it about 655 miles (1055 km) south of Mumbai, India.  Ockhi was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 969 mb.

Tropical Cyclone Ockhi continued to intensify on Friday and it is now the equivalent of a hurricane or typhoon.  An eye has appeared intermittently on satellite imagery.  A ring of strong storms surrounded the eye, although there have been occasional breaks in the northeastern segment of the ring.  Additional bands of showers and thunderstorms were occurring outside the core of the circulation.  There were more showers and thunderstorms in the western half of the circulation.  Storms near the core of Tropical Cyclone Ockhi were generating strong upper level divergence which was pumping mass away to the west and north of the cyclone.

Tropical Cyclone Ockhi will continue to be in an environment favorable for intensification for another 24 to 48 hours.  Ockhi will move over water where the Sea Surface Temperature is near 29°C.  An upper level ridge east of Ockhi is producing southeasterly winds which are blowing toward the top of the circulation.  Those winds may be the reason why more of the stronger rainbands are in the western half of the circulation.  The winds are also causing some vertical wind shear, but the shear is not strong enough to prevent intensification.  Tropical Cyclone Ockhi is likely to continue to intensify for another 24 to 36 hours and it could become the equivalent of a major hurricane during the weekend.

The upper level ridge is steering Tropical Cyclone Ockhi toward the west-northwest.  Ockhi will move more toward the north when it reaches the western end of the upper level ridge.  Tropical Cyclone Ockhi will approach the midlatitude westerly winds in two or three days and those winds will start to steer Ockhi more toward the northeast.  On its anticipated track Tropical Cyclone Ockhi could approach the west coast of India in three or four days.

Tropical Cyclone Chapala Intensifies Rapidly

Tropical Cyclone Chapala intensified rapidly on Thursday and it is almost the equivalent of a major hurricane.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Chapala was located at latitude 14.2°N and longitude 61.5°E which put it about 535 miles (865 km) east-southeast of Salalah, Oman.  Chapala was moving toward the west at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h). The minimum surface pressure was 956 mb.

Chapala has a very well organized, symmetrical circulation.  There is a well formed eye which is surrounded by a ring of strong thunderstorms.  Several spiral bands are rotating around the core of the cyclone.  The thunderstorms surrounding the eye are generating upper level divergence which is pumping out mass in all directions.

Tropical Cyclone Chapala is an environment that favors further intensification.  It is over water where the Sea Surface Temperature is around 28°C.  The upper level winds are light and there is not much vertical wind shear.  Chapala could intensify to the equivalent of a Category 4 hurricane on Friday.  After that time eyewall replacement cycles could cause fluctuations in intensity.

A ridge in north of Chapala is steering the tropical cyclone toward the west.  That same general steering motion is expected to continue for another two or three days.  On its anticipated track Tropical Cyclone Chapala could be approaching the area near the border between Oman and Yemen in 48 to 60 hours.  It could be an intense tropical cyclone at that time.

Tropical Cyclone 04A Organizes in the Arabian Sea

A center of circulation organized quickly within a broader area of thunderstorms over the Arabian Sea on Wednesday and the system was designated Tropical Cyclone 04A.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone 04A was located at latitude 13.7°N and longitude 64.0°E which put it about 705 miles east-southeast of Salalah, Oman.  The tropical cyclone was moving toward the west-northwest at 6 m.p.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 993 mb.

The organization of Tropical Cyclone 04A improved significantly on Wednesday.  A primary rainband wrapped almost entirely around the center of circulation and there were indications on various satellite images that an eye could be forming.  Additional rainbands were beginning to form in the circulation outside the core.  Thunderstorms near the center of circulation were generating upper level divergence, especially on the northeast side of the tropical cyclone.

The environment is favorable for further intensification.  Tropical Cyclone 04A is over water where the Sea Surface Temperature is near 28°C.  Although there are strong upper level westerly winds north of the cyclone, the upper level winds over it are relatively light.  As a result there is not a lot of vertical wind shear over Tropical Cyclone 04A.  The cyclone is likely to intensify during the next several days and it could intensify rapidly.  It could attain hurricane intensity in a day or two and it could eventually become the equivalent of a major hurricane.

A ridge north of Tropical Cyclone 04A is steering it slowly toward the west-northwest.  The ridge is expected to continue steering the cyclone toward the west during the next few days.  On its anticipated track Tropical Cyclone 04A could approach the coast of Oman and Yemen in four or five days.

Tropical Cyclone Ashobaa Moving South of Pakistan

Tropical Cyclone Ashobaa moved northwestward across the Arabian Sea south of Pakistan on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Ashobaa was located at latitude 20.4° and longitude 64.8°W which put it about 340 miles (550 km) south-southwest of Karachi, Pakistan.  Ashobaa was moving toward the northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 990 mb.

More thunderstorms developed near the center of Ashobaa on Monday, but vertical wind shear is still inhibiting intensification.  Ashobaa is moving over water where the Sea Surface Temperature (SST) is warm and there is sufficient energy in the upper ocean to promote intensification.  The circulation is extracting energy from the ocean and it is generating vigorous convection west of the center of circulation.  However, an upper level ridge over southern Asia is creating moderate easterly winds over the top of Ashobaa.  The resulting vertical wind shear is the reason why the strongest storms are west of the center.  Ashobaa will spend several more days in a thermodynamic environment that favors intensification and if the upper level winds lessen, it will intensify.  Eventually, when Ashobaa gets closer to land, the circulation will start to pull in drier air, which will weaken the tropical cyclone.

A ridge over India is steering Ashobaa toward the northwest.  A trough passing north of the Arabian Sea is expected to weaken the western end of the ridge and cause the tropical cyclone to turn more toward the north for a time.  Eventually, most models are forecasting that the ridge will rebuild and steer Ashobaa toward the west-northwest.   However, some models are still predicting that Ashobaa could move northward and make landfall on the northern coast of the Arabian Sea.  The spread in the guidance from the models makes the long-term track more uncertain.

Tropical Cyclone 01A Forms Over the Arabian Sea

A low level circulation formed within a larger area of thunderstorms over the Arabian Sea and the system was classified as Tropical Cyclone 01A.  At 11:00 p.m. EDT on Sunday the center of Tropical Cyclone 01A was located at latitude 18.0°N and longitude 67.5°E which put it about 490 miles (790 km) south of Karachi, Pakistan.  It was moving toward the north-northwest at 10 m.p.h. (17 km/h).  The maximum sustained wind speed was 45 m.p.h. (70 km/h) and there were gusts to 60 m.p.h. (75 km/h).  The minimum surface pressure was 994 mb.

Tropical Cyclone 01A is over warm Sea Surface Temperatures and there is sufficient energy in the upper ocean to support further intensification.  An upper level ridge over India is creating some easterly wind over the cyclone.  The strongest thunderstorms are occurring in the western half of the core of the cyclone.  The shear will inhibit intensification, but Tropical Cyclone 01A is likely to intensify during the next day or two.  Uncertainty about the future track of the cyclone also creates uncertainty about the longer term intensity forecast.

Tropical Cyclone 01A is moving northward around the western end of the ridge over India.  A trough farther to the north over Asia is expected to weaken the ridge and at that point the steering pattern will weaken.  Model guidance is inconsistent about the future track of the cyclone.  Some models forecast that Tropical Cyclone 01A will continue to move northward into Pakistan.  Other models predict that the cyclone could curve westward before it reaches Pakistan.  Thus, there is a high degree of uncertainty about the future track of Tropical Cyclone 01A.

Tropical Cyclone Nilofar Intensifies Into the Equivalent of a Major Hurricane

Light winds in the upper troposphere allowed the circulation around Tropical Cyclone Nilofar to pump out sufficient mass to enable it to intensify into the equivalent of a Major Hurricane.  At 8:00 a.m. EDT on Tuesday the center of Nilofar was located at latitude 16.8°N and longitude 61.8°E which put it about 315 miles southeast of Masirah Island, about 650 miles south-southwest of Karachi, Pakistan and about 740 miles west of Mumbai, India.  Nilofar was moving toward the north at 11 m.p.h.  The maximum sustained wind speed was 135 m.p.h. and there were wind gusts estimated to be 160 m.p.h.

The environment around Nilofar is capable of supporting an intense tropical cyclone, which is what Nilofar has become.  The upper level winds are light, which has allowed upper level divergence to spread the air in all directions.  In addition, the upper level outflow from Nilofar has interacted with surrounding weather systems to create outflow channels to the northeast and to the southwest.  The favorable atmospheric environment combined with warm Sea Surface Temperatures, which are supplying plenty of energy to Nilofar, has produced a strong tropical cyclone.  Nilofar could intensify further, although it is at the intensity where eyewall replacement cycles could begin to cause fluctuations in intensity.

Nilofar is moving around the western end of a subtropical high pressure system which is steering it to the north.  An upper level trough in the westerly flow north of Nilofar will eventually turn it toward the northeast.  Nilofar could threaten parts of Pakistan and India by the end of the week.  However, the southwesterly winds in the upper level trough will also generate more wind shear and Nilofar could start to weaken rapidly when it moves toward the coast of South Asia.

 

The Winds in Tropical Cyclone Nilofar Reach Hurricane Intensity

Tropical Cyclone Nilofar (Tropical Cyclone 04A) intensified on Sunday and it is now the equivalent of a hurricane.  At 8:00 p.m. EDT on Sunday the center of Nilofar was located at latitude 14.8°N and longitude 62.8°E, which put it about 470 miles southeast of Masirah Island, about 750 miles south-southwest of Karachi, Pakistan and about 720 miles west-southwest of Mumbai, India.  Nilofar was moving toward the north-northwest at 5 m.p.h.  The maximum sustained wind speed was 75 m.p.h. and there were wind gusts to 90 m.p.h.

Well developed upper level outflow was pumping out mass and Nilofar intensified steadily on Sunday.  The upper level outflow remains well developed and there appear to be outflow channels to the southwest and northeast.  So, further intensification is possible in the shorter term.  Nilofar is expected to move northward and eventually stronger westerly winds will increase the wind shear and start to weaken the tropical cyclone.

Nilofar has been moving slowly toward the northwest.  It is likely to continue moving northward during the next 24-48 hours.  When Nilofar gets farther north, southwesterly winds on the east side of an upper level trough will turn it more toward the northeast.  Nilofar could eventually make a landfall in Pakistan or India, but the stronger upper level winds will weaken the circulation before it reaches the coast.

 

Tropical Cyclone Forms Over the Arabian Sea

A banded structure developed within an area of thunderstorms over the Arabian Sea and it has been classified as a tropical cyclone.  At 8:00 p.m. EDT on Saturday the center of Tropical Cyclone 04A was located at latitude 14.1°N and longitude 63.0°E which put it about 515 miles south-southeast of Masirah Island.  Tropical Cyclone 04A was moving toward the north at 5 m.p.h.  The maximum sustained wind speed was 40 m.p.h. and there were gusts to 50 m.p.h.

The tropical cyclone had been moving toward the northeast, but it appears to be turning more to northwest in response to a strengthening ridge of high pressure.  It is expected to move toward the northwest during the next 36-48 hours.  As the tropical cyclone approaches Oman, an upper level trough is expected to turn it toward the northeast.  There is some spread in the model guidance about when and where the turn toward the northeast will occur.  Therefore there is greater than normal uncertainty about the track forecast at longer time periods.

Upper level divergence is pumping out mass toward the northeast and southwest of the circulation.  As a result the surface pressure should fall and the tropical cyclone is expected to intensify during the next 48-72 hours.  Winds could reach hurricane force as the tropical moves in the general direction of Oman.