Tag Archives: HWISI

Typhoon Kammuri Strengthens As It Nears Southeast Luzon

Typhoon Kammuri strengthened as it neared southeast Luzon on Sunday night.  At 10:00 p.m. EST on Sunday the center of Typhoon Kammuri was located at latitude 13.0°N and longitude 126.0°E which put it about 385 miles (625 km) east- southeast of Manila, Philippines and about 160 miles (260 km) east of Legaspi.  Kammuri was moving toward the west at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 959 mb.

Typhoon Kammuri strengthened on Sunday.  An ellipitical eye with a mean radius of 30 miles (50 km) cleared out at the center of circulation.  A ring of strong 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 Kammuri.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.  The removal of mass allowed the surface pressure to decrease.

The wind field around Typhoon Kammuri became more symmetrical on Sunday.  Winds to typhoon force extended out 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out 180 miles (290 km) from the center.  The Hurricane Intensity Index (HII) was 17.8.  The Hurricane Size Index (HSI) was 19.3 and the Hurricane Wind Intensity Size Index (HWISI) was 37.1.  Typhoon Kammuri was capable of causing serious damage.

Typhoon Kammuri will move through an environment favorable for intensification during the next 12 hours.  Kammuri will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Kammuri could strengthen into the equivalent of a major hurricane before it reaches southeastern Luzon.  Kammuri will start to weaken after the center moves over land.

Typhoon Kammuri will move south of a high pressure system over the Western North Pacific Ocean.  The high will steer Kammuri toward the west during the next several days.  On its anticipated track the center of Typhoon Kammuri will pass between Samar and Catanduanes Island before making landfall near Sorsogon on southeast Luzon.  The center of Kammuri will pass near Legaspi, Tabaco and Ligao.

Typhoon Kammuri will be capable of causing major damage in the Philippines.  Kammuri will bring strong winds to southeast Luzon.  Typhoon Kammuri could also produce winds to near typhoon force in Virac on Catanduanes Island.  Kammuri could produce a storm surge of up to 10 feet (3 meters) in locations where the wind blows water toward the coast.  Typhoon Kammuri will drop locally heavy rain over southern Luzon.  Flash floods could occur, especially in areas of steeper slopes.

Typhoon Kammuri Moves Closer to the Philippines

Typhoon Kammuri moved closer to the Philippines on Saturday.  At 10:00 p.m. EST on Saturday the center of Typhoon Kammuri was located at latitude 13.2°N and longitude 130.5°E which put it about 685 miles (1100 km) east of Manila, Philippines.  Kammuri was moving toward the west at 19 m.p.h. (29 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 110 m.p.h. (175 km/h).  The minimum surface pressure was 970 mb.

Typhoon Kammuri appeared to be getting better organized on Saturday night.  Visible satellite images of Kammuri  suggested that an eye was clearing out at the center of the typhoon.  The inner end of a rainband wrapped around much of the developing eye.  There was still a gap on the northwestern side of the eyewall, but the gap was getting smaller.  Bands of showers and thunderstorms were revolving around the more organized core of Typhoon Kammuri.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.

Winds to typhoon force extended out 50 miles from the center of circulation in the northern half of Typhoon Kammuri and out 25 miles in the southern side of the typhoon.  Winds to tropical storm force extended out 220 miles (355 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Kammuri was 13.9.  The Hurricane Size Index (HSI) was 17.0 and the Hurricane Wind Intensity Size Index (HWISI) was 30.9.

Typhoon Kammuri will move through an environment favorable for intensification during the next 36 hours.  Kammuri will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Kammuri will intensify and it could strengthen into the equivalent of a major hurricane.  Intensification could be more rapid once an eye and eyewall are full formed.

Typhoon Kammuri will move south of a high pressure system that extends from eastern Asia to the Western North Pacific Ocean.  The high will steer Kammuri toward the west during the next three days.  On its anticipated track Typhoon Kammuri could approach Catanduanes Islands and southeastern Luzon in about 36 hours.  Kammuri could be the equivalent of a major hurricane at that time.

Typhoon Kammuri Churns West Over Philippine Sea

Typhoon Kammuri churned westward over the Philippine Sea on Friday night.  At 10:00 p.m. EST on Friday the center of Typhoon Kammuri was located at latitude 13.9°N and longitude 135.7°E which put it about 1015 miles (1640 km) east of Manila, Philippines.  Kammuri was moving toward the west at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 110 m.p.h. (175 km/h).  The minimum surface pressure was 970 mb.

Typhoon Kammuri exhibited few changes on Friday.  The eye and eyewall were still not fully formed.  The tops of strong thunderstorms near the eye were obscuring the center of circulation on conventional satellite images.  Many of the stronger thunderstorms were occurring in bands in the western half of the circulation.  Bands in the eastern half of Kammuri consisted of showers and lower clouds.  Storms near the center of circulation were generating strong upper level divergence which was pumping mass away from the typhoon.

The circulation around Typhoon Kammuri did increase in size on Friday.  Winds to typhoon force extended out 50 miles (80 km).  Winds to tropical storm force extended out 230 miles (370 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Kammuri was 13.9.  The Hurricane Size Index (HSI) was 18.8 and the Hurricane Wind Intensity Size Index (HWISI) was 32.7.

Typhoon Kammuri will move through an environment favorable for intensification during the next two to three days.  Kammuri will move over water where the Sea Surface Temperature is near 29°C.  It will move through an environment where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Kammuri will intensify and it could strengthen into the equivalent of a major hurricane.  A period of more rapid intensification could occur once an eye and eyewall are fully formed.

Typhoon Kammuri will move south of a high pressure system over the Western North Pacific Ocean.  The high will steer Kammuri toward the west.  On its anticipated track Typhoon Kammuri could approach Luzon in about 72 hours.  Kammuri could be the equivalent of a major hurricane when it approaches Luzon.

Typhoon Fengshen Strengthens into Equivalent of a Major Hurricane

Typhoon Fengshen strengthened into the equivalent of a major hurricane on Friday.  At 4:00 p.m. EST on Friday the center of Typhoon Fengshen was located at latitude 23.0°N and longitude 142.9°E which put it about 175 miles (285 km) south-southeast of Io To.  Fengshen was moving toward the north at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 949 mb.

Typhoon Fengshen strengthened quickly into the equivalent of a major hurricane on Friday.  An eye with a diameter of 25 miles (40 km) developed at the center of Fengshen.  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 Typhoon Fengshen.  Storms near the core were generating strong upper level divergence which was pumping mass away to the northeast of the typhoon.

The circulation around Typhoon Fengshen increased in size on Friday.  Winds to typhoon force extended out 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out 140 miles (225) km from the center.  The Hurricane Intensity Index (HII) for Typhoon Fengshen was 23.6.  The Hurricane Size Index (HSI) was 11.2 and the Hurricane Wind Intensity Size Index (HWISI) was 34.8.

Typhoon Fengshen may have reached its peak intensity.  Fengshen will move over water where the Sea Surface Temperature is near 28°C.  So, there will be suffiicient energy in the upper levels of the Western Pacific to support intensification.  However, a large upper level trough southwest of Japan will move toward Fengshen.  The trough will produce strong southwesterly winds which will blow toward the top of the typhoon.  Those winds will cause moderate to strong vertical wind shear and the shear will cause Typhoon Fengshen to being to weaken.

A ridge of high pressure east of Typhoon Fengshen and the upper level trough southwest of Japan will interact to steer the typhoon toward the northeast during the weekend.  On its anticipated track the core of Typhoon Fengshen which contains the strongest winds will pass southeast of Iwo To.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Kalmaegi moved very slowly toward northern Luzon.  At 4:00 p.m. EST on Friday the center of Tropical Storm Kalmaegi was located at latitude 16.0°N and longitude 125.9°E which put it about 345 miles (555 km) southeast of Aparri, Philippines.  Kalmaegi was moving toward the west at 2 m.p.h. (3 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 1002 mb.

Tropical Cyclone Bulbul Moving Toward Kolkata

Tropical Cyclone Bulbul moved toward Kolkata, India on Friday.  At 4:00 p.m. EDT on Friday the center of Tropical Cyclone Bulbul was located at latitude 19.7°N and longitude 87.8°E which put it about 225 miles (360 km) south of Kolkata, India.  Bulbul was moving toward the north at 8 m.p.h. (13 k/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 861 mb.

It appeared that Tropical Cyclone Bulbul may have pulled drier air from India around the southern and eastern sides of its circulation.  Rainbands in those parts of the tropical cyclone consisted primarily of showers and lower clouds.  Microwave satellite images provided some evidence of an eye at the center of circulation.  A ring of thunderstorms around the eye exhibited weaker sections on the eastern side of the eye.  The strongest winds were occurring in the ring of storms.  Other strong bands of thunderstorms were present in the western half of the circulation.

Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of Tropical Cyclone Bulbul.  Winds to tropical storm force extended out 140 miles (220 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Bulbul was 16.5.  The Hurricane Size index (HSI) was 13.2 and the Hurricane Wind Intensity Size Index (HWISI) was 29.7.  Bulbul was capable of causing serious damage.

Tropical Cyclone Bulbul may be near its maximum intensity.  Bulbul will move over water where the Sea Surface Temperature is near 29°C.  So, there is sufficient energy in the upper Bay of Bengal to support further intensification.  However, the introduction of drier air into the southern and eastern parts of the circulation will inhibit the development of thunderstorms in those portions of the tropical cyclone.  Bulbul will move under the western end of an upper level ridge over southeast Asia.  The ridge will produce some vertical wind shear which will also inhibit further intensification.  Tropical Cyclone Bulbul could weaken when it nears the coast around the northern Bay of Bengal.

Tropical Cyclone Bulbul will move around the western end of the ridge over southeast Asia.  The ridge will steer Bulbul toward the north for another 18 to 24 hours.  On its anticipated track Tropical Cyclone Bulbul could approach the coast of India south of Kolkata in about 18 hours.  Bulbul will turn more toward the east when it moves around the northwestern part of the ridge in a day or so.

Tropical Cyclone Bulbul could be the equivalent of a hurricane/typhoon when it makes landfall in West Bengal south of Kolkata.  Bulbul will bring gusty winds to the coast of West Bengal and Bangladesh.  Tropical Cyclone Bulbul will be capable of generating a storm surge of up to 6 to 9 feet ( 2 to 3 meters) along portions of the coast around the northern Bay of Bengal.  That area is particularly prone to storm surges.  Bulbul will drop locally heavy rain over parts of West Bengal and Bangladesh when it moves inland.  Locally heavy rain could cause flash floods in some locations.

Typhoon Halong Intensifies into Equivalent of Cat. 5 Hurricane

Typhoon Halong intensified into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Typhoon Halong was located at latitude 20.4°N and longitude 150.6°E which put it about 345 miles (560 km) southwest of Minami Tori Shima, Japan.  Halong was moving toward the north-northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 180 m.p.h. (290 km/h) and there were wind gusts to 220 m.p.h. (355 km/h).  The minimum surface pressure was 900 mb.

Typhoon Halong intensified into one of the strongest tropical cyclones of 2019 over the Western North Pacific Ocean on Tuesday.  There was a circular eye with a diameter of 15 miles (24 km) at the center of Halong.  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 Typhoon Halong.  Storm near the core were generating strong upper level divergence which was pumping mass away to the northeast of the typhoon.

The circulation around Typhoon along was compact and symmetrical.  Winds to typhoon force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 115 miles (185 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Halong was 42.2.  The Hurricane Size Index (HSI) was 9.4 and the Hurricane Wind Intensity Size Index (HWISI) was 51.6.

Typhoon Halong has probably reached its peak intensity.  Halong will move over water where the Sea Surface Temperature is near 29°C.  However, an upper level trough near Japan will approach Typhoon Halong from the northwest.  The trough will produce strong southwesterly winds which will start to increase the vertical wind shear.  More wind shear will cause Halong to weaken.

The upper level trough will start to steer Typhoon Halong toward the northeast in 12 to 24 hours.  On its anticipated track Typhoon Halong will pass northwest of Minami Tori Shima on Thursday.  Even though it will weaken, Halong will bring strong, gusty winds and heavy rain.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Nakri developed over the South China Sea between the Philippines and Vietnam on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Storm Nakri was located at latitude 13.8°N and longitude 116.0°E which put it about 380 miles (615 km) west of Manila, Philippines.  Nakri was moving toward the northeast at 5 m.p.h. (8 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.

Although Tropical Storm Nakri is currently moving toward the northeast, it is forecast to move back toward the west later this week.  Nakri will move through an environment favorable for intensification.  It will move over water where the Sea Surface Temperature is near 28°C.  Tropical Storm Nakri could strengthen into a typhoon before it reaches the coast of Vietnam.

Typhoon Halong Strengthens to Equivalent of a Major Hurricane

Typhoon Halong strengthened to the equivalent of a major hurricane northeast of the Northern Marianas on Monday.  At 4:00 p.m. EST on Monday the center of Typhoon Halong was located at latitude 18.9°N and longitude 152.1°E which put it about 390 miles (630 km) south of Minami Tori Shima, Japan.  Halong was moving toward the northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 952 mb.

Typhoon Halong continued to strengthen on Monday and it reached the equivalent of a major hurricane.  A small, well formed circular eye was evident on infrared satellite images.  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 Typhoon Halong.  Storms near the core were generating strong upper level divergence which was pumping mass away from the typhoon.

The circulation around Typhoon Halong increased in size on Monday.  Winds to typhoon force extended out 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out 160 miles (260 km) from the center.  The Hurricane intensity Index (HII) for Typhoon Halong was 22.0.  The Hurricane Size Index (HSI) was 14.3 and the Hurricane Wind Intensity Size Index was 36.3.  Halong was capable of causing major damage.

Typhoon Halong will remain in an environment favorable for intensification for another 24 hours.  Halong will move over water where the Sea Surface Temperature is near 29°C.  It will move under the northwestern portion of an upper level ridge where the winds are weaker and there will be little vertical wind shear.  An upper level trough southwest of Japan will approach Typhoon Halong in 24 hours.  The trough will produce stronger southwesterly winds which will cause more vertical wind shear.  Halong will start to weaken when the wind shear increases.

Typhoon Halong will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next 36 to 48 hours.  The ridge will steer Halong toward the north-northwest.  Halong will move toward the northeast later this week after if moves around the western end of the high pressure system.  On its anticipated track Typhoon Halong could approach Minami Tori Shima in less than 72 hours.

Tropical Cyclone Maha Strengthens into Equivalent of a Major Hurricane

Tropical Cyclone Maha strengthened into the equivalent of a major hurricane on Sunday night.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Maha was located at latitude 18.2°N and longitude 64.8°E which put it about 525 miles (845 km) west of Mumbai, India.  Maha was moving toward the northwest at 4 m.p.h. (6 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 958 mb.

Tropical Cyclone Maha continued to intensify on Sunday and it became the equivalent of a major hurricane.  There was a small eye 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 Tropical Cyclone Maha.  The strongest rainbands were in the eastern half of the tropical cyclone.  Bands in the western half of Maha consisted primarily of showers and lower clouds.  Storms near the core of the circulation were generating upper level divergence which was pumping mass away from the tropical cyclone.

The circulation around Tropical Cyclone Maha was relatively small.  Winds to hurricane/typhoon force extended out 20 miles (35 km) from the center of circulation.  Winds to tropical storm force extended out 75 miles (120 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Maha was 20.6.  The Hurricane Size Index (HSI) was 6.6 and the Hurricane Wind Intensity Size Index (HWISI) was 27.2.  Maha was capable of causing localized major damage.

Tropical Cyclone Maha will move through an environment favorable for intensification for another 12 to 18 hours.  Maha will move over water where the Sea Surface Temperature is near 28°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Maha may be pulling drier air into the western half of the circulation, which could be the reason for the lack of thunderstorms in that half of the circulation.  The drier air could prevent significant additional intensification if it gets pulled into the core of the circulation.  An upper level trough will approach Maha from the west in about 18 hours.  The trough will produce stronger westerly winds which will cause the vertical wind shear to increase.  Tropical Cyclone Maha will begin to weaken when the wind shear increases.

Tropical Cyclone Maha will move around the western end of a ridge of high pressure over India and the eastern Arabian Sea during the next 24 hours.  The ridge will steer Maha slowly toward the northwest.  When the upper level trough approaches Tropical Cyclone Maha, the westerly winds will steer the tropical cyclone back toward the east.  On its anticipated track Maha could approach the coast of India north of Mumbai in about 72 hours.

Intense Tropical Cyclone Kyarr Moves Toward Oman

Intense Tropical Cyclone Kyarr moved toward Oman on Sunday.  At 11:00 p.m. EDT on Sunday the center of Tropical Cyclone Kyarr was located at latitude 18.3°N and longitude 65.2°E which put it about 460 miles (745 km) east-southeast of Masirah Island, Oman.  Kyarr was moving toward the west-northwest at 8 m.p.h. (13 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 932 mb.

The circulation around Tropical Cyclone Kyarr remained very symmetrical on Sunday.  Microwave satellite images seemed to indicate that there were two symmetric eye eyewalls surrounding the center of Kyarr.  Bands of showers and thunderstorms were revolving around the larger core of Tropical Cyclone Kyarr.  Storms near the core were generating upper level divergence which was pumping mass away from the tropical cyclone in all directions.

The formation of a second, outer eyewall caused the circulation around Tropical Cyclone Kyarr to increase in size.  Winds to hurricane/typhoon force extended out 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Kyarr was 31.6.  The Hurricane  Size Index (HSI) was 19.1 and the Hurricane Wind Intensity Size Index (HWISI) was 50.7.

The formation of concentric eyewalls indicated that an eyewall replacement cycle was in progress.  Tropical Cyclone Kyarr will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Even though Kyarr will move through an environment favorable for strong tropical cyclones, it will likely weaken while the inner eyewall dissipates.

Tropical Cyclone Kyarr will move south of a ridge of high pressure over South Asia.  The ridge will steer Kyarr in a westward direction during the next few days.  On its anticipated track Tropical Cyclone Kyarr could approach the coast of Oman in three or four days.

Tropical Cyclone Kyarr Strengthens to Equivalent of a Major Hurricane over Arabian Sea

Tropical Cyclone Kyarr strengthened to the equivalent of a major hurricane over the Arabian Sea on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Kyarr was located at latitude 16.9°N and longitude 68.6°E which put it about 705 miles (1135 km) east-southeast of Masirah Island, Oman.  Kyarr was moving toward the west at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 944 mb.

Tropical Cyclone Kyarr intensified rapidly into the equivalent of a major hurricane during the past 36 hours.  A small eye formed at the center of circulation.  A ring of strong 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 Tropical Cyclone Kyarr.  Storms near the core of Kyarr were generating strong upper level divergence which was pumping mass away from the tropical cyclone in all directions.

The circulation around Tropical Cyclone Kyarr was very symmetrical.  Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center.  The Hurricane Intensity Index (HII) was 25.1.  The Hurricane Size Index (HSI) was 15.1 and the Hurricane Wind intensity Size Index (HWISI) was 40.2.

Tropical Cyclone Kyarr will move through an environment favorable for intensification during the next 12 to 24 hours.  Kyarr will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Kyarr could strengthen during the next 24 hours.  An inner rainband could wrap around the eye and eyewall at some point.  That would start an eyewall replacement cycle which would cause Kyarr to weaken.

Tropical Cyclone Kyarr will move south of a ridge of high pressure over South Asia.  The ridge will steer Kyarr toward the west during the next few days.  On its anticipated track Tropical Cyclone Kyarr will move toward Oman.