Category Archives: Tropical Cyclones

Information about tropical cyclones

Tropical Cyclone Biparjoy Nears Indus River Delta

Tropical Cyclone Biparjoy was nearing the Indus River Delta on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Biparjoy was located at latitude 22.8°N and longitude 67.0°E which put it about 150 miles (245 km) south of Karachi, Pakistan. Biparjoy was moving toward the north-northeast at 5 m.p.h. (8 km/h). The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h). The minimum surface pressure was 985 mb.

Tropical Cyclone Biparjoy weakened on Wednesday while it moved over the northern Arabian Sea. More drier air was pulled from South Asia into the northern side of Biparjoy’s circulation. In addition, Tropical Cyclone Biparjoy moved under the southern side of an upper level ridge over South Asia. The upper level ridge produced easterly winds that blew toward top of Biparjoy’s circulation. Those winds caused the vertical wind shear to increase. The effects of the drier air and the increased vertical wind shear caused the distribution of thunderstorms to become more asymmetrical. Thunderstorms were still occurring in bands in the southern part of Biparjoy’s circulation. Bands in the other parts of Tropical Cyclone Biparjoy consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 160 miles (260 km) from the center of Biparjoy.

Tropical Cyclone Biparjoy will move through an environment that will be unfavorable for intensification during the next 12 hours. Biparjoy will move over water where the Sea Surface Temperatures are near 30˚C. However, the upper level ridge over the South Asia will continue to cause moderate vertical wind shear. More drier air will be pulled from South Asia into the northern side of Tropical Cyclone Biparjoy. The drier air will continue to inhibit formation of thunderstorms in the that part of Biparjoy. More vertical wind shear and more drier air will prevent intensification of Tropical Cyclone Biparjoy.

Tropical Cyclone Biparjoy will move around the northwestern side of a high pressure system over the Indian Ocean during the next 24 hours. The high pressure system will steer Biparjoy toward the northeast. On its anticipated track, Tropical Cyclone Biparjoy will reach the coast near the border between India and Pakistan in 12 hours. Biparjoy is likely to be the equivalent of a strong tropical storm when it reaches the Indus River Delta. The India Meteorological Department issued a Cyclone Warning for the Saurashtra and Kutch Coasts. Tropical Cyclone Biparjoy will bring strong winds and locally heavy rain to eastern Pakistan and western India. Heavy rain could cause flash floods in some locations. Biparjoy could also cause a storm surge of up to 7 feet (2 meters along the coast).

Tropical Cyclone Biparjoy Continues Toward Indus River Delta

Tropical Cyclone Biparjoy continued to move slowly toward the Indus River Valley on Tuesday. At 11:00 p.m. EDT on Tuesday the center of Tropical Cyclone Biparjoy was located at latitude 21.8°N and longitude 66.3°E which put it about 225 miles (365 km) south of Karachi, Pakistan. Biparjoy was moving toward the north at 4 m.p.h. (6 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 951 mb.

Tropical Cyclone Biparjoy remained in equilibrium with the surrounding environment on Tuesday and the intensity did not change much. A microwave satellite image showed a circular eye with a diameter of 40 miles (65 km) at the center of Biparjoy’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Thunderstorms were also occurring in bands in the southern and western parts of Tropical Cyclone Biparjoy. Bands in the northern and eastern parts of Biparjoy consisted primarily of showers and lower clouds. Storms near the center of Biparjoy’s circulation generated upper level divergence that pumped mass away to the west of the tropical cyclone.

The size of the circulation around Tropical Cyclone Biparjoy increased on Tuesday. Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of Biparjoy. Winds to tropical storm force extended out 215 miles (345 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Biparjoy was 17.8. The Hurricane Size Index (HSI) was 14.2 and the Hurricane Wind Intensity Size Index (HWISI) was 32.0. Tropical Cyclone Biparjoy was similar in size and intensity to Hurricane Sally when Sally hit South Alabama in 2020.

Tropical Cyclone Biparjoy will move through an environment that will become less favorable for intensification during the next 24 hours. Biparjoy will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the northern part of an upper level ridge over the northern Arabian Sea. The upper level ridge will produce southwesterly winds that will start to blow toward the top of Biparjoy’s circulation. Those winds will cause the vertical wind shear will increase. In addition, more drier air will be pulled from South Asia into the northern side of Tropical Cyclone Biparjoy. The drier air will continue to inhibit formation of thunderstorms in the that part of Biparjoy. More drier air and more vertical wind shear are likely to cause Tropical Cyclone Biparjoy to start to weaken during the next 24 hours.

Tropical Cyclone Biparjoy will move around the northwestern side of a high pressure system over the Indian Ocean during the next 24 hours. The high pressure system will steer Biparjoy slowly toward the north during the next 12 hours. The upper level ridge over the northern Arabian Sea will start to steer Tropical Cyclone Biparjoy toward the northeast on Wednesday. On its anticipated track, Tropical Cyclone Biparjoy will approach the coast near the border between India and Pakistan in 36 hours. Biparjoy is likely to be the equivalent of a hurricane/typhoon when it reaches the Indus River Delta. The India Meteorological Department issued a Cyclone Warning for the Saurashtra and Kutch Coasts. Tropical Cyclone Biparjoy will bring strong winds and locally heavy rain to eastern Pakistan and western India. Heavy rain could cause flash floods in some locations. Biparjoy could also cause a storm surge of up to 8 feet (2.4 meters along the coast).

Tropical Cyclone Biparjoy Churns Toward Indus River Delta

Tropical Cyclone Biparjoy continued to churn toward the Indus River Delta on Monday night. At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Biparjoy was located at latitude 20.8°N and longitude 67.1°E which put it about 285 miles (455 km) south of Karachi, Pakistan. Biparjoy was moving toward the north at 6 m.p.h. (10 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 954 mb.

Tropical Cyclone Biparjoy appeared to be in equilibrium with the surrounding environment on Monday and the intensity did not change much. A microwave satellite image showed a small circular eye at the center of Biparjoy’s circulation. The eye was surrounded by a narrow ring of thunderstorms and the strongest winds were occurring in that ring of storms. Thunderstorms were also occurring in bands in the southern half of Tropical Cyclone Biparjoy. Bands in the northern half of Biparjoy consisted primarily of showers and lower clouds. Storms near the center of Biparjoy’s circulation generated upper level divergence that pumped mass away to the west of the tropical cyclone.

The distribution of wind around Tropical Cyclone Biparjoy became more symmetrical on Monday. Winds to hurricane/typhoon force extended out 35 miles (55 km) in all directions from the center of Biparjoy. Winds to tropical storm force extended out 195 miles (315 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Biparjoy was 17.8. The Hurricane Size Index (HSI) was 16.9 and the Hurricane Wind Intensity Size Index (HWISI) was 34.7.

Tropical Cyclone Biparjoy will move through an environment that will be somewhat favorable for intensification during the next 24 hours. Biparjoy will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the axis of an upper level ridge over the Arabian Sea. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. However, drier air will be pulled from South Asia into the northern side of Tropical Cyclone Biparjoy. The drier air will continue to inhibit formation of thunderstorms in the that part of Biparjoy. Tropical Cyclone Biparjoy could remain in equilibrium with its environment during the next 24 hours if the effects of warm Sea Surface Temperatures and little vertical wind shear balance the effect of the drier air in the northern part of the circulation.

Tropical Cyclone Biparjoy will move around the northwestern side of a high pressure system over the Indian Ocean during the next 24 hours. The high pressure system will steer Biparjoy slowly toward the north. On its anticipated track, Tropical Cyclone Biparjoy could approach the coast near the border between India and Pakistan in 48 hours.

Tropical Cyclone Biparjoy Maintains Northward Track

Tropical Cyclone Biparjoy maintained its track to the north over the Arabian Sea on Sunday. At 11:00 p.m. EDT on Sunday the center of Tropical Cyclone Biparjoy was located at latitude 19.6°N and longitude 67.6°E which put it about 375 miles (605 km) south of Karachi, Pakistan. Biparjoy was moving toward the north at 5 m.p.h. (8 km/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 967 mb.

The intensity of Tropical Cyclone Biparjoy appeared to be cycling up and down every 24 hours. In addition, there was a big difference in the appearance of Biparjoy between conventional infrared and microwave satellite images. A recent microwave image showed a small elliptical eye at the center of Tropical Cyclone Biparjoy. An eye was not present on a conventional infrared satellite image. The difference in appearance was making it challenging to estimate the intensity of Biparjoy based on data remotely sensed by satellites.

Tropical Cyclone Biparjoy was still well organized. A thin ring of thunderstorms surrounded the eye on the microwave satellite image. Bands of strong thunderstorms persisted in the southern half of Biparjoy’s circulation. Bands in the northern half of the circulation consisted primarily of showers and lower clouds. Storms near the center of Biparyjoy generated upper level divergence that pumped mass away to the west of the tropical cyclone. Winds to hurricane/typhoon force extended out 40 miles (65 km) in the eastern half of Tropical Cyclone Biparjoy. Winds to tropical storm force extended out 185 miles (295 km) from the center of Biparjoy’s circulation.

Tropical Cyclone Biparjoy will move through an environment that will become less favorable for intensification during the next 24 hours. Biparjoy will move over water where the Sea Surface Temperatures are near 31˚C. It will move under the axis of an upper level ridge over the Arabian Sea. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. However, more drier air will be pulled from South Asia into the northern side of Tropical Cyclone Biparjoy. The drier air will continue to inhibit formation of thunderstorms in the that part of Biparjoy. In addition, Tropical Cyclone Biparjoy has been moving slowly and the wind could mix cooler water to the surface of the Arabian Sea. Tropical Cyclone Biparjoy will weaken during the next 24 hours if the drier air in the northern part of the circulation and the mixing of cooler water to the surface inhibit the formation of thunderstorms near the core of the circulation.

Tropical Cyclone Biparjoy will move around the western side of a high pressure system over India during the next 24 hours. The high pressure system will steer Biparjoy slowly toward the north. On its anticipated track, Tropical Cyclone Biparjoy could approach the coast near the border between India and Pakistan in three days.

Guchol Weakens to a Tropical Storm

Former Typhoon Guchol weakened to a tropical storm over the Western North Pacific Ocean south of Japan on Sunday. At 5:00 p.m. EDT on Sunday the center of Tropical Storm Guchol was located at latitude 27.4°N and longitude 136.0°E which put it about 650 miles (1050 km) south-southwest of Tokyo, Japan. Guchol was moving toward the northeast at 20 m.p.h. (32 km/h). The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h). The minimum surface pressure was 984 mb.

Former Typhoon Guchol weakened to a tropical storm on Sunday when it moved into a less favorable environment. An upper level trough west of Japan produced westerly winds that blew toward the top of Guchol’s circulation. Those winds caused moderate vertical wind shear and the wind shear caused Guchol to weaken. There was no longer an eye at the center of Guchol’s circulation. Thunderstorms were still occurring in bands in the northern and eastern parts of Tropical Storm Guchol. Bands in the western and southern parts of the circulation consisted primarily of showers and lower clouds. Storms near the center of Guchol generated upper level divergence that pumped mass away to the northeast of the tropical storm. Winds to tropical storm force extended out 175 miles (280 km) from the center of circulation.

Tropical Storm Guchol will move through an environment that will be unfavorable for intensification during the next 36 hours. Guchol will move over water where the Sea Surface Temperatures are near 26˚C. The upper level trough west of Japan will continue to produce westerly winds that will blow toward the top of Guchol’s circulation. Those winds will cause moderate vertical wind shear. Tropical Storm Guchol will continue to weaken as it moves over cooler water and is affected by moderate vertical wind shear. Guchol could make a transition to an extratropical cyclone early next week.

The upper level trough west of Japan will steer Tropical Storm Guchol toward the northeast during the next 36 hours. On its anticipated track Tropical Storm Guchol will pass south of Tokyo in less than 24 hours.

Tropical Cyclone Biparjoy Continues to Move Slowly North

Tropical Cyclone Biparjoy continued to move slowly toward the north over the Arabian Sea on Saturday night. At 11:00 a.m. EDT on Saturday the center of Tropical Cyclone Biparjoy was located at latitude 18.1°N and longitude 67.5°E which put it about 475 miles (765 km) south of Karachi, Pakistan. Biparjoy was moving toward the north at 6 m.p.h. (10 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 962 mb.

Tropical Cyclone Biparjoy appeared to be pulling drier air from India into the northern part of the circulation. Bands in the northern half of Biparjoy consisted primarily of showers and lower clouds. Thunderstorms were occurring in bands in the southern half of Tropical Cyclone Biparjoy. Storms near the center of Biparyjoy generated upper level divergence that pumped mass away to the west of the tropical cyclone. Winds to hurricane/typhoon force extended out 30 miles (50 km) in the southeastern quadrant of Tropical Cyclone Biparjoy. Winds to tropical storm force extended out 175 miles (280 km) from the center of Biparjoy’s circulation.

Tropical Cyclone Biparjoy will move through an environment somewhat favorable for intensification during the next 24 hours. Biparjoy will move over water where the Sea Surface Temperatures are near 31˚C. It will move under the axis of an upper level ridge over the Arabian Sea. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. However, drier air in the northern side of Tropical Cyclone Biparjoy will continue to inhibit formation of thunderstorms in the that part of the circulation. In addition, Biparjoy has been moving slowly and the wind could mix cooler water to the surface of the Arabian Sea. Tropical Cyclone Biparjoy could weaken during the next 24 hours if the drier air in the northern part of the circulation and the mixing of cooler water to the surface inhibit the formation of thunderstorms near the core of the circulation.

Tropical Cyclone Biparjoy will move around the northwestern side of a high pressure system over India during the next 24 hours. The high pressure system will steer Biparjoy slowly toward the north. On its anticipated track, Tropical Cyclone Biparjoy could approach the coast near the border between India and Pakistan in four days.

Typhoon Guchol Turns Northeast

Typhoon Guchol turned toward the northeast on Saturday as it moved over the Western North Pacific Ocean. At 5:00 p.m. EDT on Saturday the center of Typhoon Guchol was located at latitude 22.6°N and longitude 131.3°E which put it about 215 miles (345 km) south of Minamidiatojima, Japan. Guchol was moving toward the north-northeast at 14 m.p.h. (22 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.

Typhoon Guchol started to turn toward the northeast on Saturday, as it was affected by an upper level trough west of Japan. The upper level trough was producing westerly winds that were blowing toward the top of Guchol’s circulation. Those winds were causing the vertical wind shear to increase and the increasing shear was affecting the structure of Typhoon Guchol. There was still an eye at the center of Guchol’s circulation, but thunderstorms were only occurring in the eastern part of the eyewall. Thunderstorms were also occurring in bands in the eastern half of the typhoon. Bands in the western half of Typhoon Guchol consisted primarily of showers and low clouds. Storms in the eastern side of Guchol generated upper level divergence that pumped mass away to the northeast of the typhoon. Winds to typhoon force extended out 75 miles (120 km) from the center of Guchol. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation.

Typhoon Guchol will move through an environment that will become even less favorable for intensification during the next 24 hours. Guchol will move over water where the Sea Surface Temperatures are near 28˚C. The upper level trough west of Japan will continue to produce westerly winds that will blow toward the top of Guchol’s circulation. Those winds will cause the vertical wind shear to increase even more. The increase in wind shear will make the environment even less favorable for intensification. Typhoon Guchol will weaken during the next 24 hours.

The upper level trough west of Japan will steer Typhoon Guchol toward the northeast during the next 48 hours. On its anticipated track Typhoon Guchol could pass between Minamidaitojima and Iwo To during the next 24 hours. Guchol will pass south of Tokyo in less than 48 hours.

Typhoon Guchol Moves North

Typhoon Guchol moved toward the north over the Western North Pacific Ocean on Friday morning. At 11:00 a.m. EDT on Friday the center of Typhoon Guchol was located at latitude 18.6°N and longitude 130.0°E which put it about 465 miles (750 km) south of Minamidiatojima, Japan. Guchol was moving toward the north at 6 m.p.h. (10 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 970 mb.

Typhoon Guchol was showing evidence of weakening on Friday morning. A circular eye with a diameter of 50 miles (80 km) was at the center of Guchol’s circulation. The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms. There was a break in the northwestern part of the ring of storms. Other thunderstorms were occurring in bands in the southern and eastern sides of Typhoon Guchol. Bands in the northern and western parts of Guchol’s circulation consisted primarily of showers and lower clouds. Storms near the center of circulation generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 30 miles (50 km) from the center of Guchol. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation.

Typhoon Guchol will move through an environment that will become less favorable for intensification during the next 24 hours. Guchol will move over water where the Sea Surface Temperatures are near 28˚C. Typhoon Guchol will move closer to an upper level trough west of Japan. The upper level trough will produce westerly winds that will blow toward the northern part of Guchol’s circulation. Those winds will cause the vertical wind shear to increase. The increase in wind shear will make the environment less favorable for intensification. Typhoon Guchol could weaken during the next 24 hours.

Typhoon Guchol will move around the western part of high pressure system over the Western North Pacific Ocean. The high pressure system will steer Guchol toward the north during the next 24 hours. The upper level trough west of Japan will steer Guchol toward the northeast during the weekend. On its anticipated track Typhoon Guchol could pass between Minamidaitojima and Iwo To during fthe weekend.

Tropical Cyclone Biparjoy Moves Slowly North over Arabian Sea

Tropical Cyclone Biparjoy moved slowly toward the north over the Arabian Sea on Friday morning. At 5:00 a.m. EDT on Friday the center of Tropical Cyclone Biparjoy was located at latitude 15.3°N and longitude 66.9°E which put it about 640 miles (1035 km) south of Karachi, Pakistan. Biparjoy was moving toward the north-northeast at 5 m.p.h. (8 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 987 mb.

The distribution of thunderstorms around Tropical Cyclone Biparjoy was asymmetrical on Friday morning. Many of the thunderstorms were occurring near the center of Biparjoy and in bands in the southern half of the tropical cyclone. bands in the northern half of Biparjoy’s circulation consisted primarily of showers and lower clouds. There appeared to be some drier air in the northern side of Tropical Cyclone Biparjoy. The drier air was inhibiting the formation of thunderstorms in that part of Biparjoy. Storms near the center of Biparjoy’s circulation generated upper level divergence that pumped mass away to the west of the tropical cyclone. Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of Tropical Cyclone Biparjoy. Winds to tropical storm force extended out 125 miles (200 km) from the center of circulation.

Tropical Cyclone Biparjoy will move through an environment mostly favorable for intensification during the next 24 hours. Biparjoy will move over water where the Sea Surface Temperatures are near 31˚C. It will move under the axis of an upper level ridge over the Arabian Sea. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. However, drier air in the northern side of Tropical Cyclone Biparjoy will continue to inhibit formation of thunderstorms in the that part of the circulation. In addition, Biparjoy has been moving slowly and the wind could mix cooler water to the surface of the Arabian Sea. Tropical Cyclone Biparjoy could strengthen during the next 24 hours unless the mixing of cooler water to the surface lowers the Sea Surface Temperature under the core of the circulation.

Tropical Cyclone Biparjoy will move around the northwestern side of a high pressure system over India during the next 24 hours. The high pressure system will steer Biparjoy slowly toward the north. On its anticipated track, Tropical Cyclone Biparjoy will remain over the Arabian Sea during the next few days.

Guchol Strengthens to a Typhoon

Former Tropical Storm Guchol strengthened to a typhoon on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Typhoon Guchol was located at latitude 16.1°N and longitude 131.6°E which put it about 670 miles (1080 km) south of Minamidiatojima, Japan. Guchol was moving toward the west-northwest at 7 m.p.h. (11 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 982 mb.

Former Tropical Storm Guchol strengthened to a typhoon over the Western North Pacific Ocean west of the Marianas on Wednesday night. The inner end of a rainband wrapped around the center of Typhoon Guchol. A circular eye was visible on satellite images at the center of Guchol’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core or Typhoon Guchol. Storms near the core generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 35 miles (55 km) from the center of Guchol. Winds to tropical storm force extended out 160 miles (260 km) from the center of circulation.

Typhoon Guchol will move through an environment favorable for intensification during the next 24 hours. Guchol will move over water where the Sea Surface Temperatures are 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 Guchol is likely to intensify during the next 24 hours.

Typhoon Guchol will move around the western part of high pressure system over the Western North Pacific Ocean. The high pressure system will steer Guchol toward the northwest during the next 24 hours. Guchol will move toward the northeast later this week after it passes the western end of the high pressure system. On its anticipated track Typhoon Guchol could be between Minamidaitojima and Iwo To in four days.