Monthly Archives: December 2022

Tropical Cyclone Darian Weakens Southeast of Rodrigues

Tropical Cyclone Darian weakened over the South Pacific Ocean southeast of Rodrigues on Thursday night. At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Darian was located at latitude 26.6°S and longitude 69.9°E which put it about 635 miles (1025 km) southeast of Rodrigues. Darian was moving toward the southwest at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h). The minimum surface pressure was 994 mb.

A combination of cooler Sea Surface Temperatures and moderate vertical wind shear caused Tropical Cyclone Darian to weaken on Thursday night as it moved over the South Indian Ocean on Thursday night. Darian was moving over water where the Sea Surface Temperatures are near 25˚C. An upper level trough east of Madagascar was producing northwesterly winds that were blowing toward the top of Darian’s circulation. Those winds were causing moderate vertical wind shear. The wind shear and cooler water were also affecting the structure of Tropical Cyclone Darian. Thunderstorms were occurring bands in the southeastern part of Darian’s circulation. Bands in the other parts of Tropical Cyclone Darian consisted primarily of showers and lower clouds. There was still a large circulation around Darian. Winds to tropical storm force extended out 160 miles (260 km) from the center of circulation.

Tropical Cyclone Darian will move through an environment unfavorable for a tropical cyclone during the next few days. Darian will move over water where the Sea Surface Temperatures are colder than 25˚C. The upper level trough east of Madagascar will continue to cause moderate vertical wind shear. Cooler water and moderate vertical wind shear will cause Tropical Cyclone Darian to make a transition to an extratropical cyclone during the next few days. Darian could maintain its intensity while it goes the through the transition to an extratropical cyclone.

The upper level trough east of Madagascar will steer Tropical Cyclone Darian toward the south during the next 48 hours. On its anticipated track, Darian will move farther away from Rodrigues, Mauritius and La Reunion.

Tropical Cyclone Darian Weakens over South Indian Ocean

Tropical Cyclone Darian weakened over the South Indian Ocean on Tuesday. At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Darian was located at latitude 19.9°S and longitude 78.5°E which put it about 965 miles (1560 km) south-southeast of Diego Garcia. Darian was moving toward the southwest at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 984 mb.

Tropical Cyclone Darian weakened to the equivalent of a tropical storm when it moved over cooler water in the South Indian Ocean on Tuesday night. Thunderstorms did not grow as high into the atmosphere after Darian moved over cooler water. Thunderstorms were still occurring in bands in the southern half of Tropical Cyclone Darian’s circulation on Tuesday night. Bands in the northern half of the circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 200 miles (325 km) from the center of circulation.

Tropical Cyclone Darian will move through an environment unfavorable for a tropical cyclone during the next few days. Darian will move over water where the Sea Surface Temperatures are colder than 25˚C. It will move under the western end of an upper level ridge over the South Indian Ocean. The ridge will produce northerly winds that will blow toward the top of Darian’s circulation. Those winds will cause moderate vertical wind shear. A combination of colder water and moderate vertical wind shear will cause Tropical Cyclone Darian to continue to weaken during the next 36 hours.

Tropical Cyclone Darian will move around the northwestern part of a high pressure system over the South Indian Ocean. The high pressure system will steer Darian toward the southwest during the next 36 hours. On it anticipated track, Tropical Cyclone Darian will pass far to the south of Diego Garcia in 24 hours. Darian could be southeast of Rodrigues in 48 hours.

Tropical Cyclone Darian Strengthens Back to Equivalent of a Major Hurricane

Tropical Cyclone Darian strengthened back to the equivalent of a major hurricane over the South Indian Ocean southeast of Diego Garcia on Monday. At 10:00 a.m. EST on Monday the center of Tropical Cyclone Darian was located at latitude 16.9°S and longitude 84.5°E which put it about 1060 miles (1710 km) southeast of Diego Garcia. Darian was moving toward the southwest at 4 m.p.h. (6 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 947 mb.

After completing several eyewall replacement cycles during the past 36 hours, Tropical Cyclone Darian strengthened back to the equivalent of a major hurricane over the South Indian Ocean far to the southeast of Diego Garcia. A circular eye with a diameter of 35 miles (55 km) was at the center of Darian’s 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 Darian. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone.

The completed eyewall replacements cycles increased the size of the circulation around Tropical Cyclone Darian. Winds to hurricane/typhoon force extended out 50 miles (80 km) from the center of Darian. Winds to tropical storm force extended out 195 miles (305 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Darian was 23.6. The Hurricane Size Index (HSI) was 19.4 and the Hurricane Wind Intensity Size Index (HWISI) was 43.0.

Tropical Cyclone Darian will move through an environment favorable for a strong tropical cyclone during the next 24 hours. Darian will move over water where the Sea Surface Temperatures are near 27˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. If the inner end of a rainband wraps around the core of Tropical Cyclone Darian, then another eyewall replacement cycle could begin. A new eyewall replacement cycle would cause Darian to weaken again. Tropical Cyclone Darian will move over cooler water later this week, which is likely to cause a steadier weakening trend.

Tropical Cyclone Darian will move around the northwestern part of a high pressure system over the South Indian Ocean. The high pressure system will steer Darian toward the southwest during the next few days. On its anticipated track, Tropical Cyclone Darian will pass far to the south of Diego Garcia. Darian could be southeast of Rodrigues in three days.

Tropical Cyclone Darian Spins over South Indian Ocean

Tropical Cyclone Darian was spinning over the South Indian Ocean on Saturday night. At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Darian was located at latitude 14.8°S and longitude 84.8°E which put it about 970 miles (1565 km) east-southeast of Diego Garcia. Darian was moving toward the south-southeast at 13 m.p.h. (20 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 964 mb.

Tropical Cyclone Darian weakened as it spun over the South Indian Ocean on Saturday night. A break developed in the northeastern part of the ring of thunderstorms around the center of Darian’s circulation. The distribution of thunderstorms also became asymmetrical. Many of the thunderstorms were occurring in bands in the western half of Tropical Cyclone Darian. Bands in the eastern half of Darian consisted primarily of showers and lower clouds. Storms near the center of circulation still generated upper level divergence that pumped mass away to the south of the tropical cyclone.

The circulation around Tropical Cyclone Darian was still well organized. Winds to hurricane/typhoon force extended out 45 miles (75 km) from the center of Darian. Winds to tropical storm force extended out 160 miles (260 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Darian was 17.8. The Hurricane Size Index (HSI) was 18.2 and the Hurricane Wind Intensity Size Index (HWISI) was 36.0.

Tropical Cyclone Darian will move through an environment unfavorable for intensification during the next 24 hours. Darian will move over water where the Sea Surface Temperatures are near 27˚C. It will move under the western part of an upper level ridge centered west of Australia. The ridge will produce northeasterly winds that will blow toward the top of Darian’s circulation. Those winds will cause vertical wind shear. The wind shear may already be contributing to the asymmetrical distribution of thunderstorms. The wind shear is likely to be strong enough to cause Tropical Cyclone Darian to weaken during the next 24hours.

The upper level ridge west of Australia will steer Tropical Cyclone Darian toward the south during the next 24 hours. On its anticipated track, Tropical Cyclone Darian will move farther away from Diego Garcia.

Tropical Cyclone Darian Intensifies to Nearly Equivalent of Cat. 5 Hurricane

Tropical Cyclone Darian intensified to nearly the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Friday. At 10:00 a.m. EST on Friday the center of Tropical Cyclone Darian was located at latitude 12.4°S and longitude 83.6°E which put it about 850 miles (1375 km) east-southeast of Diego Garcia. Darian was moving toward the west at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 155 m.p.h. (250 km/h) and there were wind gusts to 190 m.p.h. (305 km/h). The minimum surface pressure was 920 mb.

Tropical Cyclone Darian appeared to go through an eyewall replacement cycle on Thursday. The inner end of a rainband wrapped around the original eye and eyewall. Two concentric eyewalls were evident on some microwave satellite images. Darian weakened during the eyewall replacement cycle. The original inner eyewall eventually dissipated and Tropical Cyclone Darian intensified rapidly on Friday. The new eyewall contracted around the center of Darian and a small 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 Tropical Cyclone Darian. Storm near the core generated upper level divergence that pumped mass away from the tropical cyclone.

The size of Tropical Cyclone Darian increased after the eyewall replacement cycle. Winds to hurricane/typhoon force extended out 60 miles (95 km) from the center of Darian. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Darian was 33.3. The Hurricane Size Index (HSI) was 20.7 and the Hurricane Wind Intensity Size Index (HWISI) was 54.0.

Tropical Cyclone Darian will move through an environment favorable for a strong tropical cyclone during the next 24 hours. Darian will move over water where the Sea Surface Temperatures are near 27˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Cyclone Darian could maintain its intensity during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then another eyewall replace cycle could begin. An eyewall replacement cycle would cause Darian to weaken again.

An upper level trough west of Australia will strengthen during the next 36 hours. Northwesterly winds blowing around the western side of the trough will steer Tropical Cyclone Darian toward the south-southeast during that time period. On its anticipated track Darian will move farther away from Diego Garcia.

Elsewhere, Tropical Cyclone Ellie dropped locally heavy rain over parts of the Northern Territory in Australia. At 10:00 a.m. EST on Friday the center of Tropical Cyclone Ellie was located at latitude 15.8°S and longitude 131.0°E which put it about 150 miles (240 km) north-northwest of Daly Waters, Australia. Ellie was moving toward the south-southeast at 11 m.p.h. (17 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. (95 km/h). The minimum surface pressure was 999 mb.

Tropical Cyclone Ellie Makes Landfall in Northwest Australia

Tropical Cyclone Ellie made landfall on the coast of northwestern Australia on Thursday. At 4:00 p.m. EST on Thursday the center of Tropical Cyclone Ellie was located at latitude 14.6°S and longitude 130.2°E which put it about 130 miles (210 km) south-southwest of Darwin, Australia. Ellie was moving toward the south-southeast at 11 m.p.h. (17 km/h). The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 992 mb.

A Tropical Cyclone Warning was in effect for the portion of the coast from Daly River Mouth to the border between the Northern Territory and Western Australia.

A low pressure system over the Timor Sea near the northwest coast of Australia strengthened on Thursday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Ellie. Tropical Cyclone Ellie made landfall on the coast south-southwest of Darwin within a few hours of being designated as a tropical cyclone. Ellie was the equivalent of a tropical storm at the time of landfall. The maximum sustained wind speed was 45 m.p.h. (75 km/h). Winds to tropical storm force extended out 85 miles (135 km/h).

Tropical Cyclone Ellie will move toward the south-southeast during the next 24 hours. Ellie will move farther inland over the western part of the Northern Territory of Australia. Tropical Cyclone Ellie will bring gusty winds and locally heavy rain to the western parts of the Northern Territory. Heavy rain could cause flash floods in some locations. Flood Watches were in effect for the Carpentaria Coastal Rivers, the Bonaparte Coastal Rivers, the North West Coastal Rivers, and Inland Northern Territory Catchments.

Elsewhere, Tropical Cyclone Darian was moving toward the west over the South Indian Ocean. At 4:00 p.m. EST on Thursday the center of Tropical Cyclone Darian was located at latitude 12.8°S and longitude 85.4°E which put it about 985 miles (1590 km) east-southeast of Diego Garcia. Darian was moving toward the west at 11 m.p.h. (17 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. (235 km/h). The minimum surface pressure was 961 mb.

Tropical Cyclone Darian Equivalent of Cat. 4 Hurricane

Tropical Cyclone Darian was the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale as it moved westward over the South Indian Ocean on Wednesday. At 4:00 p.m. EST on Wednesday the center of Tropical Cyclone Darian was located at latitude 13.2°S and longitude 88.6°E which put it about 1195 miles (1930 km) east-southeast of Diego Garcia. Darian was moving toward the west-northwest at 12 m.p.h. (19 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 925 mb.

A small circular eye was at the center of Darian’s 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 Darian. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone in all directions.

Winds to hurricane/typhoon force extended out 50 miles (80 km) from the center of Tropical Cyclone Darian. Winds to tropical storm force extended out 170 miles (275 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Darian was 31.6. The Hurricane Size Index (HSI) was 14.6 and the Hurricane Wind Intensity Size Index (HWISI) was 46.2.

Tropical Cyclone Darian will move through an environment favorable for a strong tropical cyclone during the next 24 hours. Darian will move over water where the Sea Surface Temperatures are near 27˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Cyclone Darian could maintain its intensity during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replace cycle could begin. An eyewall replacement cycle would cause Darian to weaken.

Tropical Cyclone Darian will move around the northern part of a subtropical high pressure system north of the South Indian Ocean. The high pressure system will steer Darian toward the west during the next 36 hours. On its anticipated track Tropical Cyclone Darian will be southeast of Diego Garcia later this week.

Tropical Cyclone Darian Rapidly Intensifies to Equivalent of a Major Hurricane

Tropical Cyclone Darian rapidly intensified to the equivalent of a major hurricane over the South Indian Ocean east-southeast of Diego Garcia on Tuesday. At 4:00 a.m. EST on Tuesday the center of Tropical Cyclone Darian was located at latitude 14.0°S and longitude 92.7°E which put it about 1255 miles (2355 km) east-southeast of Diego Garcia. Darian was moving toward the southwest at 6 m.p.h. (10 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 946 mb.

Tropical Cyclone Darian continued to intensify rapidly on Tuesday. A circular eye with a diameter of 25 miles (40 km) was at the center of Darian’s 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 Darian. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone in all directions.

The size of Tropical Cyclone Darian increased as it intensified rapidly. Winds to hurricane/typhoon force extended out 45 miles (75 km) from the center of Darian. Winds to tropical storm force extended out 165 miles (265 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Darian was 23.6. The Hurricane Size Index (HSI) was 16.3 and the Hurricane Wind Intensity Size Index (HWISI) was 39.9.

Tropical Cyclone Darian will move through an environment favorable for a strong tropical cyclone during the next 24 hours. Darian will move over water where the Sea Surface Temperatures are near 27˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Cyclone Darian could continue to intensify during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replace cycle could begin. An eyewall replacement cycle would cause Darian to weaken temporarily.

Tropical Cyclone Darian will move around the northern part of a subtropical high pressure system north of the South Indian Ocean. The high pressure system will steer Darian toward the west during the next few days. On its anticipated track Tropical Cyclone Darian will be southeast of Diego Garcia later this week.

Tropical Cyclone Darian Rapidly Intensifies to Equivalent of Hurricane/Typhoon

Tropical Cyclone Darian rapidly intensified to the equivalent of a hurricane/typhoon over the South Indian Ocean west of Cocos Islands on Monday. At 10:00 a.m. EST on Monday the center of Tropical Cyclone Darian was located at latitude 12.8°S and longitude 93.5°E which put it about 230 miles (370 km) west of Cocos Islands. Darian was moving toward the south-southeast at 5 m.p.h. (8 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 971 mb.

Tropical Cyclone Darian rapidly intensified to the equivalent of a hurricane/typhoon during the past 24 hours. The inner end of a rainband wrapped around the center of Darian’s circulation. An elliptical eye formed at the center of Tropical Cyclone Darian. 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 Darian’s circulation. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone in all directions. Winds to hurricane/typhoon force extended out 40 miles (65 km/h) from the center of Tropical Cyclone Darian. Winds to tropical storm force extended out 125 miles (200 km) from the center.

Tropical Cyclone Darian will move through an environment favorable for intensification during the next 24 hours. Darian will move over water where the Sea Surface Temperatures are near 27˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Cyclone Darian is likely to intensify during the next 24 hours.

Tropical Cyclone Darian will move around the southwestern part of a high pressure system centered north of Australia. The high pressure system will steer Darian slowly toward the south during the next 24 hours. On its anticipated track Tropical Cyclone Darian will remain southwest of Cocos Islands. A subtropical high pressure system over the South Indian Ocean will steer Darian toward the west later this week.

Tropical Cyclone Darian Forms West of Cocos Islands

Tropical Cyclone Darian formed over the South Indian Ocean west of Cocos Islands on Sunday. At 7:00 a.m. EST on Sunday the center of Tropical Cyclone Darian was located at latitude 11.9°S and longitude 92.8°E which put it about 270 miles (440 km) west of Cocos Islands. Darian was moving toward the southwest at 3 m.p.h. (5 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 993 mb.

The circulation around a low pressure system over the South Indian Ocean west of Cocos Islands strengthened on Sunday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Darian. The inner end of a rainband wrapped around the southern and western sides of the center of Darian’s circulation. Other bands of showers and thunderstorms were revolving around around the center of circulation. Storms near the center generated upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 100 miles (160 km) from the center of Darian.

Tropical Cyclone Darian will move through an environment favorable for intensification during the next 36 hours. Darian will move over water where the Sea Surface Temperatures are near 27˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Cyclone Darian will intensify during the next 36 hours. Darian could strengthen to the equivalent of a hurricane/typhoon.

Tropical Cyclone Darian will move around the southwestern part of a high pressure system centered north of Australia. The high pressure system will steer Darian slowly toward the southeast during the next 36 hours. On its anticipated track Tropical Cyclone Darian will pass southwest of Cocos Islands.