Monthly Archives: December 2021

Tropical Cyclone Forms over Coral Sea

Tropical Cyclone 03P formed over the Coral Sea southwest of the Solomon Islands on Saturday. At 4:00 p.m. EST on Saturday the center of Tropical Cyclone 03P was located at latitude 13.2°S and longitude 157.1°E which put it about 650 miles (1050 km) northwest of Poum, New Caledonia. Tropical Cyclone 03P was moving toward the south-southeast at 16 m.p.h. (26 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 997 mb.

The circulation around a small low pressure system over the Coral Sea strengthened on Saturday into Tropical Cyclone 03P. More thunderstorms formed near the center of the tropical cyclone. Thunderstorms also became more numerous in bands revolving around the center of circulation. Storms near the center generated upper level divergence that pumped mass away from the tropical cyclone. The circulation around the tropical cyclone was small. Winds to tropical storm force extended out 20 miles (30 km) from the center of circulation.

Tropical Cyclone 03P will move through an environment favorable for intensification during the next 36 hours. The tropical cyclone will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the western part of an upper level ridge over the South Pacific Ocean. The ridge will produce northwesterly winds that will blow toward the top of the tropical cyclone’s circulation. Those winds will cause some vertical wind shear, but the wind shear will be too small to prevent intensification. Tropical Cyclone 03P will intensify and it could strengthen to the equivalent of a hurricane/typhoon within 36 hours.

Tropical Cyclone 03P will move around the southwestern part of a high pressure system over the South Pacific Ocean during the next several days. The high pressure system will steer the tropical cyclone toward the southeast during the next 36 hours. On its anticipated track Tropical Cyclone 03P could approach the northwestern part of New Caledonia in 48 hours. The tropical cyclone is likely to be the equivalent of a hurricane/typhoon when it nears New Caledonia.

Tropical Cyclone Teratai Passes South of Christmas Island

Tropical Cyclone Teratai passed south of Christmas Island on Wednesday. At 4:00 p.m. EST on Wednesday the center of Tropical Cyclone Teratai was located at latitude 14.2°S and longitude 104.4°E which put it about 255 miles (410 km) south-southwest of Christmas Island. Teratai was moving toward the west-southwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1000 mb.

Tropical Cyclone Teratai weakened slowly as it passed over the South Indian Ocean south of Christmas Island on Wednesday. Thunderstorms were occurring in a couple of bands in the western half of Teratai’s circulation. Bands in the eastern half of the circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 70 miles (110 km) from the center of Teratai.

Tropical Cyclone Teratai will move through an environment that will be mostly unfavorable for intensification during the next several days. Teratai will move over water where the Sea Surface Temperatures are near 26˚C during the next 24 hours. It will move under the northern part of an upper level ridge centered northwest of Australia. The upper level ridge will produce easterly winds that will blow toward the top of Teratai’s circulation. Those winds will cause moderate vertical wind shear and the wind shear inhibit intensification. Tropical Cyclone Teratai could maintain its intensity during the next 24 hours, but it will move over cooler water later this week. When Teratai moves over cooler water, the reduction in available energy and the vertical wind shear will cause Tropical Cyclone Teratai to weaken.

Tropical Cyclone Teratai will move around the northern part of a high pressure system over the South Indian Ocean. The high pressure system will steer Teratai toward the west-southwest during the next several days. On its anticipated track Tropical Cyclone Teratai will move farther away from Christmas Island.

Tropical Cyclone Teratai Redevelops South of Indonesia

Tropical Cyclone Teratai redeveloped south of Indonesia on Tuesday afternoon. At 4:00 p.m. EST on Tuesday the center of Tropical Cyclone Teratai was located at latitude 12.0°S and longitude 106.4°E which put it about 380 miles (615 km) south of Jakarta, Indonesia and about 115 miles (185 km) south-southeast of Christmas Island. Teratai was moving toward the south 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 1000 mb.

After strong upper level winds blew the top off of former Tropical Cyclone Teratai late last week, the circulation in the lower levels made an extended clockwise loop southwest of Indonesia. More thunderstorms formed west of the low level center of circulation on Monday and the circulation around Tropical Cyclone Teratai strengthened during the past 24 hours. Data from scatterometers on satellites indicated that the wind speeds increased back to tropical storm force on Tuesday. The distribution of thunderstorms was still asymmetrical. Thunderstorms were occurring in bands in the western half of Teratai’s circulation. Bands in the eastern side of Tropical Cyclone Teratai consisted primarily of showers and lower clouds. Storms near the center generated upper level divergence that pumped mass away to the west of the tropical cyclone. Teratai was a small tropical cyclone. Winds to tropical storm force extended out 50 miles (80 km) from the center of circulation.

Tropical Cyclone Teratai will move through an environment that will be mostly unfavorable for intensification during the next several days. Teratai will move over water where the Sea Surface Temperatures are near 26.5˚C. It will move under the northern part of an upper level ridge centered northwest of Australia. The upper level ridge will produce easterly winds that will blow toward the top of Teratai’s circulation. Those winds will cause moderate vertical wind shear. The wind shear is already causing an asymmetrical distribution of thunderstorms and the shear will continue to inhibit intensification. Tropical Cyclone Teratai could maintain its intensity during the next 24 hours, but if the wind shear increases Teratai is likely to weaken again.

Tropical Cyclone Teratai will move around the northern part of a high pressure system over the South Indian Ocean. The high pressure system will steer Teratai toward the west-southwest during the next several days. On its anticipated track Tropical Cyclone Teratai will move south of Christmas Island during the next several days.

Tropical Cyclone Jawad Spins over Bay of Bengal

Tropical Cyclone Jawad was spinning over the Bay of Bengal east of India on Friday night. At 10:00 p.m. EST on Friday the center of Tropical Cyclone Jawad was located at latitude 16.0°N and longitude 85.0°E which put it about 150 miles (240 km) southeast of Visakhapatnam, India. Jawad was moving toward the north at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1000 mb.

Tropical Cyclone Jawad continued to spin over the Bay of Bengal east of India on Friday night. An upper level ridge over the Bay of Bengal was producing southeasterly winds that were blowing toward the top of Jawad’s circulation. Those winds were causing moderate vertical wind shear and the shear was keeping Tropical Cyclone Jawad from getting stronger. The strongest thunderstorms in Jawad were occurring in the northern half of the circulation because of the vertical wind shear. Bands in the southern half of the circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 100 miles (160 km) from the center of Tropical Cyclone Jawad.

Tropical Cyclone Jawad will move through an environment only marginally favorable for intensification during the next 24 hours. Jawad will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western end of an upper level ridge over the Bay of Bengal. The ridge will continue to produce southerly winds that will blow toward the top of Jawad’s circulation. Those winds will cause moderate vertical wind shear. The wind shear is likely to remain strong enough to prevent Tropical Cyclone Jawad from strengthening during the next 24 hours.

Tropical Cyclone Jawad will move around the western end of a high pressure system over southeast Asia. The high pressure system will steer Jawad toward the north-northeast during the next several days. On its anticipated track Tropical Cyclone Jawad will move parallel to the east coast of India during the next 36 hours. Jawad could approach Kolkata in 72 hours. Tropical Cyclone Jawad could bring gusty winds and locally heavy rain to the coastal parts of northeastern Andhra Pradesh, Odisha, and West Bengal.

Typhoon Nyatoh Brings Wind and Rain to Iwo To

Typhoon Nyatoh brought wind and rain to Iwo To on Friday. At 10:00 a.m. EST on Friday the center of Typhoon Nyatoh was located at latitude 24.3°N and longitude 142.9°E which put it about 80 miles (130 km) southeast of Iwo To. Nyatoh was moving toward the northeast at 24 m.p.h. (39 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.

Bands in the northwestern side of Typhoon Nyatoh brought strong winds and heavy rain to Iwo To on Friday. The core of Nyatoh’s circulation where the strongest winds were occurring passed to the southeast of Iwo To. An upper level trough over Japan was producing strong southwesterly winds that were blowing toward the top of Typhoon Nyatoh’s circulation. Those winds caused strong vertical wind shear and the shear started to weaken Nyatoh when it approached Iwo To. A circular eye was still present at the center of Typhoon Nyatoh, but the distribution of thunderstorms was asymmetrical. The strongest thunderstorms were occurring around the eye and in bands in the northern half of Nyatoh. Bands in the southern half of the typhoon consisted primarily of showers and lower clouds.

Even though Typhoon Nyatoh was weakening, it was still the equivalent of a major hurricane. Winds to typhoon force extended out 60 miles (95 km) from the center of Nyatoh. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Nyatoh was 23.6. The Hurricane Size Index (HSI) was 22.2 and the Hurricane Wind Intensity Size Index (HWISI) was 45.8.

The upper level trough over Japan will steer Typhoon Nyatoh quickly toward the northeast during the next 24 hours. On its anticipated track Nyatoh will move away from Iwo To and the weather conditions should improve. Typhoon Nyatoh will move through an environment that will be unfavorable for a typhoon. Nyatoh will move over water where the Sea Surface Temperatures are near 24.5˚C. The upper level trough will continue to produce strong vertical wind shear. A surface high pressure system over eastern Asia will transport drier air toward the western side of Nyatoh’s circulation. Cooler water, strong vertical wind shear, and drier air will cause Typhoon Nyatoh to weaken rapidly during the next 24 hours.

Tropical Cyclone 05B Forms over Bay of Bengal

Tropical Cyclone 05B formed over the Bay of Bengal on Thursday night. At 10:00 p.m. EST on Thursday the center of Tropical Cyclone 05B was located at latitude 14.4°N and longitude 85.8°E which put it about 360 miles (580 km) southeast of Visakhapatnam, India. Tropical Cyclone 05B was moving toward the northwest at 16 m.p.h. (26 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 1001 mb.

A low pressure system over the central Bay of Bengal strengthened on Thursday night into Tropical Cyclone 05B. The distribution of thunderstorms around Tropical Cyclone 05B was asymmetrical. The strongest thunderstorms were occurring in bands in the northern half of the tropical cyclone. Bands in the southern half of the circulation consisted primarily of showers and lower clouds. The thunderstorms in the northern half of the circulation generated upper level divergence that pumped mass away to the north of the tropical cyclone. The distribution of wind speeds was also asymmetrical. Winds to tropical storm force extended out 150 miles (240 km) in the northern half of the tropical cyclone. The winds in the southern half of the circulation were blowing at less than tropical storm force.

Tropical Cyclone 05B will move through an environment favorable for intensification during the next 24 hours. The tropical cyclone will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western end of an upper level ridge over the Bay of Bengal. The ridge will produce southerly winds that will blow toward the top of the tropical cyclone. Those winds will cause some vertical wind shear, but the wind shear will not be strong enough to prevent intensification. Tropical Cyclone 05B is likely to intensify during the next 24 hours. The India Meteorological Department will likely give the tropical cyclone a name on Friday.

Tropical Cyclone 05B will move around the western end of a high pressure system over southeast Asia. The high pressure system will steer the tropical cyclone toward the northwest during the next 24 hours. On its anticipated track Tropical Cyclone 05B will approach the coast of India northeast of Visakhapatnam in 24 hours. It will bring gusty winds and locally heavy rain to the coastal parts of northeastern Andhra Pradesh and Orissa. Tropical Cyclone 05B will move more slowly after it nears the coast and it could turn toward the northeast during the weekend.

Typhoon Nyatoh Strengthens to Equivalent of a Major Hurricane

Typhoon Nyatoh strengthened to the equivalent of a major hurricane over the Western North Pacific Ocean southwest of Iwo To on Thursday. At 10:00 a.m. EST on Thursday the center of Typhoon Nyatoh was located at latitude 18.7°N and longitude 137.1°E which put it about 540 miles (875 km) southwest of Iwo To. Nyatoh was moving toward the northeast at 15 m.p.h. (24 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 955 mb.

Typhoon Nyatoh rapidly intensified to the equivalent of a major hurricane on Thursday. A circular eye with a diameter of 35 miles (55 km) formed at the center of Nyatoh. 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 Nyatoh. Storms near the core generated strong upper level divergence that pumped mass away to the northeast of the typhoon.

The circulation around Typhoon Nyatoh increased in size on Thursday. Winds to typhoon force extended out 65 miles (105 km) from the center of Nyatoh. Winds to tropical storm force extended out 220 miles (355 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Nyatoh was 20.6. The Hurricane Size Index (HSI) was 22.1 and the Hurricane Wind Intensity Size Index (HWISI) was 42.7.

Typhoon Nyatoh will move through an environment that will become unfavorable for intensification during the next 24 hours. Nyatoh will move over water where the Sea Surface Temperatures are near 28˚C. An upper level trough near Japan will produce southwesterly winds that will blow toward the top of Nyatoh’s circulation. Those winds will cause the vertical wind shear to increase during the next 24 hours. Clockwise flow around a surface high pressure system centered over eastern Asia will transport drier air toward the northwestern part of Nyatoh’s circulation. The drier air will begin to be pulled into the northwestern part of Typhoon Nyatoh’s circulation during the next 24 hours. The combination of more vertical wind shear and drier air will cause Typhoon Nyatoh to start to weaken.

The upper level trough near Japan will steer Typhoon Nyatoh toward the northeast during the next 24 hours. On its anticipated track Typhoon Nyatoh could approach Iwo To on Friday. Although Nyatoh will weaken, it will bring strong winds and locally heavy rain to Iwo To.

Nyatoh Strengthens to a Typhoon West of the Marianas

Former Tropical Storm Nyatoh strengthened to a typhoon west of the Marianas on Wednesday. At 10:00 a.m. EST on Wednesday the center of Typhoon Nyatoh was located at latitude 15.5°N and longitude 135.6°E which put it about 580 miles (935 km) west-northwest of Guam. Nyatoh was moving toward the north-northwest at 11 m.p.h. (17 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 981 mb.

Former Tropical Storm Nyatoh continued to strengthen over the Western North Pacific Ocean west of the Marianas on Wednesday. The inner end of a rainband wrapped around the center of Typhoon Nyatoh and microwaves satellite images indicated that an eye was forming. The developing eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Nyatoh. 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 Nyatoh. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation.

Typhoon Nyatoh will move through an environment mostly favorable for intensification during the next 24 hours. Nyatoh will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western part of the axis of an upper level ridge centered near the Marianas. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Clockwise flow around a high pressure system centered over eastern Asia will transport drier air toward the northwestern part of Nyatoh’s circulation. The drier air is likely to remain northwest of Typhoon Nyatoh during the next 24 hours. Nyatoh could intensify more rapidly once the eye and eyewall become fully formed. Typhoon Nyatoh will continue to strengthen and it could intensify to the equivalent of a major hurricane during the next 24 hours. An upper level trough west of Japan will produce southwesterly winds that will begin to affect Nyatoh later this week. Those winds will create more vertical wind shear and the shear will cause Typhoon Nyatoh to weaken.

Typhoon Nyatoh will move around the western part of a high pressure system over the Western North Pacific Ocean during the next 24 hours. The high pressure system will steer Nyatoh toward the north during the next 24 hours. The upper level trough will steer Typhoon Nyatoh toward the northeast after Nyatoh moves around the western end of the high pressure system. On its anticipated track Tropical Storm Nyatoh will remain west of the Marianas during the next 24 hours. Nyatoh could approach Iwo To in 48 hours.

Tropical Cyclone Teratai Forms Southwest of Java

Tropical Cyclone Teratai formed over the South Indian Ocean southwest of Java on Wednesday morning. At 4:00 a.m. EST on Wednesday the center of Tropical Cyclone Teratai was located at latitude 9.3°S and longitude 102.2°E which put it about 375 miles (605 km) southwest of Jakarta, Indonesia. Teratai was moving toward the southwest at 7 m.p.h. (11 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.

A distinct center of circulation formed in a small low pressure system over the South Indian Ocean southwest of Java on Wednesday morning and the system was designated as Tropical Cyclone Teratai. Thunderstorms developed near the center of circulation. Shorts bands of showers and thunderstorms were revolving around the center of Teratai. Storms near the center generated upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 50 miles (80 km) from the center of Tropical Cyclone Teratai.

Tropical Cyclone Teratai will move through an environment that will be only marginally favorable for intensification during the next several days. Teratai will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western part of an upper level ridge centered north of Australia. The upper level ridge will produce northerly winds that will blow toward the top of Teratai’s circulation. Those winds will cause some vertical wind shear. Tropical Cyclone Teratai will move into an area where drier air is sinking toward the surface of the ocean. The sinking drier air will inhibit the formation of new thunderstorms. Tropical Cyclone Teratai could maintain its intensity during the next 24 hours. However, the effects of the sinking air and vertical wind shear are likely to cause Teratai to weaken later this week.

Tropical Cyclone Teratai will move around the northern part of a high pressure system over the South Indian Ocean. The high pressure system will steer Teratai toward the west-southwest during the next several days. On its anticipated track Tropical Cyclone Teratai will move farther away from Indonesia. Teratai could move north of Cocos Island later this week.