Tropical Cyclone Forms Over the Arabian Sea

A tropical cyclone formed over the Arabian Sea on Friday evening. At 11:00 p.m. EDT on Friday the center of Tropical Cyclone 05A was located at latitude 10.0°N and longitude 58.8°E which put it about 600 miles (965 km) southeast of Salalah, Oman. The tropical cyclone was moving toward the west-northwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 997 mb.

The circulation around Tropical Cyclone 05A organized quickly over the Arabian Sea on Friday evening. The inner end of a rainband wrapped around the center of the tropical cyclone’s circulation. A broken ring of thunderstorms surrounded the center of circulation and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving 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 140 miles (220 km) from the center of Tropical Cyclone 05A.

Tropical Cyclone 05A will move through an environment very favorable for intensification during the next 24 hours. The tropical cyclone 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. Tropical Cyclone 05A is likely to intensify to the equivalent of a hurricane/typhoon during the next 24 hours.

Tropical Cyclone 05A will move around the southwestern part of a high pressure system over South Asia. The high pressure system will steer the tropical cyclone toward the northwest during the next 24 hours. On its anticipated track, Tropical Cyclone 05A will move closer to Oman.

Hurricane Norma Approaches Baja California

Hurricane Norma approached the southern end of Baja California on Friday afternoon. At 5:00 p.m. EDT on Friday the center of Hurricane Norma was located at latitude 20.1°N and longitude 109.8°W which put it about 195 miles (310 km) south of Cabo San Lucas, Mexico. Norma was moving toward the north-northwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 140 m.p.h. (220 km/h). The minimum surface pressure was 955 mb.

A Hurricane Warning was in effect for the portion of the coast from Todos Santos to Los Barriles, Mexico. The Hurricane Warning included Cabo San Lucas. Tropical Storm Warnings were in effect for the portions of the coast from Todos Santos to Santa Fe, Mexico and from Los Barriles to San Evaristo, Mexico. A Tropical Storm Watch was in effect for Las Islas Marias. A Tropical Storm Watch was also in effect for the portion of the coast from Topolobampo to Bahia Tempehuaya, Mexico.

Hurricane Norma was still a major hurricane as it approached the southern end of Baja California on Friday afternoon. A circular eye with a diameter of 18 miles (30 km) was at the center of Norma’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 of Hurricane Norma. Storms near the core generated upper level divergence that pumped mass away from the hurricane.

Winds to hurricane force extended out 35 miles (55 km) from the center of Hurricane Norma. Winds to tropical storm force extended out 160 miles (260 km) from the center of Norma’s circulation. The Hurricane Intensity Index (HII) was 22.1. The Hurricane Size Index (HSI) was 13.3 and the Hurricane Wind Intensity Size Index (HWISI) was 35.4. Hurricane Norma was similar in size and intensity to Hurricane Delta when Delta hit Louisiana in 2020.

Hurricane Norma will move through an environment unfavorable for intensification during the next 24 hours. Norma will move over water where the Sea Surface Temperatures are near 29°C. However, an upper level trough west of Baja California will produce southwesterly winds that will blow toward the top of Norma’s circulation. Those winds will cause moderate vertical wind shear. The wind shear will cause Hurricane Norma will to weaken during the next 24 hours.

Hurricane Norma will move around the western part of a high pressure system over Mexico. The high pressure system will steer Norma toward the north during the next 24 hours. On its anticipated track, Hurricane Norma will approach the southern end of Baja California on Saturday morning. Norma will bring strong, gusty winds and locally heavy rain to the southern end of Baja California. Heavy rain is likely to cause flash floods in some locations. Hurricane Norma could cause a storm surge of up to 10 feet (3 meters along the coast at the southern end of Baja California.

Tammy Strengthens to a Hurricane East of the Lesser Antilles

Former Tropical Storm Tammy strengthened to a hurricane east of the Lesser Antilles on Friday morning. At 11:00 a.m. EDT on Friday the center of Hurricane Tammy was located at latitude 14.1°N and longitude 58.6°W which put it about 165 miles (265 km) east-southeast of Martinique. Tammy 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 992 mb.

Hurricane Warnings were in effect for Guadeloupe, Antigua, Barbuda, Montserrat, St. Kitts, and Nevis. Hurricane Watches were in effect for Anguilla, St. Maarten, St. Martin, and St. Baarthelemy. Tropical Storm Warnings were in effect for Dominica, Anguilla, St. Maarten, St. Martin, St. Barthelemy, Saba and St. Eustatius. Tropical Storm Watches were in effect for Martinique and Barbados.

U.S. Air Force Reserve and NOAA planes flying in former Tropical Storm Tammy found that Tammy had intensified to a hurricane on Friday morning. A circular eye with a diameter of 14 miles (22 km) formed at the center of Hurricane Tammy. 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 of Hurricane Tammy. Storms near the core generated upper level divergence that pumped mass away from the hurricane. The removal of mass caused the surface pressure to decrease on Friday morning.

Winds to hurricane force extended out 25 miles (40 km) in the northeastern quadrant of Hurricane Tammy. Winds to tropical storm force extended out 140 miles (220 km) in the eastern side of Tammy’s circulation. Winds to tropical storm force extended out 90 miles (145 km) in the western side of the circulation.

Hurricane Tammy will move through an environment somewhat favorable for intensification during the next 24 hours. Tammy will move over water where the Sea Surface Temperatures are near 30°C. It will move under the far eastern part of an upper level low over the Eastern Caribbean Sea. The upper level low will produce southwesterly winds that will blow toward the top of Tammy’s circulation. Those winds will cause moderate vertical wind shear. The wind shear will inhibit intensification, but it will not be strong enough to prevent intensification. Hurricane Tammy is likely to intensify during the next 24 hours.

Hurricane Tammy will move south of a subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Tammy toward the northwest during the next 24 hours. On its anticipated track, the center of Hurricane Tammy could be near Guadeloupe on Saturday morning.

Hurricane Tammy is likely to bring strong winds and locally heavy rain to the central and northern Leeward Islands. Heavy rain is likely to cause flash in some locations. Hurricane Tammy could cause a storm surge of up to seven feet (two meters) along the coasts of some of the islands.

Norma Prompts Hurricane Warning for Baja California

The potential risk posed by Hurricane Norma prompted the issuance of a Hurricane Warning for the southern part of Baja California. At 11:00 p.m. EDT on Thursday the center of Hurricane Norma was located at latitude 18.2°N and longitude 108.1°W which put it about 345 miles (555 km) south-southeast of Cabo San Lucas, Mexico. Norma was moving toward the north 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 140 m.p.h. (220 km/h). The minimum surface pressure was 948 mb.

A Hurricane Warning was in effect for the portion of the coast from Todos Santos to Los Barriles, Mexico. The Hurricane Warning included Cabo San Lucas. A Tropical Storm Watch was in effect for Los Islas Marias. Tropical Storm Watches were also in effect for the portions of the coast from Todos Santos to Santa Fe, Mexico and from Los Barriles to La Paz, Mexico.

Hurricane Norma weakened slowly on Thursday evening. An upper level trough west of Baja California was producing southwesterly winds that were blowing toward the top of Norma’s circulation. Those winds were causing the vertical wind shear to increase. The eye at the center of Hurricane Norma was less distinct on satellite images. Bands of showers and thunderstorms were revolving around the core of Norma’s circulation. Storms near the core generated upper level divergence that pumped mass away from the hurricane.

Winds to hurricane force extended out 35 miles (55 km) from the center of Hurricane Norma. Winds to tropical storm force extended out 150 miles (240 km) from the center of Norma’s circulation. The Hurricane Intensity Index (HII) for Hurricane Norma was 22.1. The Hurricane Size Index (HSI) was 12.5 and the Hurricane Wind Intensity Size Index (HWISI) was 34.6. Hurricane Norma was similar in size and intensity to Hurricane Delta when Delta hit southwest Louisiana in 2020.

Hurricane Norma will move through an environment unfavorable for intensification during the next 24 hours. Norma will move over water where the Sea Surface Temperatures are near 29°C. However, the upper level trough west of Baja California will continue to produce southwesterly winds that will blow toward the top of Norma’s circulation. Those winds will cause moderate vertical wind shear. The wind shear will cause Hurricane Norma will to weaken during the next 24 hours.

Hurricane Norma will move around the western part of a high pressure system over Mexico. The high pressure system will steer Norma toward the north during the next 24 hours. On its anticipated track, Hurricane Norma could approach the southern end of Baja California on Friday night. Norma will bring strong winds and locally heavy rain to the southern end of Baja California. Heavy rain is likely to cause flash floods in some locations.

Tropical Storm Sanba Drops Heavy Rain on Southern China

Tropical Storm Sanba dropped heavy rain on parts of southern China on Thursday. At 5:00 p.m. EDT on Thursday the center of Tropical Storm Sanba was located at latitude 21.3°N and longitude 109.2°E which put it about 25 miles (40 km) southeast of Beihai China. Sanba was moving toward the north-northeast at 8 m.p.h. (13 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 1001 mb.

Tropical Storm Sanba dropped heavy rain on parts of Guangxi and Guangdong in southern China on Thursday. The center of Sanba’s circulation was still over the northeastern Gulf of Tonkin. Much of the northern half of Tropical Storm Sanba was over southern China. Part of the eastern side of Sanba’s circulation was over Hainan. Winds to tropical storm force extended out 60 miles (95 km) from the center of Tropical Storm Sanba.

An upper level trough over eastern Asia and an upper level ridge centered north of the Philippines were interacting to produce southwesterly winds that were blowing toward the top of Sanba’s circulation. Those winds were causing moderate vertical wind shear and they were also causing the distribution of thunderstorms to be asymmetrical. Thunderstorms were occurring in bands in the northern and eastern parts of Tropical Storm Sanba. Bands in the southern and western parts of Sanba’s circulation consisted primarily of showers and lower clouds.

Tropical Storm Sanba will be in an environment that is mostly unfavorable for intensification during the next 24 hours. Sanba will move over water where the Sea Surface Temperatures are near 28°C. The upper level trough over eastern Asia and the upper level ridge north of the Philippines will continue to cause moderate vertical wind shear. Almost half of Sanba’s circulation will be over land and increased friction will slow the wind in those areas. Tropical Storm Sanba is likely to weaken during the next 24 hours even if the center of circulation does not move over southern China.

The movement of Tropical Storm Sanba during the next 24 hours will depend on how strong the vertical wind shear is. If the wind shear is moderate and the upper and lower parts of Sanba’s circulation remain connected, then southwesterly winds will steer Tropical Storm Sanba toward the north-northeast. If Sanba moves north-northeast it will move inland over southern China. If the vertical wind shear gets stronger, then the upper level winds will push the top part of Sanba’s circulation toward the north-northeast. If the wind shear rips the top off of Tropical Storm Sanba, then the lower part of the circulation could meander over the northeastern Gulf of Tonkin during the next 24 hours.

Tropical Storm Sanba will continue to drop heavy rain over southern China during the next 24 hours. Heavy rain will fall on parts of Guangxi and Guangdong. Prolonged heavy rain will cause floods in some locations.

Norma Rapidly Intensifies to a Major Hurricane

Hurricane Norma rapidly intensified to a major hurricane over the Eastern North Pacific Ocean on Thursday morning. At 8:00 a.m. EDT on Thursday the center of Hurricane Norma was located at latitude 17.0°N and longitude 107.5°W which put it about 430 miles (690 km) south-southeast of Cabo San Lucas, Mexico. Norma was moving toward the north 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 150 m.p.h. (240 km/h). The minimum surface pressure was 950 mb.

A Hurricane Watch was in effect for the portion of the coast from Todos Santos to Los Barriles, Mexico. The Hurricane Watch included Cabo San Lucas.

Hurricane Norma rapidly intensified to a major hurricane on Thursday morning. A circular eye with a diameter of 23 miles (37 km) was at the center of Norma’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 of Hurricane Norma. Storms near the core generated strong upper level divergence that pumped mass away from the hurricane.

Winds to hurricane force extended out 25 miles (40 km) from the center of Hurricane Norma. Winds to tropical storm force extended out 150 miles (240 km) from the center of Norma’s circulation. The Hurricane Intensity Index (HII) for Hurricane Norma was 23.6. The Hurricane Size Index (HSI) was 10.6 and the Hurricane Wind Intensity Size Index (HWISI) was 34.2. Hurricane Norma was similar in size and intensity to Hurricane Dennis when Dennis hit Northwest Florida in 2005.

Hurricane Norma will move through an environment favorable for intensification during the next 12 hours. Norma 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. Hurricane Norma could continue to intensify during the next 12 hours. An upper level trough west of Baja California will approach Norma later on Thursday. The upper level trough will produce southwesterly winds that will blow toward the top of Norma’s circulation. Those winds will cause the vertical wind shear to increase. Hurricane Norma will start to weaken when the wind shear increases.

Hurricane Norma will move around the western part of a high pressure system over Mexico. The high pressure system will steer Norma toward the north during the next 24 hours. On its anticipated track, Hurricane Norma could approach the southern end of Baja California on Friday night. Norma will bring strong winds and locally heavy rain to the southern end of Baja California. Heavy rain is likely to cause flash floods in some locations.

Tropical Storm Tammy Strengthens East of the Lesser Antilles

Tropical Storm Tammy strengthened east of the Lesser Antilles on Thursday morning. At 8:00 a.m. EDT on Thursday the center of Tropical Storm Tammy was located at latitude 13.5°N and longitude 55.1°W which put it about 465 miles (745 km) east of Guadeloupe. Tammy was moving toward the west at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 1004 mb.

Tropical Storm Watches were in effect for Barbados, Dominica, Martinique, Guadeloupe, Antigua, Barbuda, Montserrat, St. Kitts, Nevis, Saba, St. Eustatius.

A NOAA research plane found that Tropical Storm Tammy had strengthened during Wednesday night. More thunderstorms developed near the center of Tammy’s circulation. However, the distribution of thunderstorms was still asymmetrical. Many of the thunderstorms were occurring in bands in the eastern side of Tropical Storm Tammy. Bands in the western side of Tammy’s circulation consisted primarily of showers and lower clouds. Storms near the center of circulation generated upper level divergence that pumped mass away to the north and east of the tropical storm. Winds to tropical storm force extended out 140 miles (220 km) in the eastern side of Tropical Storm Tammy. Winds to tropical storm force extended out 70 miles (110 km) in the western side of Tammy.

Tropical Storm Tammy will move through an environment somewhat favorable for intensification during the next 24 hours. Tammy will move over water where the Sea Surface Temperatures are near 30°C. It will move under the far eastern part of an upper level low over the Eastern Caribbean Sea. The upper level low will produce southwesterly winds that will blow toward the top of Tammy’s circulation. The winds in the lower levels of the atmosphere are blowing from the east. The difference in wind direction between the upper and lower levels of the atmosphere will cause moderate vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Tammy could intensify gradually during the next 24 hours.

Tropical Storm Tammy will move south of a subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Tammy toward the west-northwest during the next 24 hours. On its anticipated track, Tropical Storm Tammy could approach the central and northern Leeward Islands on Friday.

Tropical Storm Tammy is likely to bring gusty winds and locally heavy rain to the central and northern Leeward Islands. Heavy rain is likely to cause flash in some locations. Tropical Storm Tammy could cause a storm surge of up to seven feet (two meters) along the coasts of some of the islands.

Norma Rapidly Intensifies to a Hurricane

Former Tropical Storm Norma rapidly intensified to a hurricane over the Eastern North Pacific Ocean south of Baja California on Wednesday. At 5:00 p.m. EDT on Wednesday the center of Hurricane Norma was located at latitude 15.6°N and longitude 108.0°W which put it about 520 miles (835 km) south-southeast of Cabo San Lucas, Mexico. Norma was moving toward the north at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 95 m.p.h. (150 km/h). The minimum surface pressure was 984 mb.

Former Tropical Storm Norma rapidly intensified to a hurricane on Wednesday. The inner end of a rainband wrapped around the center of Norma’s circulation and an eye was forming at the center. Bands of showers and thunderstorms were revolving around the core of Hurricane Norma. Storms near the core generated upper level divergence that pumped mass away from the hurricane. Winds to hurricane force extended out 25 miles (40 km) in the eastern side of Norma’s circulation. Winds to tropical storm force extended out 140 miles (220 km) from the center of Hurricane Norma.

Hurricane Norma will move through an environment very favorable for intensification during the next 24 hours. Norma 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. Hurricane Norma will intensify during the next 24 hours. Norma could intensify rapidly to a major hurricane on Thursday.

Hurricane Norma will move around the western part of a high pressure system over Mexico. The high pressure system will steer Norma toward the north during the next 24 hours. On its anticipated track, Hurricane Norma could approach the southern end of Baja California on Saturday. Norma is likely to be a hurricane when it approaches Baja California.

Tropical Storm Tammy Forms East of the Lesser Antilles

Tropical Storm Tammy formed over the Atlantic Ocean east of the Lesser Antilles on Wednesday afternoon. At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Tammy was located at latitude 13.0°N and longitude 51.7°W which put it about 625 miles (1005 km) east of the Lesser Antilles. Tammy was moving toward the west at 23 m.p.h. (37 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 1007 mb.

Tropical Storm Watches were issued for Barbados, Dominica, Martinique and Guadeloupe.

A low pressure system over the Atlantic Ocean east of the Lesser Antilles strengthened on Wednesday afternoon and the U.S. National Hurricane Center designated the system as Tropical Storm Tammy. The circulation around Tropical Storm Tammy was not well organized. Many of the thunderstorms were occurring in bands in the eastern part of Tammy’s circulation. Bands in the western part of Tropical Storm Tammy consisted primarily of showers and lower clouds. Storms near the center of Tammy’s circulation were beginning to generate upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 140 miles (220 km) in the northeastern quadrant of Tropical Storm Tammy. The winds in the other parts of Tammy were blowing at less than tropical storm force.

Tropical Storm Tammy will move through an environment somewhat favorable for intensification during the next 24 hours. Tammy will move over water where the Sea Surface Temperatures are near 30°C. It will move under the far eastern part of an upper level low over the Eastern Caribbean Sea. The upper level low will produce southwesterly winds that will blow toward the top of Tammy’s circulation. The winds in the lower levels of the atmosphere are blowing from the east. The difference in wind direction between the upper and lower levels of the atmosphere will cause moderate vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Tammy could intensify a little during the next 24 hours, if the winds in the lower levels weaken. However, if the winds in the lower levels get stronger, then Tammy could weaken to a tropical depression.

Tropical Storm Tammy will move south of a subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Tammy toward the west-northwest during the next 24 hours. On its anticipated track, Tropical Storm Tammy could be near Barbados in 36 hours.

Tropical Storm Tammy is likely to bring gusty winds and locally heavy rain to Barbados, Dominica, Martinique and Guadeloupe. Heavy rain is likely to cause flash in some locations.

Tropical Storm Sanba Forms East of Vietnam

Tropical Storm Sanba formed over the Gulf of Tonkin east of Vietnam on Wednesday. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Sanba was located at latitude 18.9°N and longitude 108.2°E which put it about 180 miles (280 km) southeast of Haiphong, Vietnam. Sanba was moving toward the northwest at 9 m.p.h. (15 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 1003 mb.

A low pressure system over the Gulf of Tonkin east of Vietnam strengthened on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Sanba. The distribution of thunderstorms in Tropical Storm Sanba was asymmetrical. Many of the thunderstorms were occurring in bands in the eastern side of Sanba’s circulation. Bands in the western part of Tropical Storm Sanba consisted primarily of showers and lower clouds. Storms near the center of Sanba’s circulation generated upper level divergence that pumped mass away to the west and north of the tropical storm. Winds to tropical storm force extended out 50 miles (80 km) in the eastern side of Tropical Storm Sanba. The winds in the western part of Sanba’s circulation were blowing at less than tropical storm force.

Tropical Storm Sanba will move through an environment somewhat favorable for intensification during the next 24 hours. Sanba 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 northwest of the Philippines. The upper level ridge will produce southeasterly winds that will blow toward the top of Sanba’s circulation. Those winds will cause some vertical wind shear but the wind shear will not be strong enough to prevent intensification. Some of the air circulating around the eastern side of Tropical Storm Sanba will flow over Hainan. The additional friction caused by the land will cause the air in that part of Sanba’s circulation to slow down. Tropical Storm Sanba could intensify gradually during the next 24 hours.

Tropical Storm Sanba will move around the western part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Sanba toward the north-northwest during the next 24 hours. On its anticipated track the center of Tropical Cyclone Sanba will pass west of Hainan. Sanba will move toward northeastern Vietnam.

Bands in the eastern side of Tropical Storm Sanba are already producing gusty winds and locally heavy rain in parts of Hainan. Bands in the western side of Sanba’s circulation are bringing rain showers to parts of northern Vietnam. Tropical Storm Sanba will continue to produce gusty winds and locally heavy rain in parts of Hainan and northern Vietnam. Heavy rain could cause flash floods in some locations.