Category Archives: Atlantic, Caribbean, and Gulf of Mexico

Atlantic TCs

Potential Tropical Cyclone Twentytwo Unlikely to Develop

Potential Tropical Cyclone Twentytwo is now unlikely to develop into a tropical depression or a tropical storm. At 10:00 p.m. EST on Friday the center of Potential Tropical Cyclone Twentytwo was located at latitude 20.0°N and longitude 76.5°W which put it about 85 miles (130 km) west of Guantanamo, Cuba. It was moving toward the northeast at 22 m.p.h. (35 km/h). The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h). The minimum surface pressure was 1006 mb.

A low pressure system over the Caribbean Sea designated as Potential Tropical Cyclone Twentytwo is no longer expected to develop into a tropical depression or a tropical storm. An upper level trough over the Gulf of Mexico is producing strong southwesterly winds that are blowing across the top of the low pressure system. Those winds are causing strong vertical wind shear. The vertical wind shear is preventing the formation of thunderstorms near the center of Potential Tropical Cyclone Twentytwo. Thunderstorms are occurring in bands in the eastern part of the low pressure system. Bands in the western part of the system and near the center of circulation consist of showers and lower clouds.

Potential Tropical Cyclone Twentytwo will move through an environment unfavorable for development of a tropical cyclone during the next 36 hours. The low pressure system will move over water where the Sea Surface Temperatures are near 29°C. However, the upper level trough over the Gulf of Mexico will continue to cause strong vertical wind shear. The vertical wind shear is likely to continue to prevent the formation of a tropical depression or a tropical storm. Potential Tropical Cyclone Twentytwo could merge with a cold front off the east coast of the U.S. during the weekend.

The upper level trough over the Gulf of Mexico will steer Potential Tropical Cyclone Twentytwo toward the northeast during the next 36 hours. On its anticipated track, Potential Tropical Cyclone Twentytwo will move across eastern Cuba and the Southeastern Bahamas on Saturday. The low pressure system will bring gusty winds and locally heavy rain to eastern Cuba, Haiti, and the Dominican Republic. Heavy rain could cause flash floods in parts of Haiti and the Dominican Republic.

Tropical Storm Watches Issued for Jamaica, Haiti, Eastern Cuba and Southeastern Bahamas

The potential risk posed by a low pressure system over the western Caribbean Sea prompted the issuance of Tropical Storm Watches for Jamaica, Haiti, eastern Cuba, the Southeastern Bahamas, and the Turks and Caicos on Thursday afternoon. The U.S. National Hurricane Center designated the low pressure system as Potential Tropical Cyclone Twentytwo. At 4:00 p.m. EST on Thursday the center of Potential Tropical Cyclone Twentytwo was located at latitude 15.2°N and longitude 81.5°W which put it about 365 miles (590 km) west-southwest of Kington, Jamaica. The low pressure system was moving toward the north-northeast at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h). The minimum surface pressure was 1004 mb.

Tropical Storm Watches were in effect for Jamaica, Haiti, the Southeastern Bahamas, the Turks and Caicos, and the Cuban provinces of Guantanamo, Santiago de Cuba, Holguin, Granma, and Las Tunas.

A U.S. Air Force Reserve Hurricane Hunter plane investigated the low pressure system over the western Caribbean Sea on Thursday afternoon. The crew of the plane found that there was a large counterclockwise rotation, but the was not a well defined low level center within that large rotation. There were several smaller counterclockwise rotations within the larger low pressure system. Thunderstorms were occurring in bands in the eastern side of Potential Tropical Cyclone Twentytwo. Bands in the western side of the low pressure system consisted primarily of showers and lower clouds.

Potential Tropical Cyclone Twentytwo will move through an environment somewhat favorable for intensification during the next 36 hours. The low pressure system will move over water where the Sea Surface Temperatures are near 30°C. It will move under the eastern side of an upper level trough over the eastern Gulf of Mexico. The upper level trough will produce southwesterly winds that will blow toward the top of the low pressure system. Those winds will cause moderate vertical wind shear. The wind shear will inhibit intensification, but the shear may not be strong enough to prevent intensification. Potential Tropical Cyclone Twentytwo is likely to intensify to a tropical storm during the next 36 hours.

The upper level trough over the eastern Gulf of Mexico will steer Potential Tropical Cyclone Twentytwo toward the northeast during the next 36 hours. On its anticipated track, the center of Potential Tropical Cyclone Twentytwo will be near Jamaica on Friday afternoon. The low pressure system will be near eastern Cuba and Haiti on Friday night. It will be over the Southeastern Bahamas and the Turks and Caicos on Saturday.

Potential Tropical Cyclone Twentytwo will bring gusty winds and locally heavy rain to Jamaica, Haiti, eastern Cuba, the Southeastern Bahamas, and the Turks and Caicos. Gusty winds could cause localized electricity outages. Heavy rain could cause flash floods in some locations.

Potential Development over Southwestern Caribbean Sea

A tropical cyclone could potentially develop over the Southwestern Caribbean Sea during the next week. An area of low pressure is expected to form near the surface over the Southwestern Caribbean Sea during the next few days. The low pressure system will form in an environment that will be favorable for the development of a tropical cyclone. The low pressure system will form over water where the Sea Surface Temperatures are near 30°C. It will form under an upper level ridge that will be over the Southwestern Caribbean Sea. The upper level winds will be weak in the ridge and there will be little vertical wind shear. The low pressure system could gradually organize into a tropical cyclone. The U.S. National Hurricane Center is indicating that the probability is 30% that a tropical cyclone forms over the Southwestern Caribbean Sea during the next seven days.

Tropical Storm Tammy Moves Away From Bermuda

Tropical Storm Tammy moved away from Bermuda on Saturday. At 11:00 a.m. EDT on Saturday the center of Tropical Storm Tammy was located at latitude 33.3°N and longitude 58.7°W which put it about 360 miles (580 km) east-northeast of Bermuda. Tammy was moving toward the east at 12 m.p.h. (19 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 985 mb.

Tropical Storm Tammy weakened on Saturday as it moved under the southern extent of the upper level westerlies in the middle latitudes. The upper level westerly winds blew toward the top of Tammy’s circulation and they also caused strong vertical wind shear. The wind shear caused the distribution of thunderstorms in Tropical Storm Tammy to become asymmetrical. Thunderstorms were occurring in bands in the eastern side of Tammy’s circulation. Bands in the western half of Tropical Storm Tammy consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 140 miles (220 km) from the center of Tammy’s circulation.

Tropical Storm Tammy will move through an environment that will be unfavorable for intensification during the next 24 hours. Tammy will move over water where the Sea Surface Temperatures are near 25°C. The upper level westerly winds will continue to cause strong vertical wind shear. The combination of marginal Sea Surface Temperatures and strong vertical wind shear will continue to create an environment unfavorable for intensification during the next 24 hours.

Tropical Storm Tammy will move around the northern side of a high pressure system over the eastern Atlantic Ocean. The high pressure system will steer Tammy toward the east during the next 24 hours. On its anticipated track, Tropical Storm Tammy will move farther away from Bermuda.

Tammy Makes a Transition Back to a Tropical Storm

Former Hurricane Tammy made a transition back to a tropical storm east of Bermuda on Friday morning. At 11:00 a.m. EDT on Friday the center of Tropical Storm Tammy was located at latitude 32.2°N and longitude 61.1°W which put it about 215 miles (350 km) east of Bermuda. Tammy was moving toward the northwest at 3 m.p.h. (5 km/h). The maximum sustained wind speed was 65 m.p.h. (95 km/h) and there were wind gusts to 80 m.p.h. (130 km/h). The minimum surface pressure was 988 mb.

Former Hurricane Tammy made a transition from an extratropical cyclone back to a tropical storm east of Bermuda on Friday morning. The circulation of Tropical Storm Tammy became separated from the occluded front that had formed on Thursday. More thunderstorms formed near the center of Tammy’s circulation. The circulation became more symmetrical and it had the appearance of a tropical storm on visible satellite images. Based on the changes in the circulation’s structure, the U.S. National Hurricane Center designated Tammy as a tropical storm again.

Bands of showers and thunderstorms were revolving around the center of Tropical Storm Tammy. Storms near the center generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 205 miles (335 km) in the northern side of Tammy’s circulation. Winds to tropical storm force extended out 90 miles in the southern side of the circulation.

Tropical Storm Tammy will be in an environment somewhat favorable for intensification during the next 24 hours. Tammy will move over water where the Sea Surface Temperatures are near 26°C. It will be in a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Storm Tammy could intensify back to a hurricane during the next 24 hours.

Tropical Storm Tammy will be in an area where the steering level winds are weak during the next 12 hours. Tammy could meander east of Bermuda during the rest of Friday. A high pressure system centered southeast of Bermuda will steer Tropical Storm Tammy toward the east during the weekend. On its anticipated track, Tropical Storm Tammy will move away from Bermuda during the weekend.

Tammy Makes Transition to Strong Extratropical Cyclone

Former Hurricane Tammy made a transition to a strong extratropical cyclone on Wednesday night. At 5:00 a.m. EDT on Thursday the center of former Hurricane Tammy was located at latitude 30.5°N and longitude 58.4°W which put it about 395 miles (640 km) east-southeast of Bermuda. Tammy was moving toward the north at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h). The minimum surface pressure was 973 mb.

Former Hurricane Tammy made a transition to a strong extratropical cyclone over the Atlantic Ocean east-southeast of Bermuda on Wednesday night. The lower part of Tammy’s circulation merged with a frontal system east of Bermuda. Tammy looked like an occluded extratropical cyclone on satellite images. An occluded front wrapped around the northern part of former Hurricane Tammy. A warm front stretched east of the occluded front. A cold front curved south to the Northern Leeward Islands. The upper part of Tammy’s circulation was captured by an upper level trough near Bermuda.

Former Hurricane Tammy was still producing winds to hurricane force. Winds to hurricane force extended out 30 miles (50 km) from the center of Tammy’s circulation. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation.

Former Hurricane Tammy is forecast to meander over the Atlantic Ocean east of Bermuda during the next few days. The upper level trough near Bermuda is between an upper level ridge over the southeastern U.S. and a second upper level ridge over the eastern Atlantic Ocean. The two ridges will keep the upper level trough from moving much. Since the upper level trough captured former Hurricane Tammy, Tammy is not likely to move much either.

There is a possibility that former Hurricane Tammy could make a transition back to a tropical cyclone during the next few days. Tammy will meander over water where the Sea Surface Temperatures are near 26°C. The vertical wind shear will decrease if the upper level trough weakens. If more thunderstorms form near the center of Tammy’s circulation and the fronts dissipate over time, then Tammy could make a transition back to a tropical cyclone.

Former Hurricane Tammy could bring gusty winds to Bermuda during the next few days. The western part of Tammy’s circulation could extend over Bermuda at times as Tammy meanders east of Bermuda.

Hurricane Tammy Spins Southeast of Bermuda

Hurricane Tammy was spinning southeast of Bermuda on Tuesday evening. At 11:00 p.m. EDT on Tuesday the center of Hurricane Tammy was located at latitude 24.9°N and longitude 60.7°W which put it about 570 miles (915 km) southeast of Bermuda. Tammy was moving toward the northeast at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h). The minimum surface pressure was 976 mb.

Hurricane Tammy started to intensify again on Tuesday evening. A small circular eye was at the center of Tammy’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 Tammy. Storms near the core generated upper level divergence that pumped mass away to the northeast of the hurricane.

Winds to hurricane force extended out 25 miles (40 km) in the eastern side of Hurricane Tammy. Winds to tropical storm force extended out 170 miles (275 km) in the eastern side of Tammy’s circulation. Winds to tropical storm force extended out 90 miles (145 km) in the western half of Hurricane Tammy.

Hurricane Tammy will move through an environment favorable for intensification during the next 24 hours. Tammy will move over water where the Sea Surface Temperatures are near 27°C. It will move under the eastern side of an upper level trough that is east of the U.S. The upper level trough will produce southwesterly winds that will blow toward the top of Tammy’s circulation. Those winds will cause some vertical wind shear, but the wind shear is not likely to be strong enough to prevent intensification. Hurricane Tammy is likely to intensify on Wednesday.

The upper level trough east of the U.S. will steer Hurricane Tammy toward the northeast during the next 24 hours. On its anticipated track, Hurricane Tammy will remain southeast of Bermuda on Wednesday.

Tropical Depression Forms Near Nicaragua

Tropical Depression Twentyone formed over the southwest Caribbean Sea near Nicaragua on Monday afternoon. At 5:00 p.m. EDT on Monday the center of Tropical Depression Twentyone was located at latitude 11.6°N and longitude 83.5°W which put it about 35 miles (55 km) southeast of Bluefields, Nicaragua. The tropical depression was moving toward the west at 5 m.p.h. (8 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. (65 km/h). The minimum surface pressure was 1007 mb.

A low pressure system over the southwest Caribbean Sea near Nicaragua strengthened on Monday afternoon and the U.S. National Hurricane Center designated the system as Tropical Depression Twentyone. More thunderstorms formed near the center of the tropical depression on Monday afternoon. Several short 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 depression.

Tropical Depression Twentyone will move around the southern side of a high pressure system over the Gulf of Mexico. The high pressure system will steer the tropical depression toward the west during the next 24 hours. On its anticipated track, Tropical Depression Twentyone will move inland over southeast Nicaragua in a few hours. The tropical depression could drop heavy rain over parts of Nicaragua. Heavy rain could cause flash floods in some locations.

Elsewhere, Hurricane Tammy moved farther north of the Leeward Islands. At 5:00 p.m. EDT on Monday the center of Hurricane Tammy was located at latitude 22.3°N and longitude 63.8°W which put it about 695 miles (1115 km) south of Bermuda. Tammy was moving toward the north-northeast 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 990 mb.

Hurricane Tammy Moves North of the Leeward Islands

Hurricane Tammy moved north of the Leeward Islands on Sunday. At 11:00 p.m. EDT on Sunday the center of Hurricane Tammy was located at latitude 20.8°N and longitude 64.0°W which put it about 190 miles (305 km) north-northwest of Anguilla. Tammy was moving toward the northwest at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h). The minimum surface pressure was 993 mb.

Hurricane Tammy maintained its intensity on Sunday as it moved north of the Leeward Islands, but Tammy was looking a little weaker on Sunday evening. An upper level trough near the east coast of the U.S. was producing strong southwesterly winds that were blowing toward the top of Tammy’s circulation. Those winds were causing strong vertical wind shear. In addition, some drier air appeared to be entering the southwestern part of Hurricane Tammy.

The effects of the strong wind shear and the drier air caused the distribution of thunderstorms in Hurricane Tammy to become asymmetrical again. Many of the thunderstorms were occurring in bands in the northern and eastern parts of Tammy’s circulation. Bands in the western and southern parts of the circulation consisted primarily of showers and lower clouds. Winds to hurricane force extended out 25 miles (40 km) from the center of Hurricane Tammy. Winds to tropical storm force extended out 115 miles (185 km) from the center of circulation.

Hurricane Tammy will move through an environment that will be unfavorable for intensification during the next 24 hours. Tammy will move over water where the Sea Surface Temperatures are near 29°C. However, the upper level trough near the east coast of the U.S. will continue to cause strong vertical wind shear. The strong wind shear will inhibit intensification and Hurricane Tammy could weaken on Monday.

Hurricane Tammy will move around the western end of a subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Tammy toward the north during the next 24 hours. On its anticipated track, Hurricane Tammy will move farther north of the Leeward Islands on Monday.

Hurricane Tammy Passes Over Barbuda

Hurricane Tammy passed over Barbuda on Saturday night. At 11:00 p.m. EDT on Saturday the center of Hurricane Tammy was located at latitude 17.8°N and longitude 61.9°W which put it about 15 miles (25 km) north-northwest of Barbuda. Tammy was moving toward the north-northwest at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h). The minimum surface pressure was 992 mb.

Hurricane Warnings were in effect for Anguilla, Barbuda, St. Maarten, St, Martin, and St. Barthelemy. Tropical Storm Warnings were in effect for Saba and St. Eustatius.

The center of Hurricane Tammy passed directly over Barbuda on Saturday evening. Tammy produced strong gusty winds and heavy rain in Barbuda. Heavy rain was likely to cause flash floods in some locations.

Hurricane Tammy showed signs of weakening a little on Saturday night. Breaks appeared in the ring of thunderstorms around the center Tammy’s circulation. The distribution of thunderstorms became more asymmetrical. Many of the thunderstorms were occurring in bands in the eastern and northern parts of Hurricane Tammy. Bands in the southern and western parts of Tammy’s circulation consisted primarily of showers and lower clouds. Storms near the center of Tammy’s circulation generated 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 Tammy. Winds to tropical storm force extended out 125 miles (200 km) from the center of circulation. The Hurricane Intensity Index (HII) was 12.7. The Hurricane Size Index (HSI) was 8.3 and the Hurricane Wind Intensity Size Index (HWISI) was 21.0. Hurricane Tammy was capable of causing localized minor damage.

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 29°C. It will move under the northeastern 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. The wind shear could be strong enough to cause Hurricane Tammy to weaken during the next 24 hours.

Hurricane Tammy will move around the western end of a subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Tammy toward the north during the next 24 hours. On its anticipated track, the center of Hurricane Tammy will move north of the Leeward Islands on Sunday.

Hurricane Tammy will continue to produce strong winds and heavy rain in Barbuda during the next few hours. The weather conditions will start to improve in Barbuda when Tammy moves north of the Leeward Islands on Sunday. Hurricane Tammy could also bring gusty winds to Anguilla, St. Maarten, St. Martin and St. Barthelemy on Sunday.