Category Archives: Atlantic, Caribbean, and Gulf of Mexico

Atlantic TCs

Tropical Storm Wanda Speeds Northeast

Tropical Storm Wanda sped toward the northeast over the Atlantic Ocean west of the Azores on Sunday morning. At 4:00 a.m. EST on Sunday the center of Tropical Storm Wanda was located at latitude 38.5°N and longitude 35.5°W which put it about 460 miles (745 km) west of the Azores. Wanda was moving toward the northeast at 17 m.p.h. (28 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.

An upper level trough and a cold front over the central Atlantic Ocean were steering Tropical Storm Wanda quickly to the northeast on Sunday morning. The upper level trough was also producing strong southwesterly winds that were blowing across the top of Wanda’s circulation. Those winds were causing strong vertical wind shear and the shear was causing Tropical Storm Wanda to weaken. The strongest thunderstorms were occurring in a band in the southeastern part of Wanda. Bands in the other parts of the circulation consisted primarily of showers and lower clouds. The strongest winds were occurring with the thunderstorms in the southeastern part of Tropical Storm Wanda. Winds to tropical storm force extended out 70 miles (110 km) in the southeastern quadrant of Wanda. The winds in the other parts of Wanda’s circulation were blowing at less than tropical storm force.

The upper level trough and the cold front will continue to steer Tropical Storm Wanda toward the northeast during the next several days. Tropical Storm Wanda will move through an environment unfavorable for intensification during the next 24 hours. Wanda will move over water where the Sea Surface Temperatures are near 20˚C. The upper level trough will continue to cause strong vertical wind shear. The cold front is moving faster than Tropical Storm Wanda and Wanda is likely to merge with the cold front during the next 24 hours. Strong vertical wind shear and cold water will cause Wanda to make a transition to an extratropical cyclone when it merges with the cold front. On its anticipated track Wanda could approach Ireland as an extratropical cyclone early next week.

Tropical Storm Wanda Turns Back to the South

Tropical Storm Wanda turned back toward the south over the central Atlantic Ocean west of the Azores on Friday morning. At 11:00 a.m. EDT on Friday the center of Tropical Storm Wanda was located at latitude 40.6°N and longitude 37.8°W which put it about 605 miles (970 km) west-northwest of the Azores. Wanda was moving toward the south-southeast at 8 m.p.h. (13 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.

Tropical Storm Wanda moved back toward the south on Friday morning as it continued to meander west of the Azores. The circulation around Tropical Storm Wanda remained well organized. The circulation was circular and there was a well defined center. Bands of showers and thunderstorms revolved around the center of Wanda. Storms near the center of circulation generated upper level divergence that pumped mass away to the north of the tropical storm. Winds to tropical storm force extended out 125 miles (200 km) on the western side of Tropical Storm Wanda. Winds to tropical storm force extended out 70 miles on the eastern side of Wanda.

Tropical Storm Wanda will move through an environment that is somewhat favorable for intensification during the next 24 hours. Wanda will move over water where the Sea Surface Temperatures are near 23˚C. Even though the water is colder than in the tropics, colder air in the middle and upper troposphere will allow for enough instability for the formation of thunderstorms. The thunderstorms that form will not rise as high into the atmosphere. Tropical Storm Wanda will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Storm Wanda could extract enough energy from the Atlantic Ocean to be able to strengthen during the next 24 hours.

Tropical Storm Wanda will move south of a high pressure system over the northern Atlantic Ocean during the next 24 hours. The high pressure system will push Wanda back toward the south during the next 24 hours. An upper level trough near the east coast of the U.S. will move eastward during the next several days. The upper level trough will cause the high pressure system to weaken. When the high weakens, the upper level trough will steer Wanda toward the northeast on Saturday. On its anticipated track Tropical Storm Wanda could approach the western Azores on Sunday.

Tropical Storm Wanda Wanders West of the Azores

Tropical Storm Wanda continued to wander over the Atlantic Ocean west of the Azores on Wednesday. At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Wanda was located at latitude 39.8°N and longitude 39.5°W which put it about 680 miles (1100 km) west-northwest of the Azores. Wanda was moving toward the north at 10 m.p.h. (16 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 992 mb.

Tropical Storm Wanda exhibited a typical structure for a late season, high latitude tropical storm. A circular eyelike feature was present at the center of Wanda. The eyelike feature was surrounded by a ring of showers and thunderstorms. The strongest winds were occurring in the ring of showers and thunderstorms. Bands of showers and thunderstorms revolved around the core of Tropical Storm Wanda. Since Wanda was over cooler Sea Surface Temperatures, the thunderstorms were not rising as high as they would have if Tropical Storm Wanda was over warmer water in the tropics. Winds to tropical storm force extended out 100 miles (160 km) on the eastern side of Wanda. Winds to tropical storm force extended out 70 miles (110 km) in the western half of the circulation.

Tropical Storm Wanda will move through an environment that is somewhat favorable for intensification during the next 24 hours. Wanda will move over water where the Sea Surface Temperatures are near 22˚C. Even though the water is colder than in the tropics, colder air in the middle and upper troposphere will allow for enough instability for the formation of thunderstorms. Thunderstorms that form will not rise as high into the atmosphere and they will not generate a lot of upper level divergence which could inhibit intensification. Tropical Storm Wanda will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Storm Wanda could extract enough energy from the Atlantic Ocean to be able to strengthen during the next 24 hours.

Tropical Storm Wanda will move west of a high pressure system over the eastern Atlantic Ocean during the next 24 hours. The high will steer Wanda toward the north-northeast during the next 24 hours. A second high pressure system will move north of Tropical Storm Wanda on Friday. The second high will push Wanda back toward the southeast. On its anticipated track Tropical Storm Wanda could approach the western Azores during the weekend.

Wanda Transitions to a Tropical Storm

Former Subtropical Storm Wanda made a transition to a tropical storm on Monday afternoon. At 5:00 p.m. EDT on Monday the center of Tropical Storm Wanda was located at latitude 34.2°N and longitude 42.2°W which put it about 885 miles (1425 km) west-southwest of the Azores. Wanda was moving toward the east-northeast at 7 m.p.h. (11 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 996 mb.

The structure of former Subtropical Storm Wanda changed on Monday. The low level center of Wanda became separated from the upper level low that was previously over the top of it. So, the two centers were no longer vertically stacked. In addition, the wind field around Wanda contracted and the strongest winds were located closer to the center of circulation. Since the new structure of Wanda was more consistent with the structure of a tropical cyclone, the National Hurricane Center reclassified Wanda as a tropical storm.

The circulation around Tropical Storm Wanda was smaller. Winds to tropical storm force extended out 45 miles (75 km) from the center of Wanda. The strongest thunderstorms were occurring in bands on the eastern side of Wanda’s circulation. Since Wanda was over water where the Sea Surface Temperature is near 24˚C, the thunderstorms were not as tall as ones that occur in tropical storms farther south. Bands in the western half of the tropical storm consisted primarily of showers and lower clouds. The storms on the eastern side of Wanda generated upper level divergence that pumped mass away to the northeast of the tropical storm.

Tropical Storm Wanda will move through an environment that is somewhat favorable for intensification during the next 24 hours. Wanda will move over water where the Sea Surface Temperatures are near 24˚C. Tropical Storm Wanda will be on the eastern side of the axis of the upper level trough. The upper level trough will produce southwesterly winds that will blow toward the top of Wanda’s circulation. Those winds will cause some vertical wind shear but the wind shear may be weak enough to allow for some intensification. Sinking, drier air could limit the formation of new thunderstorms on the western side of Wanda’s circulation and that could also inhibit intensification. Since Tropical Storm Wanda is now a smaller, more compact storm, it could extract enough energy from the Atlantic Ocean to be able to strengthen during the next 24 hours.

Since Tropical Storm Wanda is east of the axis of the upper level trough, southwesterly winds will steer Wanda toward the north-northeast during the next 36 hours. Wanda could move more toward the east later this week when it reaches a region where westerly winds are stronger. On its anticipated track Tropical Storm Wanda could approach the western Azores at the end of the week.

Subtropical Storm Wanda Meanders West of the Azores

Subtropical Storm Wanda meandered over the central Atlantic Ocean west of the Azores on Sunday. At 11:00 p.m. EDT on Sunday the center of Subtropical Storm Wanda was located at latitude 35.6°N and longitude 44.1°W which put it about 960 miles (1540 km) west of the Azores. Wanda was moving toward the southwest at 8 m.p.h. (13 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 990 mb.

The circulation of Subtropical Storm Wanda meandered within the larger circulation of an upper level trough west of the Azores on Sunday. Some drier air appeared to enter Wanda’s circulation on Sunday and fewer thunderstorms developed around the center of the subtropical storm. The strongest thunderstorms were occurring in bands in the eastern half of Subtropical Storm Wanda. Bands in the western 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 Wanda.

Subtropical Storm Wanda will move through an environment somewhat favorable for intensification during the next 36 hours. Wanda will move over water where the Sea Surface Temperatures are near 24˚C. It will remain under the axis of the upper level trough and there will be little vertical wind shear. However, drier air could limit the formation of new thunderstorms on the western side of Wanda’s circulation and that could inhibit intensification. Subtropical Storm Wanda could strengthen during the next 36 hours. If more thunderstorms form near the center of circulation Wanda could make a transition to a tropical storm during the next several days.

Subtropical Storm Wanda will meander within the upper level trough during the next 24 hours. The upper level trough will move east and it could move Wanda slowly toward the southeast during the next day or so. On its anticipated track Subtropical Storm Wanda could continue to meander west of the Azores for another day or two.

Subtropical Storm Wanda Develops West of the Azores

Subtropical Storm Wanda developed over the central Atlantic Ocean west of the Azores on Saturday night. At 11:00 p.m. EDT on Saturday the center of Subtropical Storm Wanda was located at latitude 36.2°N and longitude 45.4°W which put it about 1020 miles (1640 km) west of the Azores. Wanda was moving toward the southeast at 21 m.p.h. (33 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 1003 mb.

More thunderstorms formed near the center of a low pressure system over the central Atlantic Ocean and the National Hurricane Center designated the system as Subtropical Storm Wanda. Subtropical Storm Wanda began as an extratropical cyclone that formed near the East Coast of the U.S. The extratropical cyclone brought very strong winds to the northeastern U.S. several days ago before moving toward the central Atlantic Ocean. The extratropical cyclone became vertically stacked where the surface low pressure system was under the axis of the upper level trough. The vertical wind shear decreased when the system became vertically stacked. When the extratropical cyclone moved southeast over warmer water, the temperature difference on the opposing sides of fronts decreased and the fronts weakened. More thunderstorms developed near the center of the low pressure system and it assumed a more circular shape. The strongest winds eventually started to blow closer to the center and the National Hurricane Center designated it as Subtropical Storm Wanda.

Subtropical Storm Wanda exhibited some characteristics of a tropical cyclone. Thunderstorms formed near the center of Wanda. Bands of showers and thunderstorms formed and started to revolve around the center of circulation. The strongest rainband wrapped around the northern and eastern sides of the center of Subtropical Storm Wanda. Even though Wanda exhibited some of the characteristics of a tropical cyclone, it was under the axis of an upper level trough, which is why it was classified as a subtropical storm. Winds to tropical storm force extended out 100 miles (160 km) from the center of Subtropical Storm Wanda.

Subtropical Storm Wanda will move through an environment somewhat favorable for intensification during the next 24 hours. Wanda will move over water where the Sea Surface Temperatures are near 24˚C. It will remain under the axis of the upper level trough and there will be little vertical wind shear. Subtropical Storm Wanda is likely to strengthen during the next 24 hours. There is a chance it could intensify to a hurricane during the next several days.

Subtropical Storm Wanda will move along with the upper level trough during the next 24 hours. The upper level trough will carry Wanda slowly toward the southeast during the next several days. On its anticipated track Subtropical Storm Wanda could meander west-southwest of the Azores for several days.

Hurricane Sam Passes East of Bermuda

Hurricane Sam passed east of Bermuda on Saturday morning. At 11:00 a.m. EDT on Saturday the center of Hurricane Sam was located at latitude 33.9°N and longitude 59.3°W which put it about 335 miles (540 km) east-northeast of Bermuda. Sam was moving toward the northeast at 17 m.p.h. (28 km/h). The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 945 mb.

Hurricane Sam was still a powerful hurricane when it passed east of Bermuda on Saturday morning. Sam was rated at Category 4 on the Saffir-Simpson Scale. A circular eye with a diameter of 30 miles (50 km) was present at the center of Hurricane Sam. 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 round the core of Sam’s circulation. Storms near the core generated strong upper level divergence that pumped mass away to the north of the hurricane.

The size of the circulation around Hurricane Sam continued to increase in size as it moved farther to the north. Winds to hurricane force extended out 65 miles (10 km) from the center of Sam. Winds to tropical storm force extended out 240 miles (390 km) from the center of circulation. The Hurricane Intensity Index (HII) for Hurricane Sam was 25.1. The Hurricane Size Index (HSI) was 20.6 and the Hurricane Wind Intensity Size Index (HWISI) was 45.7.

Hurricane Sam will move through an environment capable of maintaining a major hurricane during the next 12 hours. Sam 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 during the next 12 hours. An upper level trough east of the U.S. will produce southwesterly winds that will start to affect Hurricane Sam on Sunday. Those winds will blow toward the top of Sam’s circulation and they will cause more vertical wind shear. Hurricane Sam will also move over cooler water on Sunday. The wind shear and cooler water will cause Hurricane Sam to weaken as it begins a transition to a strong extratropical cyclone.

The upper level trough east of the U.S. will steer Hurricane Sam toward the northeast later during the next several days. On its anticipated track Hurricane Sam will pass southeast of Newfoundland on Monday. Sam could be a powerful extratropical cyclone southeast of Greenland by early next week.

Elsewhere over the Atlantic Ocean, Tropical Storm Victor weakened west of the Cabo Verde Islands. At 11:00 a.m. EDT on Saturday the center of Tropical Storm Victor was located at latitude 13.1°N and longitude 37.2°W which put it about 905 miles (1455 km) west of the Cabo Verde Islands. Victor was moving toward the northwest 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 1005 mb.

Bermuda Issues Tropical Storm Warning Because of Hurricane Sam

Bermuda issued a Tropical Storm Warning because of the potential effects of Hurricane Sam. At 5:00 p.m. EDT on Thursday the center of Hurricane Sam was located at latitude 23.6°N and longitude 60.9°W which put it about 645 miles (1040 km) south-southeast of Bermuda. Sam was moving toward the northwest at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 145 m.p.h. (235 km/h) and there were wind gusts to 170 m.p.h. (280 km/h). The minimum surface pressure was 938 mb.

A Tropical Storm Warning was in effect for Bermuda.

Hurricane Sam continued to be a powerful hurricane on Thursday. Sam was rated at Category 4 on the Saffir-Simpson Scale. A circular eye with a diameter of 28 miles (44 km) was present at the center of Hurricane Sam. 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 round the core of Sam’s circulation. Storms near the core generated strong upper level divergence that pumped mass away from the hurricane.

The size of the circulation around Hurricane Sam was increasing in size as it moved farther to the north. Winds to hurricane force extended out 60 miles (95 km) from the center of Sam. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation. The Hurricane Intensity Index (HII) for Hurricane Sam was 29.8. The Hurricane Size Index (HSI) was 17.5 and the Hurricane Wind Intensity Size Index (HWISI) was 47.3.

Hurricane Sam will move through an environment capable of maintaining a major hurricane during the next 36 hours. Sam will move over water where the Sea Surface Temperatures are near 28˚C. It will move through a region where the upper level winds are weak during the next 24 hours. An upper level trough east of the U.S. will produce southwesterly winds that will start to affect Hurricane Sam later on Friday. Those winds will blow toward the top of Sam’s circulation and they will cause more vertical wind shear. The wind shear will cause Hurricane Sam to start to weaken.

Hurricane Sam will move around the western end of a high pressure system over the Atlantic Ocean during the next 24 hours. The high will steer Sam toward the north during that time period. The upper level trough east of the U.S. will start to steer Hurricane Sam toward the northeast later on Friday. On its anticipated track Hurricane Sam will pass east of Bermuda on Friday night. The western fringes of Sam could bring gusty winds and locally heavy rain to Bermuda, which is why the Tropical Storm Warning was issued.

Elsewhere over the Atlantic Ocean, Tropical Storm Victor strengthened a little southwest of the Cabo Verde Islands. At 5:00 p.m. EDT on Thursday the center of Tropical Storm Victor was located at latitude 9.9°N and longitude 30.0°W which put it about 585 miles (940 km) southwest of the Cabo Verde Islands. Victor was moving toward the west-northwest at 14 m.p.h. (22 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 1003 mb.

Tropical Storm Victor Forms South of Cabo Verde Islands

Tropical Storm Victor formed south of the Cabo Verde Islands on Wednesday afternoon. At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Victor was located at latitude 8.3°N and longitude 25.5°W which put it about 540 miles (870 km) south of the Cabo Verde Islands. Victor was moving toward the west-northwest at 13 m.p.h. (20 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 1005 mb.

The circulation around a low pressure system west of Africa strengthened on Wednesday afternoon and the National Hurricane Center designated the system as Tropical Storm Victor. There was a large circulation around Tropical Storm Victor and the circulation was still in the early stages of organization. Bands of showers and thunderstorms were revolving around the center of Victor. More thunderstorms were starting to develop near the center of circulation. The strongest thunderstorms were occurring west of the center. Storms near the center started to generate upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 60 miles in the northern half of Victor’s circulation. The winds in the southern half of the circulation were blowing at less than tropical storm force.

Tropical Storm Victor will move through an environment favorable for intensification during the next 36 hours. Victor 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 Storm Victor will strengthen gradually. Victor will intensify to a hurricane by Friday.

Tropical Storm Victor will move south of a high pressure system over the eastern Atlantic Ocean. The high will steer Victor toward the west-northwest during the next 36 hours. On its anticipated track Tropical Storm Victor will pass well to the southwest of the Cabo Verde Islands.

Elsewhere over the Atlantic Ocean, major Hurricane Sam was passing northeast of the Leeward Islands. At 5:00 p.m. EDT on Wednesday the center of Hurricane Sam was located at latitude 20.2°N and longitude 57.6°W which put it about 385 miles (620 km) east-northeast of the Northern Leeward Islands. Sam moving toward the northwest at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 945 mb.

Hurricane Sam Strengthens Back to Cat. 4

Hurricane Sam strengthened back to Category 4 on the Saffir-Simpson Scale on Tuesday morning. At 11:00 a.m. EDT on Tuesday the center of Hurricane Sam was located at latitude 17.5°N and longitude 54.3°W which put it about 580 miles (935 km) east of the Northern Leeward Islands. Sam moving toward the northwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 954 mb.

Hurricane Sam strengthened back to Category 4 after completing several Eyewall Replacement Cycles. The Eyewall Replacement Cycles also resulted in an increase in the size of Hurricane Sam. A larger circular eye with a diameter of 40 miles (65 km) was present at the center of Sam. 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 Hurricane Sam. Storms near the core generated upper level divergence that pumped mass away from the hurricane.

The circulation around Hurricane Sam was larger after the completion of the Eyewall Replacement Cycles. Winds to hurricane force extended out 40 miles (65 km) from the center of Sam. Winds to tropical storm force extended out 140 miles (225 km) from the center of circulation. The Hurricane Intensity Index (HII) for Hurricane Sam was 25.1. The Hurricane Size Index (HSI) was 14.2 and the Hurricane Wind Intensity Size Index (HWISI) was 39.3.

Hurricane Sam will move through an environment capable of sustaining a major hurricane during the next 48 hours. Sam will move over water where the Sea Surface Temperatures are near 28˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Hurricane Sam could strengthen in the favorable environment.

Hurricane Sam will move around the southwestern part of a subtropical high pressure system over the Atlantic Ocean. The high will steer Sam toward the northwest during the next 48 hours. On its anticipated track Hurricane Sam could pass northeast of the Northern Leeward Islands on Thursday. Sam could be southeast of Bermuda by Friday.