Category Archives: Atlantic, Caribbean, and Gulf of Mexico

Atlantic TCs

Tropical Depression Three Strengthens to Tropical Storm Bret

Former Tropical Depression Three strengthened to Tropical Storm Bret east of the Lesser Antilles on Monday afternoon. At 5:00 p.m. EDT on Monday the center of Tropical Storm Bret was located at latitude 11.3°N and longitude 42.2°W which put it about 1295 miles (2085 km) east of the Lesser Antilles. Tropical Storm Bret was moving toward the west at 21 m.p.h. (33 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 1008 mb.

Satellite images provided evidence that the circulation around former Tropical Depression Three strengthened on Monday afternoon and the National Hurricane Center upgraded the system to Tropical Storm Bret. The inner end of a rainband wrapped part of the way around the center of Tropical Storm Bret. Other bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center of Bret’s circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 45 miles (75 km) in the eastern side of Tropical Storm Bret. The winds on the western side of the circulation were blowing at less than tropical storm force.

Tropical Storm Bret will move through an environment favorable for intensification during the next 36 hours. Bret will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the axis of an upper level ridge over the tropical Atlantic Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Storm Bret will intensify during the next 36 hours. Bret could strengthen to a hurricane later this week.

Tropical Storm Bret will move south of a subtropical high pressure system over the Atlantic Ocean. The subtropical high will steer Bret toward the west during the next 36 hours. Bret could move more toward the west-northwest later this week. On its anticipated track, Tropical Storm Bret could approach the Lesser Antilles on Thursday. Bret could be a hurricane by that time. Planes are scheduled to start to fly reconnaissance missions into Tropical Storm Bret starting on Wednesday afternoon.

Tropical Depression Three Forms East of Lesser Antilles

Tropical Depression Three formed over the Atlantic Ocean east of the Lesser Antilles on Monday morning. At 11:00 a.m. EDT on Monday the center of Tropical Depression Three was located at latitude 11.0°N and longitude 40.3°W which put it about 1425 miles (2295 km) east of the Lesser Antilles. Tropical Depression Three was moving toward the west at 21 m.p.h. (33 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 1009 mb.

A circulation within a tropical wave previously designated as Invest 92L strengthened on Monday morning and the National Hurricane Center designated the system as Tropical Depression Three. More thunderstorms were developing near the center of Tropical Depression Three. Other 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 Three will move through an environment favorable for intensification during the next 36 hours. The tropical depression will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the axis of an upper level ridge over the tropical Atlantic Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Depression Three is likely to strengthen to a tropical storm during the next 24 hours. It could strengthen to a hurricane later this week.

Tropical Depression Three will move south of a subtropical high pressure system over the Atlantic Ocean. The subtropical high will steer the tropical depression toward the west during the next 36 hours. It could move more toward the west-northwest later this week. On its anticipated track, Tropical Depression Three could approach the Lesser Antilles on Thursday. It could be a hurricane by that time.

Potential Development over Tropical Atlantic

A tropical wave over the eastern Atlantic Ocean has the potential to develop into a tropical depression during the next few days. The tropical wave has been designated as Invest 92L. At 2:00 a.m. EDT on Saturday the center of Invest 92L was located at latitude 10.1°N and longitude 26.2°W which put it about 2265 miles (3655 km) east of the Lesser Antilles. The tropical wave was moving toward the west at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 25 m.p.h. (40 km/h) and there were wind gusts to 35 m.p.h. (55 km/h). The minimum surface pressure was 1011 mb.

The National Hurricane Center (NHC) indicated that there was a high probability (70%) a tropical wave over the eastern Atlantic Ocean will develop into a tropical depression during the next seven days. NHC designated the system as Invest 92L. The tropical wave was already exhibiting signs of organization on Saturday morning. Visible satellite images provided evidence of some rotation in the middle levels of the tropical wave. More thunderstorms were forming in bands associated with the tropical wave.

The tropical wave will move through an environment favorable for the formation of a tropical depression during the next few days. Invest 92L will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the axis of an upper level ridge over the tropical Atlantic Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Invest 92L is likely to develop into a tropical depression during the next few days.

The tropical wave will move south of a subtropical high pressure system over the Atlantic Ocean. The subtropical high will steer Invest 92L toward the west during the next few days. On its anticipated track, Invest 92L will move toward the Lesser Antilles.

Arlene Weakens to a Tropical Depression

Former Tropical Storm Arlene weakened to a tropical depression northwest of Cuba on Saturday. At 11:00 a.m. EDT on Saturday the center of Tropical Depression Arlene was located at latitude 24.2°N and longitude 85.1°W which put it about 145 miles (230 km) west-southwest of Dry Tortugas. Arlene was moving toward the south-southeast at 7 m.p.h. (11 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 1000 mb.

Former Tropical Storm Arlene weakened to a tropical depression over the Gulf of Mexico northwest of Cuba on Saturday morning. An upper level trough over the eastern Gulf of Mexico produced westerly winds that blew across the top of Arlene’s circulation. Those winds caused strong vertical wind shear. In addition, drier air was pulled into the circulation around former Tropical Storm Arlene. The combination of strong vertical wind shear and drier air caused many of the thunderstorms in Arlene’s circulation to weaken. Most of the bands revolving around the center of Tropical Depression Arlene consisted primarily of showers and lower clouds. There were still a few thunderstorms in bands on the eastern side of Arlene.

Tropical Depression Arlene will move through an environment that will be unfavorable for intensification during the next 24 hours. Arlene will move over water where the Sea Surface Temperatures are near 27˚C.’ However, the southern part of the upper level trough over the eastern Gulf of Mexico will continue to produce westerly winds that will blow toward the top of Arlene’s circulation. Those winds will keep causing the strong vertical wind shear. The drier air in the circulation around Arlene will continue to inhibit the formation of thunderstorms. The strong vertical wind shear and the drier air are likely to cause Tropical Depression Arlene to continue to weaken during the next 24 hours.

Tropical Depression Arlene will be south of a large surface high pressure system over the eastern U.S. The high pressure system will move south on Saturday and it will push Arlene toward the east-southeast. On its anticipated track Tropical Depression Arlene will move north of Cuba by Saturday evening.

Tropical Depression Two Strengthens to Tropical Storm Arlene

Former Tropical Depression Two strengthened to Tropical Storm Arlene over the eastern Gulf of Mexico on Friday afternoon. At 2:00 p.m. EDT on Friday the center of Tropical Storm Arlene was located at latitude 26.7°N and longitude 86.2°W which put it about 265 miles (425 km) west of Ft. Meyers, Florida. Arlene 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 1002 mb.

An Air Force Reserve Hurricane Hunter reconnaissance plane found sustained wind speeds to tropical storm force in the northeastern part of former Tropical Depression Two on Thursday afternoon and the National Hurricane Center upgraded the system to Tropical Storm Arlene. The distribution of thunderstorms in Tropical Storm Arlene was asymmetrical. Many of the thunderstorms were occurring in bands in the northeastern quadrant of Arlene’s circulation. Bands in the other parts of the tropical storm consisted primarily of showers and lower clouds. Storms near the center of Arlene generated upper level divergence that pumped mass away to the northeast of the tropical storm. Winds to tropical storm force extended out 65 miles (105 km) in the northeastern quadrant of Tropical Storm Arlene. The winds in the other parts of Arlene were blowing at less than tropical storm force.

Tropical Storm Arlene will move into an environment that will become unfavorable for intensification during the next 24 hours. Arlene will move over water where the Sea Surface Temperatures are near 27˚C. However, Tropical Storm Arlene will move under the southern part of an upper level trough over the eastern Gulf of Mexico. The upper level trough will produce westerly winds that will blow toward the top of Arlene’s circulation. Those winds will cause the vertical wind shear to increase. Drier air to the north and west of Tropical Storm Arlene will continue to inhibit the formation of thunderstorms in the western part of Arlene. The vertical wind shear and the drier air are likely to cause Tropical Storm Arlene to start to weaken during the next 24 hours.

Tropical Storm Arlene will be south of a large surface high pressure system over the eastern U.S. The high pressure system will move south on Friday and it will push Tropical Storm Arlene toward the south. On its anticipated track Tropical Storm Arlene will stay west of Florida. Arlene could move near the western end of Cuba by Saturday evening.

Tropical Depression Two Forms over Northeast Gulf of Mexico

Tropical Depression Two formed over the northeast Gulf of Mexico on Thursday afternoon. At 5:00 p.m. EDT on Thursday the center of Tropical Depression Two was located at latitude 28.0°N and longitude 86.6°W which put it about 250 miles (400 km) west of St. Petersburg, Florida. The tropical depression was moving toward the west-northwest at 2 m.p.h. (3 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 1007 mb.

Surface observations from buoys in the Gulf of Mexico and data acquired by a U.S. Air Force Hurricane Hunter reconnaissance plane indicated that a low pressure system over the northeast Gulf of Mexico had formed into a tropical depression on Thursday afternoon. Tropical Depression Two had a broad low level center of circulation. The distribution of thunderstorms in the tropical depression was asymmetrical. Many of the thunderstorms were occurring in bands in the eastern and northern part of Tropical Depression Two. Bands in the western and southern parts of the tropical depression consisted primarily of showers and lower clouds.

The surface center of Tropical Depression Two was slightly east of the axis of an upper level trough over the eastern Gulf of Mexico. The upper level trough was producing southwesterly winds that were blowing toward the top of the tropical depression. Those winds were causing vertical wind shear and the wind shear was contributing to the asymmetrical distribution of thunderstorms. In addition, drier air was north and west of Tropical Depression Two. The drier air was inhibiting the development of thunderstorms in the western part of the depression’s circulation.

Tropical Depression Two will be in an environment only marginally favorable for intensification during the next 24 hours. The tropical depression will be over water where the Sea Surface Temperatures are near 27˚C. However, the upper level trough over the eastern Gulf of Mexico will continue to cause vertical wind shear. The drier air will also continue to inhibit the formation of thunderstorms in the western part of the tropical depression. If the vertical wind shear does not get any stronger, then the tropical depression could strengthen to a tropical storm during the next 24 hours. On the other hand, if the wind shear increases, then the tropical depression could start to weaken.

Tropical Depression Two will be south of a large surface high pressure system over the eastern U.S. The steering currents will be weak during the next 12 hours and the tropical depression may not move much. The high pressure system will move south on Friday and it will start to push Tropical Depression Two toward the south. On its anticipated track Tropical Depression Two will stay southwest of Florida. It could move near the western end of Cuba by Saturday night.

Low Pressure System Develops over Gulf of Mexico

A weak low pressure system developed over the eastern Gulf of Mexico on Wednesday. The system was designated as Invest 91L by the National Hurricane Center. At 2:00 p.m. EDT on Wednesday the center of Invest 91L was located at latitude 26.4°N and longitude 85.9°W which put it about 275 miles (445 km) west of Naples, Florida. The low pressure system was nearly stationary. The maximum sustained wind speed was 25 m.p.h. (40 km/h) and there were wind gusts to 35 m.p.h. (55 km/h). The minimum surface pressure was 1009 mb.

A weak low pressure system developed over the eastern Gulf of Mexico on Wednesday and the system was designated as Invest 91L. The circulation around Invest 91L was not well organized. There was a broad counterclockwise rotation around the center of the low pressure system. At least one smaller center of rotation, that might have formed in a cluster of thunderstorms that dissipated on Tuesday night, was visible in the eastern side of the broader rotation. There were bands of showers and thunderstorms in the eastern and northern sides of the low pressure system. Bands in the western and southern parts of the system consisted primarily of lower clouds.

Invest 91L will be in an environment only marginally favorable for development of a tropical cyclone during the next 24 hours. The surface low pressure system will be over water where the Sea Surface Temperatures are near 27˚C. It will be under the eastern side of an upper level trough over the northeastern Gulf of Mexico. The upper level trough will produce southwesterly winds that will blow across the top of Invest 91L. Those winds will cause wind shear and the wind shear will inhibit the development of the surface low pressure system. There is also drier air over the northern Gulf of Mexico. The drier air will inhibit the formation of thunderstorms in the northern and western parts of Invest 91L. The National Hurricane Center is indicating that the probability is 20% that Invest 91L develops into a tropical cyclone during the next 48 hours. A reconnaissance plane is tentatively scheduled to investigate the system on Thursday afternoon, if necessary.

Invest 91L will continued to be under the eastern side of the upper level trough over the eastern Gulf of Mexico during the next 24 hours. The steering winds are weak under the upper level trough. So, Invest 91L could move with the upper level trough. The upper level trough is forecast to move slowly toward the east. Invest 91L could move slowly toward the southeast. If Invest 91L develops into a tropical cyclone with taller thunderstorms, then the winds in the middle troposphere could steer it more toward the north. Bands in the eastern side of the low pressure system are likely to bring locally heavy rain to parts of central and south Florida.

Tropical Cyclone Development Unlikely

The National Hurricane Center indicated on Monday that a strong extratropical cyclone over the Atlantic Ocean south of Nova Scotia is unlikely to make a transition to a tropical cyclone. At 1:00 p.m. EST on Monday the center of the extratropical cyclone was located at latitude 37.8°N and longitude 63.8°W which put it about 460 miles (745 km) south of Halifax, Nova Scotia. The extratropical cyclone was moving toward the north-northeast at 10 m.p.h. (16 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 986 mb.

The National Hurricane Center (NHC) issued a special Tropical Weather Outlook on Monday morning for a strong extratropical cyclone over the Atlantic Ocean south of Nova Scotia. NHC indicated in the Tropical Weather Outlook that it was unlikely the extratropical cyclone would make a transition to a tropical cyclone or a subtropical cyclone. The extratropical cyclone was subsequently designated at Invest 90L.

A circular area of showers and thunderstorms developed at the center of a large, occluded extratropical cyclone south of Nova Scotia on Monday. A clear circular area was visible at the center of the area of showers and thunderstorms on satellite images. The clear area resembled the appearance of an eye in a tropical cyclone. The thunderstorms did not extend high into the troposphere because the center of the extratropical cyclone was over water where the Sea Surface Temperatures are near 20˚C. The circular area of showers and thunderstorms in the middle of the extratropical cyclone was surrounded by a large area of cold, dry air. Bands of low clouds and showers were occurring in the cold, dry air. The extratropical cyclone was producing a large area of winds to tropical storm force.

The extratropical cyclone will move through an area that is only marginally favorable for a transition to a subtropical cyclone or a tropical cyclone. The extratropical cyclone will move over over water where the Sea Surface Temperatures are colder than 20˚C. It will move under the eastern part of an upper level low south of Nova Scotia. The upper level low will produce southerly winds that will blow toward the top of the extatropical cyclone. However, the upper level low is almost stacked vertically with the surface low pressure systems. So, the winds at different levels of the atmosphere are similar and there will be little vertical wind shear. Cold, dry air will continue to surrounded the circular area of thunderstorms at the center of the extratropical cyclone. Cold Sea Surface Temperatures and cold, dry air around the area of thunderstorms will inhibit a transition to a subtropical cyclone. There is a slight chance the extratropical cyclone could make a transition to a subtropical cyclone during the next 24 hours before it moves over even colder water.

The upper level low will steer the extratropical cyclone toward the north during the next 24 hours. On its anticipated track the extratropical cyclone could reach Nova Scotia on Tuesday. It will bring gusty winds and locally heavy rain to Nova Scotia.

Possible Subtropical Development Southeast of Bermuda

A low pressure system southeast of Bermuda could develop into a subtropical storm during the next few days. At 9:00 a.m. EST on Monday the center of the low pressure system was located at latitude 24.0°N and longitude 55.0°W which put it about 855 miles (1380 km) southeast of Bermuda. The low pressure system was moving toward the north 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 1005 mb.

A low pressure system southeast of Bermuda has the potential to develop into a subtropical storm this week. There is already a strong surface circulation around the low pressure system. The surface low pressure system is located northeast of an upper level low. Bands of showers and thunderstorms were occurring in the northern and eastern parts of the surface low pressure system. Bands in the southern and western parts of the surface low consisted primarily of showers and lower clouds.

The low pressure system southeast of Bermuda will move through an environment somewhat favorable for the development of a subtropical storm during the next 48 hours. The low pressure system will move over water where the Sea Surface Temperatures are near 26˚C. It will move under the northeastern part of an upper level low. The upper level low will produce southeasterly winds that will blow across the top of the surface low. Those winds will cause some vertical wind shear. The vertical wind shear will likely make the environment unfavorable for the development of a tropical storm. However, the wind shear may be weak enough to allow for the surface low to make a transition to a subtropical storm. The National Hurricane Center is indicating there is a probability of 40% that the surface low pressure system develops into a subtropical storm during the next five days.

The upper low will steer the surface low pressure system slowly toward the northwest during the next 48 hours. On its anticipated track the surface low pressure system will remain far to the southeast of Bermuda.

Tropical Depression Nicole Drops Heavy Rain over Southeast U.S.

Tropical Depression Nicole dropped heavy rain over parts of the southeastern U.S. on Friday morning. At 10:00 a.m. EST on Friday the center of Tropical Depression Nicole was located at latitude 34.2°N and longitude 84.3°W which put it about 35 miles (55 km) north of Atlanta, Georgia. Nicole was moving toward the north-northeast at 23 m.p.h. (37 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 1001 mb.

Tropical Storm Nicole dropped heavy rain over parts of the southeastern U.S. on Friday morning. Heavy rain was falling over eastern Tennessee and eastern Kentucky. Bands in the far eastern side of Nicole’s circulation contained thunderstorms that were dropping heavy rain over parts of eastern South Carolina, eastern North Carolina and southeastern Virginia. Easterly winds blowing around the northern side of Nicole’s circulation were enhancing convergence and rising motion ahead of a cold front moving toward the eastern U.S. The enhanced convergence and rising motion was contributing to rain that was falling in the region from Delaware to Ohio.

The cold front approaching the eastern U.S. and an upper level trough over the central U.S. will steer Tropical Depression Nicole quickly toward the north-northeast during Friday. On its anticipated track the center of Tropical Depression Nicole will be over West Virginia by Friday evening. Heavy rain falling over parts of the southeastern U.S. and Appalachians could cause flooding. Flood Watches were in effect for parts of northern South Carolina, western North Carolina and southern Virginia. There could be enough low level wind shear for tornadoes to develop in the bands on the far eastern side of the circulation around Tropical Depression Nicole. A Tornado Watch was in effect for eastern South Carolina, eastern North Carolina and southeastern Virginia.