Category Archives: Atlantic, Caribbean, and Gulf of Mexico

Atlantic TCs

Tropical Depression Three Strengthens Into Tropical Storm Cristobal

Former Tropical Depression Three strengthened into Tropical Storm Cristobal on Tuesday.  At 12:15 p.m. EDT on Tuesday the center of Tropical Storm Cristobal was located at latitude 19.3°N and longitude 92.7°W which put it about 75 miles (120 km) northwest of Ciudad del Carmen, Mexico.  Cristobal was moving toward the southwest at 3 m.p.h. (5 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 1004 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Campeche to Puerto de Veracruz, Mexico

An Air Force Reserve Hurricane Hunter plane investigating former Tropical Depression Three on Tuesday found sustained winds of 40 m.p.h. (65 km/h) and the National Hurricane Center designated the system as Tropical Storm Cristobal.  The formation of Tropical Storm Cristobal on June 2 is the earliest date for the formation on the third named storm over the Atlantic Basin (including the Caribbean Sea and Gulf of Mexico) in the historical record.

The reconnaissance plane found that the circulation around Tropical Storm Cristobal was continuing to get better organized.  More thunderstorms were forming near the center of circulation.  Bands of showers were revolving around the center of Cristobal.  Storms near the center were generating upper level divergence which was pumping mass away to the east of the tropical storm.  Winds to tropical storm force extended out 40 miles (65 km) from the center of circulation.

Tropical Storm Cristobal will move through an environment favorable for intensification during the next 12 to 24 hours.  Cristobal will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western side of an upper level ridge centered over the western Caribbean Sea.  The ridge will produce southerly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will not be great enough to prevent intensification.  Tropical Storm Cristobal is likely to strengthen during the next 12 to 24 hours.

Tropical Storm Cristobal will move around the northwestern part of a larger counterclockwise circulation sometimes called a Central American Gyre (CAG).  The CAG will steer Cristobal toward the southwest during the next few hours.  Tropical Storm Cristobal will move more toward the south on Tuesday night.  The larger CAG will slowly contract around the circulation of Cristobal during the next several days.  Tropical Storm Cristobal will meander slowly near the south coast of the Bay of Campeche while the CAG contracts.  Eventually, a subtropical high pressure system over the western Atlantic Ocean will steer Cristobal northward toward the U.S.

Tropical Storm Cristobal will mix cooler water to the surface while it meanders over the southern Bay of Campeche.  The cooler water will reduce the energy available to Cristobal and the tropical storm could weaken during the middle of the week.  Tropical Storm Cristobal will weaken even more if the center of circulation moves over land.  Cristobal will drop heavy rain over Campeche, Tabasco and eastern Veracruz.  Prolonged heavy rain is likely to cause flash floods in some locations.

Tropical Depression Three Develops Over Bay of Campeche

Tropical Depression Three developed over the Bay of Campeche on Monday afternoon.  At 5:00 p.m. EDT on Monday the center of Tropical Depression Three was located at latitude 19.6°N and longitude 91.2°W which put it about 55 miles (90 km) north-northeast of Carmen, Mexico.  The depression was moving toward the west-northwest at 7 m.p.h. (11 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.

The government of Mexico issued a Tropical Storm Warning for the portion of the coast from Campeche to Puerto de Veracruz.  

The remnants of the center of circulation of former Tropical Storm Amanda moved northward across Honduras and emerged over the eastern Bay of Campeche on Monday afternoon.  The National Hurricane Center designated the system as Tropical Depression Three and initiated advisories on the system.

More thunderstorms began to form on the northern side of Tropical Depression Three after the center of circulation moved over the eastern Bay of Campeche.  More thunderstorms were developing near the center.  Bands of showers and thunderstorms that included the remnants of the the circulation of former Tropical Storm Amanda were revolving around the center of the depression.

Tropical Depression Three will move through an environment favorable for intensification during the next 24 hours.  The depression will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western side of an upper level ridge over the northwestern Caribbean Sea.  The ridge will produce northerly winds which will blow toward the top of the depression.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Depression Three is likely to intensify into a tropical storm on Tuesday.

Tropical Depression Three will move around the northern side of a larger counterclockwise circulation sometimes called a Central American Gyre (CAG).  The CAG will steer the depression toward the west-northwest during the next 12 to 24 hours.   The depression could move toward the southwest on Tuesday when it moves around the northwestern part of the CAG.  On its anticipated track Tropical Depression Three could approach the coast around the southern Bay of Campeche.   The depression could drop heavy rain over Campeche, Tabasco and eastern Veracruz.  The heavy rain could cause flash floods in some locations.

Tropical Storm Bertha Brings Wind and Rain to the Carolinas

Tropical Storm Bertha brought wind and rain to the Carolinas on Wednesday.  Bertha weakened to a tropical depression after it moved inland on Wednesday afternoon.  At 11:00 p.m. EDT on Wednesday the center of Tropical Depression Bertha was located at latitude 36.0°N and longitude 80.5°W which put it about 40 miles (65 km) west of Greensboro, North Carolina.  Bertha was moving toward the north 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 1009 mb.

Flash Flood Watches were in effect for northeast South Carolina, southern and west central North Carolina, southwest Virginia and southwest West Virginia.

Tropical Storm Bertha developed rapidly on Wednesday morning and it was still strengthening when it made landfall on the coast of South Carolina.  The center of Bertha officially made landfall east of Charleston near Mount Pleasant around midday on Wednesday.  NOAA buoy 41004 which is located southeast of Charleston measured a sustained wind speed of 40 m.p.h (65 km/h) and a gust of 58 m.p.h. (94 km/h).  NOAA buoy 41029 (Capers Nearshore) measured a surface pressure of 1005.8 mb when the center of Bertha passed near it.

A weather station at Shaw Air Force Base measured 2.00 inches (51 mm)  of rain.  A weather station in downtown Charleston, South Carolina measured 1.61 inches (41 mm).  Charlotte, North Carolina received 1.64 inches (42 mm), Greensboro received 1.09 inches (28 mm) and Winston Salem received 1.04 inches (26 mm).

Tropical Depression Bertha will move around the western end of a surface high pressure system over the Atlantic Ocean.  The high will steer Bertha toward the north on Thursday.  On its anticipated track Tropical Depression Bertha will move across western Virginia, West Virginia, eastern Ohio and western Pennsylvania.  Bertha will drop rain over those areas on Thursday.  Locally heavy rain could cause flooding in some locations.

Storm Storm Bertha Forms Near South Carolina

Tropical Storm Bertha formed quickly near the coast of South Carolina on Wednesday morning.  At 8:00 a.m. EDT on Wednesday the center of Tropical Storm Bertha was located at latitude 32.7°N and longitude 79.4°W which put it about 30 miles (50 km) east-southeast of Charleston, South Carolina.  Bertha was moving toward the northwest at 9 m.p.h. (15 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 1009 mb.

The National Hurricane Center issued a Tropical Storm Warning for the portion of the coast from Edisto Beach to South Santee River, South Carolina.

The circulation around a low pressure system off the southeast coast of the U.S. organized quickly on Wednesday morning.  A distinct center of circulation was evident on radar.  Radar and satellite images also showed bands of showers and thunderstorms revolving around the center of circulation.  NOAA buoy 41004 southeast of Charleston, South Carolina measured a sustained wind speed of 40 m.p.h. (65 km/h) and a gust to 58 m.p.h. (94 km/h).  Based on all of that information the National Hurricane Center designated the system as Tropical Storm Bertha.

Tropical Storm Bertha will move around the western end of a high pressure system over the Atlantic Ocean.  The high will steer Bertha toward the north during the next 24 hours.  On its anticipated track Tropical Storm Bertha will make landfall on the coast of South Carolina east of Charleston later on Wednesday.  Bertha will move over water where the Sea Surface Temperature is near 24°C.  It will move under the western side of an upper level ridge over the western Atlantic Ocean.  The ridge will produce southerly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear.  Based on recent trends Tropical Storm Bertha could strengthen before it makes landfall.  Bertha will drop heavy rain over eastern South Carolina and eastern North Carolina.  The heavy rain could cause floods in some locations.  Waves will cause erosion along the coast of South Carolina and North Carolina.

Tropical Storm Arthur Brings Wind and Rain to Eastern North Carolina

Tropical Storm Arthur brought wind and rain to eastern North Carolina on Monday.  At 8:00 a.m. EDT on Monday the center of Tropical Storm Arthur was located at latitude 34.5°N and longitude 75.9°W which put it about 50 miles (80 km) south-southwest of Cape Hatteras, North Carolina.  Arthur was moving toward the north-northeast at 15 m.p.h. (24 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.

A Tropical Storm Warning was in effect for the portion of the coast from Surf City to Duck, North Carolina including Pamlico and Albemarle Sounds.

Tropical Storm Arthur began to move more quickly toward the Outer Banks of North Carolina on Monday morning.  The distribution of thunderstorms and winds around Arthur was asymmetric.  The strong thunderstorms were occurring in bands in the eastern half of the circulation.  The strongest winds were occurring in those bands.  Bands in the western half of Tropical Storm Arthur consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 90 miles (145 km) in the eastern half of Arthur.  The winds in the western half of Arthur were mostly less than tropical storm force.

The asymmetric structure of Tropical Storm Arthur meant that the strongest winds were occurring east of the Outer Banks of North Carolina.  A buoy at Diamond Shoals was reporting a sustained wind speed of 33 m.p.h. (54 km/h) and wind gusts to 47 m.p.h. (76 km/h).  The wind speeds along the coast of North Carolina were much weaker.  Tropical Storm Arthur was dropping moderate rain over eastern North Carolina.   Wind blowing water toward the coast was causing the water level to rise in some locations.  Waves were causing erosion on some beaches.

A large upper level trough will approach Tropical Storm Arthur from the west.  The trough will turn Arthur more toward the east later on Monday.  On its anticipated track, Tropical Storm Arthur should move away from North Carolina on Monday afternoon.  Weather conditions should improve gradually when Arthur moves farther form the coast.

Tropical Storm Arthur Prompts Warning for North Carolina

Tropical Storm Arthur prompted the National Hurricane Center to issue a Tropical Storm Warning for a portion of the coast of North Carolina.  A Tropical Storm Warning was in effect for the portion of the coast from Surf City to Duck, North Carolina including Pamlico and Albemarle Sounds.

At 11:00 a.m. EDT on Sunday the center of Tropical Storm Arthur was located at latitude 30.5°N and longitude 77.4°W which put it about 345 miles (560 km) south-southwest of Cape Hatteras, North Carolina.  Arthur was moving toward the north-northeast at 9 m.p.h. (15 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. (96 km/h).  The minimum surface pressure was 1002 mb.

The circulation around Tropical Storm Arthur exhibited more organization on Sunday morning.  Several bands of showers and thunderstorms were wrapping around the eastern and northern parts of the circulation.  Bands on the western side of Arthur still consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 115 miles (185 km) from the center of circulation on the eastern side of Tropical Storm Arthur.  The winds on the western side of Arthur were mostly below tropical storm force.

Tropical Storm Arthur will move through an environment favorable for intensification during the next 24 hours.  Arthur will move over water where the Sea Surface Temperature is near 25°C.  It will move under an upper level ridge centered off the southeast coast of the U.S.  The winds in the upper ridge are relatively weak and there will not be a lot of vertical wind shear.  Tropical Storm Arthur is likely to get stronger during the next 24 hours.

Tropical Storm Arthur will move around the western end of a high pressure system during the next 24 hours.  The ridge will steer Arthur toward the north-northeast during the next day or so.  A large upper level trough over the central U.S. will approach Tropical Storm Arthur on Monday.  The trough will steer Arthur more toward the east.  On its anticipated track Tropical Storm Arthur will approach the coast of North Carolina on Monday.  Arthur will bring gusty winds to the coast.  Wind blowing toward the shore will cause the water level to rise.  Waves will cause beach erosion.

Tropical Depression One Strengthens Into Tropical Storm Arthur

Tropical Depression One strengthened into Tropical Storm Arthur on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Arthur was located at latitude 29.4°N and longitude 77.7°W which put it about 420 miles (675 km) south-southwest of Cape Hatteras, North Carolina.  Arthur was moving toward the north-northeast 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 1006 mb.

A Tropical Storm Watch remains in effect for the portion of the coast from Surf City to Duck, North Carolina including Pamlico and Albemarle Sounds.

Surface observations and data from aircraft reconnaissance indicated that Tropical Depression One strengthened on Saturday night and the National Hurricane Center designated the system as Tropical Storm Arthur.  Thunderstorms continued to develop near the center of circulation and storms near the center generated upper level divergence which pumped mass away to the east of the depression.  Bands of showers and thunderstorms were developing.  The strongest bands were in the eastern half of the circulation.  Winds to tropical storm force extended out 80 miles (130 km) from the center in the eastern side of Tropical Storm Arthur.  Most of the winds in the western side of the circulation were less than tropical storm force.

Tropical Storm Arthur will move through an environment favorable for intensification during the next 24 hours.  Arthur will move over water where the Sea Surface Temperature is near 25°C.  An upper level trough over the eastern Gulf of Mexico and an upper level ridge east of Florida will interact to produce southerly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear but the shear will not be strong enough to prevent intensification.  Tropical Storm Arthur will strengthen on Sunday.

The upper level trough and upper level ridge will steer Tropical Storm Arthur toward the north-northeast during the next 36 to 48 hours.  On its anticipated track Tropical Storm Arthur will approach the coast of North Carolina on Monday.  It will bring gusty winds and heavy rain to parts of the coast.  Wind blowing water toward the coast will cause the water level to rise and there will be erosion of the beaches.

Tropical Depression One Forms East of Florida

Tropical Depression One formed east of Florida on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Depression One was located at latitude 28.4°N and longitude 78.6°W which put it about 125 miles (200 km) east of Melbourne, Florida.  The depression was moving toward the north-northeast at 13 m.p.h. (20 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 1008 mb.

A Tropical Storm Watch was issued for the portion of the coast from Surf City to Duck, North Carolina including Pamlico and Albemarle Sounds.

Surface observations and data from aircraft reconnaissance indicated that a distinct low pressure system formed east of Florida on Saturday and the National Hurricane Center designated the system as Tropical Depression One.  More thunderstorms developed near the center of circulation.  Storms near the center began to generate upper level divergence which pumped mass away to the east of the depression.  The strongest winds were occurring in the inner part of the circulation, which was consistent with the typical structure of a tropical cyclone.  Bands of showers and thunderstorms were developing.  The strongest bands were in the eastern half of the circulation.

Tropical Depression One will move through an environment favorable for intensification during the next several days.  The depression will move over water where the Sea Surface Temperature is near 25°C.  An upper level trough over the eastern Gulf of Mexico and an upper level ridge east of Florida will interact to produce southerly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear but the shear will not be strong enough to prevent intensification.  Tropical Depression One will strengthen into a tropical storm.

The upper level trough and upper level ridge will steer Tropical Depression One toward the north-northeast during the next 36 to 48 hours.  On its anticipated track Tropical Depression One will approach the coast of North Carolina on Monday.  It will be a tropical storm by that time.  It will bring gusty winds and heavy rain to parts of the coast.  Wind blowing water toward the coast will cause the water level to rise and there will be erosion of the beaches.

Disturbance South of Florida Keys

A disturbance south of the Florida Keys is currently designated at Invest 90L.  The disturbance could develop into a tropical or subtropical cyclone during the next few days.  At 8:00 p.m. EDT on Thursday the center of Invest 90L was located at latitude 23.9°N and longitude 81.2°W which put it about 55 miles (85 km) south of Marathon, Florida.  It was moving toward the east-northeast at 5 m.p.h. (8 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 1013 mb.

A small trough in the middle troposphere moved over a stationary front south of the Florida Keys on Thursday.  Satellite images and radar loops detected rotation in the middle troposphere.  There was a broad counterclockwise rotation south of the Keys and radar loops also revealed several small counterclockwise rotations within the broader mid-level circulation.  However, there did not appear to be a distinct center of circulation with lower pressure at the surface.

Invest 90L is forecast to move toward the northeast during the next several days.  It will move into an environment more favorable for development into a tropical or subtropical cyclone.  Invest 90L will move over water where the Sea Surface Temperature is near 27°C.  There will be an upper level trough over the eastern Gulf of Mexico, but a small upper level ridge will develop east of Florida.  The combination of the upper level trough and the upper ridge will produce a region of upper level divergence east of Florida.  The upper level divergence will pump mass away and the surface pressure will decrease in that area.  A surface low pressure system is likely to form on Friday or Saturday.  The National Hurricane Center is indicating that there is an 80% probability of the formation of a tropical or subtropical cyclone.  A reconnaissance plane is tentatively scheduled to investigate the system on Friday afternoon, if necessary.

Possible Development Near the Bahamas

A low pressure system could develop near the Bahamas on Friday or Saturday.  The National Hurricane Center is indicating that there is a 70% probability that the low pressure system could develop into a subtropical cyclone.

A stationary frontal boundary extends from south of Florida across the Bahamas.  A small upper level trough called a shortwave over the southwestern U.S. will move east toward the stationary front later this week.  When the upper level trough approaches the stationary front, a low pressure system is likely to develop near the Bahamas.  If thunderstorms develop near the center of the low pressure system, then it could exhibit the structure of a tropical or subtropical cyclone.  The Sea Surface Temperature near the Bahamas is near 26°C.  So, the water will be warm enough to support the development of a tropical cyclone.  However, the winds blowing around the upper level trough will cause moderate vertical wind shear.  The wind shear may be strong enough to inhibit the development of a tropical cyclone.  However, the shear may not be strong enough to prevent the development of a subtropical cyclone.  If the low pressure system strengthens into a subtropical storm, it will be designated Subtropical Storm Arthur.