Tag Archives: South Carolina

Humberto Strengthens Into a Hurricane

Former Tropical Storm Humberto strengthened into a hurricane on Sunday evening.  At 11:00 p.m. EDT on Sunday the center of Hurricane Humberto was located at latitude 29.4°N and longitude 77.6°W which put it about 785 miles (1260 km) west of Bermuda.  Humberto was moving toward the northeast at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 988 mb.

Former Tropical Storm Humberto strengthened steadily on Sunday and the circulation exhibited greater organization.  The inner end of a rainband wrapped around the center of circulation and an eye appeared to be developing.  There was a broken ring of thunderstorms around the developing eye and the strongest winds were occurring in the eastern side of the ring.  Bands of showers and thunderstorms were revolving around the core of Hurricane Humberto.  There were more rainbands in the eastern half of the circulation.  Winds to hurricane force extended out about 25 miles (40 km) from the center of circulation.  Wind to tropical storm force extended out about 150 miles (240 km) on the eastern side of Humberto and out about 70 miles (110 km) on the western side.

Hurricane Humberto will move through an environment favorable for intensification during the next two to three days.  Humberto will move over water where the Sea Surface Temperature is near 29°C.  Am upper level trough over the eastern U.S. will produce southwesterly winds which will cause some vertical wind shear.  However, the shear will not be strong enough to prevent intensification.  Hurricane Humberto will intensify during the next 24 to 48 hours and it could strengthen into a major hurricane.

Hurricane Humberto moved around the western end of a subtropical high pressure system over the western Atlantic Ocean.  Humberto will move slowly toward the northeast on Monday.  The upper level trough and the subtropical high will combine to steer Humberto toward the east during the next few days.  On its anticipated track Hurricane Humberto could approach Bermuda by late on Wednesday.

Tropical Storm Humberto Develops East of the Bahamas

Former Tropical Depression Nine strengthened into Tropical Storm Humberto east of the Bahamas on Friday night.  At 11:00 p.m. EDT on Friday night the center of Tropical Storm Humberto was located at latitude 25.6°N and longitude 75.2°W which put it about 130 miles (210 km) east-southeast of Great Abaco, Bahamas.  Humberto was moving toward the northwest at 6 m.p.h. (10 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 1008 mb.

Tropical Storm Warnings were in effect for the Abacos, the Berry Islands, Bimini, Eleuthera, Grand Bahama Island and New Providence.

A NOAA research aircraft flying through former Tropical Depression Nine on Friday night determined that the depression had strengthened into Tropical Storm Humberto.  The aircraft reported that the maximum sustained wind speed had increased to 40 m.p.h. (65 km/h).  The circulation around Tropical Storm Humberto was still poorly organized.  A few thunderstorms developed just to the north of the center of circulation.  A band of showers and thunderstorms curved around the eastern side of the circulation.  Bands in the other parts of Tropical Storm Humberto consisted primarily of showers and lower clouds.

Tropical Storm Humberto will move through an environment somewhat favorable for intensification during the next few days.  Humberto will move over water where the Sea Surface Temperature is near 29°C.   A large upper level low over the Gulf of Mexico will produce southerly winds which will blow toward the top of the tropical storm. Those winds will cause moderate vertical wind shear and they will inhibit intensification.  The upper low is forecast to move westward away from Humberto and the wind shear could decrease during the weekend. Tropical Storm Humberto is forecast to slowly become more organized and it could strengthen into a hurricane.

The upper low over the Gulf of Mexico will help to steer Tropical Storm Humberto toward the northwest during the next day or two.  A strong upper level trough over the Great Lakes will start to turn Humberto toward the east later in the weekend.  On its anticipated track the center of Tropical Storm Humberto could move near the Northwestern Bahamas.  If Humberto brings wind and rain to that region, it will hinder efforts to recover from Hurricane Dorian.

Tropical Depression Nine Develops Near the Bahamas

Tropical Depression Nine developed near the Bahamas on Friday afternoon.  At 5:00 p.m. EDT on Friday the center of Tropical Depression Nine was located at latitude 25.6°N and longitude 75.0°W which put it about 140 miles (225 km) east-southeast of Great Abaco, Bahamas.  It was moving toward the northwest at 8 m.p.h. (13 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.

Tropical Storm Warnings were in effect for the Abacos, the Berry Islands, Bimini, Eleuthera, Grand Bahama Island and New Providence.  A Tropical Storm Watch was in effect for the portion of the Florida coast from Jupiter Inlet to the Volusia/Brevard County Line.

An Air Force Reserve Hurricane Hunter plane was able to identify a low level center of circulation in a tropical disturbance near the Bahamas on Friday afternoon and the National Hurricane Center designated the system as Tropical Depression Nine.  The center of circulation developed on the southwestern side of a cluster of thunderstorms just east of the Bahamas.  The circulation around the depression was still in the early stages of organization.  Most of the stronger thunderstorms were occurring in the eastern half of the tropical depression.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.

Tropical Depression Nine will move through an environment somewhat favorable for intensification during the next few days.  The tropical depression will move over water where the Sea Surface Temperature is near 29°C.  A large upper level low over the Gulf of Mexico will produce southerly winds which will blow toward the top of the depression.  Those winds will cause moderate vertical wind shear and they will inhibit intensification.  The upper low is forecast to move westward away from the  tropical depression and the wind shear could decrease during the weekend.  Tropical Depression Nine is forecast to slowly become more organized and it could strengthen into a tropical storm.

The upper low over the Gulf of Mexico will help to steer Tropical Depression Nine toward the northwest during the next day or two.  A strong upper level trough over the Great Lakes will start to turn the depression toward the east later in the weekend.  On its anticipated track the center of the depression could move near the Northwestern Bahamas.  If Tropical Depression Nine brings wind and rain to that region, it will hinder efforts to recover from Hurricane Dorian.

Tropical Storm Warnings Issued for Northwestern Bahamas

The government of the Bahamas issued Tropical Storm Warnings for the Northwestern Bahamas on Friday afternoon.  Tropical Storm Warnings were issued for the Abacos, Berry Islands, Bimini, Eleuthera, Grand Bahama Island and New Providence.  A tropical disturbance over the Southeastern Bahamas was forecast to strengthen into a tropical storm, which prompted the issuance of the Tropical Storm Warnings.  The National Hurricane Center (NHC) initiated advisories on the disturbance at 5:00 p.m. EDT on Thursday and NHC designated the system at Potential Tropical Cyclone Nine.

At 5:00 p.m. EDT on Thursday the broad center of Potential Tropical Cyclone Nine was located at latitude 23.7°N and longitude 74.8°W which put it about 235 miles (380 km) southeast of Great Abaco.  It was moving toward the northwest at 8 m.p.h. (13 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 1008 mb.

The circulation around Potential Tropical Cyclone Nine was very poorly organized.  There was a very broad center around which the air was turning cyclonically.  An Air Force Reserve Hurricane Hunter reconnaissance plane was finding weak winds near the broad center.  Most of the strong thunderstorms were northeast of the broad center of the disturbance.  The stronger winds here occurring near those thunderstorms.  There did not appear to be any significant banding of the showers and thunderstorms.

A large upper level low over the Gulf of Mexico was producing moderate southerly winds which were blowing across the western side of Potential Tropical Cyclone Nine.  Those winds were causing moderate vertical wind shear.  A small upper level ridge was developing between the upper low over the Gulf and another smaller upper low near Bermuda.  Winds were weaker under the ridge and that was the likely reason the stronger thunderstorms were in the northeastern part of the disturbance.  It is possible that a new center of circulation could develop near one of the clusters of thunderstorms.

Potential Tropical Cyclone Nine will move through an area somewhat favorable for intensification.  It will move over water where the Sea Surface Temperature is near 29°C.  The upper low over the Gulf of Mexico is forecast to move westward which would cause the vertical wind shear to decrease.  If the shear decreases, then a distinct low level center of circulation could develop.  If a distinct center forms, then the system would be designated as a tropical depression.  Potential Tropical Cyclone Nine has the potential to strengthen into a tropical storm during the next 24 to 48 hours.

The future track of Potential Tropical Cyclone Nine will depend on the place where a center of circulation forms and how strong the system becomes.  A stronger tropical cyclone would be steered by winds higher in the atmosphere.  If Potential Tropical Cyclone Nine strengthens significantly then the upper level low over the Gulf of Mexico and the developing upper level ridge will combine to the system toward the northwest during the next day or two.  A cold front moving southeast across the Great Lakes and Ohio River Valley could turn the system toward the northeast later in the weekend.  Under that scenario Potential Tropical Cyclone Nine would move across the Northwestern Bahamas on Friday.  It could approach southeast Florida on Saturday.

On the other hand, if Potential Tropical Cyclone Nine does not develop, or if it remains a weak tropical cyclone, then it would be steered by winds lower in the atmosphere.  In that case the system could be steered more toward the west-northwest and it could move across Florida into the Gulf of Mexico.   The guidance from numerical models is very divergent about the predicted future track of Potential Tropical Cyclone Nine.  In any case the system will bring some wind and rain to the Northwestern Bahamas and that will hinder efforts to recover from Hurricane Dorian.

Hurricane Dorian Brings Wind and Rain to the Carolinas

Hurricane Dorian brought wind and rain to the Carolinas on Thursday while the center move just off the coast.  At 11:00 p.m. EDT on Thursday the center of Hurricane Dorian was located at latitude 33.6°N and longitude 77.4°W which put it about 70 miles southwest of Cape Lookout, North Carolina.  Dorian was moving toward the northeast at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 958 mb.

A Hurricane Warning was in effect for the portion of the coast from Edisto Beach, South Carolina to the North Carolina/Virginia border including Albemarle and Pamlico Sounds. Tropical Storm Warnings were in effect for the portion of the coast from the North Carolina/Virginia border to Fenwick Island, Delaware, for Chesapeake Bay south of Drum Point and for the Tidal Potomac south of Cobb Island. A Tropical Storm Warning was in effect for the portion of the coast from Woods Hole to Sagamore Beach, Massachusetts including Martha’s Vineyard and Nantucket. A Hurricane Watch has been issued for all of Nova Scotia. Tropical Storm Watches have been issued for Prince Edward Island, for the Magdalen Islands and for New Brunswick from Fundy National Park to Shediac. A Tropical Storm Watch was issued for Newfoundland from Francois to Boat Harbor.

Hurricane Dorian weakened very slowly on Thursday while the center of circulation moved just off the coast.  The pressure remained nearly steady around 958 mb.  A circular eye with a diameter of 35 miles (55 km) was at the center of circulation.  A ring of thunderstorms surrounded the eye and the strongest winds were in that ring of storms.  Winds to hurricane force extended out about 60 miles (95 km) from the center of Hurricane Dorian.  Winds to tropical storm force extended out about 220 miles (330 km) from the center.

The core of Hurricane Dorian with the strongest winds remained over the Atlantic Ocean.  Numerous location along the coast of South Carolina and North Carolina reported winds to topical storm force.  Rainbands rotating around the northern half of Dorian dropped locally heavy rain over coastal areas of South Carolina and North Carolina.  Thunderstorms in some of the bands generated tornadoes and there were scattered reports of wind damage.  Hurricane Dorian caused a storm surge of 4 to 7 feet (1.3 to 2.3 meters) along the coast.

An upper level trough over the eastern U.S. began to steer Hurricane Dorian toward the northeast.  Dorian began to move faster later on Thursday.  The upper level trough will steer Hurricane Dorian rapidly toward the northeast during the next few days.  On its anticipated track Dorian will bring wind and rain to eastern North Carolina on Friday.  Dorian will also cause a storm surge along the coast.  Hurricane Dorian will pass southeast of New England on Friday night.  Dorian will bring wind and rain to the Canadian Maritime provinces and Newfoundland during the weekend.

Major Hurricane Dorian Moves Toward the Carolinas

Major Hurricane Dorian moved toward the Carolinas on Wednesday night.  At 11:00 p.m. EDT on Wednesday the center of Hurricane Dorian was located at latitude 31.3°N and longitude 79.6°W which put it about 105 miles (170 km) south of Charleston, South Carolina.  Dorian was moving toward the north at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 115 m.p.h. (195 km/h) and there were wind gusts to 140 m.p.h. (220 km/h).  The minimum surface pressure was 955 mb.

A Hurricane Warning was in effect for the portion of the coast from Savannah River, Georgia to the North Carolina/Virginia border including Albemarle and Pamlico Sounds.  A Hurricane Watch was in effect for the portion of the coast from the mouth of the St. Mary’s River, Florida to Savannah River, Georgia.  Tropical Storm Warnings were in effect for the portions of the coast from the mouth of the St. Mary’s River to Savannah River, Georgia and from the North Carolina/Virginia border to Chincoteague, Virginia.  A Tropical Storm Warning was also in effect for Chesapeak Bay south of Smith Point.  Tropical Storm Watches were in effect for the portion of the coast from Chincoteague, Virginia to Fenwick Island, Delaware, for Chesapeake Bay from Smith Point to Drum Point and for the Tidal Potomac south of Cobb Island.

Hurricane Dorian strengthened back into a major hurricane on Wednesday night as it moved over the warm water in the Gulf Stream.  A large eye with a diameter of 45 miles (75 km) became more circular and symmetrical.  The ring of thunderstorms surrounding the eye became continuous and a little thicker.  The strongest winds were occurring in that ring of storms.  Other bands of showers and thunderstorms revolving around the core of Hurricane Dorian also got stronger.  Storms around the core of Dorian generated upper level divergence which pumped mass away from the hurricane and the surface pressure decreased.

The circulation around Hurricane Dorian increased in size on Wednesday.  Winds to hurricane force extended out about 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out about 200 miles (320 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Dorian was 20.6.  The Hurricane Size Index (HSI) was 22.6 and the Hurricane Wind Intensity Size Index (HWISI) was 43.2.  Hurricane Dorian was capable of causing widespread major damage.

Hurricane Dorian will move through an environment favorable for intensification during the next 12 hours.  Dorian will move over water where the Sea Surface Temperature is near 28°C.  It will move through a region where the upper level winds are weak and there is little vertical wind shear.  Hurricane Dorian could get a little stronger during the night.  An upper level trough over the central U.S. will move toward Hurricane Dorian on Thursday.  The upper level trough will produce southwesterly winds which will blow toward the top of the hurricane.  Those winds will cause the vertical wind shear to increase, which will cause Dorian to start to weaken.

Hurricane Dorian will move around the western end of a subtropical ridge over the western Atlantic Ocean.  The ridge will steer Dorian toward the north on Wednesday night.  The upper level trough will turn Hurricane Dorian toward the northeast on Thursday.  On its anticipated track Hurricane Dorian could approach the coast of South Carolina on Thursday morning.  Dorian will move along the coast of North Carolina on Thursday afternoon and Thursday night.

Even if the center of Hurricane Dorian stays just south of the coast of South Carolina and North Carolina, the large circulation means that locations near the coast are likely to get hurricane force winds.  Winds blowing water toward the coast could cause storm surges of 5 to 8 feet (1.5 to 2.5 meters) in some locations.  Dorian could also drop locally heavy rain and cause flash flooding  near the coast.

Elsewhere, Tropical Storm Fernand made landfall north of La Pesca, Mexico on Wednesday and Tropical Storm Gabrielle developed south of the Azores.  Ar 11:00 p.m. EDT on Wednesday the center of Tropical Depression Fernand was located at latitude 25.0°N and longitude 99.0°W which put it about 100 miles (160 km) west-northwest of La Pesca, Mexico.  Dorian was moving toward the west-northwest at 9 m.p.h. (15 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.

At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Gabrielle was located at latitude 21.5°N and longitude 34.4°W which put it about 1220 miles (1965 km) south-southwest of the Azores.  Gabrielle was moving toward the northwest at 7 m.p.h. (11 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 m/h).  The minimum surface pressure was 1002 mb.

Hurricane Dorian Moves Parallel to Florida Coast

Hurricane Dorian moved parallel to the east coast of Florida on Tuesday night.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Dorian was at latitude 28.4°N and longitude 79.0°W which put it about 95 miles (155 km/h) east of Cape Canaveral, Florida.  Dorian was moving toward the north-northwest at 6 m.p.h. (9 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (215 km/h).  The minimum surface pressure was 959 mb.

Hurricane Warnings were in effect for the portions of the coast from Sebastian Inlet to Ponte Vedra Beach, Florida and from Savannah River, Georgia to Surf City, North Carolina.  Hurricane Watches were in effect for the portion of the coast from Ponte Vedra Beach to Savannah River, Georgia and from Surf City, North Carolina to the North Carolina/Virginia border including Albemarle and Pamlico Sounds.  Tropical Storm Warnings were in effect for the portion of the coast from Jupiter Inlet to Sebastian Inlet, Florida and from Ponte Vedra Beach, Florida to Savannah, River, Georgia.  Tropical Storm Watches were also in effect for the Northwestern Bahamas including the Abacos and Grand Bahama Island.  Tropical Storm Watches were in effect for the portion of the coast from the North Carolina/Virginia border to Chincoteague, Virginia and for Chesapeake Bay south of Smith Point.

Although Hurricane Dorian was moving again, it exhibited the structure of a hurricane that had been stationary for a day and had undergone an eyewall replacement cycle.  There was a large ragged eye with a diameter of 35 miles (55 km) at the center of circulation.  The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Multiple bands of showers and thunderstorms were revolving around the large core of Hurricane Dorian.  Storm near the core were generating upper level divergence which was pumping mass away from the hurricane.

An eyewall replacement cycle caused the size of the circulation around Hurricane Dorian to increase.  Winds to hurricane force extended out about 60 miles (95 km) from the center of circulation.  Wind to tropical storm force extended out about 175 miles (285 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Dorian was 19.2.  The Hurricane Size Index (HSI) was 19.9 and the Hurricane Wind Intensity Size Index (HWISI) was 39.1.

Hurricane Dorian will move through an environment favorable for intensification on Wednesday.  Dorian will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  However, the large size of Hurricane Dorian will limit potential intensification.  Hurricane Dorian could intensify a little on Wednesday.  An upper level trough over the U.S. will approach Dorian on Wednesday night.  The trough will produce southwesterly winds which will cause more vertical wind shear on Thursday.

Hurricane Dorian will move around the western end of a subtropical high pressure system over the western Atlantic Ocean on Wednesday.  The high will steer Dorian toward the north-northwest.  The upper level trough will turn Dorian toward the northeast on Wednesday night.  On its anticipated track Hurricane Dorian will move nearly parallel to the east coast of Florida on Wednesday.  Dorian could approach the coast of South Carolina by Wednesday night.

Elsewhere Tropical Storm Fernand was over the western Gulf of Mexico and Tropical Depression was west of the Cabo Verde Islands.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Fernand was located at latitude 23.2°N and longitude 96.4°W which put it about 100 miles (155 km) east-southeast of La Pesca, Mexico.  Fernand was moving toward the west at 3 m.p.h. (5 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 1000 mb.  A Tropical Storm Warning was in effect for the portion of the coast from Puerto Altimira, Mexico to the Mouth of the Rio Grande, River.

At 11:00 p.m. EDT on Tuesday the center of Tropical Depression Eight was located at latitude 19.1°N and longitude 32.8°W which put it about 615 miles (995 km) west-northwest of the Cabo Verde Islands.  It was moving toward the northwest at 8 m.p.h. (13 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.

Tropical Storm Fernand Forms Over W. Gulf of Mexico, Dorian Edges Away From Bahamas

Tropical Storm Fernand formed over the western Gulf of Mexico and powerful Hurricane Dorian edged slowly away from the Northwestern Bahamas on Tuesday afternoon.  At 2:00 p.m. EDT on Tuesday the center of Tropical Storm Fernand was located at latitude 23.5°N and longitude 95.3°W which put it about 160 miles (260 km) east of La Pesca, Mexico.  Fernand was moving toward the west at 7 m.p.h. (11 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.

The government of Mexico issued a Tropical Storm Warning that was in effect for the portion of the coast from Barra del Tordo to the mouth of the Rio Grande River.

The circulation around an area of low pressure over the western Gulf of Mexico exhibited greater organization on Tuesday afternoon and the National Hurricane Center designated the system as Tropical Storm Fernand.  The circulation around Fernand consisted of a broad area of lower pressure.  One rainband wrapped around the northern periphery of the circulation and a second rainband wrapped around the western periphery of the circulation.  Bands in other parts of the circulation consisted primarily of showers and low clouds.  Winds to tropical storm force extended out about 105 miles (170 km) from the center of the circulation on the western side of Fernand.

Tropical Storm Fernand will move through an environment favorable for intensification during the next 24 hours.  Fernand will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Fernand is likely to strengthen during the next 24 hours.  However, the broad circulation will limit how fast the tropical storm can intensify.

Tropical Storm Fernand will move south of an ridge of high pressure over the southern U.S.  The ridge will Fernand toward the west-northwest during the next day or two.  On its anticipated track Tropical Storm Fernand is expected to make landfall on the coast of Mexico between La Pesca and Mezquital on Wednesday.  Fernand will bring gusty winds and locally heavy rain.  The rain could cause flash floods where Tropical Storm Fernand moves inland over northeastern Mexico.  Fernand could also cause a storm surge of 6 feet (2 meters) along the coast.

Elsewhere over the Atlantic Ocean, powerful Hurricane Dorian began to edge slowly away from the Northwestern Bahamas.  At 2:00 p.m. EDT on Tuesday the center of Hurricane Dorian was located at latitude 27.5°N and longitude 78.7°W which put it about 105 miles (170 km) east of Ft. Pierce, Florida.  Dorian was moving toward the northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (215 km/h).  The minimum surface pressure was 959 mb.

Hurricane Warnings were in effect for the portions of the coast from Jupiter Inlet to Ponte Vedra Beach, Florida and from Edisto Beach to South Santee River, South Carolina.  Hurricane Watches were in effect for the portions of the coast from Ponte Vedra Beach to Edisto Beach and from South Santee River to Duck, North Carolina including Albemarle and Pamlico Sounds.  Tropical Storm Warnings were in effect for the portions of the coast from Deerfield Beach to Jupiter Inlet, Florida and from Ponte Vedra Beach to Edisto Beach.  The Hurricane Warnings for the Northwestern Bahamas including the Abacos and Grand Bahama Island had been changed to Tropical Storm Warnings, since Dorian was moving away from those locations.

Hurricane Dorian finally started to move around the western end of a subtropical high pressure system over the Atlantic Ocean on Tuesday.  An upper level trough over the U.S. will turn Dorian toward the northeast on Wednesday.  On its anticipated track the center of Hurricane Dorian will stay offshore and move parallel to east coast of Florida.  A small deviation to the west could bring the core of Dorian close to the coast.  The center of Hurricane Dorian could move very close to the coast of South Carolina and North Carolina on Thursday.  The circulation around Hurricane Dorian increased in size on Tuesday.  Winds to hurricane force extended out about 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out about 170 miles (275 km) from the center.

Hurricane Dorian Hammers the Northwestern Bahamas

Hurricane Dorian hammered the Northwestern Bahamas on Monday.  After pounding the Abacos on Sunday night, Hurricane Dorian moved slowly across Grand Bahama Island before stalling over that island for much of Monday.  There were reports of significant storms surges, numerous injuries and some fatalities.  Dorian was still battering Grand Bahama Island on Monday night.

At 11:00 p.m. EDT on Monday the center of Hurricane Dorian was located at latitude 26.9°N and longitude 78.5°W which put it about 30 miles (50 km) north-northeast of Freeport, Bahamas and about 100 miles (160 km) east of West Palm Beach, Florida.  Dorian was essentially stationary.  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 946 mb.

Hurricane Warnings were in effect for the Abacos and Grand Bahama Island.  A Hurricane Warning was also in effect for the portion of the Florida coast from Jupiter Inlet to Ponte Vedra Beach.  Hurricane Watches were in effect for the portions of the coast from Deerfield Beach to Jupiter Inlet and from Ponte Vedra Beach, Florida to South Santee River, South Carolina.  A Tropical Storm Warning was also in effect for the portion of the coast from Deerfield Beach to Jupiter Inlet.  Tropical Storm Watches were in effect for the portion of the coast from Golden Beach to Deerfield Beach and for Lake Okeechobee.

Hurricane Dorian weakened slowly on Monday.  As it remained nearly stationary the winds around Dorian mixed cooler water to the surface.  Hurricane Dorian was unable to extract enough energy from the ocean to maintain its extreme intensity,  The circulation in core of Dorian developed two concentric eyewalls.  The concentric eyewalls suggested that the hurricane had started an eyewall replacement cycle which may have also contributed to the reduction of the wind speed.

The concentric eyewalls also produced an increase in the size of the circulation around Hurricane Dorian.  Winds to hurricane force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out abou 150 miles from the center.  The Hurricane Intensity Index (HII) was 25.1.  The Hurricane Size Index (HSI) was 15,2 and the Hurricane Wind Intensity Size Index (HWISI) was 40.3.

Hurricane Dorian was south of a high pressure system over the western Atlantic Ocean.  The high was blocking Dorian and preventing the hurricane from moving toward the north.  The western end of the high is forecast to weaken on Tuesday.  When the end of the high weakens, it will allow Hurricane Dorian to move toward the northwest.  An upper level trough over the U.S. will approach Dorian on Wednesday.  The trough is forecast to turn Dorian toward the northeast.  On its anticipated track Hurricane Dorian could approach the Central Florida coast by Tuesday night.  Dorian could approach the Carolinas on Wednesday night.

Hurricane Dorian will move into an environment favorable for intensification when it starts moving again on Tuesday.  Dorian will move over water where the Sea Surface Temperature is near 29°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  However, Hurricane Dorian could still be in the weakening part of the eyewall replacement cycle and Dorian may not intensify despite the favorable environment.  The upper level trough will produce southwesterly winds which will cause wind shear to increase on Wednesday.  The increase in wind shear will likely cause Hurricane Dorian to weaken when it approaches the Carolinas.

Hurricane Dorian Pounds Northwest Bahamas, Warning Issued for Florida

Hurricane Dorian pounded the Northwestern Bahamas on Sunday afternoon and a Hurricane Warning was issued for a portion of the southeast Florida coast.  Dorian was one of the strongest Atlantic hurricanes on record.  At 5:00 p.m. EDT on Sunday the center of Hurricane Dorian was locate at latitude 26.6°N and longitude 77.3°W which put it about 175 miles (280 km) east of West Palm Beach, Florida.  Dorian was moving toward the west at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 185 m.p.h. (295 km/h) and there were wind gusts to 220 m.p.h. (355 km/h).  The minimum surface pressure was 910 mb.

A Hurricane Warning was issued for the portion of the coast of Florida from Jupiter Inlet to the Volusia/Brevard County Line.  Hurricane Warnings were also in effect for the Northwestern Bahamas including the Abacos, Berry Islands, Bimini, Eleuthera, Grand Bahama Island and New Providence.  Hurricane Watches were in effect for the portion of the coast from Deerfield Beach to Jupiter Inlet, Florida and from the Volusia/Brevard County Line to the Flagler/Volusia County Line.  A Hurricane Watch was also in effect for Andros Island.  A Tropical Storm Warning was in effect for the portion of the coast from Deerfield Beach to Jupiter Inlet, Florida.  Tropical Storm Watches were in effect for the portion of the coast from  Golden Beach to Deerfield Beach, Florida and for Lake Okeechobee.

The core of Hurricane Dorian moved over Great Abaco Island on Sunday afternoon.  Dorian intensified rapidly to an intense Category 5 hurricane on the Saffir-Simpson Scale when it reached the warm water around the Bahamas.  The pressure decreased rapidly to 910 mb and the winds increased to 185 m.p.h. (295 km/h).  There was a circular eye with a diameter of 12 miles (19 km) at the center of Hurricane Dorian.  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 Dorian.  Storms near the core were generating strong upper level divergence which was pumping mass away from the hurricane.

The circulation around Hurricane Dorian increased in size on Sunday.  Winds to hurricane force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 140 miles (220 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Dorian was 44.1.  The Hurricane Size Index (HSI) was 14,3 and the Hurricane Wind Intensity Size Index (HWISI) was 58.4.  Hurricane Dorian was capable of causing regional catastrophic damage.  Dorian was stronger than Hurricane Andrew was when Andrew hit southeast Florida in 1992.

Hurricane Dorian will remain in a favorable environment for intense hurricanes for another 24 to 36 hours.  Dorian will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  It appeared that an inner rainband may have wrapped around the existing eye and eyewall.  Radar images indicated that there could be two concentric eyewalls.  If there are two eyewalls, then an eyewall replacement cycle is underway.  Hurricane Dorian will weaken, at least temporarily when the inner eyewall dissipates.  However, Dorian will get larger when the strongest winds occur in the outer eyewall.

Hurricane Dorian will move near the western end of a subtropical high pressure system over the western Atlantic Ocean.  The high will steer Dorian slowly toward the west-northwest during the next 24 to 36 hours.  Eventually, Hurricane Dorian will move more toward the north when it moves around the western end of the high.  On its anticipated track Hurricane Dorian will linger over the Northwestern Bahamas on Sunday night.  The core of Dorian will pass over or very near Grand Bahama Island.  It could cause catastrophic damage on the Abacos and Grand Bahama Island.  Hurricane Dorian could approach the east coast of Florida on Tuesday.