Tag Archives: Hurricane Helene

Hurricane Helene Makes Landfall in North Florida

The center of Hurricane Helene officially made landfall in North Florida on Thursday night.  The center of Helene crossed the coast of Florida near the mouth of the Aucilla River west-southwest of Perry.  At 11:00 p.m. EDT on Thursday the center of Hurricane Helene was located at latitude 29.9°N and longitude 83.9°W which put the center about 40 miles (65 km) southeast of Tallahassee, Florida and about 10 miles (15 km) west-southwest of Perry.  Helene was moving toward the north-northeast at 24 m.p.h. (39 km/h).  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (265 km/h).  The minimum surface pressure was 938 mb.

A Hurricane Warning is in effect for the portion of the coast from Anclote River to Mexico Beach, Florida.

A Hurricane Watch is in effect for the portion of the coast from Anclote River to Englewood, Florida.  The Hurricane Watch includes Tampa Bay.

A Tropical Storm Warning is in effect for the portion of the coast from Anclote River to Flamingo, Florida.  The Tropical Storm Warning includes Tampa Bay.  A Tropical Storm Warning is in effect for the Lower and Middle Florida Keys west of Channel 5 Bridge.  A Tropical Storm Warning is in effect for the Dry Tortugas.  A Tropical Storm Warning is in effect for the portion of the coast from Mexico Beach to the Okaloosa/Walton County Line, Florida.  A Tropical Storm Warning is in effect for the portion of the coast from Flamingo, Florida to Little River Inlet, South Carolina.  A Tropical Storm Warning is in effect for Lake Okeechobee. 

Hurricane Helene intensified to Category 4 on the Saffir-Simpson Scale before it made landfall on the coast of Florida.  A circular eye with a diameter of 32 miles (52 km) was at the center of Helene’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the center of Hurricane Helene. Storms near the center of Helene generated strong upper level divergence that pumped large quantities of mass away from the hurricane. The removal of large quantities of mass was causing the surface pressure to decrease.

The circulation around Hurricane Helene was large. Winds to hurricane force extended out 60 miles (95 km) from the center of Helene’s circulation. Winds to tropical storm force extended out 310 miles (500 km) in the eastern side of Hurricane Helene.  Winds to tropical storm force extended out 140 miles (225 km) in the western side of Helene’s circulation.

The Hurricane Intensity Index (HII) is 28.3. The Hurricane Size Index (HSI) is 21.2 and the Hurricane Wind Intensity Size Index (HWISI) 49.5.  Hurricane Helene is stronger than Hurricane Irma was when Irma hit southwest Florida in 2017.  However, Helene is not quite as big as Irma was.

Hurricane Helene will move around the eastern side of an upper level trough over the Mississippi River Valley.  The upper level trough will steer Helene quickly toward the north during the next 24 hours.  On its anticipated track, Hurricane Helene will move across Georgia on Friday.

Hurricane Warnings are in effect for parts of northern Florida, southeastern Alabama and southwestern Georgia.  The Hurricane Warnings include Tallahassee, Florida and Macon, Georgia.

Tropical Storm Warnings are in effect for the Florida Peninsula, northwest Florida eastern Alabama, northern and eastern Georgia, all of South Carolina, southwestern North Carolina, and southeastern Tennessee.  The Tropical Storm Warnings include Atlanta, Georgia and Charleston, South Carolina.

Hurricane Helene will weaken gradually as it moves farther inland.  Hurricane Helene will bring strong winds and heavy rain to Georgia on Friday.  Heavy rain will also fall over the southern Appalachians.  Heavy rain is likely to cause flash floods.

Flood Watches are in effect for Florida, eastern Alabama, Georgia, western South Carolina, western North Carolina and eastern Tennessee.

Hurricane Helene will continue to cause a storm surge along the west coast of Florida during the next few hours.

A Storm Surge Warning is in effect for the portion of the coast from Mexico Beach to Flamingo, Florida.  The Storm Surge Warning includes Tampa Bay and Charlotte Harbor.

Hurricane Helene Strengthens to Cat. 4

Hurricane Helene strengthened to Category 4 on the Saffir-Simpson Scale on Thursday evening.  At 6:00 p.m. EDT on Thursday the center of Hurricane Helene was located at latitude 28.0°N and longitude 84.5°W which put the center about 165 miles (270 km) south of Tallahassee, Florida.  Helene was moving toward the north-northeast at 23 m.p.h. (37 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 947 mb.

A Hurricane Warning is in effect for the portion of the coast from Anclote River to Mexico Beach, Florida.

A Hurricane Watch is in effect for the portion of the coast from Anclote River to Englewood, Florida.  The Hurricane Watch includes Tampa Bay.

A Tropical Storm Warning is in effect for the portion of the coast from Anclote River to Flamingo, Florida.  The Tropical Storm Warning includes Tampa Bay.  A Tropical Storm Warning is in effect for the Lower and Middle Florida Keys west of Channel 5 Bridge.  A Tropical Storm Warning is in effect for the Dry Tortugas.  A Tropical Storm Warning is in effect for the portion of the coast from Mexico Beach to the Okaloosa/Walton County Line, Florida.  A Tropical Storm Warning is in effect for the portion of the coast from Flamingo, Florida to Little River Inlet, South Carolina.  A Tropical Storm Warning is in effect for Lake Okeechobee. 

A NOAA Hurricane Hunter aircraft found that Hurricane Helene was continuing to strengthen to on Thursday evening.  An eye with a diameter of 30 miles (48 km) was at the center of Helene’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Helene.  Storms near the center of Helene generated strong upper level divergence that pumped large quantities of mass away from the hurricane.  The removal of large quantities of mass was causing the surface pressure to decrease.

The circulation around Hurricane Helene was large.  Winds to hurricane force extended out 60 miles (95 km) from the center of Helene’s circulation.  Winds to tropical storm force extended out 345 miles (555 km) in the eastern side of Hurricane Helene.  Winds to tropical storm force extended out 140 miles (225 km) in the western side of Helene’s circulation.

The Hurricane Intensity Index (HII) is 25.1.  The Hurricane Size Index (HSI) is 23.6 and the Hurricane Wind Intensity Size Index (HWISI) 48.7.  Hurricane Helene is stronger than Hurricane Irma was when Irma hit southwest Florida in 2017.  However, Helene is not quite as big as Irma was.

Hurricane Helene will move through an environment favorable for intensification for the next few hours.  Helene will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge over the eastern Gulf of Mexico.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear. Hurricane Helene could intensify a little more during the next few hours.

Hurricane Helene will move around the western end of a high pressure system over the western Atlantic Ocean.  The high pressure system will steer Helene toward the north-northeast during the next 24 hours.  On its anticipated track, Hurricane Helene will make landfall on the coast of northern Florida at Apalachee Bay Thursday evening.  Helene will be a major hurricane when it reaches the coast.

Hurricane Helene will be a major hurricane when it reaches northern Florida.  Helene will be a large and dangerous hurricane.  Hurricane Helene will bring strong winds and heavy rain to northern Florida.  Heavy rain is likely to cause floods.

Flood Watches are in effect for Florida, eastern Alabama, Georgia, western South Carolina, western North Carolina and eastern Tennessee.

Helene could also cause a storm surge of up to 20 feet (6.1 meters) along portions of the west coast of Florida.

A Storm Surge Warning is in effect for the portion of the coast from Mexico Beach to Flamingo, Florida.  The Storm Surge Warning includes Tampa Bay and Charlotte Harbor.

An upper level trough over the Mississippi River Valley will steer Hurricane Helene quickly toward the north-northeast after it makes landfall.  Since the circulation around Helene is so large, Hurricane Helene will produce hurricane force winds in inland locations as well.

Hurricane Warnings are in effect for parts of northern Florida, southeastern Alabama and southwestern Georgia.  The Hurricane Warnings include Tallahassee, Florida and Macon, Georgia.

Tropical Storm Warnings are in effect for the Florida Peninsula, northwest Florida eastern Alabama, northern and eastern Georgia, all of South Carolina, southwestern North Carolina, and southeastern Tennessee.  The Tropical Storm Warnings include Atlanta, Georgia and Charleston, South Carolina.

Hurricane Helene is likely to cause widespread electricity outages as it moves inland over the southeastern U.S.

Helene Intensifies to a Major Hurricane

Hurricane Helene intensified to a major hurricane over the eastern Gulf of Mexico on Thursday.  At 2:00 p.m. EDT on Thursday the center of Hurricane Helene was located at latitude 26.7°N and longitude 84.9°W which put the center about 205 miles (335 km) south of Apalachicola, Florida.  Helene was moving toward the north-northeast at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 140 m.p.h. (225 km/h).  The minimum surface pressure was 959 mb.

A Hurricane Warning is in effect for the portion of the coast from Anclote River to Mexico Beach, Florida.

A Hurricane Watch is in effect for the portion of the coast from Anclote River to Englewood, Florida.  The Hurricane Watch includes Tampa Bay.

A Tropical Storm Warning is in effect for the portion of the coast from Anclote River to Flamingo, Florida.  The Tropical Storm Warning includes Tampa Bay.  A Tropical Storm Warning is in effect for the Lower and Middle Florida Keys west of Channel 5 Bridge.  A Tropical Storm Warning is in effect for the Dry Tortugas.  A Tropical Storm Warning is in effect for the portion of the coast from Mexico Beach to the Okaloosa/Walton County Line, Florida.  A Tropical Storm Warning is in effect for the portion of the coast from Flamingo, Florida to Little River Inlet, South Carolina.  A Tropical Storm Warning is in effect for Lake Okeechobee. 

A U.S. Air Force Hurricane Hunter aircraft found that Hurricane Helene had strengthened to a major hurricane on Thursday afternoon.  An eye with a diameter of 30 miles (48 km) was at the center of Helene’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Helene.  Storms near the center of Helene generated strong upper level divergence that pumped large quantities of mass away from the hurricane.

The circulation around Hurricane Helene was large.  Winds to hurricane force extended out 60 miles (95 km) from the center of Helene’s circulation.  Winds to tropical storm force extended out 345 miles (555 km) in the eastern side of Hurricane Helene.  Winds to tropical storm force extended out 140 miles (225 km) in the western side of Helene’s circulation.

The Hurricane Intensity Index (HII) is 22.1.  The Hurricane Size Index (HSI) is 17.6 and the Hurricane Wind Intensity Size Index (HWISI) 39.7.  Hurricane Helene is stronger than Hurricane Irma was when Irma hit southwest Florida in 2017.  However, Helene is not as big as Irma was.

Hurricane Helene will move through an environment favorable for intensification during the next few hours.  Helene will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge over the eastern Gulf of Mexico.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Hurricane Helene is likely to intensify during the next few hours.  Helene could strengthen to Category 4 on the Saffir-Simpson Scale.

Hurricane Helene will move around the western end of a high pressure system over the western Atlantic Ocean.  The high pressure system will steer Helene toward the north-northeast during the next 24 hours.  On its anticipated track, Hurricane Helene will make landfall on the coast of northern Florida at Apalachee Bay Thursday evening.  Helene will be a major hurricane when it reaches the coast.

Hurricane Helene will be a major hurricane when it reaches northern Florida.  Helene will be a large and dangerous hurricane.  Hurricane Helene will bring strong winds and heavy rain to northern Florida.  Heavy rain is likely to cause floods.

Flood Watches are in effect for Florida, eastern Alabama, Georgia, western South Carolina, western North Carolina and eastern Tennessee.

Helene could also cause a storm surge of up to 20 feet (6.1 meters) along portions of the west coast of Florida.

A Storm Surge Warning is in effect for the portion of the coast from Mexico Beach to Flamingo, Florida.  The Storm Surge Warning includes Tampa Bay and Charlotte Harbor.

An upper level trough over the Mississippi River Valley will steer Hurricane Helene quickly toward the north-northeast after it makes landfall.  Since the circulation around Helene is so large, Hurricane Helene will produce hurricane force winds in inland locations as well.

Hurricane Warnings are in effect for parts of northern Florida, southeastern Alabama and southwestern Georgia.  The Hurricane Warnings include Tallahassee, Florida and Macon, Georgia.

Tropical Storm Warnings are in effect for the Florida Peninsula, northwest Florida eastern Alabama, northern and eastern Georgia, all of South Carolina, southwestern North Carolina, and southeastern Tennessee.  The Tropical Storm Warnings include Atlanta, Georgia and Charleston, South Carolina.

Hurricane Helene is likely to cause widespread electricity outages as it moves inland over the southeastern U.S.

Hurricane Helene Strengthens to Cat. 2

Hurricane Helene strengthened to Category 2 on the Saffir-Simpson Scale over the eastern Gulf of Mexico on Thursday morning.  At 8:00 a.m. EDT on Thursday the center of Hurricane Helene was located at latitude 24.5°N and longitude 85.9°W which put the center about 365 miles (585 km) south of Apalachicola, Florida.  Helene was moving toward the north-northeast at 12 m.p.h. (19 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 960 mb.

A Hurricane Warning is in effect for the portion of the coast from Anclote River to Mexico Beach, Florida.

A Hurricane Watch is in effect for the portion of the coast from Anclote River to Englewood, Florida.  The Hurricane Watch includes Tampa Bay.  .

A Tropical Storm Warning is in effect for the portion of the coast from Anclote River to Flamingo, Florida.  The Tropical Storm Warning includes Tampa Bay.  A Tropical Storm Warning is in effect for the Lower and Middle Florida Keys west of Channel 5 Bridge.  A Tropical Storm Warning is in effect for the Dry Tortugas.  A Tropical Storm Warning is in effect for the portion of the coast from Mexico Beach to the Okaloosa/Walton County Line, Florida.  A Tropical Storm Warning is in effect for the portion of the coast from Flamingo, Florida to Little River Inlet, South Carolina.  A Tropical Storm Warning is in effect for Lake Okeechobee.  A Tropical Storm Warning was also in effect for the Cuban provinces of Artemisa, Pinar del Rio and Isle of Youth.

A U.S. Air Force Hurricane Hunter aircraft found that Hurricane Helene had strengthened to Category 2 on the Saffir-Simpson Scale on Thursday morning.  An eye with a diameter of 30 miles (48 km) was at the center of Helene’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Helene.  Storms near the center of Helene generated strong upper level divergence that pumped large quantities of mass away from the hurricane.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The circulation around Hurricane Helene was large.  Winds to hurricane force extended out 60 miles (95 km) from the center of Helene’s circulation.  Winds to tropical storm force extended out 345 miles (555 km) in the eastern side of Hurricane Helene.  Winds to tropical storm force extended out 140 miles (225 km) in the western side of Helene’s circulation.

The Hurricane Intensity Index (HII) is 16.5.  The Hurricane Size Index (HSI) is 17.6 and the Hurricane Wind Intensity Size Index (HWISI) 34.1.  Hurricane Helene is similar in intensity to Hurricane Idalia that hit northeast Florida in 2023.  However, Helene is much bigger than Idalia was.  Helene is still intensifying.  So, Helen will be stronger than Idalia was when i reaches the coast.

Hurricane Helene will move through an environment favorable for intensification during the next 12 hours.  Helene will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge over the eastern Gulf of Mexico.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Hurricane Helene will intensify during the next 12 hours.  Helene is likely to strengthen to a major hurricane by Thursday afternoon.  Helene could intensify rapidly at times.

Hurricane Helene will move around the western end of a high pressure system over the western Atlantic Ocean.  The high pressure system will steer Helene toward the north-northeast during the next 24 hours.  On its anticipated track, Hurricane Helene will make landfall on the coast of northern Florida at Apalachee Bay Thursday evening.  Helene is likely to be a major hurricane when it reaches the coast

Hurricane Helene is likely to be a major hurricane when it reaches northern Florida.  Helene will be a large and dangerous hurricane.  Hurricane Helene will bring strong winds and heavy rain to northern Florida.  Heavy rain is likely to cause floods.

Flood Watches are in effect for Florida, eastern Alabama, Georgia, western South Carolina, western North Carolina and eastern Tennessee.

Helene could also cause a storm surge of up to 20 feet (6.1 meters) along portions of the west coast of Florida.

A Storm Surge Warning is in effect for the portion of the coast from Mexico Beach to Flamingo, Florida.  The Storm Surge Warning includes Tampa Bay and Charlotte Harbor.

An upper level trough over the Mississippi River Valley will steer Hurricane Helene quickly toward the north-northeast after it makes landfall.  Since the circulation around Helene is so large, Hurricane Helene will produce hurricane force winds in inland locations as well.

Hurricane Warnings are in effect for parts of northern Florida, southeastern Alabama and southwestern Georgia.  The Hurricane Warnings include Tallahassee, Florida and Macon, Georgia.

Tropical Storm Warnings are in effect for the Florida Peninsula, northwest Florida eastern Alabama, northern and eastern Georgia, all of South Carolina, southwestern North Carolina, and southeastern Tennessee.  The Tropical Storm Warnings include Atlanta, Georgia and Charleston, South Carolina.

Hurricane Helene is likely to cause widespread electricity outages as it moves inland over the southeastern U.S.

Helene Strengthens to a Hurricane

Former Tropical Storm Helene strengthened to a hurricane northeast of the Yucatan Peninsula on Wednesday morning.  At 11:00 a.m. EDT on Wednesday the center of Hurricane Helene was located at latitude 21.6°N and longitude 86.3°W which put the center about 500 miles (810 km) south-southwest of Tampa, Florida.  Helene was moving toward the north-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 95 m.p.h. (150 km/h).  The minimum surface pressure was 979 mb.

A Hurricane Warning is in effect for the portion of the coast from Anclote River to Mexico Beach, Florida.  A Hurricane Warning is in effect for the portion of the coast from Cabo Catoche to Tulum, Mexico.  That Hurricane Warning includes Cancun and Cozumel.

A Hurricane Watch is in effect for the portion of the coast from Anclote River to Englewood, Florida.  The Hurricane Watch includes Tampa Bay.  A Hurricane Watch is also in effect for the Cuban province of Pinar del Rio.

A Tropical Storm Warning is in effect for the portion of the coast from Anclote River to Flamingo, Florida.  The Tropical Storm Warning includes Tampa Bay.  A Tropical Storm Warning is in effect for the Lower and Middle Florida Keys west of Channel 5 Bridge.  A Tropical Storm Warning is in effect for the Dry Tortugas.  A Tropical Storm Warning is in effect for the portion of the coast from Mexico Beach to the Okaloosa/Walton County Line, Florida.  A Tropical Storm Warning is in effect for the portion of the coast from Flamingo, Florida to South Santee River, South Carolina.  A Tropical Storm Warning is in effect for Lake Okeechobee.  A Tropical Storm Warning is in effect for the portion of the coast from Rio Lagartos to Cabo Catoche, Mexico. A Tropical Storm Warning was also in effect for the Cuban provinces of Artemisa, Pinar del Rio and Isle of Youth.

A Tropical Storm Watch is in effect for the portion of the coast from South Santee River to Little River Inlet, South Carolina.

A U.S. Air Force Reserve Hurricane Hunter aircraft found that former Tropical Storm Helene had strengthened to a hurricane on Wednesday morning.  The inner end of a rainband wrapped around the northern, western and southern sides of the center of Helene’s circulation.  An eye appeared to be forming at the center of Hellene.  Bands of showers and thunderstorms were revolving around the core of Hurricane Helene.  Storms near the core generated strong upper level divergence that pumped mass away from the hurricane.  The removal of mass caused the surface pressure to decrease.

Winds to hurricane force extended out 25 miles (40 km) from the center of Hurricane Helene.  Winds to tropical storm force extended out 275 miles (445 km) in the eastern side of Helene’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) in the eastern side of Hurricane Helene.

Hurricane Helene will move through an environment favorable for intensification during the next 24 hours.  Helene will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge over the western Gulf of Mexico and the northwestern Caribbean Sea.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Hurricane Helene will intensify during the next 24 hours.  Helene is likely to strengthen to a major hurricane by Thursday afternoon.  Helene could intensify rapidly after an inner core with an eye and an eyewall is fully developed.

Hurricane Helene will move around the western end of a high pressure system over the western Atlantic Ocean.  The high pressure system will steer Helene toward the north during the next 24 hours.  On its anticipated track, Hurricane Helene will approach northern Florida on Thursday afternoon.  Helene is likely to be a major hurricane when it reaches the northeastern Gulf of Mexico.

Hurricane Helene is likely to be a major hurricane when it approaches northern Florida on Thursday.  Helene will bring strong winds and heavy rain to northern Florida.  Heavy rain is likely to cause floods.

Flood Watches are in effect for Florida, eastern Alabama, and Georgia.

Helene could also cause a storm surge of up to 15 feet (4.5 meters) along portions of the west coast of Florida.

A Storm Surge Warning is in effect for the portion of the coast from Indian Pass to Flamingo, Florida.  The Storm Surge Warning includes Tampa Bay and Charlotte Harbor.

A Storm Surge Watch is in effect for the portion of the coast from Indian Pass to Mexico Beach, Florida.

Hurricane Florence Moves Closer to the Carolinas

Hurricane Florence moved closer to the Carolinas on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Hurricane Florence was located at latitude 32.0°N and longitude 73.7°W which put it about 280 miles (455 km) east-southeast of Wilmington, North Carolina.  Florence was moving toward the northwest at 17 m.p.h. (28 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. (210 km/h).  The minimum surface pressure was 957 mb.

A Hurricane Warning was in effect for the portion of the coast from South Santee River, South Carolina to Duck, North Carolina including Pamlico and Albemarle Sounds.  A Hurricane Watch was in effect for the portion of the coast from Edisto Beach, South Carolina to South Santee River, South Carolina.  A Tropical Storm Warning is in effect for the portion of coast from Duck, North Carolina to the North Carolina-Virginia border.  A Tropical Storm Watch was in effect for the portion of the coast from the North Carolina-Virginia border to Cape Charles Light, Virginia and for Chesapeake Bay south of New Point Comfort.

The wind speed in Hurricane Florence decreased on Wednesday but the circulation increased in size.  It appeared that another eyewall replacement cycle could have started.  Satellite microwave images suggested that there could be two eyewalls and a reconnaissance plane reported a double wind maxima.  Both of those things could be evidence of concentric eyewalls.  In addition, counterclockwise flow around a small upper level low near Florida may have produced southerly winds that blew toward the south side of Hurricane Frances.  Those winds may have inhibited the upper level divergence to the south of Florence.  Since the hurricane was unable to pump out as much mass, the surface pressure increased and the wind speed decreased.

The circulation of Hurricane Florence increased in size on Wednesday.  Winds to hurricane force extended out about 80 miles (130 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 Florence was 19.2.  The Hurricane Size Index (HSI) was 25.5 and the Hurricane Wind Intensity Size Index (HWISI) was 44.7.  Those indices are very similar to the numbers for Hurricane Jeanne just before Jeanne made landfall in southeast Florida in 2004.

Hurricane Florence will move through an environment favorable for intensification on Thursday.  Florence will move over water where the Sea Surface Temperature is near 29°C.  Florence will move farther away from the upper low near Florida and the low should not inhibit divergence to the south of the hurricane as much.  In addition, Hurricane Florence will move over the warm water in the Gulf Stream about 6 to 12 hours before it reaches the coast.  It will be able to extract extra energy at that time.  If the inner core becomes more organized, then Hurricane Florence could intensify on Thursday.  If the inner core does not get better organized, then Florence will likely maintain its current intensity or weaken slowly.

Hurricane Florence will move near the western end of the subtropical high pressure system over the western Atlantic Ocean.  The high will steer Florence toward the northwest on Thursday.  On its anticipated track the center of Hurricane Florence will be near the coast of North Carolina on Thursday night.  A ridge over the eastern U.S. is likely to block the northward motion of Hurricane Florence when it reaches the coast.  The ridge will steer Florence slowly toward the west-southwest on Friday and Saturday.

Hurricane Florence will have the impact of a major hurricane regardless of the actual sustained wind speed.  The large circulation and slow rate of movement when Florence reaches the coast means that locations could experience strong winds for extended periods of time.  Wind damage and power outages could be extensive.  Some places in North Carolina had a rainy summer and strong winds could uproot trees.  Hurricane Florence will produce a dangerous storm surge along the coast.  The surge could exceed 10 feet (3 meters) in some locations east of where the center makes landfall.  The slow forward speed also means that Hurricane Florence could drop locally heavy rain and severe flooding could occur.

Elsewhere the rest of the Atlantic Ocean was also very active.  Tropical Storm Isaac was nearing the Lesser Antilles, Hurricane Helene was weakening south of the Azores and Subtropical Storm Joyce formed northwest of Helene.

At 11:00 p.m. EDT on Thursday the center of Tropical Storm Isaac was located at latitude 15.3°N and longitude 58.0°W which put it about 220 miles (355 km) east of Dominica.  Isaac was moving toward the west at 20 m.p.h. (32 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 1006 mb.  Tropical Storm Warnings were in effect for Guadeloupe, Martinique and Dominica.  Tropical Storm Watches were in effect for Antigua, Montserrat, St, Kitts and Nevis, Saba and St. Eustatius, St. Martin and St. Maarten.

At 11:00 p.m. EDT on Thursday the center of Hurricane Helene was located at latitude 22.4°N and 36.9°W which put it about 1270 mile (2045 km) south-southwest of the Azores.  Helene was moving toward the north at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 95 m.p.h. (155 km/h).  The minimum surface pressure was 983 mb.

At 11:00 p.m. EDT on Thursday the center of Subtropical Storm Joyce was located at latitude 15.3°N and longitude 46.6°W which put it about 910 miles (1465 km) west-southwest of the Azores.  Joyce was moving toward the southwest at 6 m.p.h. (10 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 1006 mb.

Hurricane Warnings Issued for Carolinas for Hurricane Florence

Hurricane Warnings were issued for the Carolinas on Tuesday for the potential impacts of Hurricane Florence.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Florence was located at latitude 28.4°N and longitude 68.7°W which put it about 670 miles (1075 km) east-southeast of Cape Fear, North Carolina.  Florence was moving toward the west-northwest at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 140 m.p.h. (220 km/h) and there were wind gusts to 165 m.p.h. (270 km/h).  The minimum surface pressure was 946 mb.

A Hurricane Warning was in effect for the portion of the coast from South Santee River, South Carolina to Duck, North Carolina.  Hurricane Watches were in effect for the portions of the coast from Edisto Beach to South Santee River, South Carolina and from Duck, North Carolina to the North Carolina-Virginia border.  Tropical Storm Watches were in effect for the portions of the coast from Duck, North Carolina to Cape Charles Light, Virginia and for Chesapeake Bay south of New Point Comfort.

Hurricane Florence completed an eyewall replacement cycle and it continues to be a powerful hurricane.  There was a circular eye with a diameter of 30 miles (48 km) at the center of Florence.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  The eyewall replacement cycle resulted in a larger circulation.

Winds to hurricane force extended out about 60 miles (95 km) from the center of circulation of Hurricane Florence.  Winds to tropical storm force extended out about 175 miles (280 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Florence was 28.2.  The Hurricane Size Index (HSI) was 18.9 and the Hurricane Wind Intensity Size Index (HWISI) was 47.1.  Hurricane Florence is capable of causing extensive significant damage.

Hurricane Florence will move through an environment favorable for strong hurricanes during the next 24 to 36 hours.  Florence 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.  Hurricane Florence is likely to maintain its intensity and it could strengthen.  If another eyewall replacement cycle occurs, then there could be fluctuations in intensity.

Hurricane Florence will move around the western end of a subtropical high pressure system over the western Atlantic Ocean.  The high will steer Florence toward the west-northwest during the next 24 to 36 hours.  On its anticipated track Hurricane Florence could approach the coast of the Carolinas later on Thursday.  The steering winds are forecast to weaken when Florence nears the coast and there is great uncertainty about the track when that occurs.  Hurricane Florence will bring strong winds to coastal North Carolina and eastern South Carolina.  Wind pushing water toward the shore will cause a significant storm surge.  A slow forward speed will mean that Hurricane Florence will drop a lot of rain and there is a risk of significant flooding of rivers and streams.

Elsewhere over the Atlantic Ocean, Tropical Storm Isaac was speeding toward the Lesser Antilles and Hurricane Helene was weakening far south of the Azores.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Isaac was located at latitude 14.5°N and longitude 52.3°W which put it about 580 miles (935 km) east of Martinique.  Isaac was moving toward the west at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 999 mb.  Tropical Storm Warnings were in effect for Dominica, Martinique and Guadeloupe.  Tropical Storm Watches were in effect for Antigua, Montserrat, St. Kitts and Nevis, and Saba and St. Eustatius.

At 11:00 p.m. EDT on Tuesday the center of Hurricane Helene was located at latitude 18.0°N and longitude 35.4°W which put it about 1479 miles (2370 km) south-southwest of the Azores.  Helene was moving toward the northwest at 10 m.p.h. (16 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 973 mb.

Hurricane Florence Causes Watches for Carolinas, Isaac for the Lesser Antilles

The potential impacts of Hurricane Florence caused Hurricane Watches to be issued for the Carolinas on Tuesday morning while the approach of Tropical Storm Isaac also caused Watches to be issued for some of the Lesser Antilles.  At 11:00 a.m. EDT on Tuesday the center of Hurricane Florence was located at latitude 26.7°N and longitude 65.3°W which put it about 905 miles (1455 km) east-southeast of Cape Fear, North Carolina.  Florence was moving toward the west-northwest at 16 m.p.h. (26 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 950 mb.  A Hurricane Watch was in effect for the portion of the coast from Edisto Beach, South Carolina to the North Carolina-Virginia border including Pamlico and Albemarle Sounds.

Hurricane Florence was nearing the end of an eyewall replacement cycle on Tuesday morning.  A thin ring of showers and thunderstorms around the center of circulation was all that was left of the original eyewall.  A larger ring of thunderstorms surrounded an eye with a diameter of 36 miles (58 km).  Several other bands of showers and thunderstorms surround the new, larger eyewall.  Storms near the core of Hurricane Florence generated strong upper level divergence which pumped mass away from the hurricane.

The eyewall replacement cycle temporarily weakened Hurricane Florence, but it also made the circulation larger.  Winds to hurricane force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 150 miles (240 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Florence was 25.1.  The Hurricane Size Index (HSI) was 15.3 and the Hurricane Wind Intensity Size Index (HWISI) was 40.4.

Hurricane Florence will be moving through an environment favorable for strong hurricanes.  Florence 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.  Hurricane Florence is likely to strengthen during the next 24 hours, but additional eyewall replacement cycles could cause the intensity to fluctuate.

Hurricane Florence will move around the western end of the subtropical high pressure system over the western Atlantic Ocean.  The high will steer Florence in a general west-northwesterly direction.  On its anticipated track the center of Hurricane Florence could approach the coast of North Carolina and South Carolina on Thursday.  It will very likely be a major hurricane at that time.

Tropical Storm Isaac moved steadily toward the Lesser Antilles and Watches were issued for some of those islands.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Isaac was located at latitude 14.6°N and longitude 49.7°W which put it about 775 miles (1250 km) east of the Lesser Antilles.  Isaac was moving toward the west at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 996 mb.  Hurricane Watches were in effect for Guadeloupe, Martinique and Dominica.  Tropical Storm Watches were in effect for Antigua and Montserrat.

Elsewhere over the tropical Atlantic Ocean, Hurricane Helene moved far south of the Azores.  At 11:00 a.m. EDT on Tuesday the center of Hurricane Helene was located at latitude 16.5°N and longitude 34.3°W which put it about 1550 miles (2495 km) south-southwest of the Azores.  Helene was moving toward the northwest at 12 m.p.h. (19 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. (210 km/h).  The minimum surface pressure was 966 mb.

Florence Strengthens Into a Major Hurricane

Hurricane Florence strengthened into a Major Hurricane on Monday.  At 11:00 p.m. EDT on Monday the center of Hurricane Florence was located at latitude 25.9°N and longitude 62.4°W which put it about 1085 miles (1745 km) east-southeast of Cape Fear, North Carolina.  Florence was moving toward the west-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 140 m.p.h. (220 km/h) and there were wind gusts to 165 m.p.h. (270 km/h).  The minimum surface pressure was 944 mb.

Hurricane Florence intensified rapidly on Monday morning and early afternoon.  An eye with a diameter of 18 miles (29 km) formed at the center of circulation.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Florence.  Storms near the core were generating strong upper level divergence which pumped mass away from the hurricane.

Hurricane Florence increased in size on Monday.  Winds to hurricane force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 150 miles (240 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Florence was 28.2.  The Hurricane Size Index (HSI) was 14.0 and the Hurricane Wind Intensity Size Index (HWISI) was 42.2.  Hurricane Florence was capable of causing extensive significant damage.

Microwave satellite imagery indicated that an inner rainband may have wrapped around the original eye and eyewall.  An eyewall replacement cycle may have begun and that may have halted the rapid intensification of Hurricane Florence.  Florence could weaken during the next few hours while the inner eyewall weakens.  Hurricane Florence will move through an area capable of supporting strong hurricanes on Tuesday and Wednesday.  Florence 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.  If the inner eyewall dissipates during the next day or so, then Hurricane Florence could strengthen again.

Hurricane Florence will move around the western end of the subtropical high pressure system during the next several days.  The high will steer Florence toward the west-northwest.  On its anticipated track Hurricane Florence will approach the coast of North Carolina on Thursday afternoon.  The winds steering Florence could weaken as it approaches the coast and the track forecast becomes much more uncertain at that time.

Elsewhere, Hurricane Helene and Tropical Storm Isaac were spinning over the tropical Atlantic Ocean.  At 11:00 p.m. EDT on Monday the center of Hurricane Helene was located at latitude 15.5°N and longitude 32.4°W which put it about 1590 miles (2555 km) south of the Azores.  Helen was moving toward the west-northwest at 12 m.p.h. (19 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. (210 km/h).  The minimum surface pressure was 968 mb.

At 11:00 p.m. EDT on Monday the center of Tropical Storm Isaac was located at latitude 14.5°N and longitude 46.9°W which put it about 960 miles (1550 km) east of the Lesser Antilles.  Isaac was moving toward the west at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 997 mb.