Monthly Archives: September 2024

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.

John Strengthens Back to a Hurricane Near West Coast of Mexico

Former Tropical Storm John strengthened back to a hurricane over the Eastern North Pacific Ocean near the west coast of Mexico on Thursday morning.  At 8:00 a.m. EDT on Thursday the center of Hurricane John was located at latitude 17.3°N and longitude 102.6°W which put the center about 55 miles (90 km) south-southwest of Lazaro Cardenas, Mexico.  John was moving toward the west-northwest at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 979 mb.

A Hurricane Warning is in effect for the portion of the coast from Tecpan de Galeana to Punta San Telmo, Mexico.

A Tropical Storm Warning is in effect for the portion of the coast from Punta Maldonado to Tecpan de Galeana, Mexico.  The Tropical Storm Storm Warning includes Acapulco.  A Tropical Storm Warning is also in effect for the portion of the coast from Punta San Telmo to Manzanillo, Mexico.

Former Tropical Storm John strengthened back to a hurricane on Thursday morning as the center moved over the Eastern North Pacific Ocean just off the west coast of Mexico.  A small circular eye formed at the center of Hurricane John.  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 revolved around the core of John’s circulation.  Storms near the core of John generated upper level divergence that pumped mass away from the hurricane.

The circulation around Hurricane John was small.  Winds to hurricane force extended out 15 miles (25 km) from the center of John’s circulation.  Winds to tropical storm force extended out 140 miles (225 km) in the southeastern quadrant of Hurricane John.  Winds to tropical storm force only extended out 70 miles (110 km) in the other parts of John’s circulation.

Hurricane John will move through an environment favorable for intensification during the next 18 hours.  John will move over water where the Sea Surface Temperatures are near 30°C.  It will be in a region where the upper level winds are weak and there will be little vertical wind shear. Hurricane John will intensify during the next 18 hours as long as the eye stays over water.

Hurricane John will move around the southwestern part of a high pressure system over Mexico.  The high pressure system will steer John slowly toward the north-northwest during the next 24 hours. On its anticipated track, Hurricane John will make another landfall on the west coast of Mexico on Thursday night.

Hurricane John will bring strong winds and locally heavy rain to the west coast of Mexico.  The strongest winds and heaviest rain will occur in Guerrero and Colima.  Heavy rain is likely to cause flash floods and mudslides.  Hurricane John could also cause a storm surge of up to 8 feet (2.4 meters along the coast.

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.

Tropical Storm John Redevelops West of Acapulco

Tropical Storm John redeveloped over the Eastern North Pacific Ocean west of Acapulco on Wednesday.  At 2:00 p.m. EDT on Wednesday the center of Tropical Storm John was located at latitude 16.5°N and longitude 101.4°W which put the center about 105 miles (165 km) west-southwest of Acapulco, Mexico.  John was moving toward the north-northeast at 3 m.p.h. (5 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 999 mb.

A Hurricane Watch is in effect for the portion of the coast from Zihuatanejo to Acapulco, Mexico.

A Tropical Storm Warning is in effect for the portion of the coast from Punta Maldonado to Lazaro Cardenas, Mexico.  The Tropical Storm Warning includes Acapulco.

The middle level circulation of former Hurricane John drifted west-southwest during the past 36 hours.  When the middle level circulation moved back over the Eastern North Pacific Ocean, it began to spin up a surface low pressure system.  The surface low pressure system intensified on Wednesday and the U.S. National Hurricane Center designated it as Tropical Storm John.

The circulation around Tropical Storm John organized rapidly on Wednesday.  The inner end of a rainband wrapped around the eastern, northern and western sides of the center of John’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Tropical Storm John.  Storms near the center generated upper level divergence that pumped mass away from the tropical storm.

The strongest winds were occurring in the eastern side of Tropical Storm John.  Winds to tropical storm force extended out 80 miles (130 km) in the eastern side of John’s circulation.  The winds in the western side of Tropical Storm John were blowing at less than tropical storm force.

Tropical Storm John will move through an environment favorable for intensification during the next 24 hours.  John will move over water where the Sea Surface Temperatures are near 30°C.  It will be in a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm John will intensify during the next 24 hours.  John could strengthen back to a hurricane.

Tropical Storm John will move around the southwestern part of a high pressure system over Mexico.  The high pressure system will steer John slowly toward the north during the next 24 hours.  On its anticipated track, Tropical Storm John will make another landfall on the coast of Mexico on Thursday.  The center of John’s circulation is likely to make landfall between Acapulco and Zihuatanejo.

Tropical Storm John  could be a hurricane when it makes landfall.  John will bring strong winds and locally heavy rain to the coast of Mexico between Acapulco and Zihuatanejo.  Heavy rain will also fall over Guerrero as John moves inland again.  Heavy rain is likely to cause flash floods in some locations.  Tropical Storm John could cause a storm surge of up to 7 feet (2 meters) along parts of the coast of Guerrero.

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.

Tropical Storm Helene Prompts Hurricane and Storm Surge Warnings for Florida

The risk posed by Tropical Storm Helene prompted the issuance of a Hurricane Warning and a Storm Surge Warning for the west coast of Florida.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Helene was located at latitude 19.7°N and longitude 84.7°W which put the center about 155 miles (250 km) east-southeast of Cozumel, Mexico.  Helene was moving toward the west-northwest at 12 m.p.h. (19 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 995 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 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 Lake Okeechobee.  A Tropical Storm Watch is in effect for the portion of the coast from the Palm Beach/Martin County Line, Florida to Savannah River, Georgia.

Tropical Storm Helene strengthened on Tuesday afternoon.  The center of Helene’s circulation was near NOAA buoy 42056.  The buoy measured a surface pressure of 996 mb.

The inner end of a rainband started to wrap around the center of Tropical Storm Helene.  More thunderstorms formed near the center of Helene’s circulation.  More thunderstorms also developed in bands in the western side of Tropical Storm Helene.  Storms near the center of Helene’s circulation generated more upper level divergence that pumped mass away from the tropical storm.  The removal of more mass caused the surface pressure to decrease.

Even though Tropical Storm Helene was strengthening, the distribution of wind speeds around Helene was still asymmetrical.  Winds to tropical storm force extended out 175 miles (280 km) in the eastern side of Tropical Storm Helene.  The winds in the western side of Helene’s circulation were blowing at less than tropical storm force.

Tropical Storm 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.  Tropical Storm Helene will intensify during the next 24 hours. Helene is likely to strengthen to a hurricane by Wednesday morning.  Helene could intensify rapidly after an inner core with an eye and an eyewall develops.

Tropical Storm 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 northwest during the next 24 hours.  On its anticipated track, Tropical Storm Helene will be near the northeastern tip of the Yucatan Peninsula on Wednesday morning.  Helene will move over the eastern Gulf of Mexico on Wednesday.  Helene is likely to approach northern Florida on Thursday afternoon.

Tropical Storm Helene is likely to be a hurricane when it reaches the northeastern tip of the Yucatan Peninsula.  Helene will bring strong winds and heavy rain to the northeastern part of the Yucatan Peninsula and to western Cuba.

Tropical Storm Helene could 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.  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.

Tropical Storm Helene Forms Over Northwest Caribbean Sea

Tropical Storm Helene formed over the Northwestern Caribbean Sea on Tuesday.  At 2:00 p.m. EDT on Tuesday the center of Tropical Storm Helene was located at latitude 19.4°N and longitude 84.5°W which put the center about 175 miles (280 km) south of the western tip of Cuba.  Helene was moving toward the west-northwest at 12 m.p.h. (19 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 999 mb.

A Hurricane Watch is in effect for the portion of the coast from Indian Pass to Englewood, Florida.  The Hurricane Watch includes Tampa Bay.  A Hurricane Watch is in effect for the portion of the coast from Cabo Catoche to Tulum, Mexico.  The Hurricane Watch includes Cancun and Cozumel.  A Hurricane Watch is also in effect for the Cuban province of Pinar del Rio.

A Tropical Storm Warning is in effect for the Lower Florida Keys west of Seven Mile 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 Rio Lagartos to Tulum, Mexico.  The Tropical Storm Warning includes Cancun and Cozumel.  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 Middle Florida Keys from Seven Mile Bridge to Channel 5 Bridge.  A Tropical Storm Watch is in effect for the portion of the coast from Englewood to Flamingo, Florida.  A Tropical Storm Watch is in effect for the portion of the coast from the Walton/Bay County Line to Indian Pass, Florida.

A U.S. Air Force Reserve Hurricane Hunter reconnaissance aircraft found that a low pressure system previously designated as Potential Tropical Cyclone Nine had strengthened over the Northwestern Caribbean Sea on Tuesday morning.  Based on data collected by the reconnaissance flight, the U.S. National Hurricane Center designated the system as Tropical Storm Helene.

The circulation around Tropical Storm Helene exhibited more organization on Tuesday.  The reconnaissance plane found a well defined low level center of circulation.  Even though the circulation around Helene was more organized, the distribution of thunderstorms was still asymmetrical.  Thunderstorms were occurring in bands in the eastern side of Tropical Storm Helene.  Bands in the western side of Helene consisted primarily of showers and lower clouds.  More thunderstorms were starting to develop in the bands in the western side of Helene’s circulation.  Storms near the center of Helene began to generate upper level divergence that pumped mass away from the tropical storm.

The distribution of wind speeds in Tropical Storm Helene was also asymmetrical.  Winds to tropical storm force extended out 140 miles (225 km) in the eastern side of Helene’s circulation.  The winds in the western side of Tropical Storm Helene were blowing at less than tropical storm force.

Tropical Storm 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.  Tropical Storm Helene will intensify during the next 24 hours.  Helene is likely to strengthen to a hurricane by Wednesday morning.

Tropical Storm 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 northwest during the next 24 hours.  On its anticipated track, Tropical Storm Helene will be near the northeastern tip of the Yucatan Peninsula on Wednesday morning.  Helene will move over the eastern Gulf of Mexico on Wednesday.  Helene is likely to approach northern Florida on Thursday afternoon.

Tropical Storm Helene is likely to be a hurricane when it reaches the northeastern tip of the Yucatan Peninsula.  Helene will bring strong winds and heavy rain to the northeastern part of the Yucatan Peninsula and to western Cuba.

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

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

Hurricane John Hits Mexico

Rapidly intensifying Hurricane John hit the coast of Mexico near Punta Maldonado on Monday night.  At 11:00 p.m. EDT on Monday the center of Hurricane John was located at latitude 16.3°N and longitude 98.8°W which put the center about 15 miles (25 km) west of Punta Maldonado, Mexico.   John was moving toward the north at 8 m.p.h. (13 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).v  The minimum surface pressure was 959 mb.

A Hurricane Warning was in effect for the portion of the coast from Acapulco to Bahias de Huatulco, Mexico.

A Tropical Storm Warning was in effect for the portion of the coast from Bahias de Huatulco to Salina Cruz, Mexico. 

Hurricane John rapidly intensified to a major hurricane as it approached the coast of Mexico near Punta Maldonado on Monday night.  A circular eye with a diameter of 6 miles (10 km) was at the center of John’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 core of Hurricane John.

The circulation around Hurricane John was very small.  Winds to hurricane force extended out 15 miles (25 km) from the center of John’s circulation.  Winds to tropical storm force extended out 45 miles (75 km) from the center of Hurricane John.

The Hurricane Intensity Index (HII) for Hurricane John was 22.1  The Hurricane Size Index (HSI) was 4.1 and the Hurricane Wind Intensity Size Index (HWISI) was 26.1.  Hurricane John was capable of causing localized major damage.

Hurricane John will move inland over eastern Guerrero and western Oaxaca on Tuesday.  John will bring strong winds and heavy rain to the region around Punta Maldonado.  Heavy rain is likely to cause flash floods in some locations.  Hurricane John could also cause a storm surge of up to 12 feet (3.6 meters) along the coast near Punta Maldonado.

Hurricane John will weaken very quickly as it moves inland because of the small size of its circulation.  Even though John will weaken quickly, it will still drop heavy rain over parts of eastern Guerrero and western Oaxaca.  Flash floods are likely to occur in that region on Tuesday before Hurricane John dissipates.

John Rapidly Intensifies to a Hurricane South of Mexico

Former Tropical Storm John rapidly intensified to a hurricane over the Eastern North Pacific Ocean south of Mexico on Monday.  At 2:00 p.m. EDT on Monday the center of Hurricane John was located at latitude 15.1°N and longitude 98.4°W which put the center about 85 miles (135 km) south of Punta Maldonado, Mexico.   John was moving toward the north at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 980 mb.

A Hurricane Warning was in effect for the portion of the coast from Punta Maldonado to Bahias de Huatulco, Mexico.

A Tropical Storm Warning was in effect for the portion of the coast from Bahias de Huatulco to Salina Cruz, Mexico.  A Tropical Storm Warning was also in effect for the portion of the coast from Punta Maldonado to Acapulco, Mexico.

Former Tropical Storm John continued to intensify rapidly on Monday afternoon.  A small eye was present at the center of Hurricane John.  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 core of Hurricane John.  Storms near the core of John’s circulation generated strong upper level divergence that pumped mass away from the hurricane.

The circulation around Hurricane John was small.  Winds to hurricane force extended out 15 miles (25 km) from the center of John’s circulation.  Winds to tropical storm force extended out 45 miles (75 km) from the center of Hurricane John.

Hurricane John will move through an environment favorable for intensification during the next 24 hours.  John will move over water where the Sea Surface Temperatures are near 30°C.  It will be in a region where the upper level winds are weak and there will be little vertical wind shear. Hurricane John will intensify during the next 24 hours.  John could continue to intensify rapidly.  Hurricane John could to strengthen to a major hurricane.

Hurricane John will move around the southeastern part of a large counterclockwise circulation over southern Mexico sometimes called a Central American Gyre (CAG).  The large counterclockwise circulation will steer John slowly toward the north during the next 24 hours.  On its anticipated track, the center of Hurricane John will reach the coast of Mexico near Punta Maldonado on Tuesday.

Hurricane John could be a major hurricane when it approaches the coast of Mexico.  John will bring strong winds and heavy rain to parts of southern Mexico.  Very heavy rain is likely to fall in Chiapas, Oaxaca, and southeast Guerrero.  Heavy rain is likely to cause flash floods in some locations.  Tropical Storm John also could cause a storm surge of 12 feet (3.6 meters) along parts of the coast.