Tag Archives: St. Kitts

Tammy Strengthens to a Hurricane East of the Lesser Antilles

Former Tropical Storm Tammy strengthened to a hurricane east of the Lesser Antilles on Friday morning. At 11:00 a.m. EDT on Friday the center of Hurricane Tammy was located at latitude 14.1°N and longitude 58.6°W which put it about 165 miles (265 km) east-southeast of Martinique. Tammy was moving toward the west-northwest at 7 m.p.h. (11 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 992 mb.

Hurricane Warnings were in effect for Guadeloupe, Antigua, Barbuda, Montserrat, St. Kitts, and Nevis. Hurricane Watches were in effect for Anguilla, St. Maarten, St. Martin, and St. Baarthelemy. Tropical Storm Warnings were in effect for Dominica, Anguilla, St. Maarten, St. Martin, St. Barthelemy, Saba and St. Eustatius. Tropical Storm Watches were in effect for Martinique and Barbados.

U.S. Air Force Reserve and NOAA planes flying in former Tropical Storm Tammy found that Tammy had intensified to a hurricane on Friday morning. A circular eye with a diameter of 14 miles (22 km) formed at the center of Hurricane Tammy. 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 Tammy. Storms near the core generated upper level divergence that pumped mass away from the hurricane. The removal of mass caused the surface pressure to decrease on Friday morning.

Winds to hurricane force extended out 25 miles (40 km) in the northeastern quadrant of Hurricane Tammy. Winds to tropical storm force extended out 140 miles (220 km) in the eastern side of Tammy’s circulation. Winds to tropical storm force extended out 90 miles (145 km) in the western side of the circulation.

Hurricane Tammy will move through an environment somewhat favorable for intensification during the next 24 hours. Tammy will move over water where the Sea Surface Temperatures are near 30°C. It will move under the far eastern part of an upper level low over the Eastern Caribbean Sea. The upper level low will produce southwesterly winds that will blow toward the top of Tammy’s circulation. Those winds will cause moderate vertical wind shear. The wind shear will inhibit intensification, but it will not be strong enough to prevent intensification. Hurricane Tammy is likely to intensify during the next 24 hours.

Hurricane Tammy will move south of a subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Tammy toward the northwest during the next 24 hours. On its anticipated track, the center of Hurricane Tammy could be near Guadeloupe on Saturday morning.

Hurricane Tammy is likely to bring strong winds and locally heavy rain to the central and northern Leeward Islands. Heavy rain is likely to cause flash in some locations. Hurricane Tammy could cause a storm surge of up to seven feet (two meters) along the coasts of some of the islands.

Tropical Storm Tammy Strengthens East of the Lesser Antilles

Tropical Storm Tammy strengthened east of the Lesser Antilles on Thursday morning. At 8:00 a.m. EDT on Thursday the center of Tropical Storm Tammy was located at latitude 13.5°N and longitude 55.1°W which put it about 465 miles (745 km) east of Guadeloupe. Tammy was moving toward the west at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 1004 mb.

Tropical Storm Watches were in effect for Barbados, Dominica, Martinique, Guadeloupe, Antigua, Barbuda, Montserrat, St. Kitts, Nevis, Saba, St. Eustatius.

A NOAA research plane found that Tropical Storm Tammy had strengthened during Wednesday night. More thunderstorms developed near the center of Tammy’s circulation. However, the distribution of thunderstorms was still asymmetrical. Many of the thunderstorms were occurring in bands in the eastern side of Tropical Storm Tammy. Bands in the western side of Tammy’s circulation consisted primarily of showers and lower clouds. Storms near the center of circulation generated upper level divergence that pumped mass away to the north and east of the tropical storm. Winds to tropical storm force extended out 140 miles (220 km) in the eastern side of Tropical Storm Tammy. Winds to tropical storm force extended out 70 miles (110 km) in the western side of Tammy.

Tropical Storm Tammy will move through an environment somewhat favorable for intensification during the next 24 hours. Tammy will move over water where the Sea Surface Temperatures are near 30°C. It will move under the far eastern part of an upper level low over the Eastern Caribbean Sea. The upper level low will produce southwesterly winds that will blow toward the top of Tammy’s circulation. The winds in the lower levels of the atmosphere are blowing from the east. The difference in wind direction between the upper and lower levels of the atmosphere will cause moderate vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Tammy could intensify gradually during the next 24 hours.

Tropical Storm Tammy will move south of a subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Tammy toward the west-northwest during the next 24 hours. On its anticipated track, Tropical Storm Tammy could approach the central and northern Leeward Islands on Friday.

Tropical Storm Tammy is likely to bring gusty winds and locally heavy rain to the central and northern Leeward Islands. Heavy rain is likely to cause flash in some locations. Tropical Storm Tammy could cause a storm surge of up to seven feet (two meters) along the coasts of some of the islands.

Tropical Storm Fiona Brings Wind and Rain to the Leeward Islands

Tropical Storm Fiona brought wind and rain to the Leeward Islands on Friday night. At 11:00 p.m. EDT on Friday the center of Tropical Storm Fiona was located at latitude 16.6°N and longitude 62.2°W which put it about 55 miles (90 km) west-northwest of Guadeloupe. Fiona was moving toward the west at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 1002 mb.

Tropical Storm Warnings were in effect for Saba, St. Eustatius, St. Maarten, Antigua, Barbuda, St. Kitts, Nevis, Montserrat, Anguilla, Guadeloupe, St. Martin and St. Barthelemy, Puerto Rico, Culebra, Vieques, the U.S. Virgin Islands, the British Virgin Islands and the portion of the coast from Cabo Caucedo to Puerto Plata, Dominican Republic. Tropical Storm Watches were in effect for Dominica and for the portion of the coast from Cabo Caucedo to Barahona, Dominican Republic.

More thunderstorms developed near the center of Tropical Storm Fiona on Friday night which caused Fiona to strengthen. Although there were more thunderstorms near the center of circulation, most of the thunderstorms were still occurring in bands on the eastern side of Tropical Storm Fiona. Bands in the western half of the circulation consisted primarily of showers and lower clouds. The new thunderstorms near the center of Fiona generated upper level divergence that pumped mass away to the north and east of the tropical storm. Winds to tropical storm force extended out 140 miles (220 km) from the center of Tropical Storm Fiona.

Tropical Storm Fiona will move through an environment somewhat favorable for intensification during the next 24 hours. Fiona will move over water where the Sea Surface Temperatures are near 29˚C. An upper level ridge over the tropical Atlantic Ocean will produce southwesterly winds that will blow toward the top of Tropical Storm Fiona. Those winds will cause vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Fiona could continue to strengthen gradually, but the wind shear will limit intensification during the next 24 hours.

Tropical Storm Fiona will move around the southern side of the subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Fiona toward the west-northwest during the next 36 hours. Tropical Storm Fiona will continue to cause gusty winds and locally heavy rain to the northern Leeward Islands during the next 12 hours. Heavy rain could cause flash floods in some locations. On its anticipated track Tropical Storm Fiona could be southeast of Puerto Rico by Saturday evening. Fiona could be near the eastern end of the Dominican Republic by Sunday evening. There is a chance that Fiona could be a hurricane by that time.

Tropical Storm Fiona Approaches the Leeward Islands

Tropical Storm Fiona approached the Leeward Islands on Friday afternoon. At 2:00 p.m. EDT on Friday the center of Tropical Storm Fiona was located at latitude 16.2°N and longitude 60.3°W which put it about 75 miles (120 km) east of Guadeloupe. Fiona was moving toward the west at 14 m.p.h. (22 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 1005 mb.

Tropical Storm Warnings were in effect for Saba, St. Eustatius, St. Maarten, Antigua, Barbuda, St. Kitts, Nevis, Montserrat, Anguilla, Guadeloupe, St. Martin and St. Barthelemy, Puerto Rico, Culebra, Vieques, the U.S. Virgin Islands, and the British Virgin Islands. Tropical Storm Watches were in effect for Dominica and the portion of the coast from Cabo Engano to Cabo Frances Viejo, Dominican Republic.

Tropical Storm Fiona was nearing the Leeward Islands on Friday afternoon. The distribution of thunderstorms in Tropical Storm Fiona continued to be asymmetrical. Most of the thunderstorms were occurring in bands in the eastern side of Fiona’s circulation. Bands in the western half of the circulation consisted primarily of showers and lower clouds. Tropical Storm Fiona was moving under the northern side of an upper level ridge over the tropical Atlantic Ocean. The ridge was producing southwesterly winds that were blowing toward the top of Fiona’s circulation. Those winds were causing moderate vertical wind shear and the wind shear was causing the asymmetrical distribution of thunderstorms. Winds to tropical storm force extended out 140 miles (220 km) from the center of Fiona.

Tropical Storm Fiona will move through an environment somewhat favorable for intensification during the next 24 hours. Fiona will move over water where the Sea Surface Temperatures are near 28˚C. However, the upper level ridge over the tropical Atlantic Ocean will continue to cause vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Fiona could strengthen a little, but the wind shear will limit intensification during the next 24 hours.

Tropical Storm Fiona will move around the southern side of the subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Fiona toward the west during the next 36 hours. On its anticipated track Tropical Storm Fiona will move over the Leeward Islands on Friday evening. Fiona will bring gusty winds and locally heavy rain to the northern Leeward Islands. Heavy rain could cause flash floods in some locations. Tropical Storm Fiona could be southeast of Puerto Rico by Saturday evening.

Tropical Storm Fiona Prompts Watch for Puerto Rico

The potential effects of Tropical Storm Fiona prompted the issuance of Tropical Storm Watches for Puerto Rico and the Virgin Islands on Thursday afternoon. Tropical Storm Warnings were in effect for the northern Leeward Islands. At 5:00 p.m. EDT on Thursday the center of Tropical Storm Fiona was located at latitude 16.3°N and longitude 55.4°W which put it about 425 miles (685 km) east of the Leeward Islands. Fiona was moving toward the west at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 1006 mb.

Tropical Storm Warnings were in effect for Saba, St. Eustatius, St. Maarten, Antigua, Barbuda, St. Kitts, Nevis, Montserrat, Anguilla, Guadeloupe, St. Martin and St. Barthelemy. Tropical Storm Watches were in effect for Puerto Rico, Culebra, Vieques, the U.S. Virgin Islands, and the British Virgin Islands.

Tropical Storm Fiona continued to be affected by strong vertical wind shear on Thursday afternoon. The center of Fiona was surrounded by a swirl of showers and lower clouds. Thunderstorms were occurring in bands in the eastern edge of Fiona’s circulation. Tropical Storm Fiona was under the northern part of an upper level ridge over the tropical Atlantic Ocean. The upper level ridge was producing westerly winds that were blowing across the top of Fiona’s circulation. Those winds were causing strong vertical wind shear and the wind shear was blowing the tops off of many of the thunderstorms that start to develop. The vertical wind shear was causing the low level circulation around Tropical Storm Fiona to look a little less organized. Winds to tropical storm force extended out 140 miles (220 km) from the center of Fiona’s circulation.

Tropical Storm Fiona will move through an environment marginally favorable for intensification during the next 36 hours. Fiona will move over water where the Sea Surface Temperatures are near 28˚C. However, the upper level ridge over the tropical Atlantic Ocean will continue to cause vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Fiona could weaken if the upper level winds get stronger. The upper level winds could be weaker when Fiona moves over the northeastern Caribbean Sea during the weekend.

Tropical Storm Fiona will move around the southern side of the subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Fiona toward the west during the next 36 hours. On its anticipated track Tropical Storm Fiona could approach the Leeward Islands on Friday afternoon. Fiona could bring gusty winds and locally heavy rain to the northern Leeward Islands. Tropical Storm Fiona could be southeast of Puerto Rico by Saturday evening.

Tropical Storm Fiona Prompts Warnings for Leeward Islands

A potential threat posed by Tropical Storm Fiona prompted the issuance of Tropical Storm Warnings for some of the Leeward Islands. At 11:00 a.m. EDT on Thursday the center of Tropical Storm Fiona was located at latitude 16.6°N and longitude 54.3°W which put it about 495 miles (800 km) east of the Leeward Islands. Fiona was moving toward the west at 14 m.p.h. (22 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 1002 mb.

Tropical Storm Warnings were in effect for Saba, St. Eustatius, St. Maarten, Antigua, Barbuda, St. Kitts, Nevis, Montserrat and Anguilla. Tropical Storm Watches were in effect for Guadeloupe, St. Martin and St. Barthelemy.

Tropical Storm Fiona was being affected by strong vertical wind shear on Thursday morning. The center of Fiona was surrounded by a swirl of showers and lower clouds. Thunderstorms were occurring in bands in the eastern edge of Fiona’s circulation. Tropical Storm Fiona was under the northern part of an upper level ridge over the tropical Atlantic Ocean. The upper level ridge was producing westerly winds that were blowing across the top of Fiona’s circulation. Those winds were causing strong vertical wind shear and the wind shear was blowing the tops off of many of the thunderstorms that start to develop. In spite of the vertical wind shear, the low level circulation around Tropical Storm Fiona was still well organized. Winds to tropical storm force extended out 140 miles (220 km) from the center of Fiona’s circulation.

Tropical Storm Fiona will move through an environment marginally favorable for intensification during the next 36 hours. Fiona will move over water where the Sea Surface Temperatures are near 28˚C. However, the upper level ridge over the tropical Atlantic Ocean will continue to cause vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Fiona could weaken if the upper level winds get stronger. The upper level winds could be weaker when Fiona moves over the northeastern Caribbean Sea during the weekend.

Tropical Storm Fiona will move around the southern side of the subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Fiona toward the west during the next 36 hours. On its anticipated track Tropical Storm Fiona could approach the Leeward Islands on Friday afternoon. Fiona could bring gusty winds and locally heavy rain to the northern Leeward Islands. Tropical Storm Fiona could be southeast of Puerto Rico by Saturday evening.

TD 7 Strengthens to Tropical Storm Fiona, Watches Issued for Leeward Islands

Former Tropical Depression Seven strengthened to Tropical Storm Fiona on Wednesday evening and Tropical Storm Watches were issued for the Leeward Islands. At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Fiona was located at latitude 16.7°N and longitude 52.0°W which put it about 650 miles (1045 km) east of the Leeward Islands. Fiona was moving toward the west at 16 m.p.h. (26 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 1002 mb.

Tropical Storm Watches were in effect for Saba, St. Eustatius, St. Maarten, Antigua, Barbuda, St. Kitts, Nevis, Montserrat and Anguilla.

Remotely sensed data gathered by satellites indicated that the circulation around former Tropical Depression Seven had strengthened on Wednesday evening and the National Hurricane Center upgraded the system to Tropical Storm Fiona. The distribution of thunderstorms in Tropical Storm Fiona was asymmetric. Almost all of the thunderstorms were occurring in bands in the eastern half of Fiona’s circulation. Bands in the western half of the circulation consisted primarily of showers and lower clouds. Storms in the eastern half of the circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 140 miles (220 km) on the eastern side of Tropical Storm Fiona. The winds in the western half of the circulation were blowing at less than tropical storm force.

Tropical Storm Fiona will move through an environment somewhat favorable for intensification during the next 36 hours. Fiona will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western part of an upper level ridge over the tropical Atlantic Ocean. The ridge will produce southwesterly winds that will blow toward the top of Fiona’s circulation. Those winds will cause some vertical wind shear and the wind shear will inhibit intensification. Tropical Storm Fiona could intensify if the upper level winds weaken.

Tropical Storm Fiona will move around the southern side of the subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Fiona toward the west during the next 48 hours. On its anticipated track Tropical Storm Fiona could approach the Leeward Islands on Friday afternoon. Fiona could bring gusty winds and locally heavy rain to the northern Leeward Islands.

Tropical Depression Fourteen Forms Over Western Caribbean

Tropical Depression Fourteen formed over the western Caribbean Sea on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Tropical Depression Fourteen was located at latitude 15.1°N and longitude 79.7°W which put it about 235 miles (375 km) east of Cabo Gracias a Dios.  The depression was moving toward the west at 21 m.p.h. (33 km/h).  The maximum sustained wind speed was 35 m.p.h. (55km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1007 mb.

A Tropical Storm Watch was issued for the portion of the coast of Honduras from the border with Nicaragua to Punta Castilla including the Bay Islands.

Satellite images on Thursday morning indicated that a center of circulation had developed within a tropical wave over the western Caribbean Sea and the National Hurricane Center designated the system as Tropical Depression Fourteen.  The circulation around Tropical Depression Fourteen was still organizing.  Bands of showers and thunderstorms were developing and they were beginning to revolve around the center of circulation.  Storms near the center started to generate upper level divergence which was pumping mass away from the depression.

Tropical Depression Fourteen will move through an environment favorable for intensification during the next 36 to 48 hours.  The depression 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 the will be little vertical wind shear.  Tropical Depression Fourteen will strengthen during the next day or two.

Tropical Depression Fourteen will move around the southwester part of a subtropical high pressure system over the North Atlantic Ocean.  The high will steer the depression toward the west-northwest during the next 24 hours.  The depression will turn toward the northwest on Friday when it gets closer to the western end of the high.  On its anticipated track Tropical Depression Fourteen will pass near the coast of Honduras on Friday.  It will approach the Yucatan Peninsula on Saturday.  The depression could drop heavy rain over eastern Honduras and flash floods will be possible.

Elsewhere over the Atlantic Ocean,, Tropical Depression Thirteen was speeding toward the northern Leeward Islands.  At 11:00 a.m. EDT on Thursday the center of Tropical Depression Thirteen was located at latitude 16.0°N and longitude 52.0°W which put it about 750 miles (1205 km) east-southeast of the northern Leeward Islands.  The depression was moving toward the west-northwest at 21 m.p.h. (33km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1008 mb.

Tropical Storm Watches were in effect for Saba and St. Eustatius, St. Maarten, St. Kitts, Nevis, Antigua, Barbuda and Anguilla.

Potential Tropical Storm Prompts Warnings for Puerto Rico, Virgin Islands, Leeward Islands

A low pressure system that has the potential to organize into a tropical storm prompted the issuance of Tropical Storm Warnings for Puerto Rico, the Virgin Islands and many of the Leeward Islands on Tuesday morning.  At 11:00 a.m. EDT on Tuesday the center of Potential Tropical Cyclone Nine was located at latitude 13.8°N and longitude 53.7°W which put it about 585 miles (940 km) east-southeast of the Leeward Islands.  It was moving toward the west at 23 m.p.h. (37 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 1007 mb.

Tropical Storm Warnings were issued for Puerto Rico, Culebra, Vieques, the U.S. Virgin Islands, Antigua, Barbuda, the British Virgin Islands, Montserrat, St. Kitts, Nevis, Guadeloupe, Martinique, St. Martin, Saba, St. Eustatius, and St. Maarten.

The circulation around Potential Tropical Cyclone Nine was very broad and it stretched from the southwest toward the northeast.  The stronger thunderstorms were occurring in the southwestern and northeastern ends of the circulation.  There were few thunderstorms or bands in the broad middle of the low pressure system.  Winds to tropical storm force extended out 200 miles (320 km) on the northern side of the circulation.  The winds in the southern half of the low pressure system were blowing at less than tropical storm force.

Potential Tropical Cyclone Nine will move through an environment favorable for intensification during the next two days.  It 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.  The large broad circulation will contribute to a slow, gradual intensification.  If thunderstorms consolidate around a center of circulation and an inner core begins to form, then the system may be designated as a tropical storm.

Potential Tropical Cyclone Nine will move south of a subtropical high pressure system over the North Atlantic Ocean.  The high will steer the potential tropical storm toward the west-northwest during the next several days.  On its anticipated track Potential Tropical Cyclone Nine could approach the Leeward Islands on Wednesday morning.  It could approach the Virgin Islands and Puerto Rico by Wednesday night.  The large circulation means that Potential Tropical Nine will bring a prolonged period of gusty winds.  It could also drop heavy rain and cause flash floods on some islands.

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.