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Hurricane Dorian Strengthens East of the Bahamas

Hurricane Dorian resumed strengthening east of the Bahamas on Thursday night after exhibiting little change of intensity during much of the day.  At 11:00 p.m. EDT on Thursday the center of Hurricane Dorian was located at latitude 23.3°N and longitude 68.4°W which put it about 580 miles (930 km) east of the Northwestern Bahamas.  Dorian was moving toward the northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 977 mb.

The structure of Hurricane Dorian exhibited little change for much of Thursday.  Storms around the core of Dorian grew stronger on Thursday evening.  An eye with a diameter of 10 miles (16 km) developed at the center of circulation.  A nearly complete ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Hurricane Dorian.  Storms near the core were generating upper level divergence which was pumping mass away from the hurricane.  The removal of mass allowed the surface pressure to start decreasing again.  The circulation around Dorian was still relatively small.  Winds to hurricane force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 100 miles (160 km) from the center.

Hurricane Dorian will move through an environment favorable for intensification during the next 24 to 48 hours.  Dorian will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Dorian is likely to intensify to major hurricane status on Friday.  There is the potential for Dorian to strengthen to Category 5 on the Saffir-Simpson Scale during the weekend.  When Hurricane Dorian becomes a major hurricane, eyewall replacement cycles could cause fluctuations in its intensity.

A ridge of high pressure will build north of Hurricane Dorian on Friday.  The high will block Dorian from moving toward the north and it will turn the hurricane toward the west.  On its anticipated track Hurricane Dorian could approach the Northwestern Bahamas on Sunday and the east coast of Florida on Monday.  Dorian is likely to be a small, but very dangerous hurricane.

Hurricane Dorian Strengthens North of Puerto Rico

Hurricane Dorian strengthened north of Puerto Rico on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Hurricane Dorian was located at latitude 19.7°N and longitude 66.0°W which put it about 90 miles (145 km) north of San Juan, Puerto Rico.  Dorian was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 110 m.p.h. (170 km/h).  The minimum surface pressure was 986 mb.

The circulation around Hurricane Dorian strengthened steadily on Wednesday.  A circular eye with a diameter of 14 miles (22 km) formed at the center of circulation.  A closed ring of thunderstorms surrounded the eye and the strongest winds were occurring in the northeastern part of that ring.  Bands of showers and thunderstorms were revolving around the core of Hurricane Dorian.  Storms near the core were generating upper level divergence which was pumping mass away to the north and northeast of the hurricane.  The circulation around Hurricane Dorian remained fairly small.  Winds to hurricane force extended out about 20 miles (30 km) in the northeastern quadrant of Dorian.  Winds to tropical storm force extended out about 70 miles from the center of circulation.

Hurricane Dorian will move through an environment favorable for intensification during the next several days.  Dorian will move over water where the Sea Surface Temperature is near 29°C.  It will move into an area where the upper level winds are relatively weak and there will be little vertical wind shear.  Hurricane Dorian is very likely to intensify during the next 48 hours and it could intensify rapidly at times.  Dorian is likely to strengthen into a major hurricane.

An upper level low near the Bahamas will pull Hurricane Dorian toward the northwest during the next 24 to 36 hours.  A strong ridge of high pressure will build north of Dorian on Friday.  The high will block Dorian from moving north and it will turn it toward the west-northwest.  On its anticipated track Hurricane Dorian could be near the northern Bahamas on Saturday night.  Dorian could approach the east coast of Florida by later on Sunday.  Dorian is likely to be a major hurricane when it approaches Florida.

Tropical Storm Dorian Strengthens, Hurricane Warnings for Virgin Islands

Tropical Storm Dorian strengthened on Wednesday morning and it was on the verge of becoming a hurricane.  Hurricane Warnings were issued for Vieques, Culebra, the U.S. Virgin Islands and the British Virgin Islands. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Dorian was located at latitude 17.5°N and longitude 64.5°W which put it about 25 miles (40 km) south of St. Croix.  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 999 mb.

Hurricane Warnings were in effect for Vieques, Culebra, the U.S. Virgin Islands, and the British Virgin Islands.  A Tropical Storm Warning and a Hurricane Watch was in effect for Puerto Rico.  A Tropical Storm Watch was in effect for the portion of the coast of the Dominican Republic from Isla Saona to Samana.

The circulation around Tropical Storm Dorian exhibited much greater organization on Wednesday morning.  A ring of strong thunderstorms wrapped almost completely around the center of circulation.  The strongest winds were occurring in the northeastern part of that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Dorian.  Storms near near the core were generating upper level divergence which was pumping mass away to the north and northeast of the tropical storm.  The circulation also increased in size on Wednesday morning.  Winds to tropical storm force extended out about 70 miles (110 km) from the center of circulation.

Tropical Storm Dorian will move through an environment favorable for intensification during the next few days.  Dorian will move over water where the Sea Surface Temperature is near 29°C.  It will move northeast of an upper level low during the next 24 hours.  The low will produce some southerly winds which will blow toward the top of the circulation, but the winds will not be strong enough to prevent intensification.  The wind shear will decrease on Friday and Dorian could strengthen into a major hurricane near the Bahamas.

The upper level low will help to steer Tropical Storm Dorian toward the northwest during the next 24 to 36 hours.  A ridge of high pressure will build north of Dorian on Friday.  The ridge will block Dorian from moving north and it will steer Dorian toward the west-northwest.  On its anticipated track Tropical Storm Dorian will pass over the Virgin Islands near the eastern end of Puerto Rico today.  Dorian will be near the northern Bahamas on Saturday and it could approach the east coast of Florida by Sunday night.  Dorian could be a major hurricane when it approaches the east coast of the U.S.

Elsewhere over the Atlantic Ocean, former Tropical Storm Erin weakened to a tropical depression.  At 11:00 a.m. EDT on Wednesday the center of Tropical Depression Erin was located at latitude 33.6°N and longitude 72.8°W which put it about 190 miles (305 km) southeast of Cape Hatteras, North Carolina.  Erin was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1006 mb.

Tropical Storm Dorian Moves Toward Puerto Rico

Tropical Storm Dorian moved toward Puerto Rico on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Dorian was located at latitude 16.0°N and longitude 63.0°W which put it about 275 miles (440 km) east-southeast of Ponce, Puerto Rico.  Dorian was moving toward the northwest at 13 m.p.h. (20 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.

A Hurricane Watch was issued for Puerto Rico.  Tropical Storm Warnings were in effect for Puerto Rico, Culebra, Vieques, the U.S. Virgin Islands and the British Virgin Islands.  A Tropical Storm Watch was issued for the coast of the Dominican Republic from Isla Saona to Puerto Plata.

The original low level center of Tropical Storm Dorian passed south of Barbados and St. Lucia on Tuesday morning.  Dorian dropped heavy rain and there were reports of flash floods on Martinique.  The original center weakened on Tuesday afternoon and a new low level center formed about 60 miles farther to the north.  The formation of a new center of circulation caused the forecast future track of Tropical Storm Dorian to be shifted northward as well.

Even with the formation of a new center of circulation, the overall circulation around Tropical Storm Dorian did not change much on Tuesday.  The circulation around Dorian remained small.  Winds to tropical storm force only extended out about 45 miles (75 km) from the center of circulation.  A broken ring of thunderstorms surrounded the new low level center.  Bands of showers and thunderstorms were revolving the center of Tropical Storm Dorian.  Storms near the center were producing upper level divergence which was pumping mass away to the north of the tropical storm.

Tropical Storm Dorian will move through an environment somewhat favorable for intensification on Wednesday.  Dorian will move over water where the Sea Surface Temperature is near 29°C.  An upper level low northwest of Puerto Rico will produce southerly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, which will inhibit intensification.  A large mass of drier air is north of Tropical Storm Dorian and the drier air could also inhibit intensification if it gets pulled into the circulation around Dorian.  The small size of the circulation around Tropical Storm Dorian means that it could weaken or strengthen quickly if the environmental conditions change significantly.  Dorian is likely to weaken when it crosses Puerto Rico on Wednesday night.

The upper low northwest of Puerto Rico will help to steer Tropical Storm Dorian toward the northwest on Wednesday.  On its anticipated track Tropical Storm Dorian could reach Puerto Rico by Wednesday evening.  Dorian will bring gusty winds and it will drop locally heavy rain on Puerto Rico.  Locally heavy rain could cause flash floods in some locations.  A high pressure system will build north of Tropical Storm Dorian on Thursday and Friday.  The high will turn Dorian back toward the west-northwest.  Dorian could approach the east coast of Florida on Sunday.

Elsewhere over the Atlantic Ocean, Tropical Depression Six strengthened into Tropical Storm Erin southeast of Cape Hatteras on Tuesday night.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Erin was located at latitude 31.9°N and longitude 72.1°W which put it about 300 miles (485 km) southeast of Cape Hatteras, North Carolina.  Erin was moving toward the west at 2 m.p.h. (3 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. (65 km/h).  The minimum surface pressure was 1005 mb.  Tropical Storm Erin is forecast to move northeast toward Nova Scotia.

Tropical Depression Three Forms East of Florida

Tropical Depression Three formed east of Florida on Monday.  More thunderstorms developed near the center of a small low pressure system over the Northwestern Bahamas on Monday afternoon and the National Hurricane Center (NHC) designated the system as Tropical Depression Three.  At 5:00 p.m. EDT on Monday the center of Tropical Depression Three was located at latitude 25.6°N and longitude 78.6°W which put it about 120 miles (195 km) southeast of West Palm Beach, Florida.  The depression was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1013 mb.

More thunderstorms developed around the center of a small low pressure system that was embedded in the northern end of a tropical wave over the Bahamas on Monday.  Most of the thunderstorms were forming in bands on the eastern side of the circulation.  Based on data from satellites NHC determined that a closed circulation had formed at the surface.  There were fewer thunderstorms in the western half of the circulation.  Storms in the eastern half of the depression were exhibiting upper level divergence to the north and east.

Tropical Depression Three will move through an environment somewhat favorable for intensification during the next 24 hours.  The depression will move over water where the Sea Surface Temperature is near 29°C.  It will be in under the western side of an upper level ridge.  The ridge could enhance upper level divergence on Tuesday.  The wind aloft will be relatively weak, although a thin upper trough near the east coast of the U.S. will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear but the shear will not be strong enough to prevent intensification.  The surface pressure is relatively high and that could slow any intensification.  A larger upper level trough will develop over the eastern U.S. on Tuesday and the trough will produce stronger southwesterly winds.  Those winds will create much more shear on Wednesday.

Tropical Depression Three will move around the western end of a subtropical high pressure system over the western Atlantic Ocean.  The high will steer the depression toward the northwest during the next 12 hours.  Tropical Depression Three is likely to more more toward the north later on Tuesday when it reaches the western end of the ridge.  On its anticipated track the center of Tropical Depression Three could be near the southeast coast of Florida in about 12 hours.  The center is not currently forecast to make landfall, but the depression could bring squally weather and an increased chance for rain to the southeast coast of the U.S. during the next several days.

Hurricane Michael Makes Landfall in Northwest Florida

Powerful Hurricane Michael made landfall in Northwest Florida Wednesday afternoon.  The center of Hurricane Michael officially made landfall between Panama City and Mexico Beach, Florida.  At 2:00 p.m. EDT on Wednesday the center of Hurricane Michael was located at latitude 30.0°N and longitude 85.5°W which put it about 20 miles (30 km) southeast of Panama City, Florida.  Michael was moving toward the north-northeast at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 155 m.p.h. (250 km/h) and there were wind gusts to 180 m.p.h. (290 km/h).  The minimum surface pressure was 919 mb.

Hurricane Michael intensified rapidly right up to landfall on the Gulf Coast.  The minimum surface pressure decreased from 933 mb to 919 mb in the six hours prior to landfall.  With a maximum sustained wind speed of 155 m.p.h. (250 km/h) Hurricane Michael was at the top end of Category 4 on the Saffir-Simpson Scale.  Michael is the strongest hurricane on record to make landfall on that portion of the Gulf Coast and it was one of the most intense hurricanes to make landfall anywhere along the coast of the U.S. during the month of October.

Even though Hurricane Michael is moving inland, a Hurricane Warning remains in effect for the portion of the coast from the Alabama-Florida border to Suwanee River, Florida.  A Tropical Storm Warning is in effect from the Suwanee River to Chassahowitzka, Florida.  A Tropical Storm Warning is also in effect for the Atlantic Coast from Fernandina Beach, Florida to Duck, North Carolina including Albemarle and Pamlico Sounds.  A Tropical Storm Watch remains in effect from Chassahowitzka to Anna Maria Island, Florida.

Winds to hurricane force extended out about 45 miles (75 km) from the center of Hurricane Michael at the time of landfall.  Winds to tropical storm force extended out about 185 miles (290 km) from the center of circulation.  The Hurricane Intensity Index (HII) was 33.3.  The Hurricane Size Index (HSI) was 16.1 and the Hurricane Wind Intensity Size Index (HWISI) was 49.4.  Hurricane Michael will cause regional significant damage.

Tyndall Air Force Base reported a wind gust of 119 m.p.h. (191 km/h).  The Florida State University Panama City Campus reported a wind gust of 116 m.p.h. (187 km/h).   The Panama City Treatment Plant reported a wind gust of 94 m.p.h. (151 km/h).

The coast along the northeastern Gulf of Mexico is very vulnerable to storm surges.  The winds were pushing water toward the coast in the eastern half of the circulation of Hurricane Michael.  Some locations could have a storm surge of 10 to 15 feet (3 to 5 meters).  There have already been reports of damage due to storm surge.

An upper level trough will steer Hurricane Michael toward the northeast.  Michael will weaken as it moves inland, but it will carry hurricane force winds over northeastern Florida, extreme southeastern Alabama and southern Georgia.  The center of Hurricane Michael will pass between Dothan, Alabama and Tallahasse, Florida.  it will move toward Albany, Georgia and then pass south of Macon, Georgia.  Michael will move across South Carolina and North Carolina as a tropical storm before exiting the U.S. near Norfolk, Virginia.

Hurricane Michael will cause widespread power outages and numerous outages are already occurring in northwest Florida.  Michael will also produce locally heavy rain and flash floods could occur as it moves inland.  Wind and rain will disrupt efforts in South Carolina and North Carolina to recover from the effects of Hurricane Florence.

One of the most unusual aspects of Hurricane Michael was that it intensified rapidly right up until it made landfall in northwest Florida.  In the past most major hurricanes weakened while they approached the coast along the northern Gulf of Mexico.  Those hurricanes encountered drier air and more vertical wind shear and they weakened.  The Sea Surface Temperatures in the northern Gulf of Mexico is 2°C to 3°C warmer than normal and that may have contributed to the rapid intensification of Hurricane Michael before landfall.  Hurricane Camille in 1969 also intensified right up until it made landfall in Mississippi.  However, Camille occurred in August, while Hurricane Michael occurred in October.

Powerful Hurricane Michael Nearing North Florida

Powerful hurricane Michael was nearing north Florida on Wednesday morning.  Michael intensified rapidly to Category 4 on the Saffir-Simpson Scale during the overnight hours.  At 8:00 a.m. EDT on Wednesday the center of Hurricane Michael was located at latitude 29.0°N and longitude 86.3°W which put it about 90 miles south-southwest of Panama City, Florida.  Michael was moving toward the north at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 170 m.p.h. (275 km/h).  The minimum surface pressure was 933 mb.

A Hurricane Warning was in effect for the portion of the coast from the Alabama-Florida border to Suwanee River, Florida.  Tropical Storm Warnings were in effect for the portions of the coast from the Alabama-Florida border to the Alabama-Mississippi border and from Suwanee River to Chassahowitzka, Florida.  A Tropical Storm Warning was in effect for the Atlantic Coast from Fernandina Beach, Florida to Surf City, North Carolina.  Tropical Storm Watches were in effect for the portions of the coast from the Alabama-Mississippi border to the Mouth of the Pearl River and from Chassahowitzka to Anna Maria Island, Florida.  A Tropical Storm Watch was also in effect from Surf City to Duck, North Carolina including Albemarle and Pamlico Sounds.

Hurricane Michael intensified rapidly during the past 12 hours.  An eye with a diameter of 20 miles (32 km) is surrounded by a ring of strong thunderstorms.  The strongest winds are occurring in that ring of storms.  Storms near the core of Hurricane Michael are generating strong upper level divergence which is pumping large quantities of mass away from the hurricane.  The removal of mass allowed the surface pressure to decrease rapidly to 933 mb.

Winds to hurricane force extend out about 45 m.p.h. (75 km/h) from the center of Hurricane Michael.  Winds to tropical storm force extend out about 185 miles (290 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Hurricane Michael is 29.9.  The Hurricane Size Index (HSI) is 16.1 and the Hurricane Wind Intensity Size Index (HWISI) is 46.0.  Hurricane Michael is capable of causing regional significant damage.

Hurricane Michael is stronger than any other hurricane to hit north Florida in the historical record.  Michael is similar in intensity to what Hurricane Charley was when Charley hit southwest Florida in 2004.  Hurricane Michael is bigger than Charley was in 2004.

An upper level trough over the Central U.S. and a subtropical high pressure system over the western Atlantic Ocean are combining to steer Hurricane Michael toward the north.  The trough will turn Michael toward the northeast when it reaches the coast.  On its anticipated track Hurricane Michael will make landfall near Panama City and Port St. Joe, Florida in about six hours.

Hurricane Michael will bring destructive winds to the coast of north Florida.  The strongest winds will be near the center and east of the center.  Those winds will push water toward the coast and a storm surge of 10 to 15 feet (3 to 5 meters) will occur east of where the center of Michael makes landfall.  The coast of the northeast Gulf of Mexico is very vulnerable to storm surges and significant damage will occur.

The center of Hurricane Michael will move between Dothan, Alabama and Tallahassee, Florida.  It will pass near Albany, Georgia and then move south of Macon, Georgia.  The center of Michael could move near Columbia, South Carolina and then it could exit the East Coast of the U.S. near Norfolk, Virginia.

Michael will bring hurricane force winds to northeast Florida, extreme southeast Alabama and southern Georgia.  There will be widespread power outages.  Winds to tropical storm force will occur in South Carolina and North Carolina.  Hurricane Michael will drop locally heavy rain when it moves inland.  The wind and rain will disrupt efforts to recover from the effects of Hurricane Florence in South Carolina and North Carolina.

Michael Strengthens to a Major Hurricane

Hurricane Michael strengthened into a major hurricane on Tuesday afternoon.  At 5:00 p.m. EDT on Tuesday the center of Hurricane Michael was located at latitude 26.0°N and longitude 86.4°W which put it about 290 miles (470 km) south of Panama City, Florida.  Michael was moving toward the north at 12 m.p.h. (19 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 957 mb.

A Hurricane Warning is in effect for the portion of the coast from the Alabama-Florida border to the Suwanee River, Florida.  Tropical Storm Warnings are in effect for the portions of the coast from the Alabama-Florida border to the Alabama-Mississippi border, from Suwanee River to Chassahowitzka, Florida and from Fernandina Beach, Florida to South Santee River, South Carolina on the Atlantic Coast.  Tropical Storm Watches are in effect for the portions of the coast from the Alabama-Mississippi border to the Mouth of the Pearl River, from Chassahowitzka to Anna Maria Island, Florida and from South Santee, River South Carolina to Duck, North Carolina including Albemarle and Pamlico Sounds.

The inner core of Hurricane Michael tightened on Tuesday afternoon.  The diameter of the eye decreased from 30 miles (50 km) to 22 miles (35 km).  The ring of thunderstorms around the eye tightened around the smaller eye and the strongest winds were closer to the center of circulation.  Storms around the core of Michael were generating upper level divergence which was pumping mass away from the hurricane.  The removal of mass allowed the surface pressure to decrease from 965 mb to 957 mb during the past six hours.

Winds to hurricane force extend out about 45 miles (75 km) from the center of Hurricane Michael.  Winds to tropical storm force extend out about 170 miles (280 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Hurricane Michael is 22.1.  The Hurricane Size Index (HSI) is 14.6 and the Hurricane Wind Intensity Size Index (HWISI) is 36.7.  Hurricane Michael is capable of causing regional major damage.

Hurricane Michael will move through an environment favorable for intensification for another 12 to 18 hours.  Michael will move over water where the Sea Surface Temperature is near 29°C.  An upper level trough over the Central U.S. is producing westerly winds which are blowing toward the top of Hurricane Michael, but those winds are not causing enough vertical wind shear to prevent intensification.  Hurricane Michael could intensify to Category 4 on the Saffir-Simpson Scale before it makes landfall.

Hurricane Michael is moving between a subtropical high pressure system over the western Atlantic Ocean and the upper level trough over the Central U.S.  Those two weather systems are steering Michael toward the north and that general motion is expected to continue for another 12 hours.  On its anticipated track Hurricane Michael will make landfall near Panama City and Port St. Joe, Florida early on Wednesday afternoon.  The upper level trough will steer Michael more toward the northeast after it makes landfall.  The center of Michael is likely to move between Dothan, Alabama and Tallahassee, Florida and it could pass near Albany, Georgia.

Hurricane Michael will bring strong winds to northwest Florida, extreme southeast Alabama and southern Georgia.  There will be wind damage and widespread power outages could occur.  The coast of the northeastern Gulf of Mexico is very vulnerable to storm surges.  Hurricane Michael will produce a storm surge of 10 to 15 feet (3 to 5 meters) at some points along the coast.  Michael will drop locally heavy rain.  Although Hurricane Michael will weaken when it moves inland, it will bring gusty winds and heavy rain to South Carolina and North Carolina.  Hurricane Michael will hinder efforts in those states to recover from the effects of Hurricane Florence.

Michael Strengthens Into a Hurricane, Watches Issued for Gulf Coast

Former Tropical Storm Michael strengthened into a hurricane on Monday morning and Watches were issued for portions of the Gulf Coast.  At 11:00 a.m. EDT on Monday the center of Hurricane Michael was located at latitude 21.2°N and longitude 84.9°W which put it about 50 miles (80 km) south of the western end of Cuba.  Michael was moving toward the north 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 982 mb.

A Hurricane Watch was in effect for the portion of the coast from the Alabama-Florida border to Suwanee River, Florida.  Tropical Storm Watches were in effect for the portions of the coast from the Alabama-Florida border to the Alabama-Mississippi border and from Suwanee River to Anna Maria Island, Florida.  A Hurricane Warning was in effect for the Cuban province of Pinar del Rio.  Tropical Storm Warnings were in effect for the Cuban province of Isle of Youth and for the portion of the coast from Tulum to Cabo Catoche, Mexico.

Hurricane Michael continued to organize quickly.  A circular eye with a diameter of about 30 miles (50 km) was forming at the center of Michael.  A ring of strong thunderstorms was wrapping around the eye and the strongest winds were occurring in the ring of storms.  Several bands of showers and thunderstorms were wrapping around the core of Hurricane Michael.  Storms near the core were generating upper level divergence which was pumping mass away from the hurricane.

Winds to hurricane force extended out about 30 miles (50 km) primarily to the northeast of the center of Hurricane Michael.  Winds to tropical storm force extended out about 175 miles (280 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Hurricane Michael was 10.4.  The Hurricane Size Index (HSI) was 6.8 and the Hurricane Wind Intensity Size Index (HWISI) was 17.2.

Hurricane Michael will move into an environment that will become increasingly favorable for intensification.  Michael will move over water where the Sea Surface Temperature is near 30°C.  An upper level trough over the Gulf of Mexico was producing westerly winds which were blowing toward the top of the circulation.  Those winds were causing some vertical wind shear.  However, the upper level trough will move westward away from Hurricane Michael and the wind shear will decrease.  Hurricane Michael will continue to strengthen when it moves over the Gulf of Mexico and it could intensify rapidly once the eye and eyewall are fully formed.  Hurricane Michael is likely to strengthen into a major hurricane.

Hurricane Michael will move around the western end of a subtropical high pressure system centered over the western Atlantic Ocean.  The high will steer Michael in a northerly direction during the next several days.  It will get bigger and stronger during the next 48 hours.  On its anticipated track Hurricane Michael will approach the northeast coast of the Gulf of Mexico on Wednesday.  It is likely to be a major hurricane at that time.  Hurricane Michael has the potential to cause a storm surge of 10 to 15 feet (3 to 5 meters) at the coast.  It will bring strong winds which could cause regional major damage and result in significant power outages.  Locally heavy rain could cause flooding in some locations.

Tropical Storm Michael Strengthens East of Yucatan

Tropical Storm Michael strengthened east of the Yucatan peninsula on Sunday.  At 8:00 p.m. EDT on Sunday the center of Tropical Storm Michael was located at latitude 19.9°N and longitude 85.4°W which put it about 105 miles (170 km) east-southeast of Cozumel, Mexico.  Michael was moving toward the north at 5 m.p.h. (8 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 997 mb.

A Tropical Storm Warning was in effect for the Cuban provinces of Pinar del Rio and the Isle of Youth.  A Tropical Storm Warning is also in effect for the portion of the coast from Tulum to Cabo Catoche, Mexico.

The circulation around Tropical Storm Michael is still organizing and the distribution of thunderstorms is asymmetrical.  Most of the thunderstorms are occurring in bands in the eastern half of the circulation.  A new center of circulation formed on Sunday afternoon near those thunderstorms.  Many of the rainbands in the western half of Tropical Storm Michael contain primarily showers and lower clouds.  One outer rainband in the southwestern periphery of the circulation does contain numerous thunderstorms.  The strongest winds are occurring in the rainbands on the eastern side of Tropical Storm Michael.  The winds are weaker on the western side of the circulation.  Storms on the eastern side of Michael are generating some upper level divergence which was pumping mass away from the tropical storm and was allowing the surface pressure to decrease.

An upper level trough over the Gulf of Mexico is producing westerly winds which are blowing across the top of Tropical Storm Michael.  Those winds are causing moderate vertical wind shear which was slowing the rate of intensification, but the shear is not strong enough to prevent Michael from strengthening.  The wind shear is probably the reason for the asymmetrical distribution of thunderstorms.  The upper level trough will move westward during the next few days and the upper level winds will weaken.  Michael will move over water where the Sea Surface Temperature is warmer than 30°C.  Tropical Storm Michael will strengthen slowly during the next 24 hours.  However, it will intensify more rapidly on Tuesday when the upper level winds weaken.  Michael will strengthen into a hurricane when it moves over the Gulf of Mexico and it could intensify into a major hurricane.

Tropical Storm Michael has been moving slowly while the circulation organizes and the center reforms.  Michael will move around the southwestern part of the subtropical high pressure system over the western North Atlantic Ocean.  The high will steer Michael in a northward direction during the next two or three days.  On its anticipated track the center of Tropical Storm Michael will pass between the western end of Cuba and the Yucatan peninsula on Monday.  Michael could approach northern Florida by Wednesday.  It will be a hurricane at that time and it could be a major hurricane.  Michael could produce strong winds, a significant storm surge and drop heavy rain when it reaches the coast.