Tag Archives: Florida

Tropical Depression One Forms East of Florida

Tropical Depression One formed east of Florida on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Depression One was located at latitude 28.4°N and longitude 78.6°W which put it about 125 miles (200 km) east of Melbourne, Florida.  The depression was moving toward the north-northeast 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 1008 mb.

A Tropical Storm Watch was issued for the portion of the coast from Surf City to Duck, North Carolina including Pamlico and Albemarle Sounds.

Surface observations and data from aircraft reconnaissance indicated that a distinct low pressure system formed east of Florida on Saturday and the National Hurricane Center designated the system as Tropical Depression One.  More thunderstorms developed near the center of circulation.  Storms near the center began to generate upper level divergence which pumped mass away to the east of the depression.  The strongest winds were occurring in the inner part of the circulation, which was consistent with the typical structure of a tropical cyclone.  Bands of showers and thunderstorms were developing.  The strongest bands were in the eastern half of the circulation.

Tropical Depression One will move through an environment favorable for intensification during the next several days.  The depression will move over water where the Sea Surface Temperature is near 25°C.  An upper level trough over the eastern Gulf of Mexico and an upper level ridge east of Florida will interact to produce southerly 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.  Tropical Depression One will strengthen into a tropical storm.

The upper level trough and upper level ridge will steer Tropical Depression One toward the north-northeast during the next 36 to 48 hours.  On its anticipated track Tropical Depression One will approach the coast of North Carolina on Monday.  It will be a tropical storm by that time.  It will bring gusty winds and heavy rain to parts of the coast.  Wind blowing water toward the coast will cause the water level to rise and there will be erosion of the beaches.

Disturbance South of Florida Keys

A disturbance south of the Florida Keys is currently designated at Invest 90L.  The disturbance could develop into a tropical or subtropical cyclone during the next few days.  At 8:00 p.m. EDT on Thursday the center of Invest 90L was located at latitude 23.9°N and longitude 81.2°W which put it about 55 miles (85 km) south of Marathon, Florida.  It was moving toward the east-northeast at 5 m.p.h. (8 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 1013 mb.

A small trough in the middle troposphere moved over a stationary front south of the Florida Keys on Thursday.  Satellite images and radar loops detected rotation in the middle troposphere.  There was a broad counterclockwise rotation south of the Keys and radar loops also revealed several small counterclockwise rotations within the broader mid-level circulation.  However, there did not appear to be a distinct center of circulation with lower pressure at the surface.

Invest 90L is forecast to move toward the northeast during the next several days.  It will move into an environment more favorable for development into a tropical or subtropical cyclone.  Invest 90L will move over water where the Sea Surface Temperature is near 27°C.  There will be an upper level trough over the eastern Gulf of Mexico, but a small upper level ridge will develop east of Florida.  The combination of the upper level trough and the upper ridge will produce a region of upper level divergence east of Florida.  The upper level divergence will pump mass away and the surface pressure will decrease in that area.  A surface low pressure system is likely to form on Friday or Saturday.  The National Hurricane Center is indicating that there is an 80% probability of the formation of a tropical or subtropical cyclone.  A reconnaissance plane is tentatively scheduled to investigate the system on Friday afternoon, if necessary.

Possible Development Near the Bahamas

A low pressure system could develop near the Bahamas on Friday or Saturday.  The National Hurricane Center is indicating that there is a 70% probability that the low pressure system could develop into a subtropical cyclone.

A stationary frontal boundary extends from south of Florida across the Bahamas.  A small upper level trough called a shortwave over the southwestern U.S. will move east toward the stationary front later this week.  When the upper level trough approaches the stationary front, a low pressure system is likely to develop near the Bahamas.  If thunderstorms develop near the center of the low pressure system, then it could exhibit the structure of a tropical or subtropical cyclone.  The Sea Surface Temperature near the Bahamas is near 26°C.  So, the water will be warm enough to support the development of a tropical cyclone.  However, the winds blowing around the upper level trough will cause moderate vertical wind shear.  The wind shear may be strong enough to inhibit the development of a tropical cyclone.  However, the shear may not be strong enough to prevent the development of a subtropical cyclone.  If the low pressure system strengthens into a subtropical storm, it will be designated Subtropical Storm Arthur.

Tropical Storm Nestor Causes Severe Weather in Florida

Tropical Storm Nestor caused severe weather in Florida.  At 2:00 p.m. EDT on Saturday the center of Tropical Storm Nestor was located at latitude 29.7°N and longitude 85.1°W which put it about 5 miles (10 km) west of Apalachicola, Florida.  Nestor was moving toward the east-northeast at 23 m.p.h. (38 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 Tropical Storm Watch was in effect for the portion of the coast from Ochlockonee River to Suwanee River, Florida.

Tropical Storm Nestor began a transition to an extratropical cyclone as it approached the coast of Florida.  Strong westerly winds in the middle latitudes created significant vertical wind shear.  In addition, the circulation around Nestor pulled cooler, drier air into the western and southern parts of the tropical storm.  The effects of the upper level westerly winds and cooler, drier air caused the strongest rising motion to occur in bands well to the east of the center of circulation.  The strongest thunderstorms occurred in bands southeast of the low level center.

The vertical wind shear was strong enough that rotation developed in some of the thunderstorms over the Florida Peninsula.  Several tornado warnings were issued on Friday night because radar indicated likely rotation.  There were reports of property damage due to possible tornadoes in Cape Coral in Lee County, near Winston in Polk County, in Plant City in Hillsborough County and in Seminole in Pinellas County.

The center of Tropical Storm Nestor officially made landfall on St. Vincent Island west of Apalachicola on Saturday afternoon.  Many of the stronger thunderstorms had moved east of Florida by Saturday afternoon.  There were still bands of showers and thunderstorms moving over the Florida Peninsula.  Flow diverging from a surface high pressure system centered over the northeastern U.S. was converging with the flow around the northern part of Tropical Storm Nestor.  The convergence was generating a large area of rising motion.  Showers and thunderstorms were occurring over northern Florida, southeastern Alabama, southern Georgia and parts of South Carolina.

Tropical Storm Nestor will move toward the northeast as an extratropical cyclone during the next several days.  On its anticipated track the center of Nestor will move across southern Georgia and near the coast of South Carolina and North Carolina.  The low pressure system will continue to drop rain over those areas.  There has been below normal rainfall over the southeastern U.S. in recent weeks.  So, the rain is unlikely to cause flooding in most places.

Tropical Storm Nestor Speeds Toward Northwest Florida

Tropical Storm Nestor sped toward northwest Florida on Friday afternoon.  The National Hurricane Center designated a strong low pressure system over the Gulf of Mexico as Tropical Storm Nestor on Friday afternoon.  At 2:00 p.m. EDT on Friday the center of Tropical Storm Nestor was located at latitude 26.3°N and longitude 89.5°W which put it about 355 miles (570 km) southwest of Panama City, Florida.  Nestor was moving toward the northeast at 22 m.p.h. (35 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 1001 mb.

Tropical Storm Warnings were in effect for the portions of the coast from Grand Isle, Louisiana to the mouth of the Pearl River, Mississippi and from the Mississippi/Alabama border to Yankeetown, Florida.  A Storm Surge Warning was in effect for the portion of the coast from Indian Pass to Clearwater Beach, Florida.

Tropical Storm Nestor exhibited an asymmetrical structure that is commonly seen in late season tropical storms over the Gulf of Mexico.  The strongest thunderstorms were occurring in bands in the eastern side of Nestor.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  The tropical storm force winds were occurring in the eastern half of Tropical Storm Nestor.  Winds to tropical storm force extended out 175 miles (280 km) in the eastern side of the circulation.  The winds in the western half of Nestor were mostly less than tropical storm force.

Drier air was being pulled around the western side of Tropical Storm Nestor.  In addition, an upper level trough over the western Gulf of Mexico was producing southwesterly winds which were blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear.  The combination of the drier air and the vertical wind shear was responsible for the asymmetrical distribution of thunderstorms and strong winds in the eastern half of the circulation.

Tropical Storm Nestor will move through an environment only marginally favorable for further intensification during the next 12 hours.  Nestor will move over water where the Sea Surface Temperature is near 29°C.  So, there is plenty of energy in the upper part of the Gulf of Mexico to support intensification.  However, the drier air and wind shear will inhibit intensification.  Tropical Storm Nestor will start a transition to an extratropical cyclone on Saturday.  Nestor could strengthen somewhat during the extratropical transition, but it could be over land before that occurs.

The upper level trough over the Western Gulf of Mexico will steer Nestor quickly toward the northeast during the next 48 hours.  On its anticipated track Tropical Storm Nestor could make landfall on the coast of northwest Florida between Panama City and Apalachicola.  Nestor will bring gusty winds to northern Florida on Saturday.  Strong southerly winds on the eastern side of Tropical Storm Nestor will push water toward the coast and a storm surge of 3 to 6 feet (1 to 2 meters) will occur around the northeastern Gulf of Mexico.  Nestor could drop locally heavy rain over parts of northern Florida, southeast Alabama, southern Georgia and South Carolina.  Tropical Storm Nestor will make landfall near where Hurricane Michael did so much damage in 2018.  Recovery efforts have been slow in that area and Nestor could set back the ongoing recovery from Hurricane Michael.

Low Pressure System Forms Over Southwest Gulf of Mexico

A surface low pressure system formed over the southwestern Gulf of Mexico on Wednesday.  At 8:00 p.m. EDT on Wednesday the center of the low pressure system was located at latitude 20.8°N and longitude 95.4°W which put it about 70 miles (110 km) east-southeast of Nautla, Mexico.  The low was moving toward the north at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1009 mb.

The northern end of a trough of low pressure moved over the Bay of Campeche on Wednesday and a surface low formed when the trough moved over the southwestern Gulf of Mexico.  More thunderstorms developed near the center of the low pressure system.  Divergence from a surface high pressure system over the U.S. was converging with the northern periphery of the circulation around the surface low and a band of showers and thunderstorms was occurring over the west central Gulf of Mexico.  Storms near the center of the low were starting to generate some upper level divergence.

The low pressure system will move through an environment that will be favorable for intensification during the next 24 to 36 hours.  The low will move over water where the Sea Surface Temperature is near 29°C.  It will move under an upper level ridge where the winds are weak and divergent.  The low could intensify slowly if it gets better organized on Thursday.  The National Hurricane Center is indicating that there is a 60% probability of formation of either a tropical or subtropical storm.  A reconnaissance plane has been tentatively tasked to investigate the low pressure system on Thursday afternoon.

The upper level ridge over the surface low pressure system will steer the low toward the northeast during the next several days.  On its anticipated track the low could approach the northeastern coast of the Gulf of Mexico on Friday.  The low will bring gusty winds and locally heavy rain.  The winds will generate higher waves and there could be a storm surge of 3 to 6 feet (1 to 2 meters).

Humberto Strengthens Into a Hurricane

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

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

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

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

Tropical Storm Humberto Develops East of the Bahamas

Former Tropical Depression Nine strengthened into Tropical Storm Humberto east of the Bahamas on Friday night.  At 11:00 p.m. EDT on Friday night the center of Tropical Storm Humberto was located at latitude 25.6°N and longitude 75.2°W which put it about 130 miles (210 km) east-southeast of Great Abaco, Bahamas.  Humberto was moving toward the northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 1008 mb.

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

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

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

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

Tropical Depression Nine Develops Near the Bahamas

Tropical Depression Nine developed near the Bahamas on Friday afternoon.  At 5:00 p.m. EDT on Friday the center of Tropical Depression Nine was located at latitude 25.6°N and longitude 75.0°W which put it about 140 miles (225 km) east-southeast of Great Abaco, Bahamas.  It was moving toward the northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1009 mb.

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

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

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

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

Tropical Storm Warnings Issued for Northwestern Bahamas

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

At 5:00 p.m. EDT on Thursday the broad center of Potential Tropical Cyclone Nine was located at latitude 23.7°N and longitude 74.8°W which put it about 235 miles (380 km) southeast of Great Abaco.  It was moving toward the northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1008 mb.

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

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

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

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

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