Tag Archives: Mississippi

Florence Strengthens Into a Major Hurricane

Hurricane Florence strengthened rapidly into a major hurricane on Wednesday morning.  At 11:00 a.m. EDT on Wednesday the center of Hurricane Florence was located at latitude 22.0°N and longitude 45.7°W which put it about 1370 miles (2205 km) east-southeast of Bermuda.  Florence was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 125 m.p.h. (205 km/h) and there were wind gusts to 145 m.p.h. (235 km/h).  The minimum surface pressure was 957 mb.

Hurricane Florence strengthened rapidly on Wednesday morning.  A small circular eye formed at the center of circulation.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Florence.  Storms near the core were generating upper level divergence which was pumping mass away from the hurricane.

The circulation of Hurricane Florence is small.  Winds to hurricane force extend out about 20 miles (30 km) from the center of circulation.  Winds to tropical storm force extend out about 95 miles (155 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Florence is 23.6.  The Hurricane Size Index (HSI) is 7.0 and the Hurricane Wind Intensity Size Index (HWISI) is 30.6.

Hurricane Florence will move through an environment capable of supporting a strong hurricane.  Florence is currently over water where the Sea Surface Temperature is near 27°C and it will move over warmer water during the next several days.  An upper level trough north of Florence is producing westerly winds which are blowing toward the top of the hurricane.  However, those winds do not seem to be creating significant vertical wind shear.  Hurricane Florence could maintain its intensity and there is a chance it could get stronger when it moves over warmer water.  Because of the small circulation, if there are changes in the environment around Hurricane Florence, then the intensity could change quickly.  Also, any eyewall replacement cycles could cause the intensity to fluctuate.

Hurricane Florence will move south of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Florence in a general northwesterly direction during the next few days.  On its anticipated track Hurricane Norman could be southeast of Bermuda by early next week.  The guidance from the numerical models has been variable and there is still much uncertainty about the track Hurricane Florence will take later next week.

Elsewhere, Tropical Depression Gordon was dropping rain on Alabama and Mississippi.  At 11:00 a.m. EDT on Wednesday the center of Tropical Depression Gordon was located at latitude 32.3°N and longitude 90.2°W which put it about 5 miles (10 km) west of Jackson, Mississippi.  Gordon was moving toward the northwest at 14 m.p.h. (22 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.

Tropical Storm Gordon Makes Landfall on the Gulf Coast.

Tropical Storm Gordon made landfall on the Gulf Coast near Pascagoula, Mississippi on Tuesday night.  At 11:30 p.m. EDT on Tuesday the center of Tropical Storm Gordon was located at latitude 30.4°N and longitude 88.4°W which put it about 30 miles (50 km) east of Biloxi, Mississippi.  Gordon was moving toward the northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 997 mb.

A Hurricane Warning was in effect for the portion of the coast from the Mouth of the Pearl River to the Alabama-Florida border.  A Tropical Storm Warning was in effect for the portion of the coast from the Okaloosa-Walton County line to the Alabama-Florida border.

The circulation of Tropical Storm Gordon was asymmetrical.  The strongest bands of showers and thunderstorms were north and east of the center of circulation.  The strongest winds were occurring in those bands.  A C-MAN station on Dauphin Island, Alabama reported a sustained wind speed of 62 m.p.h. (100 km/h) and a wind gust of 72 m.p.h. (117 km/h).  The winds were much weaker south and west of the center of Tropical Storm Gordon and there was little rain in those parts of the tropical storm.

Tropical Storm Gordon will start to weaken as the center moves inland.  Gordon will continue to move around the western end of a high pressure system over the western Atlantic Ocean.  The high will steer Tropical Storm Gordon toward the northwest during the next day or two.  On its anticipated track Tropical Storm Gordon will move across southern Mississippi on Wednesday and over Arkansas on Thursday.  The wind will be strong enough to cause minor damage and it will cause some power outages.  Locally heavy rain and the potential for flash floods are the greater risks.  Flash Flood Warnings were in effect for parts of West Florida and Southwest Alabama.  Flash Flood Watches were in effect for Mississippi and Southeastern Arkansas.

Elsewhere over the tropical Atlantic Ocean, Hurricane Florence was continuing to intensify east of the northern Leeward Islands.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Florence was located at latitude 20.7°N and longitude 43.9°W which put it about 1515 miles (2440 km) east-southeast of Bermuda.  Florence was moving toward the west-northwest 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 976 mb.

Tropical Storm Gordon Nears Gulf Coast

Tropical Storm Gordon moved closer to the Gulf Coast of the U.S. on Tuesday morning.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Gordon was located at latitude 28.5°N and longitude 86.8°W which put it about 145 miles (235 km) east-southeast of the mouth of the Mississippi River.  Gordon was moving toward the northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 1001 mb.

A Hurricane Warning was in effect for the portion of the coast from the mouth of the Pearl River to the Alabama-Florida border.  Tropical Storm Warnings were in effect for the portions of the coast from Grand Isle, Louisiana to the mouth of the Pearl River including Lake Pontchartrain and from the Alabama-Florida border to the Okaloosa-Walton County line in Florida.

The circulation of Tropical Storm Gordon appeared to be getting more organized on Tuesday morning.  More thunderstorms developed near the center of circulation.  Storms near the center were generating upper level divergence which was pumping mass away to the east of the tropical storm.  Several bands of showers and thunderstorms north and east of the center were moving toward the Gulf Coast.  The bands southwest of the center consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out about 80 miles (130 km) from the center of circulation, but the winds were weaker in the southwestern quadrant of Tropical Storm Gordon.

Tropical Storm Gordon could strengthen into a hurricane before it makes landfall.  Gordon will move over water where the Sea Surface Temperature is near 30°C.  An upper level trough over the southeastern U.S. was producing southwesterly winds which were blowing toward the top of the circulation.  Those winds were causing some vertical shear, but they will not be strong enough to prevent intensification.  The surface pressure decreased slightly on Tuesday morning.  Increased friction near the coast could cause the circulation to tighten around the center, when Tropical Storm Gordon gets closer to the Gulf Coast.

Tropical Storm Gordon will move around the southwestern end of a subtropical high pressure system over the western Atlantic Ocean.  The high will steer Gordon in a general northwesterly direction during the next several days.  On its anticipated track the center of Hurricane Gordon is likely to make landfall on the northern Gulf Coast on Tuesday night.  Gordon will produce winds to near hurricane force at the coast.  It could cause a storm surge of 5 to 8 feet (1.5 to 2.5 meters) east of the center where the wind blows water toward the coast.  The highest storm surge will occur in bays and the mouths of streams and rivers where the shape of the coast funnels water into those areas.  Tropical Storm Gordon will also drop heavy rain over portions of northwest Florida, southwest Alabama, Mississippi and eastern Louisiana.  Locally heavy rain could create the potential for flash floods.

Elsewhere over the Atlantic Ocean, former Tropical Storm Florence strengthened into the third Atlantic hurricane of 2018.  At 11:00 a.m. EDT on Tuesday the center of Hurricane Florence was located at latitude 19.7°N and longitude 42.5°W which put it about 1270 miles (2045 km) east-northeast of the Lesser Antilles.  Florence was moving toward the west-northwest at 12 m.p.h. (19 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 990 mb.

Tropical Storm Gordon Forms, Causes Warnings for South Florida

Former Potential Tropical Cyclone Seven developed a distinct center of circulation on Sunday morning and the National Hurricane Center upgraded the system to Tropical Storm Gordon.  At 8:30 a.m. EDT on Sunday the center of Tropical Storm Gordon was located at latitude 25.1°N and longitude 80.6°W which put it about 10 miles (15 km) west of Key Largo, Florida.  Gordon was moving toward the west-northwest at 16 m.p.h. (26 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 1009 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Golden Beach to Bonita Beach, Florida.  A Tropical Storm Warning was in effect for the Florida Keys from Craig Key to Ocean Reef including Florida bay.  A Tropical Storm Warning was in effect for the portion of the coast from the Alabama-Florida border to Morgan City, Louisiana including Lake Pontchartrain.

The circulation of Tropical Storm Gordon became much better organized during the past 12 hours.  A distinct low level center of circulation formed and many more thunderstorms developed.  A C-MAN station on Fowey Rock, Florida reported sustained winds of 49 m.p.h. (80 km/h) supporting the designation as a tropical storm.  The circulation of Tropical Storm Gordon was still organizing.  More thunderstorms were developing in bands northeast of the center of circulation than in other parts of the tropical storm.  Those storms were beginning to generate upper level divergence which was pumping mass away from the core of Gordon.

Tropical Storm Gordon will be moving through an environment favorable for intensification during the next 36 hours.  Gordon will be moving over water where the Sea Surface Temperature is near 30°C.  It will be moving through a region where the upper level winds will be weak and there will be little vertical wind shear.  Tropical Storm Gordon will continue to intensify and it could intensify more rapidly once the inner core becomes better organized.  There is a chance that Gordon could strengthen into a hurricane before it reaches the north coast of the Gulf of Mexico.

Tropical Storm Gordon will move around the west end of a subtropical high pressure system over the western Atlantic Ocean.  The ridge will steer Gordon in  a general west-northwesterly direction.  On its anticipated track Tropical Storm Gordon will move away from South Florida later today.  Gordon could approach the north coast of the Gulf of Mexico late on Tuesday.  Locally heavy rain could cause floods in South Florida.  Tropical Storm Gordon could produce a storm surge of 6 to 9 feet (2 to 3 meters) along parts of the northern Gulf Coast.

Potential Tropical Cyclone Seven Causes Tropical Storm Watch for U.S. Gulf Coast

Potential Tropical Cyclone Seven caused the National Hurricane Center to issue a Tropical Storm Watch for a portion of the U.S. Gulf Coast on Sunday afternoon.  A Tropical Storm Watch was in effect for the portion of the coast from the Alabama-Florida border to Morgan City, Louisiana including Lake Pontchartrain.  At 5:00 p.m. EDT on Sunday the center of Potential Tropical Cyclone Seven was located at latitude 22.7°N and longitude 77.3°W which put it about 275 miles (445 km) east-southeast of Marathon, Florida.  It was moving toward the west-northwest at 15 m.p.h (24 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 1012 mb.

Bands of showers and thunderstorms began to form in a tropical wave over the Bahamas and the National Hurricane Center designated the system as Potential Tropical Cyclone Seven in order to be able to issue the Tropical Storm Watch for the north coast of the Gulf of Mexico.  The circulation of Potential Tropical Cyclone Seven was still organizing.  A distinct low level center of circulation had not formed.  Bands of showers and thunderstorms were developing and the bands were starting to revolve around the inner part of the weather system.  Thunderstorms were beginning to generate some upper level divergence.

Potential Tropical Cyclone Seven will be moving into an environment favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge is forecast to develop over Potential Tropical Cyclone Seven.  If that occurs, then the upper level winds would be weak and there would be little vertical wind shear.  Potential Tropical Cyclone Seven is forecast to intensify into Tropical Storm Gordon.  If the system moves slowly enough, there is a chance it could strengthen into a hurricane before it reaches the Gulf Coast.

Potential Tropical Cyclone Seven will move around the western end of a subtropical high pressure system over the western Atlantic Ocean.  The high will steer Potential Tropical Cyclone Seven in a general west-northwesterly direction.  On its anticipated track the system will move over the Florida Keys on Monday.  It will be over the eastern Gulf of Mexico on Tuesday and the system could reach the northern Gulf Coast late on Tuesday or early on Wednesday.

Elsewhere over the tropical Atlantic, Tropical Storm Florence was moving quickly away from the Cabo Verde Islands.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Florence was located at latitude 17.4°N and longitude 34.6°W which put it about 700 miles (1125 km) west of the Cabo Verde Islands.  Florence was moving toward the west-northwest at 15 m.p.h. (24 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 1000 mb.

Unusual Tropical Depression Alberto Reaches Michigan

Unusual Tropical Depression Alberto reached southern Michigan on Wednesday as it continued its northward journey from the Gulf of Mexico.  At 11:00 p.m. EDT on Wednesday the center of Tropical Depression Alberto was located at latitude 42.4°N and longitude 85.3°W which put it about 45 miles southwest of Lansing, Michigan.  Alberto was moving toward the north-northeast at 26 m.p.h. (43 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 996 mb.

The circulation of Tropical Depression Alberto remained intact even though it had been over land for more than two days.  There was a distinct low level center of circulation.  Several bands of showers and thunderstorms were revolving around the center of circulation.  Storms in the core of the circulation were generating upper level divergence.  Tropical Depression Alberto looked like a tropical cyclone on both satellite and radar imagery.

Gusty winds in some of the bands of showers and thunderstorms caused damage to trees and power lines in Indiana and Ohio.  Most of the damage was minor.  The peripheral parts of the circulation of Tropical Depression Alberto interacted with other weather system to produce bands of heavier rain over parts of the southeastern U.S.  The heavy rain contributed to flooding in several states.

Tropical Depression Alberto will move northeast across the Great Lakes and into Canada on Thursday.  The broader circulation around Alberto will again interact with other weather systems to produce bands of heavier rain.  The potential flooding will exist in several states in the southeastern U.S. and Great Lakes region.

Subtropical Storm Alberto Strengthens on Its Way to Northwest Florida

Subtropical Storm Alberto strengthened on Sunday as it moved closer to northwest Florida.  At 11:00 p.m. EDT on Sunday the center of Subtropical Storm Alberto was located at latitude 28.5°N and longitude 85.8°W which put it about 95 miles (155 km) south-southwest of Apalachicola, Florida.  Alberto was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and the were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 991 mb.  A Tropical Storm Warning was in effect for the portion of the coast from Suwannee River, Florida to the border between Alabama and Mississippi.

The circulation of Subtropical Storm Alberto became more organized on Sunday.  A band of showers and thunderstorms wrapped around the center of circulation.  A band of drier air wrapped around the circulation just outside the rainband.  The band of drier air kept the circulation from developing a completely tropical structure and the National Hurricane Center continued to classify Alberto as a subtropical storm.  Alberto moved closer to the center of an upper level low over the Gulf of Mexico.  The upper level winds were weaker near the center of the low and the vertical wind shear decreased.  An upper level ridge over the Florida peninsula enhanced upper level divergence to the east of Alberto and the surface pressure decreases on Sunday.

Subtropical Storm Alberto will move through an environment somewhat favorable for intensification on Monday.  Alberto will move over water where the Sea Surface Temperature is near 28°C.  The upper level low will continue to produce some vertical wind shear.  The band of drier air will limit the development of thunderstorms outside the primary rainband.  Some intensification is possible during the next 12 hours, but the wind shear and drier air should limit any strengthening.

The upper low and the ridge over Florida will steer Subtropical Storm Alberto slowly toward the northwest.  On its anticipated track the center of Subtropical Storm Alberto is expected to make landfall over northwest Florida on Monday.  Alberto will be capable of causing minor wind damage.  Wind blowing water toward the coast will produce a storm surge of up to 4 to 7 feet (1.3 to 2.3 meters).  Alberto will drop heavy rain over parts of the southeastern U.S. and flooding could occur in some locations.

Subtropical Storm Alberto Moves Into the Gulf of Mexico

Subtropical Storm Alberto moved over the southeastern Gulf of Mexico on Saturday.  At 11:00 p.m. EDT on Saturday the center of Subtropical Storm Alberto was located at latitude 23.9°N and longitude 84.6°W which put it about 120 miles (195 km) west-southwest of the Dry Tortugas.  Alberto was moving toward the north-northeast at 13 m.p.h. (20 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 1001 mb.

Tropical Storm Warnings were in effect for the Dry Tortugas and the portions of the coast from Bonita Beach to Anclote River and from the Aucilla River to the border between Alabama and Mississippi.  A Tropical Storm Watch was in effect from the border between Alabama and Mississippi to the Mouth of the Pearl River.

The circulation of Subtropical Storm Alberto remained poorly organized on Saturday.  Several low level centers dissipated and new low level centers of circulation developed on the southwestern edge of an area of thunderstorms northeast of the center.  Even though the center of circulation reorganized several times, the pressure did decrease slowly during the day.  The strongest wind speeds were occurring in the area of thunderstorms northeast of the center of circulation.  The winds were weaker south and west of the center.

Subtropical Storm Alberto will move through an environment that will become more favorable for intensification during the next 48 hours.  Alberto will move over water where the Sea Surface Temperature is near 28°C.  An upper level trough over the western Gulf of Mexico was producing southwesterly winds which were blowing across the top of the circulation.  Those winds were causing significant vertical wind shear which was inhibiting the intensification of Subtropical Storm Alberto.  The shear was also preventing thunderstorms from persisting near the center of circulation, which was keeping Alberto from making a transition to a tropical storm.  An upper level ridge was forming over Florida.  The ridge was starting to enhance upper level divergence to the east of Subtropical Storm Alberto.

The upper level trough will gradually evolve into a closed upper level low.  The vertical wind shear will slowly decrease during the next several days.  When the shear decreases, it will allow Subtropical Storm Alberto to strengthen.  Less vertical wind shear will also let thunderstorms persist closer to the center of circulation.  If thunderstorms persist near the center, then Alberto could exhibit the structure of a tropical cyclone and it could be designated as a tropical storm.  Subtropical Storm Alberto could intensify into a hurricane over the northern Gulf of Mexico.

The reformations of the low level center of circulation increase the uncertainty of track forecasts.  The upper level trough is likely to steer Subtropical Storm Alberto toward the north on Sunday.  Alberto could turn more toward the north-northwest when the trough changes into an upper level low.  On its anticipated track Subtropical Storm Alberto could approach the coast of the northern Gulf of Mexico within 48 hours.  Alberto could be a strong tropical storm or a hurricane at that time.

Subtropical Storm Alberto will be capable of causing minor wind damage when it makes landfall.  Alberto will drop locally heavy rain north and east of the center of circulation.  Flood Watches have been issued for several states in the southeastern U.S.  The Gulf Coast is very susceptible to storm surge.  There will be increases in the water level along the eastern and northern Gulf Coast where the winds blow water toward the shore.

Subtropical Storm Alberto Forms Over Northwest Caribbean Sea

Subtropical Storm Alberto formed over the northwestern Caribbean Sea on Friday morning.  The National Hurricane Center (NHC) designated an area of low pressure as Subtropical Storm Alberto on Friday morning based on data from buoys and ship reports.  At 5:00 p.m. EDT on Friday the center of Subtropical Storm Alberto was located at latitude 19.4°N and longitude 86.3°W which put it about 85 miles (135 km) south-southeast of Cozumel, Mexico.  Alberto was moving toward the east 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. (80 km/h).  The minimum surface pressure was 1005 mb.

A Tropical Storm Watch has been issued for the portion of the U.S. coast from Indian Pass, Florida to Grand Isle, Louisiana including New Orleans.  The government of Mexico issued a Tropical Storm Watch for the portion of the coast from Tulum to Cabo Catoche.  The government of Cuba issued a Tropical Storm Watch for the province of Pinar del Rio.

The circulation around Subtropical Storm Alberto was asymmetrical.  The low level center of circulation was located just to east of the Yucatan Peninsula.  The strongest thunderstorms were occurring in a band located about 100 miles (160 km) east and north of the center.  Flow around 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 strong vertical wind shear which was the reason why the thunderstorms were occurring well to the east of the center of circulation.

Subtropical Storm Alberto will move through an environment marginally favorable for intensification during the next 24 to 36 hours.  Alberto will move over water where  the Sea Surface Temperature is near 28°C.  So, there is sufficient energy in the upper ocean to support intensification.  However, the upper level trough will continue to cause moderate to strong vertical wind shear during the next day or so.  The wind shear will inhibit intensification.  Some gradual strengthening is possible.  The winds are weaker near the axis of the upper level trough.  If Alberto moves under the axis of the trough when it reaches the northern Gulf of Mexico, then the wind shear will decrease.  Alberto could strengthen more quickly if that happens.  There is a chance that Alberto could reach hurricane intensity.  If more thunderstorms form closer to the center of circulation, then NHC could change the designation of Alberto to a tropical storm.

Subtropical Storm Alberto is moving around the western end of a large high pressure system over the Atlantic Ocean.  The high is steering Alberto slowly toward the north-northeast.  A general motion toward the north is forecast during the next day or so.  When Alberto gets farther north, the upper level trough could steer it more toward the north-northwest.  There is a chance that the steering currents could weaken when Alberto nears the Gulf Coast.  Thus, there is much more uncertainty about the track forecast after that time.

The greatest risk with Subtropical Storm Alberto will be locally heavy rain and the potential for flooding.  Most of the heavy rain is likely to fall north and east of the center.  Much less rain is likely to fall from the western side of Alberto.  The coast of the Gulf of Mexico is very susceptible to storm surges.  The water level will rise along the eastern and northern coasts of the Gulf of Mexico where the winds blow the water toward the shoreline.

Cyclone Likely to Form Over Gulf of Mexico

A cyclone is likely to form over the Gulf of Mexico during the upcoming weekend.  A broad area of low pressure at the surface is currently centered over the Yucatan Peninsula.  The area of low pressure is currently designated as Invest 90L.  The circulation around the low pressure system is not well organized at the current time.  The center of the surface low is over the Yucatan Peninsula.  Showers and lower clouds are occurring near the center of the low.  Stronger thunderstorms are occurring on the eastern side of the low over the northwestern Caribbean Sea.  Sustained winds of 20 m.p.h. to 30 m.p.h. (30 km/h to 50 km/h) were blowing across the northwestern Caribbean Sea.  The winds were weaker over land near the center of circulation.

An upper level trough over the Gulf of Mexico was producing strong westerly winds which were blowing over the top of the surface low.  Those winds were causing strong vertical wind shear and the wind shear was one of the reasons why the stronger thunderstorms were occurring east of the center of circulation.  Sinking motion in the western portion of the upper level trough was bringing drier air to the surface and the drier air was inhibiting the formation of thunderstorms in the western side of the surface low.

The National Hurricane Center (NHC) indicated in a Special Tropical Weather Outlook at 2:00 p.m. EDT on Thursday that there is a 70% probability of the formation of a subtropical or tropical depression during the next 48 hours.  NHC has tentatively tasked a reconnaissance aircraft to investigate the low pressure system on Friday afternoon if necessary.

The wind speeds are slower near the axis of the upper level trough.  If the surface low pressure system moves under the axis of the upper level trough, then there would be less vertical wind shear and a cyclone could form.  If thunderstorms develop near the center of circulation after the center moves over the northwestern Caribbean Sea or southeastern Gulf of Mexico, then NHC would likely designate the system as a tropical depression.  If the thunderstorms develop farther away from the center of circulation and the circulation does not exhibit a tropical appearance, then NHC could classify the system as a subtropical depression.  NHC would issue advisories on the cyclone even if it is designated a subtropical depression.

There is a strong high pressure system over the Atlantic Ocean and the high is likely to steer the surface low toward the north.  The Sea Surface Temperature of the water in the southeastern Gulf of Mexico is near 27°C.  So, there is enough energy to support the formation of a tropical cyclone.  Most of the stronger thunderstorms are likely to continue to form in the eastern side of the circulation because of the vertical wind shear and drier air to the northwest of the surface low.  The low pressure system could slowly organize into a tropical storm during the weekend.

Heavy rain and the potential for flooding are the greatest risks with this low pressure system.  There will be some storm surge along the eastern and northern coasts of the Gulf of Mexico as counterclockwise rotation around the low blows water toward the shore.