Tag Archives: Cayman Islands

Tropical Storm Delta Develops South of Jamaica

Former Tropical Depression Twentysix strengthened into Tropical Storm Delta south of Jamaica on Monday morning.  At 8:00 a.m. EDT on Monday the center of Tropical Storm Delta was located at latitude 16.4°N and longitude 78.4°W which put it about 65 miles east of the Mouth of the Mississippi River and about 130 miles south of Negril, Jamaica.  Delta was moving toward the west-northwest at 9 m.p.h.  The maximum sustained wind speed was 40 m.p.h.  The minimum surface pressure was 1004 mb.

A Hurricane Watch was in effect for the Isle of Youth, Pinar del Rio and Artemisa, Cuba.  A Tropical Storm Warning was in effect for the Cayman Islands.  A Tropical Storm Watch was in effect for La Habana, Cuba.

More thunderstorms developed near the center of former Tropical Depression Twentysix on Monday morning and the National Hurricane Center upgraded the system to Tropical Storm Delta.  The circulation around Tropical Storm Delta was still organizing.  Bands of showers and thunderstorms were revolving around the center of Delta.  The strongest rainbands were in the southern half of the circulation.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm.  The removal of mass allowed the pressure to decrease, which caused the wind speed to increase.

Tropical Storm Delta will move through an environment which will be very favorable for intensification.  Delta will move over water where the Sea Surface Temperature is near 30˚C.  It will move under an upper level ridge where the winds are weak.  There will be little vertical wind shear.  Tropical Storm Delta will intensify and it could strengthen into a hurricane by Tuesday night.  Once an inner core with an eye and an eyewall develops, Delta could intensify rapidly.  There is a chance Tropical Storm Delta could strengthen into a major hurricane.

Tropical Storm Delta will move around the western end of a subtropical high pressure system over the western Atlantic Ocean.  The high will steer Delta toward the northwest during the next few days.  On its anticipated track Tropical Storm Delta could reach the Cayman Islands on Monday night.  Delta could be near the western end of Cuba by Tuesday night and it is likely to be a hurricane at that time.  Delta could approach the central Gulf Coast on Thursday night.  It could be a major hurricane when it approaches the Gulf Coast.

Elsewhere, Tropical Storm Gamma weakened as it meandered north of the Yucatan Peninsula.  Strong southerly winds in the upper levels blew the top off of Tropical Storm Gamma on Sunday night.  At 8:00 a.m. EDT on Monday the center of Tropical Storm Gamma was located at latitude 22.6°N and longitude 87.5°W which put it about 165 miles (270 km) east-northeast of Progreso, Mexico.  Gamma was moving toward the south-southwest at 2 m.p.h. (3 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 1001 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Cancun to Dzilam, Mexico.  A Tropical Storm Watch was in effect for the portion of the coat from Dzilam to Campeche, Mexico.

Tropical Storm Marco Weakens Near Louisiana

Tropical Storm Marco weakened near Louisiana on Monday morning.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Marco was located at latitude 28.5°N and longitude 88.5°W which put it about 55 miles (90 km) southeast of the Mouth of the Mississippi River.  Marco was moving toward the north-northwest at 8 m.p.h. (13 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 Tropical Storm Warning was in effect for the portion of the coast from Morgan City, Louisiana to the Mississippi/Alabama border including New Orleans, Lake Pontchartrain and Lake Maurepas.

An upper level trough over Texas produced strong southwesterly winds which sheared the top off of Tropical Storm Marco on Monday morning.  Stronger thunderstorms were confined to a few bands northeast of the center of circulation.  Bands around the center and in other parts of Marco consisted of showers and lower clouds.  Winds to tropical storm force were only occurring in the thunderstorms northeast of the center.

Since the wind shear is expected to continue, the circulation around Tropical Storm Marco is expected to spin down.  As Marco weakens it will be steer more by the winds in the lower atmosphere.  A subtropical high pressure system over the Atlantic Ocean is expected to expand to the west during the next several days.  The high will turn the low level circulation of Tropical Storm Marco more toward the west.  On its anticipated track Tropical Storm Marco will make landfall over southeastern Louisiana on Monday night.  Marco will bring gusty winds and some rain, but its impact is likely to be minor.

Elsewhere, Tropical Storm Laura was moving near the south coast of Cuba.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Laura was located at latitude 21.2°N and longitude 80.6°W which put it about 65 miles east-southeast of Cayo Largo, Cuba.  Laura was moving toward the west-northwest at 20 m.p.h. (32 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 the Florida Keys from Craig Key to Key West and for the Dry Tortugas.  Tropical Storm Warnings were in effect for Little Cayman and Cayman Brac.  Tropical Storm Warnings were also in effect for the Cuban provinces of Camaguey, Las Tunas, Ciego De Avila, Sancti Spiritus, Villa Clara, Cienfuegos, Matanzas, Mayabeque, La Habana, Artemisa, Pinar Del Rio and Isle of Youth.

The circulation around Tropical Storm Laura was not as well organized on Monday morning.  Passage of Hispaniola and eastern Cuba disrupted the northern half of the circulation.  The strongest thunderstorms were occurring in bands in the southern half of the circulation.  Bands in the northern half of the circulation consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 175 miles (280 km) on the eastern side of Laura.  The winds on the western side of the circulation were blowing at less than tropical storm force.

Tropical Storm Laura will move near the south coast of Cuba for another 18 hours.  Since nearly half the circulation will be blowing across Cuba, it will continue to disrupt the northern half of the tropical storm.  Laura will move over the Gulf of Mexico on Tuesday.  When Tropical Storm Laura reaches the Gulf, it will move into a very favorable environment.  Laura will move over water where the Sea Surface Temperature is near 30°C.  It will move into a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Laura will intensify into a hurricane over the Gulf of Mexico and it could rapidly strengthen into a major hurricane.  Laura is expected to move over the northwestern Gulf of Mexico on Wednesday.

Low Pressure Forms Near Northwest Caribbean Sea

An area of low pressure formed near the northwestern Caribbean Sea on Monday and the system has been designated as Invest 93L.  At 8:00 p.m. EDT on Monday the center of Invest 93L was located at latitude 14.0°N and longitude 83.0°W which put it about 75 miles (120 km) south-southeast of Cabo Gracias a Dios.  It was moving toward the north at 6 m.p.h. (9 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.

An area of low pressure formed in the southern portion of an area of showers and thunderstorms that has persisted over the western Caribbean Sea for several days.  The circulation of Invest 93L is not well organized.  There is no well organized center of circulation nor are there well organized rainbands.  Most of the showers and thunderstorms are occurring in the northern portion of the circulation.  There are not many showers or thunderstorms in the southern half of the circulation.  Much of the western half of the circulation is over Nicaragua and Honduras.

Invest 93L will move through an environment mostly favorable for the development of a tropical cyclone during the next few days.  It will move over water where the Sea Surface Temperature is near 30°C.  Invest 93L is near the axis of an upper level ridge.  So, the upper level winds are weak over the system.  There are stronger winds farther north over the northern Caribbean Sea.  Invest 93L will be slow to develop as long as almost half of the circulation is over land.  Development will be more likely when the center moves farther away from land.

Invest 93L is just west of the axis of the ridge, which is steering the system slowly toward the north.  That general motion is forecast to continue for several more days.  On its anticipated track Invest 93L will move over the northwestern Caribbean Sea later this week.  Invest 93L will drop locally heavy rain over Nicaragua and Honduras and it could cause flash floods in some areas.

Invests 92L, 93L Monitored for Possible Development

Two weather systems designated as Invest 92L and Invest 93L are being monitored for possible development into tropical cyclones.  Invest 92L is a tropical wave that is speeding toward the Windward Islands.  At 2:00 p.m. EDT on Sunday the center of Invest 92L was located at latitude 7.3°N and longitude 49.4°W which put it about 800 miles (1290 km) east-southeast of the Windward Islands.  It was moving toward the west-northwest at 24 m.p.h. (39 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.

Invest 93L consists of a broad area of low pressure over the northwestern Caribbean Sea.  At 2:00 p.m. EDT on Sunday the surface center of Invest 93L was located at latitude 19.0°N and longitude 87.1°W which put it about 145 miles (230 km) south of Cancun, Mexico.  It was moving toward the north-northwest at 5 m.p.h. (8 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 1006 mb.

Invest 92L is a tropical wave and it has not yet develop a well defined surface center.  There is some evidence of cyclonic rotation on visible satellite imagery and there could be a center in the middle levels of the circulation.  Most of the stronger thunderstorms are located north and west of the center.  The are some bands of showers and thunderstorms south and west of the center.  There is some upper level divergence from the thunderstorms north and west of the center, but it is not well developed at the current time.

Invest 92L is in an environment that is moderately favorable to development of a tropical cyclone.  It is moving over water where the Sea Surface Temperature is near 28°C.  It is in a region of rapid easterly flow, but the wind speed is fairly similar at all levels.  So, there is not a lot of vertical wind shear.  The rapid easterly flow could be inhibiting the formation of a well defined center of circulation.  Invest 92L will be in a moderately favorable environment for about another 36 hours.  An upper level trough over the eastern Caribbean Sea will create increased vertical wind shear when Invest 92L reaches that location.  The National Hurricane Center is indicating that there is a 60% probability that Invest 92L will develop into a tropical cyclone during the next two days.

Invest 92L is being steered rapidly toward the west-northwest by a subtropical high north of it.  A fairly quick motion toward the west-northwest is expected to continue for the next few days.  On its anticipated track Invest 92L could be near the Windward Islands by late Monday.  Even it if does not develop into a tropical cyclone, the system will bring gusty winds and locally heavy rain to those islands.

The structure of Invest 93L is much more complicated.  There is a very broad but weak surface low pressure system over the Yucatan peninsula and the center of that low is being used as the center of the Invest.  However, there is a strong mid-level center of circulation near latitude 18.7°N and longitude 82.9°W which is about 115 miles (185 km) west-southwest of Grand Cayman.  Invest 93L is producing winds to near tropical storm force and those winds are occurring in thunderstorms associated with the mid-level circulation.  It is possible that downdrafts in those thunderstorms could transport enough momentum to the surface to generate a new surface center beneath the mid-level center.

Invest 93L is moving in an environment that will be favorable for the development of a tropical cyclone.  An upper level ridge is building between the trough over the eastern Caribbean Sea and another upper level trough over the northwestern Gulf of Mexico.  The trough over the northwestern Gulf is producing strong southwesterly winds which are causing vertical wind shear over the surface low over the Yucatan peninsula.  However, the upper level ridge is producing an area of slower winds over the mid-level center and there is less vertical wind shear there.  In fact, the upper level ridge is enhancing upper level divergence over the mid-level center.  If that continues, surfaces pressure will begin to decrease in that region.  The National Hurricane is indicating that there is a 70% probability of development of a tropical cyclone or a subtropical cyclone during the next two days.

Invest 93L is moving slowly north-northwestward around the western end of the subtropical high over the Atlantic Ocean.  A general north-northwesterly motion is expected to continue for another day or two, but there is some spread in the guidance from the numerical models.  If a cyclone forms from the surface low over the Yucatan peninsula, then the greatest risk would be to the western Gulf of Mexico.  If a new surface center forms farther east under the mid-level center, then there would be a greater risk for the central and eastern Gulf of Mexico.  Interests around the Gulf should monitor Invest 93L.