Tropical Cyclone Sagar Strengthens Over Gulf of Aden

Tropical Cyclone Sagar (01A) strengthened over the Gulf of Aden on Thursday.  At 11:00 a.m. EDT on Thursday the center of Tropical Cyclone Sagar was located at latitude 12.8°N and longitude 47.8°E which put it about 210 miles (335 km) east of Aden, Yemen.  Sagar was moving toward the west-southwest 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 992 mb.

The circulation of Tropical Cyclone Sagar became more organized on Thursday.  An eyelike feature appeared at the center of circulation.  A partial ring of thunderstorms wrapped around the northeast, northwest and southwest quadrants of the incipient eye.  There was a break in the ring of storms southeast of the center.  The strongest winds were occurring in the partial ring.  Additional bands of showers and thunderstorms were occurring north and west of the center of circulation.  Bands south and east of the center consisted primarily of low clouds and showers.  Storms near the center of circulation were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out about 70 miles (110 km) from the center of circulation.

Tropical Cyclone Sagar will move through an environment somewhat favorable for intensification during the next 24 to 36 hours.  Sagar will move over water where the Sea Surface Temperature is near 29°C to 30°C.  So, there is plenty of energy in the upper ocean to support intensification.  Sagar is moving south of an upper level ridge.  The ridge is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing some vertical wind shear and they are part of the reason why the strong storm are occurring mainly in the western half of the circulation.  The wind shear is not strong enough to prevent intensification and Tropical Cyclone Sagar is likely to continue to strengthen during the next 24 hours.  It could strengthen into the equivalent of a hurricane/typhoon.  Much drier air is over the Arabian Peninsula and Somalia.  When Sagar approaches the coast of the Gulf of Aden, it will start to pull drier air into the circulation and that will cause Sagar to weaken.

The upper level ridge is steering Tropical Cyclone Sagar toward the west-southwest and that general motion is expected to continue during the next several days.  On its anticipated track Tropical Cyclone Sagar could be south of Aden in about 36 hours.  Sagar could approach the coast of western Somalia and Djibouti in two or three days.  Tropical Cyclone Sagar will bring gusty winds and it could cause some storm surge at the coast.  The greater risk is for locally heavy rain near the coast of Yemen and over north Somalia.  The rain could be heavy enough to produce flash floods in some locations.

Tropical Cyclone 01A Forms Over the Gulf of Aden

Tropical Cyclone 01A formed over the Gulf of Aden on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone 01A was located at latitude 13.0°N and longitude 48.6°E which put it about 265 miles (425 km) east of Aden, Yemen.  It was moving toward the west at 7 m.p.h. (11 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 995 mb.

A distinct low level center of circulation developed in an area of showers and thunderstorms that moved from the Arabian Sea to the Gulf of Aden.  Several bands of stronger thunderstorms formed west of the center of circulation and the strongest winds were occurring in these bands.  Bands in the eastern half of the circulation consisted primarily of low clouds and showers.  The storms west of the center were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out about 60 miles (95 km) from the center of circulation.

Tropical Cyclone 01A will move through an environment somewhat favorable for intensification during the next 24 to 36 hours.  It will move over water where the Sea Surface Temperature is near 29°C.  Tropical Cyclone 01A is moving south of an upper level ridge.  The ridge is producing westerly winds which were blowing toward the top of the circulation.  Those winds may be part of the reason why the stronger thunderstorms are occurring on the western side of the center  The winds are causing some vertical wind shear, but the shear is not likely to be strong enough to prevent intensification.  Tropical Cyclone 01A is likely to strengthen as long as it stays over the Gulf of Aden and it could intensify into the equivalent of a hurricane.  Much drier air is over the Arabian Peninsula and over eastern Africa.  Tropical Cyclone 01A will likely weaken when it moves closer to land and starts to pull drier air into the circulation.

The upper level ridge is steering Tropical Cyclone 01A toward the west.  The ridge is forecast to strengthen and to steer the tropical cyclone a little to the south of west during the next several days.  On its anticipated track Tropical Cyclone 01A is expected to remain over the Gulf of Aden for several more days.  Bands of showers and thunderstorms could bring locally heavy rain to coastal portions of Yemen and northern parts of Somalia.

System Could Bring Heavy Rain to Southeast U.S.

A weather system over the southeastern Gulf of Mexico could bring heavy rain to the southeastern U.S. this week.  An upper level low over the eastern Gulf of Mexico could transfer enough kinetic energy down to the lower troposphere to spin up a low at the surface.  Air flowing around the eastern side of the low is contributing to upper level divergence over Florida.  The divergence enhanced rising motion over Florida and rain fell over parts of the southern and central portions of that state.

The weather system is forecast to move slowly northward during the next several days.  The Sea Surface Temperatures in the southeastern Gulf of Mexico are 24°C to 26°C.  There is enough energy in the upper levels of the water to support the formation of a tropical cyclone.  The upper level low will create southerly winds which will cause moderate vertical wind shear.  The shear will inhibit development, although those winds could contribute to upper level divergence to the east of the weather system.  Upper level divergence could allow the surface pressure to decrease and a low pressure system could form at the surface.  The National Hurricane Center (NHC) issued a special Tropical Weather Outlook on Sunday afternoon on the weather system.  NHC indicated the probability was 40% that a tropical or subtropical cyclone could form during the next five days.

Guidance from numerical models suggest that the weather system will move slowly northward over the eastern Gulf of Mexico during the next few days.  Counterclockwise rotation around the low will transport moist air northward on the eastern side of the low.  The moist air combined with upper level divergence will create the potential for locally heavy rainfall over the southeastern U.S.  Heavy rain could result in floods in some locations.

Tropical Depression 04W Forms East of the Northern Marianas

Tropical Depression 04W formed east of the Northern Marianas very late on Friday.  At 11:00 p.m. EDT on Friday the center of Tropical Depression 04W was located at latitude 18.8°N and longitude 148.5°E which put it about 185 miles (300 km) east of Agrihan.  It was moving toward the northwest at 11 m.p.h. (17 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 1003 mb.

An area of showers and thunderstorms persisted for much of the past week east of the Northern Marianas.  Several smaller centers of circulation formed within the area of showers and storms, but those centers ran into strong upper level winds and weakened because strong vertical wind shear and they dissipated.  Another center formed on Friday, but the upper level winds were a little weaker and the center persisted.  An upper level trough south of Japan was still producing southwesterly winds which were blowing toward the top of the circulation.  Those winds were producing moderate vertical wind shear, but the center of circulation persisted.  Most of the thunderstorms were occurring in bands east of the center of circulation.  The bands west of the center consisted primarily of low clouds and showers.

Tropical Depression will move through an area marginally favorable for intensification during the next 24 hours.  it will move over water where the Sea Surface Temperatures are near 28°C.  So, there will be enough energy in the upper ocean to support some intensification.  The upper level trough south of Japan will continue to cause moderate vertical wind shear, but the upper level winds could be weak enough to allow for further intensification.  Tropical Depression 04W could strengthen into a tropical storm on Saturday.

Tropical Depression 04W is moving near the southwestern part of a ridge over the North Pacific Ocean.  The ridge is steering the depression toward the northwest and that general motion is expected to continue for another day or two.  On its anticipated track Tropical Depression 04W is expected to pass near the northernmost Mariana Islands.  It could pass near Asuncion Island, the Maug Islands, Supply Reef and Farallon de Pajaros.  Tropical Depression 04W could bring gust winds, locally heavy rain and higher waves to those places.

Tropical Depression 01E Forms Southwest of Baja California

Tropical Depression 01E formed southwest of Baja California on Thursday afternoon.  A distinct low level center of circulation formed inside a larger area of low pressure that was previously designated as Invest 90E.  The National Hurricane Center (NHC) determined that the system possessed sufficient organization and NHC designated it as Tropical Depression 01E.  At 5:00 p.m. EDT on Thursday the center of Tropical Depression 01E was located at latitude 12.4°N and longitude 126.5°W which put it about 1310 miles (2105 km) west-southwest of the southern tip of Baja California.  Tropical Depression 01E was moving toward the west-northwest 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 1007 mb.

Tropical Depression 01E formed in a larger area of low pressure that was moving slowly westward over the Eastern North Pacific Ocean.  More thunderstorms formed near the center of the low pressure system and a distinct low level center became apparent on visible satellite images.  An upper level trough located west of the depression was producing southwesterly winds which are blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and the shear was limiting the development of thunderstorms in the western half of the depression.  Most of the stronger thunderstorms were occurring east of the center of circulation.  The bands in the western half of the depression consisted mostly of lower clouds and showers.  Storms east of the center were producing some upper level divergence which was pumping mass away to the east of the depression.

Tropical Depression 01E will move through an environment only marginally favorable for intensification.  It will move over water where the Sea Surface Temperature is near 27°C.  So, there is enough energy in the upper ocean to support intensification.  However, the upper level trough will continue to produce moderate vertical wind shear.  The upper level winds could be strong enough to prevent further intensification.  If the upper level winds slow, then there is a chance the depression could strengthen into a tropical storm during the next day or two.

Tropical Depression 01E is moving south of a subtropical ridge which is steering the depression toward the west-northwest.  The subtropical ridge is forecast to steer the depression in a general westerly direction during the next several days.  On its anticipated track Tropical Depression 01E poses no immediate threat to any land areas.

System to Bring Wind, Rain to Bahamas and South Florida

A complex weather system near the Bahamas is forecast to move westward and it will bring gusty winds and locally heavy rain to parts of the Bahamas and South Florida during the weekend.  The circulation is strongest in the middle and upper troposphere.  An upper level low is centered near the Bahamas.  Showers and thunderstorms are occurring north and east of the upper low.  There is not a distinct center of circulation in the lower troposphere or at the surface.  There is a small upper level ridge to the east of the upper low and the ridge is producing some upper level divergence which is pumping mass away to the east of the system.

The system will move through an environment that is only marginally favorable for the development of a tropical cyclone.  It will move over water where the Sea Surface Temperature is near 26°C.  So, there is potentially enough energy in the upper ocean to support the development of a minimal tropical cyclone.  The upper low and the ridge to the east are southerly winds near the Bahamas and westerly winds southeast of the Bahamas.  Those winds are causing strong vertical wind shear.  The winds are weaker near the center of the upper low, but there are no thunderstorms in that region at the current time.  If a surface low were to develop under the center of the upper low, then there would be the possibility of some slow development.  A second, possible scenario is that a subtropical cyclone develops north and east of the upper low where the showers and thunderstorms are forming.

The National Hurricane Center (NHC) issued a special Tropical Weather Outlook on this system at 10:45 a.m. EDT on Friday.  NHC indicated that “no significant development” is expected and it gives a 0% probability of the formation of a tropical cyclone.

The upper level low is forecast to move south-southwest over the northwestern Caribbean Sea during the next 72 hours.  The surface and lower parts of the system are forecast to move across the Bahamas toward South Florida during the weekend.  Since the showers and thunderstorms are occurring north and east of the upper low, this could bring gusty winds and locally heavy rain to parts of the Bahamas and South Florida during the weekend.  Some of the humid air on the northeastern periphery of the system could be pulled toward the Carolinas ahead of an approaching cold front.  The moist air could enhance rainfall in eastern South Carolina and eastern North Carolina when the cold front moves through those places and lifts the air.

Tropical Cyclone Flamboyan Forms East of Diego Garcia

Tropical Cyclone Flamboyan formed over the South Indian Ocean east of Diego Garcia on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Garcia was located at latitude 10.6°S and longitude 89.2°E which put it about 1190 miles (1925 km) east-southeast of Diego Garcia.  Flamboyan was moving toward the west-southwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 995 mb.

A distinct low level center of circulation developed inside a large areas of showers and thunderstorms east of Diego Garcia on Saturday and the system was designated as Tropical Cyclone Flamboyan.  The circulation of Tropical Cyclone Flamboyan organized steadily during the day.  Several bands of showers and thunderstorms were revolving the core of the circulation.  Storms near the core were generating upper level divergence which was pumping away mass from the tropical cyclone in all directions.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

Tropical Cyclone Flamboyan will be moving through an environment favorable for intensification during the next day or two.  Flamboyan will move over water where the Sea Surface Temperature is near 28°C.  It is located under an upper level ridge and the upper level winds are weak.  Flamboyan will move through an area where there is little vertical wind shear.  Warm water and little shear will allow Tropical Cyclone Flamboyan to intensify and it could strengthen into the equivalent of a hurricane/typhoon.

Tropical Cyclone Flamboyan is moving around the western end of a subtropical ridge, which is steering the tropical cyclone toward the west-southwest.  Flamboyan will turn more toward the south when it rounds the western end of the ridge.  On its anticipated track Tropical Cyclone Flamboyan will move farther away from Cocos Island and it will pass well southeast of Diego Garcia.

Tropical Cyclone Fakir Brings Wind and Rain to Mauritius and La Reunion

Tropical Cyclone Fakir brought wind and rain to Mauritius and La Reunion on Tuesday.  At 5:00 a.m. EDT on Tuesday the center of Tropical Cyclone Fakir was located at latitude 21.9°S and longitude 56.6°E which put it about 80 miles (130 km) southeast of St. Denis, La Reunion.  Fakir was moving toward the southeast at 25 m.p.h. (40 km/h).  The maximum sustained wind 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 983 mb.  Fakir was the equivalent of a hurricane/typhoon.

The center of Tropical Cyclone Fakir passed between Mauritius and La Reunion on Tuesday and it brought gusty winds and heavy rain.  An eye formed at the center of circulation and a narrow ring of thunderstorms wrapped tightly around the eye.  The strongest winds were occurring in the ring of storms.  Bands of showers and thunderstorms were occurring south and east of the center of circulation.  The bands north and west of the center consisted primarily of light showers and low clouds.  Winds to tropical storm force extended out about 170 miles (270 km) from the center.

Tropical Cyclone Fakir was capable of causing minor wind damage on Mauritius and La Reunion.  Fakir was also dropping heavy rain and the rain was likely to produce flash floods in some locations.  Tropical Cyclone Fakir was moving rapidly to the southeast.  So, conditions on Mauritius and La Reunion are likely to improve later on Tuesday when the core of Fakir moves away.  Fakir has peaked in intensity.  Although it is moving over water where the Sea Surface Temperature is near 27°C, Tropical Cyclone Fakir has moved under an area of strong upper level winds blowing from the northwest.  Those winds will cause strong vertical wind shear, which will weaken Fakir.

Tropical Cyclone Fakir Strengthens Rapidly Northwest of La Reunion

Tropical Cyclone Fakir strengthened rapidly northwest of La Reunion on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Cyclone Fakir was located at latitude 18.2°S and longitude 54.5°E which put it about 220 miles (355 km) north-northwest of St. Denis, La Reunion.  Fakir was moving toward the southeast at 22 m.p.h. (35 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 992 mb.

A center of circulation developed early Monday in an area of thunderstorms east of Madagascar and the system was designated as Tropical Cyclone Fakir.  The circulation organized quickly and in a few hours Fakir strengthened into the equivalent of a strong tropical storm.  A primary rainband wrapped around the southern and western sides of the center of circulation.  There were some indications of the potential development of an eye at the center.  Additional bands of showers and thunderstorms developed south and east of the core of Tropical Cyclone Fakir.  Storms in the core of Fakir generated strong upper level divergence which pumped away mass to the southeast of the circulation.  The removal of mass allowed the surface pressure to decrease quickly and the winds to increase in response to that decrease.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

Tropical Cyclone Fakir could remain in an environment favorable for intensification for another 12 to 18 hours.  Fakir 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.  Tropical Cyclone Fakir is moving around the southwestern portion of an upper level ridge located over the South Indian Ocean.  The ridge is producing northwesterly winds which were blowing toward the top of the circulation.  The winds were causing moderate vertical wind shear, but they were not strong enough to prevent Fakir from strengthening rapidly on Monday.  Tropical Cyclone Fakir could become the equivalent of a hurricane/typhoon during the next 12 to 18 hours.  Fakir will move under stronger upper level winds in a day or so and then it will start to weaken because of the stronger vertical wind shear.

The upper level ridge is steering Tropical Cyclone Fakir rapidly toward the southeast and that general motion is expected to continue for several more days.  On its anticipated track Tropical Cyclone Fakir will approach Mauritius and La Reunion in about 12 hours.  It could be nearly the equivalent of a hurricane/typhoon at that time.  Fakir will bring gusty winds and heavy rain to Mauritius and La Reunion.  Minor wind damage is possible.  Locally heavy rain could cause flash floods.  The most likely track takes the center of Tropical Cyclone Fakir between Mauritius and La Reunion.  The western side of the circulation is a little weaker than the eastern side is.  If Fakir follows that track, then the strongest wind and heaviest rain could affect Mauritius.  However, Fakir will also affect La Reunion.

Tropical Cyclone Keni Brings Winds and Rain to Fiji

Tropical Cyclone Keni brought wind and rain to Fiji on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Keni was located at latitude 19.4°S and longitude 178.0°E which put it about 100 miles (160 km) west-southwest of Suva, Fiji.  Keni was moving toward the east-southeast at 21 m.p.h. (34 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 976 mb.

Tropical Cyclone Keni intensified rapidly on Monday into the equivalent of a hurricane/typhoon.  A primary rainband wrapped tightly around the center of circulation and a small eye formed at the center.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Other bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Keni.  The strongest bands were east and south of the center of circulation.  Storms in the core of Keni were generating upper level divergence which was pumping away mass to the east of the tropical cyclone.  Winds to hurricane/typhoon force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 155 miles (250 km) from the center.

Tropical Cyclone Keni will remain in an environment favorable for intensification for about another 12 to 18 hours.  It will move over water where the Sea Surface Temperature is near 28°C.  Keni is moving under the southwestern portion of an upper level ridge which is producing northwesterly winds which blowing toward the top of the circulation.  Those winds were causing some vertical wind shear, but the shear will not be strong enough to prevent intensification during the next few hours.  Tropical Cyclone Keni will move under strong upper level winds in about 12 to 18 hours and then the wind shear will increase.  Increased wind shear will cause Keni to start to weaken.

The ridge is steering Tropical Cyclone Keni toward the east-southeast and that general motion is expected to continue for another 12 to 18 hours.  An upper level trough approaching from the west will steer Keni more toward the southeast after that time.  On its anticipated track the core and strongest part of Tropical Cyclone Keni will pass southwest of Fiji.  However, clockwise flow around Keni will continue to cause gusty winds and drop heavy rain on Fiji.  The heavy rain could cause flash floods.  Keni could bring wind and rain to Tonga in 18 to 24 hours.