Monthly Archives: March 2018

Tropical Cyclone Hola Passes Near Iles Loyaute

Tropical Cyclone Hola passed near the Iles Loyaute (Loyalty Islands) on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Hola was located at latitude 20.9°S and longitude 168.0°E which put it about 175 miles (280 km) northeast of Noumea, New Caledonia.  Hola was moving toward the southeast at 19 m.p.h. (31 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 969 mb.

The circulation of Tropical Cyclone Hola exhibited signs of weakening on Friday.  The eye appeared and disappeared intermittently.  There were occasional breaks in the rings of thunderstorms around the intermittent eye.  The distribution of rainbands became more asymmetrical.  All of the stronger bands were south and east of the center of circulation.  The bands north and west of the center consisted primarily of showers and low clouds.  An upper level trough off the east coast of Australia was producing northwesterly winds which were blowing toward the top of the circulation.  Those winds were also causing moderate vertical wind shear and they may have tilted the upper portion of the circulation toward the southeast.

Tropical Cyclone Hola will weaken during the next few days.  Hola will initially pass over water where the Sea Surface Temperature is near 28°C.  However, the upper level trough will continue to cause moderate vertical wind shear which will weaken Hola.  Tropical Cyclone Hola will also move over colder water when it moves farther to the south.  The colder water and vertical wind shear will cause the structure of Tropical Cyclone Hola to transition gradually to an extratropical cyclone during the next several days.

The upper level trough is pushing Tropical Cyclone Hola toward the southeast and a general southeasterly motion will continue.  On its anticipated track Tropical Cyclone Hola will move away from the Iles Loyaute and New Caledonia.  Hola could approach northern New Zealand in a couple of days.

The strongest winds and heavy rain were occurring on the eastern side of Tropical Cyclone Hola.  Hola will continue to bring gusty winds and locally heavy rain to the Iles Loyaute until it moves away.  It should have minimal impacts on New Caledonia.  Tropical Cyclone Hola could make landfall on the North Island of New Zealand in two or three days.  It could be a strong extratropical cyclone at that time and it could bring strong wind and heavy rain to parts of northern New Zealand.

Tropical Cyclone Hola Stalls Between Vanuatu and New Caledonia

Tropical Cyclone Hola stalled between Vanuatu and New Caledonia on Thursday.  At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Hola was located at latitude 18.4°S and longitude 165.5°E which put it about 200 miles (320 km) west of Port Vila, Vanuatu.  Hola was moving toward the south at 2 m.p.h. (3 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 961 mb.

Tropical Cyclone Hola weakened slightly while it move slowly between Vanuatu and New Caledonia.  The small eye was no longer visible on satellite images.  Thunderstorms were still occurring in the core of the circulation.  Most of the bands of showers and thunderstorms were in the eastern half of the circulation.  There were fewer thunderstorms west of the center of circulation.  The wind field exhibited a similar asymmetrical distribution.  Winds to hurricane/typhoon force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 150 miles (240 km) in the eastern half of the circulation and about 100 miles (160 km) in the western half of the circulation.

Tropical Cyclone Hola will move through an environment marginally favorable for intensification on Friday.  Hola will move over water where the Sea Surface Temperature is near 30°C.  An upper level trough east of Australia will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause increasing vertical wind shear and the shear could become strong enough to inhibit intensification.  Tropical Cyclone Hola could intensify during the next 12 to 24 hours, but it will begin to weaken when the shear increases.

Tropical Cyclone Hola is near the western end of a subtropical ridge and it was in a region where the steering winds were weak on Thursday.  The upper level trough east of Australia will start to steer Hola toward the southeast on Friday.  On its anticipated track the center of Tropical Cyclone Hola could approach the Iles Loyaute (the Loyalty Islands) within 24 hours.  Hola will likely still be the equivalent of a hurricane/typhoon at that time.

Tropical Cyclone Hola Brings Wind and Rain to Vanuatu

Tropical Cyclone Hola brought strong winds and heavy rain to Vanuatu on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Hola was located at latitude 17.4°S and longitude 165.5°E  which put it about 180 miles (290 km) west of Port Vila, Vanuatu.  Hola was moving toward the west-southwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (205 km/h).  The minimum surface pressure was 959 mb.

Tropical Cyclone Hola intensified rapidly into the equivalent of a hurricane/typhoon on Wednesday.  A very small circular eye developed at the center of circulation.  A ring of strong thunderstorms formed around the eye and the strongest winds were occurring in that ring of storms.  Rainbands were revolving around the core of the Tropical Cyclone Hola.  The strongest rainbands were occurring in the eastern side of the circulation.  The rainbands were weaker in the western half of Hola.  Storms around the core of the circulation were generating strong upper level divergence which was pumping mass away to the east of the tropical cyclone.  The circulation of Tropical Cyclone Hola was fairly small.  Winds to hurricane/typhoon force extended out about 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out about 120 miles (195 km) from the center.

Tropical Cyclone Hola will move through an environment favorable for intensification for another 24 to 36 hours.  Hola will move over water where the Sea Surface Temperature is near 30°C.  It is moving under a region where the upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Hola is likely to intensify during the next 24 hours and it could become the equivalent of a major hurricane.

Tropical Cyclone Hola was moving around the northwestern end of a subtropical ridge which was steering the tropical cyclone toward the west-northwest.  Hola is forecast to turn more toward the south when it rounds the end of the ridge on Thursday.  It could move toward the southeast when it moves farther south.  On its anticipated track Tropical Cyclone Hola could approach New Caledonia and the Iles Loyaute in a little over 24 hours.

Rainbands in the eastern half of Tropical Cyclone Hola brought gusty winds and locally heavy rain to parts of Vanuatu on Wednesday.  Wind and rain could increase over New Caledonia and the Iles Loyaute by Friday.

Tropical Cyclone Hola Develops Over Vanuatu

Tropical Cyclone Hola developed over Vanuatu on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Cyclone Hola was located at latitude 16.2°S and longitude 168.1°E which put it near Ambrym and about 110 miles (180 km) north of Port Vila, Vanuatu.  Hola was moving toward the west-southwest 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 992 mb.

A large area of showers and thunderstorms northwest of Fiji moved slowly westward toward Vanuatu during the past few days.  The system was designated Tropical Cyclone Hola when a center of circulation developed in the area of storms on Tuesday.  Thunderstorms formed on all sides of the center, but there were more thunderstorms on the western side of the center.  Bands of showers and storms were beginning to revolve around the core of the circulation.  The storms near the center were starting to generate upper level divergence which was pumping mass away from the center of circulation.

Tropical Cyclone Hola will move through an environment favorable for intensification during the next two or three days.  Hola will move over water where the Sea Surface Temperature is near 30°C.  The upper level winds over that area are weak and there is little vertical wind shear.  Tropical Cyclone Hola should intensify during the next 48 to 72 hours.  Rapid intensification could occur once the core of the circulation is fully organized.  Hola could strengthen into the equivalent of a hurricane/typhoon during the next 24 hours.  Hola could become the equivalent of a major hurricane within three days.

Tropical Cyclone Hola is moving near the northwestern end of a subtropical ridge which is steering Hola toward the west-southwest.  A slow motion toward the southwest is forecast during the next day or so while Hola rounds the northwestern end of the ridge.  Tropical Cyclone Hola will turn more toward the southeast after it rounds the subtropical ridge.  On its anticipated track the center of Tropical Cyclone Hola will move near Ambrym, Malekula, Paama, Lopevi, and Epi.  Hola is forecast to pass west of Port Vila, but it could be near New Caledonia and the Iles Loyaute in two or three days.

Tropical Cyclone Hola will strengthen as it moves slowly toward the southwest during the next 24 hours.  The stronger tropical cyclone will produce gusty winds and it will drop heavy rain over the central parts of Vanuatu.  Heavy rain will fall over Espiritu Santo, Maewo, Ambae, Pentecost, Malo, Ambrym, Paama, Lopevi, Tongoa, Epi, Emae, the Shepherd Islands, Nguna, Emao, and Efate.  Locally heavy rain could create the potential for floods in some of those locations.

Tropical Cyclone Dumazile Drops Heavy Rain on La Reunion

Tropical Cyclone Dumazile dropped heavy rain on La Reunion on Monday.  At 4:00 p.m. EST on Monday the center of Tropical Cyclone Dumazile was located at latitude 23.3°S and longitude 52.5°E which put it about 260 miles (420 km) southwest of St. Denis, La Reunion.  Dumazile was moving toward the south-southeast at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 949 mb.

Tropical Cyclone Dumazile strengthened into the equivalent of a major hurricane on Monday.  It was a large, powerful tropical cyclone.  There was a small circular eye at the center of the circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Several rainbands were revolving around the core of the circulation.  The storms around the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone.  Winds to hurricane/typhoon force extended out about 90 miles (145 km) from the center of circulation.  Winds to tropical storm force extended out about 250 miles (400 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Dumazile was 20.6.  The Hurricane Size Index (HSI) was 30.3 and the Hurricane Wind Intensity Size Index (HWISI) was 50.9.  Those indices indicate that Tropical Cyclone Dumazile would be capable of causing extensive major damage if it made landfall.

Although the core of Tropical Cyclone Dumazile passed between Madagascar and La Reunion, the circulation was so large that rainbands on the eastern side of Dumazile passed over La Reunion.  Those rainbands dropped locally heavy rain and there were unconfirmed reports of flooding in parts of La Reunion.

Tropical Cyclone Dumazile has likely reached its peak intensity.  Dumazile is currently moving over water where the Sea Surface Temperature is near 28°C, but the tropical cyclone will move over colder water when it moves farther south.  An upper level trough near southern Africa is producing northwesterly winds which are blowing toward the top of the circulation.  Those winds are generating vertical wind shear and the shear is forecast to increase during the next several days.  The colder water and increased wind shear are forecast to weaken Tropical Cyclone Dumazile during the next few days.

Tropical Cyclone Dumazile has rounded the western end of a subtropical ridge and it is now moving toward the south-southeast.  A general southeastward motion is forecast for the next two or three days.  On its anticipated track Tropical Cyclone Dumazile should move away from Madagascar and La Reunion.

Tropical Cyclone Dumazile Passes Between Madagascar and La Reunion

Tropical Cyclone Dumazile passed between Madagascar and La Reunion on Sunday night.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Dumazile was located at latitude 20.7°S and longitude 51.1°E which put it about 280 miles (450 km) west of St. Denis, La Reunion.  Dumazile was moving toward the south-southeast at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (205 km/h).  The minimum surface pressure was 961 mb.

Dumazile is a very well organized tropical cyclone. The circulation is symmetrical and there is a small circular eye at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds are occurring in that ring.  Bands of showers and thunderstorms are revolving around the core of the circulation.  Storms in the core are generating strong upper level divergence which is pumping mass away from the tropical cyclone.  Winds to hurricane/typhoon force extended out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extended out about 230 miles (370 km) from the center.

Tropical Cyclone Dumazile will move through an environment favorable for intensification for about another 24 hours.  Dumazile will move over water where the Sea Surface Temperature is near 29°C.  It will move under an area where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Dumazile could strengthen into the equivalent of a major hurricane on Monday.  When Dumazile moves farther south in a day or so, it will move over cooler water and into an area where the upper level winds are stronger.  Cooler water and more vertical wind shear will cause Tropical Cyclone Dumazile to weaken when that happens.

Tropical Cyclone Dumazile has rounded the western end of a subtropical ridge and it is now moving toward the south-southeast.  A general southeasterly motion is expected during the next few days.  On its anticipated track Tropical Cyclone Dumazile will move away from Madagascar.  Dumazile is forecast to pass southwest of La Reunion.

Tropical Cyclone Dumazile Brings Wind and Rain to Eastern Madagascar

Tropical Cyclone Dumazile brought wind and rain to eastern Madagascar on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Dumazile was located at latitude 17.0°S and longitude 51.5°E which put it about 90 miles (145 km) east of Ambodifotatra, Madagascar.  Dumazile was moving toward the southwest at 8 m.p.h. (13 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 979 mb.

Tropical Cyclone Dumazile intensified rapidly into the equivalent of a hurricane/typhoon on Saturday.  Satellite images suggested that an eye was forming at the center of circulation.  The developing eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in the ring of storms.  Additional bands of showers and thunderstorms were revolving around the core of the circulation.  Storms in the core were generating strong upper level divergence which was pumping large quantities of mass away from 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 200 miles (320 km) from the center.

Tropical Cyclone Dumazile will move through an environment very favorable for intensification during the next 24 hours.  Dumazile will move over water where the Sea Surface Temperature is near 30°C.  It will continue to move through a region where the upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Dumazile is likely to continue to intensify rapidly on Sunday and it could strengthen into the equivalent of a major hurricane.

Tropical Cyclone Dumazile is moving around the western end of a subtropical high pressure system which is steering the tropical cyclone toward the southwest.  Dumazile is likely to move more toward the south as it moves around the western end of the ridge.  On its anticipated track the core of Tropical Cyclone Dumazile is forecast to pass east of the coast of Madagascar.  However, rainbands on the western side of the circulation will bring gusty winds and locally heavy rain to parts of eastern Madagascar.  Heavy rain could cause flash floods in some locations.

Tropical Cyclone 11S Forms East of Northern Madagascar

Tropical Cyclone 11S formed east of the northern tip of Madagascar on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone 11S was located at latitude 13.2°S and longitude 54.3°E which put it about 535 miles (865 km) north of St. Denis, La Reunion.  It was moving toward the southeast at 4 m.p.h. (6 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 996 mb.

A distinct center of circulation finally developed on Friday in an area of thunderstorms that had been stationary northeast of Madagascar.  A primary band of storms wrapped around the northern side of the center of circulation and then storms began to develop near the center.  Additional bands of showers and thunderstorms were revolving around the core of the circulation and the structure of the circulation was organized enough to be classified as a tropical cyclone.  Storms near the center of circulation began to generate upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone 11S will be moving through an environment that is very favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  Tropical Cyclone 11S is located under an upper level ridge and the upper level winds are weak.  There is little vertical wind shear to inhibit intensification.  Tropical Cyclone 11S will intensify during the weekend and it is likely to intensify rapidly at times.  Tropical Cyclone 11S could strengthen into the equivalent of a major hurricane during the next two or three days.

Tropical Cyclone 11S and its precursor have been in an area where the steering winds were weak.  A subtropical ridge located to the east of the tropical cyclone is forecast to strengthen.  The ridge will steer Tropical Cyclone 11S toward the south-southwest.  Early model guidance suggests that the center of the tropical cyclone will move between Madagascar and La Reunion, but there is still uncertainty in the future track of the system.