Category Archives: South Pacific

Tropical Cyclone Solo (23P) Intensifying Slowly Over the Coral Sea

Tropical Cyclone Solo (23P) intensified slowly over the Coral Sea on Friday.  At 6:00 p.m. EDT on Friday the center of Tropical Cyclone Solo was located at latitude 17.1°S and longitude 161.1°E which put it about 470 miles northwest of Noumea, New Caledonia and about 470 miles west of Port Vila, Vanuatu.  Solo was moving toward the south-southeast at 13 m.p.h.  The maximum sustained wind speed was 60 m.p.h. and there were gusts to 80 m.p.h.  The minimum surface pressure was 983 mb.

Solo is moving over warm Sea Surface Temperatures, but an upper level high to the east of it is producing northerly winds over the top of the circulation.  The vertical wind shear is causing more of the stronger thunderstorms to be located south of the center and it is inhibiting the intensification of Solo.  As a result it is intensifying slowly and that trend is expected to continue for the next day or two.  Eventually, when Solo moves to a higher latitude, stronger upper level winds will create more vertical wind shear and weaken it.

Solo is moving around the western end of a subtropical ridge.  As it gets farther south, Solo is expected to move more toward the southeast.  On its projected track, Solo would approach New Caledonia in about 36 hours.  It could be near hurricane intensity at that time.  Solo could bring strong winds and heavy rainfall to New Caledonia when it moves past.

Tropical Cyclone 23P Organizes Rapidly Over the Coral Sea

A well organized circulation developed rapidly within an area of thunderstorms over the Coral Sea and the system was designated Tropical Cyclone 23P.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone 23P was located at latitude 14.4°S and longitude 160.5°E which put it about 670 miles northwest of Noumea, New Caledonia and about 600 miles west-northwest of Port Vila, Vanuatu.  It was moving toward the southwest at 12 m.p.h.  The maximum sustained wind speed was 50 m.p.h. and there were gusts to 65 m.p.h.  The minimum surface pressure was 989 mb.

Tropical Cyclone 23P is located in an area where the upper level winds are light.  That allowed thunderstorms to develop and wrap around the core of the circulation.  Upper level divergence is pumping out mass in all directions and the pressure is decreasing.  The tropical cyclone is over Sea Surface Temperatures which are near 30°C, which means there is plenty of energy in the upper ocean to support further intensification.  Tropical Cyclone 23P could reach hurricane intensity in a day or two.

The tropical cyclone is moving around the western end of a subtropical ridge, which is steering it toward the southwest.  As it moves around the end of the ridge, it will turn more toward the southeast.  On its expected track Tropical Cyclone 23P could approach New Caledonia in 48 to 72 hours.

Tropical Cyclone Pam Weakening North of New Zealand

Tropical Cyclone Pam is on a weakening trend as it moves north of New Zealand.  At 11:00 p.m. EDT on Saturday the center of Tropical Cyclone Pam was located at latitude 29.3°S and longitude 175.0°E which put it about 500 miles north of Auckland, New Zealand.  Pam was moving toward the south-southeast at 33 m.p.h.  The maximum sustained wind speed was 115 m.p.h. and there were gusts to 135 m.p.h.  The minimum surface pressure was 948 mb.

Pam has moved over water where the Sea Surface Temperature is 25°C and it is no longer able to extract sufficient energy from the ocean to maintain its intensity.  Stronger winds in the upper levels are increasing the vertical wind shear over the circulation and the weakening trend should continue.  The steering flow should carry Pam east of New Zealand and farther out into the South Pacific Ocean.

Intense Tropical Cyclone Pam Moving Over Southeastern Vanuatu

Very intense Tropical Cyclone Pam has been moving over some of the southeastern islands of Vanuatu  during Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Cyclone Pam was located at latitude 19.3°S and longitude 169.1°E which put ti about 10 miles northwest of Tanna, Vanuatu and about 120 miles northeast of Noumea, New Caledonia.  Pam was moving toward the south at 12 m.p.h.  The maximum sustained wind speed was 155 m.p.h. and it was estimated that there were wind gusts to 190 m.p.h.  The minimum surface pressure was 922 mb.

The center of Pam moved very close to the islands of Efate, Erromango and Tanna.  Given the size and intensity of the circulation, it is likely that it caused significant damage on those islands.  Pam may have reached its peak intensity and there are some indications that it could be undergoing an eyewall replacement cycle.  Some fluctuation or decrease in intensity is likely during the next 24 hours.

The center of Pam is projected to pass east of New Caledonia.  However, it may get close enough to cause significant damage, especially to the islands of Ouvea, Lifou and Mare, which will be closer to the center of circulation.  Pam should begin to weaken more quickly as it moves farther south in the general direction of New Zealand.

 

Pam Reaches Equivalent of Category 5 Hurricane

Tropical Cyclone Pam continued to intensify on Thursday and it has attained an intensity equivalent to a Category 5 hurricane on the Saffir-Simpson Scale.  At 5:00 p.m. the center of Tropical Cyclone Pam was located at latitude 15.0°S and longitude 169.6°E which put it about 100 miles east of Maewo, Vanuatu and about 560 miles northwest of Fiji.  Pam was moving toward the west-southwest at 10 m.p.h.  The maximum sustained wind speed was 160 m.p.h. and it was estimated that there could be wind gusts to 200 m.p.h.  The minimum surface pressure was 918 mb.

Pam is in an almost ideal environment for a tropical cyclone.  The Sea Surface Temperatures are warm and the upper level winds are very light.  It has a well developed circulation with a tight inner core.  Upper level divergence is pumping out mass in all directions.  Some further intensification is possible during the shorter term.  Eventually, when Pam moves farther south in a couple of days, it will move over cooler Sea Surface Temperatures and into a region where the upper level winds are stronger.  At that time it should start a steady weakening trend.  In the interim eyewall replacement cycles could produce fluctuations in intensity, but Pam is likely to be a big strong tropical cyclone for several more days.

An upper level ridge to the east of Pam is steering it generally toward the south.  It has moved a little west of due south today and that has brought the western part of the circulation closer to Vanuatu.  Any further westward movement could bring strong winds very close to Maewo, Pentecote, Ambrym, Epi, Efate and numerous smaller islands in southeastern Vanuatu.  Pam is a large, strong tropical cyclone and it is capable of causing serious damage on any island it crosses.

 

Tropical Cyclone Pam Still Intensifying

Tropical Cyclone Pam continued to intensify on Wednesday and it is now the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Pam was located at latitude 12.6°S and longitude 170.2°E which put it about 200 miles northeast of Espiritu Santo and about 670 miles northwest of Fiji.  Pam was moving toward the south-southeast at 6 m.p.h.  The maximum sustained wind speed was 130 m.p.h. and there were gusts to 160 m.p.h.  The minimum surface pressure was 937 mb.

A large eye formed in the center of Pam and the strongest winds are occurring in the ring of thunderstorms surrounding the eye.  Pam is moving over warm Sea Surface Temperatures and the upper level winds are fairly light.  As a result, it has developed strong upper level outflow in most directions.  The environment is favorable for further intensification, but strong tropical cyclones often go through eyewall replacement cycles which produce fluctuations in the intensity

Pam is being steered southward by an subtropical ridge to the east of the tropical cyclone.  This general steering pattern is expected to continue during the next several days.  The projected path of Pam takes the center east of Vanuatu and New Caledonia and west of Fiji.  However, a slight deviation to the west could bring strong winds to some of the islands of Vanuatu.

Tropical Cyclone Pam Intensifying Quickly

Tropical Cyclone Pam continued to intensify quickly on Tuesday.  At 10:00 p.m. EDT on Tuesday the center of Tropical Cyclone Pam was located at latitude 11.0°S and longitude 169.8°E which put it about 710 miles northwest of Fiji and about 220 miles north-northeast of Espiritu Santo.  Pam was moving toward the southwest at 5 m.p.h.  The maximum sustained wind speed was 115 m.p.h. and there were wind gusts to 135 m.p.h.  The minimum surface pressure was 948 mb.

Pam remains in a very favorable environment.  It is over warm Sea Surface Temperatures and it is in a region of light upper level winds.  The strong core of the tropical cyclone has generated well developed upper level outflow that is pumping out mass in all directions.  Unless it is interrupted by an eyewall replacement cycle, the intensification is likely to continue.

Pam is being steering toward the south by a subtropical ridge located to its east.  The ridge strengthened slightly on Tuesday and pushed the tropical cyclone slightly to the west of the projected track.  The ridge is expected to continue to steer Pam toward the south during the next few days.  The projected track continues to predict that Pam will move east of Vanuatu and New Caledonia and west of Fiji.  However, a further deviation to the west could bring the circulation closer to Vanuatu.  Because of the intensify and large size of the circulation, impacts could be serious if Pam moves over any islands.

 

Tropical Cyclone Pam Intensifying Rapidly Northwest of Fiji

A circulation core developed rapidly in a large area of thunderstorms east of the Solomon Islands and the system was classified as Tropical Cyclone Pam on Monday.  At 10:00 p.m. EDT on Monday the center of Tropical Cyclone Pam was located at latitude 9.8° and longitude 170.4°E which put it about 790 miles northwest of Fiji.  Pam was moving toward the south-southeast at 7 m.p.h.  The maximum sustained wind speed was 75 m.p.h. and there were gusts to 90 m.p.h.  The minimum surface pressure was 974 mb.

Pam intensified rapidly on Monday and reached hurricane intensity within 24 hours of being classified as a tropical cyclone.  It is over Sea Surface Temperatures warmer than 30°C and it has moved into an area where the upper level winds are relatively light.  It normally takes the circulation in a large tropical disturbance a long time to consolidate around an inner core.  However, Pam has well developed upper level outflow, which has pumped out mass and enabled the system to intensify rapidly.  Pam is expected to remain in a very favorable environment and continued rapid intensification is likely.  It could become a very powerful tropical cyclone during the next several days.

Pam is moving around the western end of a subtropical ridge with is steering it in a south-southeasterly direction.  That generally steering pattern is expected to continue for the next several days.  The projected path of Pam carries it west of Fiji and east of Vanuatu and New Caledonia.  Given the large size and intensity of the tropical cyclone, any deviation from the projected path could increase the risk posed by Tropical Cyclone Pam.

 

Tropical Cyclone Ola Intensifying Northwest of New Caledonia

Tropical Cyclone Ola intensified rapidly on Saturday as it moved over the Coral Sea northwest of New Caledonia.  At 8:00 p.m. EST on Saturday the center of Ola was located at latitude 19.9°S and longitude 162.9°E which put it about 260 miles northwest of Noumea, New Caledonia.  Ola was moving toward the south-southeast at 8 m.p.h.  The maximum sustained wind speed was 80 m.p.h. and there were gusts to 95 m.p.h.  The minimum surface pressure was 970 mb.

Ola is moving over warm Sea Surface Temperatures (SSTs) and the environmental winds are generating upper level divergence to the southeast of the circulation.  The divergence pumped out mass and surface pressure decreased rapidly.  As a result, Ola intensified into the equivalent of a hurricane on Saturday.  Ola will remain over warm SSTs, but it will move into an area of stronger upper level winds when it moves farther southward.  It could intensify more during the next 24 hours, but it is likely to begin to weaken in 36 to 48 hours because of increasing vertical wind shear.

Counterclockwise flow around the western end of a subtropical ridge is steering Ola in a general southward direction.  That motion is expected to continue for another 24 hours.  A ridge of high pressure is expected to build south of Ola in a day or so.  The ridge could block Ola from moving any farther toward the south and turn it toward the southwest.  On the expected track, Ola would stay west of New Caledonia.  It is expected to weaken before it reaches Australia.

 

Tropical Cyclone Niko Passing East of Tahiti

The center of Tropical Cyclone Niko is passing east of Tahiti.  At 11:00 p.m. EST on Wednesday the center of Tropical Cyclone Niko was located at latitude 17.8°N and longitude 147.9°E which put it about 120 miles east of Papeete, Tahiti.  Niko was moving toward the south-southeast at 13 m.p.h.  The maximum sustained wind speed was 60 m.p.h. and there were gusts to 75 m.p.h.  The minimum surface pressure was estimated to be 985 mb.

Niko is a small tropical cyclone and even though it is passing within 120 miles of Tahiti, it is having a minimal effect on the weather there.  A subtropical ridge is expected to continue to steer Niko south-southeasterly direction, which will carry it away from Tahiti, although it could come close to the island of Mehetia.  The north-northwesterly winds that are steering Niko are also creating some wind shear.  The wind shear is limiting the intensification of Niko, but it is still over warm Sea Surface Temperatures and some intensification is possible on Thursday.  By Friday Niko is likely to be far enough south that is will start to move over cooler Sea Surface Temperatures and encounter stronger upper level winds.  So, Niko is likely to start to weaken in about 36 to 48 hours.