Category Archives: South Pacific

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.

Tropical Cyclone Keni Forms East of Vanuatu

Tropical Cyclone Keni formed east of Vanuatu on Sunday.  At 11:00 p.m EDT on Sunday the center of Tropical Cyclone Keni was located at latitude 16.9°S and longitude 172.0°E which put it about 215 miles (350 km) east of Port Vila, Vanuatu.  Keni was moving toward the east-southeast 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 994 mb.

A distinct center of circulation consolidated in an area of showers and thunderstorms between Vanuatu and Fiji on Sunday and the Fiji Meteorological Service designated the system as Tropical Cyclone Keni.   The circulation of Tropical Cyclone Keni organized quickly.  Several bands of thunderstorms wrapped part of the way around the center of circulation.  Other bands of showers and thunderstorms were revolving around the core of the circulation.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone Keni will move through an environment favorable for intensification during the next 24 hours.  Keni will move over water where the Sea Surface Temperature is near 28°C.  It is under a small upper level ridge and the upper level winds are weak.  So, there will be little vertical wind shear on Monday.  Tropical Cyclone Keni will intensify during the next 24 hours and it could become the equivalent of a hurricane/typhoon.

Tropical Cyclone Keni on the southwestern edge of a subtropical ridge which is steering Keni toward the east-southeast.  A general motion toward the east-southeast is expected to continue for another 24 to 36 hours.  On its anticipated track Tropical Cyclone Keni could be approaching Fiji within 24 hours.  Keni could be the equivalent of a hurricane/typhoon when it near Fiji.  Keni will bring gusty winds and locally heavy rain to parts of Fiji.  The heavy rain could cause flash floods in some locations.

Tropical Cyclone Iris Weakens East of Queensland

Tropical Cyclone Iris weakened over the Coral Sea east of Queensland on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Iris was located at latitude 19.6°S and longitude 152.3°E which put it about 230 miles (370 km) east-northeast of Mackay, Australia.  Iris was moving toward the east-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 990 mb.

An upper level ridge east of Australia was producing strong northwesterly winds which were blowing toward the top of Tropical Cyclone Iris.  Those winds were causing strong vertical wind shear which weakened Iris on Wednesday.  The stronger thunderstorms were occurring in bands southeast of the center of circulation.  The bands in other parts of the circulation consisted primarily of showers and low clouds.  The wind shear was not quite strong enough to blow the top off of the circulation, but the shear was preventing upper level divergence on the northern side of Tropical Cyclone Iris.

Tropical Cyclone Iris will move over water where the Sea Surface Temperature is near 28°C.  So, there is enough energy in the upper ocean to support a tropical cyclone.  However, the upper level ridge will continue to cause strong vertical wind shear and Tropical Cyclone Iris is likely to slowly weaken during the next several days.

Tropical Cyclone Iris is moving slowly toward the east-southeast.  If the vertical wind shear blows the top half of the circulation away to the southeast, then Iris would be steered by the winds in the lower atmosphere.  A high pressure system in the lower atmosphere over Australia would begin to steer Tropical Cyclone Iris back toward the northwest.  On its anticipated track the center of Tropical Cyclone Iris is expected to remain east of Queensland.  Rainbands on the western periphery have occasionally brought rain to the coast of Queensland, but most of the rain is falling over the ocean.

Tropical Cyclone Iris Prompts Warnings for Queensland

The proximity of Tropical Cyclone Iris prompted the Australian Bureau of Meteorology to issued Warnings and Watches for the east coast of Queensland on Monday.  A Warning was issued for the portion of the coast from Ayr to Sarina including Mackay and the Whitsunday Islands.  A Watch was issued for the portion of the coast from Sarina to St. Lawrence.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Iris was located at latitude 17.1°S and longitude 149.0°E which put it about 210 miles (335 km) northeast of Townsville, Australia.  Iris was moving toward the southeast at 3 m.p.h. (4 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 994 mb.

The circulation of Tropical Cyclone Iris was asymmetrical.  Most of the showers and thunderstorms were located south and east of the center of circulation.  The bands north and west of the center consisted primarily of low clouds and showers.  Tropical Cyclone Iris was near the western end of an upper level ridge.  The ridge was producing northwesterly winds which were blowing toward the top of the circulation.  Those winds were producing moderate vertical wind shear and they were probably responsible for the asymmetrical distribution of thunderstorms.

Tropical Cyclone Iris will be moving through an environment marginally favorable for intensification during the next 48 hours.  Iris will move over water where the Sea Surface Temperature is near 29°C.  However, the upper level ridge will continue to produce moderate vertical wind shear.  The shear will be strong enough to inhibit intensification.  If the strength of the upper level winds slows, then Tropical Cyclone Iris could strengthen, but if the upper level winds get faster, then Iris will weaken.  The forecast is for slow intensification, but there is high uncertainty about the intensity forecast.

The subtropical ridge east of Iris is steering Tropical Cyclone Iris slowly toward the southeast.  A general motion toward the southeast is expected to continue for several more days.  On its anticipated track the center of Tropical Cyclone Iris is expected to stay east of the coast of Queensland.  However, Tropical Cyclone Iris could come close enough to the coast to bring gusty winds and locally heavy rain to locations under Warnings and Watches.

Tropical Cyclone Iris Redevelops East of Queensland.

Tropical Cyclone Iris redeveloped east of Queensland on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Tropical Cyclone Iris was located at latitude 16.9°S and longitude 148.7°E which put it about 190 miles (310 km) east of Cairns, Australia.  Iris was moving toward the southwest at 8 m.p.h. (13 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.

Tropical Cyclone Iris formed over the Coral Sea last week but wind strong vertical shear quickly weakened Iris into an area of low pressure.  The low pressure system meandered over the Coral Sea east of Australia during the past few days.  More thunderstorms developed near the center of circulation on Sunday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Iris again.

The circulation around Tropical Cyclone Iris was still reorganizing on Sunday night.  A distinct low level center of circulation was evident on visible satellite images.  More thunderstorms were developing near the center.  A primary rainband wrapped around the northern, eastern and southern sides of the center of circulation.  Bands northwest of the center consisted mainly of showers and low clouds.  Storms near the core of the circulation generated upper level divergence which was pumping mass away to the east of the tropical cyclone.

Tropical Cyclone Iris will move through an environment somewhat favorable for intensification on Monday.  Iris will move over water where the Sea Surface Temperature is 29°C.  It is moving around the western end of an upper level ridge.  The ridge is producing northwesterly winds which were blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and they may have been the reason for the lack of strong rainbands northwest of the center of circulation.  The wind shear is likely to inhibit intensification, but it probably won’t prevent Tropical Cyclone Iris from intensifying on Monday.

Tropical Cyclone Iris was moving around the western end of a subtropical ridge which was steering Iris toward the southwest.  Iris will likely move more toward the south and then southeast as it rounds the western end of the ridge.  On its anticipated track Tropical Cyclone Iris is expected to remain east of Queensland.

Elsewhere over the South Pacific Ocean Tropical Cyclone Josie was swirling south of Fiji.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Josie was located at latitude 21.1°S and longitude 178.1°E which put it about 185 miles (300 km) south of Suva, Fiji.  Josie was moving toward the south-southeast at 14 m.p.h. (22 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 999 mb.

Tropical Cyclone Josie Brings Wind and Rain to Fiji

Tropical Cyclone Josie brought wind and rain to Fiji on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Josie was located at latitude 19.2°S and longitude 177.4°E which put it about 105 miles (170 km) southwest of Suva, Fiji.  Josie was moving toward the east-southeast at 14 m.p.h. (22 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 998 mb.

Tropical Cyclone Josie formed within an area of thunderstorms that had persisted west of Fiji for several days.  A center of circulation developed within the area of thunderstorms and the Fiji Meteorological Service designated the system as Tropical Cyclone Josie.  The circulation of Tropical Cyclone Josie was somewhat asymmetrical.  Most of the stronger thunderstorms were occurring in the eastern half of the circulation.  The strongest winds were occurring in a primary rainband east of the center of circulation,  The bands in the western half of the circulation consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out about 160 miles (260 km) east of the center of circulation.

Tropical Cyclone Josie will move through an area somewhat favorable for intensification during the next day or two.  Josie will move over water where the Sea Surface Temperature is near 28°C.  It will move near an area where westerly winds are blowing in the upper levels and those winds may already be responsible for the asymmetrical distribution of stronger storms.  The upper level winds will cause moderate vertical wind shear, but the shear may not be strong enough to prevent some intensification.  Tropical Cyclone Josie could intensify slowly during the next 24 to 48 hours.

Tropical Cyclone Josie is moving near the eastern end of a ridge which is steering Josie toward the east-southeast.  The westerly winds in the middle troposphere will continue to steer Tropical Cyclone Josie toward the southeast during the next several days.  On its anticipated track the center of Josie will pass south of Viti Levu.  The center of Tropical Cyclone Josie will move near Kadavu and Ono in about 12 hours.  Even though the center of circulation will pass south of Viti Levu, Tropical Cyclone Josie will drop heavy rain there and the potential for flash floods will exist.  Josie will also bring gusty winds and heavy rain to Kadavu and Ono.

Tropical Cyclone Nora Develops Rapidly North of Australia

Tropical Cyclone Nora developed rapidly north of Australia over the Arafura Sea on Thursday.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Nora was located at latitude 10.0°S and longitude 136.8°E which put it about 160 miles (260 km) north of Nhulunbuy, Australia.  Nora was moving toward the east at 3 m.p.h. (5 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 986 mb.

A center of circulation organized quickly on Thursday in an area of thunderstorms over the Arafura Sea and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Nora.  A primary rainband wrapped around the western and northern side of the center of circulation.  An eye appeared to be forming at the center of Tropical Cyclone Nora.  Bands of showers and thunderstorms were revolving around the core of the circulation.  Storms around the core were generating well developed upper level divergence which was pumping mass away from the tropical cyclone.  The removal of mass was allowing the surface pressure to decrease rapidly and the wind speeds were increasing in response.

The Australian Bureau of Meteorology issued Warnings for the portions of the coast from Elcho Island to Cape Shield including Cape Wessel and from Pormpuraaw to Thursday Island.  A Watch was in effect for the portion of the coast from Pormpuraaw to the border between the Northern Territory and Queensland including Mornington Island.

Tropical Cyclone Nora will move through an environment very favorable for intensification during the next 48 hours.  Nora will move over water where the Sea Surface Temperature is near 30°C.  It will move through an area where the upper level winds are weak and there is little vertical wind shear.  Nora is likely to intensify rapidly and it is likely to become the equivalent of a hurricane/typhoon within 24 hours.  Tropical Cyclone Nora could become the equivalent of a major hurricane within 24 to 48 hours.

Tropical Cyclone Nora was moving through an area where steering winds are weak and it was moving slowly toward the east.  A subtropical ridge east of Australia is expected to strengthen.  The ridge is forecast to steer Nora more toward the south in 12 to 24 hours.  On its anticipated track Tropical Cyclone Nora is expected to move over the Gulf of Carpentaria toward the coast of Queensland.  Nora could strengthen into a dangerous tropical cyclone.

Elsewhere, Tropical Cyclone Marcus continued to churn west of Australia.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Marcus was located at latitude 20.6°S and longitude 106.0°E which put it about 555 miles (895 km) west-northwest of Learmonth, Australia.  Marcus was moving toward the south at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 951 mb.

Tropical Cyclone 13P Develops Over the Coral Sea

Tropical Cyclone 13P developed over the Coral Sea northwest of New Caledonia on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Cyclone 13P was located at latitude 17.2°S and longitude 159.7°E which put it about 550 miles (885 km) northwest of Noumea, New Caledonia.  It was moving toward the south at 11 m.p.h. (17 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 998 mb.

A distinct low level center of circulation developed within an area of showers and thunderstorms over the Coral Sea on Monday.  The strongest rainband extended from northeast of the center, south of the the center and then west of the center.  Additional rainbands were forming in other part of the circulation.  Storms near the center of circulation were beginning to generate upper level divergence which was pumping mass away to the south of the tropical cyclone.

Tropical Cyclone 13P will move through an environment favorable for intensification on Tuesday.  It will move over water where the Sea Surface Temperature is near 29°C.  An upper level trough near the east coast of Australia is producing northerly winds which are blowing toward the top of the circulation.  The core of Tropical Cyclone 13P is east of the strongest upper level winds, but the winds are causing moderate vertical wind shear.  Despite the vertical shear, the tropical cyclone is forecast to intensify during the next 24 hours.

Tropical Cyclone 13P is moving around the western end of a subtropical ridge which is steering it toward the south.  There is some variability in the guidance from the numerical models about the future strength of the ridge.  Some models do not strengthen the ridge much and those model predict that Tropical Cyclone 13P will move almost straight southward.  Other models increase the strength of the ridge and steer the tropical cyclone more toward the south-southwest.  A general motion toward the south or south-southwest seems most likely during the next 24 to 36 hours.  On its anticipated track the core of Tropical Cyclone 13P would pass west of New Caledonia, but it could move closer to the east coast of Australia.

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.