Tag Archives: Port Vila

Tropical Cyclone May Develop Northeast of Vanuatu

A tropical cyclone may develop over the South Pacific Ocean northeast of Vanuatu during the next several days. At 2:00 p.m. EDT on Monday the center of a low pressure system, also designated at Invest 91P, was located at latitude 13.5°S and longitude 171.7°E which put it about 375 miles (600 km) northeast of Port Vila, Vanuatu. The low pressure system was moving toward the south-southwest at 4 m.p.h (6 km/h). The maximum sustained wind speed was 20 m.p.h. (30 km/h) and there were wind gusts to 30 m.p.h. (50 km/h). The minimum surface pressure was 1010 mb.

More thunderstorms formed just to the southwest of the center of a low pressure system over the South Pacific Ocean northeast of Vanuatu on Monday. Thunderstorms also formed in bands revolving around the center of the low pressure system. The storms just southwest of the center of circulation began to generate upper level divergence that started to pump mass away from the low pressure system. The better organization exhibited by the low pressure system increased the potential that the low may develop into a tropical cyclone during the next several days.

The low pressure system will move into an environment that is favorable for the development of a tropical cyclone. The low pressure system will move over water where the Sea Surface Temperatures are near 27˚C. It will move under the western side of an upper level ridge over the South Pacific Ocean. The ridge will produce northerly winds that will blow toward the top of the low pressure system. Those winds will cause some vertical wind shear, but the shear will not be great enough to prevent intensification. The low pressure system could strengthen to a tropical cyclone during the next several days.

The low pressure system will move around the western end of a high pressure system over the South Pacific Ocean. The high pressure system will steer the low pressure system toward the south-southwest during the next several days. On its anticipated track the low pressure system could approach southern Vanuatu later this week.

Tropical Cyclone Harold Strengthens to Equivalent of Cat. 5 Hurricane

Tropical Cyclone Harold strengthened to the equivalent of a Category 5 hurricane on Monday.  After weakening while the eye crossed the southern end of Espiritu Santo, the core of Harold rapidly intensified and the tropical cyclone became even more powerful.  At 11:00 a.m. EDT on Monday the center of Tropical Cyclone Harold was located at latitude 16.2°S and longitude 169.4°E which put it about 120 miles (195 km) north-northeast of Port Vila, Vanuatu.  Harold was moving toward the east-southeast at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 165 m.p.h.  and there were wind gusts to 200 m.p.h. (320 km/h).  The minimum surface pressure was 912 mb.

The inner core of Tropical Cyclone Harold weakened when the eye moved across the southern end of Espiritu Santo.  For a time the eye was less distinct of satellite images.  However, the eye cleared out quickly after it moved back over water and the core of Harold strengthened further.  By Monday a small, well formed eye was evident infrared satellite images.  The eye had a diameter of 12 miles (19 km).  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Harold.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone.

Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of Tropical Cyclone Harold.  Winds to tropical storm force extended out 190 miles (305 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Tropical Cyclone Harold was 36.8.  The Hurricane Size Index (HSI) was 16.0 and the Hurricane Wind Intensity Size Index (HWISI) was 52.8.  Harold was capable of causing catastrophic damage.

The core of Tropical Cyclone Harold passed over the southern end of Espiritu Santo.  It then passed near the northern end of Malekula before battering Pentecost and Ambrym.  Harold likely caused catastrophic wind damage in those locations.  Tropical Cyclone Harold also dropped locally heavy rain over Espiritu Santo, Malekula, Pentecost, Maewo, and Ambrym.  Flash flooding probably occurred on those islands.

Tropical Cyclone Harold will move through an environment capable of support an intense tropical cyclone during the next several days.  Harold will move over water where the Sea Surface Temperature is near 30°C.  It will move under the southwestern part of an upper level ridge over the South Pacific Ocean.  The ridge will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Tropical Cyclone Harold to weaken.  Tropical cyclones generally do not maintain Category 5 intensity for an extended period of time.  So, Tropical Cyclone Harold is likely to start to weaken within 24 hours.

Tropical Cyclone Harold will move around the southwestern part of a high pressure system over the South Pacific Ocean.  The high will steer Harold toward the east-southeast during the next few days.  On its anticipated track Tropical Cyclone Harold will move away from Vanuatu.  Harold could approach Fiji within 36 hours and it could still be the equivalent of a major hurricane at that time.

Tropical Storm Kammuri Passes South of Guam

Tropical Storm Kammuri passed south of Guam on Tuesday.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm Kammuri was located at latitude 11.8°N and longitude 141.8°E which put it about 225 miles (365 km) southwest of Guam.  Kammuri was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 985 mb.  The Tropical Storm Warnings for Guam, Rota, Saipan and Tinian were discontinued.

The circulation around Tropical Storm Kammuri exhibited greater organization on Tuesday.  Rainbands around the center of circulation were more circular.  Storms near the center were generating upper level divergence which was pumping mass away to the north and west of the tropical storm.  There were also more thunderstorms in bands north and west of the center of Kammuri.  Bands southeast of the center consisted primarily of showers and lower clouds.  The wind field around Tropical Storm Kammuri was also asymmetrical.  Winds to tropical storm force extended out farther in the northern half of the circulation.  Winds to tropical storm force extended out 240 miles (340 km) to the northeast of the center of Kammuri.  In contrast, tropical storm force winds only extended out 75 miles (120 km) to the southeast of the center of circulation.

Tropical Storm Kammuri will move through an environment favorable for intensification during the next few days.  Kammuri will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western end of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear.  The shear will slow the rate of intensification, but it will not be strong enough to prevent Tropical Storm Kammuri from getting stronger.  Kammuri is likely to intensify into a typhoon during the next 24 hours and it could strengthen into the equivalent of a major hurricane later this week.

Tropical Storm Kammuri will move around the western end of a subtropical high pressure system over the Western Pacific Ocean during the next 48 to 72 hours.  The ridge will steer Kammuri toward the northwest.  A second high pressure system will move eastward from Asia in about three days.  The second high will block Tropical Storm Kammuri from moving any farther toward the north and the high will steer Kammuri toward the west during the weekend.  On its anticipated track Tropical Storm Kammuri will gradually move closer to the Philippines.

Elsewhere, over the South Pacific Ocean near Vanuatu vertical wind shear weakened Tropical Cyclone Rita.  At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Rita was located at latitude 15.3°S and longitude 169.0°E which put it about 180 miles (290 km) north of Port Vila, Vanuatu.  Rita was moving toward the south 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 1000 mb.

Tropical Storm Kammuri Forms, Warnings Issued for Marianas

Tropical Storm Kammuri formed on Monday and warnings were issued for the Marianas.  At 10:00 p.m. EST on Monday the center of Tropical Storm Kammuri was located at latitude 10.2°N and longitude 149.0°E which put it about 415 miles (665 km) southeast of Guam.  Kammuri was moving toward the west-northwest at 16 m.p.h. (26 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 1000 mb.

Tropical Storm Warnings were in effect for Guam, Rota, Tinian and Saipan.

More thunderstorms formed near the center of a large low pressure system southeast of Guam on Monday and the Japan Meteorological Agency designated the system as Tropical Storm Kammuri.  The circulation around Kammuri was still organizing on Monday night.  Multiple bands of showers and thunderstorms were forming and the bands were starting to revolve around the center of circulation.  Storms near the center began to generate upper level divergence which was pumping mass away from the tropical storm in all directions.

Tropical Storm Kammuri will move through an environment favorable for intensification during the next few days.  Kammuri will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Kammuri will continue to intensify and it could strengthen into a typhoon within 36 hours.  Kammuri could eventually intensify into the equivalent of a major hurricane.

Tropical Storm Kammuri will move south of a subtropical high pressure system over the Western North Pacific Ocean during the next two days.  The high will steer Kammuri toward the west-northwest.  On its anticipated track the center of Tropical Storm Kammuri will pass south of Guam in about 18 to 24 hours.  Kammuri could bring gusty winds and locally heavy rain.  An upper level trough will approach Tropical Storm Kammuri from the northwest in about 48 hours.  The trough will weaken the upper level ridge and the steering currents will weaken.  Kammuri could meander after the steering currents weaken.

Elsewhere, over the South Pacific Ocean Tropical Cyclone Rita was weakening northeast of Vanuatu.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Rita was located at latitude 14.3°S and longitude 170.0°E which put it about 265 miles (430 km) north-northeast of Port Vila, Vanuatu.  Rita was moving toward the south-southwest at 9 m.p.h. (15 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 990 mb.

Tropical Cyclone Rita Develops North of Vanuatu

Tropical Cyclone Rita developed over the South Pacific Ocean north of Vanuatu on Sunday.  At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Rita was located at latitude 11.5°S and longitude 169.4°E which put it about 455 miles (730 km) north of Port Vila, Vanuatu.  Rita was moving toward the south-southeast at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 987 mb.

A center of circulation in an area of low pressure north of Vanuatu exhibited greater organization on Sunday and the system was designated Tropical Cyclone Rita.  Rita had a distinct low level center of circulation.  A band of showers and thunderstorms wrapped around the western and northern sides of the center.  Other rainbands were revolving around the center of circulation.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out 120 miles (195 km) from the center of circulation.

Tropical Cyclone Rita will move through an environment relatively favorable for intensification during the next 24 hours.  Rita will move over water where the Sea Surface Temperature is near 28°C.  It will move under the western end of an upper level ridge over the South Pacific Ocean.  The ridge will produce northerly winds which will blow toward the top of the tropical cyclone.  Those winds will cause moderate vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be strong enough to prevent Tropical Cyclone Rita from getting stronger.  Rita could strengthen into the equivalent of a hurricane/typhoon during the next 24 hours.

The ridge over the South Pacific Ocean will steer Tropical Cyclone Rita toward the south during several days.  On its anticipated track the center to Rita could approach Vanuatu in 48 to 72 hours.

Tropical Cyclone Oma Spins Northwest of Vanuatu

Tropical Cyclone Oma continued to spin over the Coral Sea northwest of Vanuatu on Thursday.  At 7:00 p.m. EST on Thursday the center of Tropical Cyclone Oma was located at latitude 15.3°N and longitude 165.1°E which put it about 260 miles (420 km) northwest of Port Vila, Vanuatu.  Oma was nearly stationary.  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 979 mb.

Tropical Cyclone Oma exhibited evidence of greater organization on Thursday.  The inner end of a rainband wrapped more tightly around the center of circulation.  Other bands of showers and thunderstorms also exhibited greater organization.   Storms around the center of circulation generated more upper level divergence which pumped mass away from the tropical cyclone.  Winds to tropical storm force extended out about 200 miles (320 km) from the center of circulation.

Once Tropical Cyclone Oma starts to move, it will move through an area favorable for intensification.  Oma 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 Cyclone Oma will be likely to intensify and it will likely strengthen into the equivalent of a hurricane/typhoon.

Tropical Cyclone Oma has been in an area where the winds at the steering level were weak and it has moved little during the past several days.  An upper level ridge east of Oma is forecast to strengthen during the next few days.  When the ridge strengthens, it will start to steer Tropical Cyclone Oma toward the southwest.  On its anticipated track Oma will move slowly away from Vanuatu and it could be north of New Caledonia in a few days.

Tropical Cyclone Oma Forms Northwest of Vanuatu

Tropical Cyclone Oma formed over the Coral Sea northwest of Vanuatu on Tuesday.  At 10:00 a.m. EST on Tuesday the center of Tropical Cyclone Oma was located at latitude 13.8°S and longitude 165.6°E which put it about 330 miles (535 km) northwest of Port Vila, Vanuatu.  Oma was moving toward the east at 7 m.p.h. (11 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 988 mb.

A distinct low level center of circulation formed within a broader area of low pressure northwest of Vanuatu on Tuesday and the Fiji Meteorological Service designated the system as Tropical Cyclone Oma.  The distribution of thunderstorms around Oma was asymmetrical.  Many of the stronger thunderstorms were occurring in bands northwest of the center of circulation.  Bands southeast of the center consisted primarily of showers and lower clouds.  The thunderstorms northwest of the center were generating upper level divergence which was pumping mass away to the northwest of the tropical cyclone.

An upper level ridge northeast of Vanuatu was producing southeasterly winds which were blowing toward the top of Tropical Cyclone Oma.  Those winds were causing moderate vertical wind shear and they were inhibiting upper level divergence to the southeast of Oma.  The wind shear was the probable cause of the asymmetrical distribution of thunderstorms.

Tropical Cyclone Oma will move through an environment somewhat favorable for intensification during the next several days.  The upper level ridge will continue to cause vertical wind shear.  However, Oma will move over water where the Sea Surface Temperature is near 30°C.  Tropical Cyclone Oma could slowly strengthen during the next day or two.

Tropical Cyclone Oma is currently embedded in a monsoon trough that is steering it toward the east.  A subtropical ridge is forecast to strengthen east of Vanuatu.  Oma will slow down while the ridge builds east of Vanuatu and it could linger northwest of Vanuatu for several days.  The ridge will eventually turn Tropical Cyclone Oma toward the south.  The timing and location of that turn will be important.  If Oma moves farther east before it turns southward, then it could approach northwest Vanuatu in 24 to 36 hours.  If Oma stalls and then turns southward, then the strongest part of the tropical cyclone could pass west of Vanuatu.  Tropical Cyclone Oma could eventually move near New Caledonia in a few days.

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.