Tag Archives: Tonga

Tropical Cyclone Pola Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Pola strengthened to the equivalent of a hurricane/typhoon on Wednesday.  At 4:00 a.m. EST on Wednesday the center of Tropical Cyclone Pola was located at latitude 20.2°S and longitude 177.6°W which put it about 170 miles (275 km) west-northwest of Nuku’alofa, Tonga.  Pola was moving toward the south-southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 969 mb.

There was a small, circular eye at the center of Tropical Cyclone Pola.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Storms near the core of Pola were generating upper level divergence which was pumping mass away from the tropical cyclone.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Pola.  The strongest rainbands were occurring in the northwestern half of the circulation.  Bands in the southeastern half of Pola consisted primarily of showers and lower clouds.  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 160 miles (260 km) from the center.

Tropical Cyclone Pola will move through an environment favorable for support a strong tropical cyclone for another day or so.  Pola will move over water where the Sea Surface Temperature is near 28°C.  It will move through a region where the upper level winds are weak and there will not be much vertical wind shear.  Tropical Cyclone Pola could strengthen during the next 24 hours.  Pola will stat to move over cooler water on Thursday.  An upper level trough will approach Tropical Cyclone Pola from the west.  The trough will produce northwesterly winds which will increase the vertical wind shear.  A combination of cooler water and more vertical wind shear will cause Pola to weaken.  Tropical Cyclone Pola could make a transition to an extratropical cyclone later this week.

Tropical Cyclone Pola will move around the western end of a subtropical ridge over the South Pacific Ocean.  The ridge will steer Pola toward the south-southwest during the next day or two.  Eventually, the upper level trough will turn Tropical Cyclone Pola toward the southeast.  On its anticipated track the core of Pola and the strongest winds will pass west of Tonga.  Rainbands on the eastern side of the circulation could bring gusty winds and heavy rain at times to parts of Tonga.

Elsewhere, Typhoo Wutip continued to weaken west-northwest of the Marianas.  At 4:00 a.m. EST on Wednesday the center of Typhoon Wutip was located at latitude 16.3°N and longitude 139.4°E which put it about 370 miles (595 km) west-northwest of Guam.  Wutip was moving toward the north-northwest at 6 m.p.h. (10 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 981 mb.

Tropical Cyclone Pola Organizes Quickly Between Fiji and Tonga

Tropical Cyclone Pola organized quickly between Fiji and Tonga on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Cyclone Pola was located at latitude 18.8°S and longitude 176.7°W which put it about 185 miles (295 km) north-northwest of Nuku’alofa, Tonga.  Pola was moving toward the south at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 55 m.p.h. (90 km/h) and there were wind gusts to 70 m.p.h. (110 km/h).  The minimum surface pressure was 988 mb.

A well organized low level center of circulation consolidated within a much larger area of showers and thunderstorms north of Tonga on Tuesday and the Fiji Meteorological Service classified the system as Tropical Cyclone Pola.  A small circular eye was beginning to appear at the center of circulation on some satellite images.  The eye was surrounded by a narrow ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Storms near the center of Pola were generating upper level divergence which was pumping mass away from the tropical cyclone.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Pola.  Winds to tropical storm force extended out about 175 miles (280 km) from the center of circulation.

Tropical Cyclone Pola will move through an environment favorable for intensification during the next 24 to 36 hours.  Pola 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 Cyclone Pola will intensify during the next day or so and it could strengthen into the equivalent of a hurricane/typhoon.  Pola will move over colder water and into a region where the upper level winds are stronger later this week and it will start to weaken at that time.

Tropical Cyclone Pola will move around the northwestern portion of a subtropical ridge over the South Pacific Ocean.  The ridge will steer Pola in a southward direction.  On its anticipated track the core and strongest part of Tropical Cyclone Pola will pass west of Tonga.  The outer rainbands on the western side of the circulation could bring gusty winds and locally heavy rain to parts of southeastern Fiji.  Rainbands on the eastern side of the circulation could also bring gusty winds and locally heavy rain to parts of Tonga.

Elsewhere, Typhoon Wutip was weakening west of the Marianas.  At 4:00 p.m. EST on Tuesday the center of Typhoon Wutip was located at latitude 15.7°N and longitude 139.9°E which put it about 345 miles (560 km) west-northwest of Guam.  Wutip was moving toward the north at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (215 km/h).  The minimum surface pressure was 972 mb.

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 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.

Powerful Tropical Cyclone Gita Hits Tonga, Threatens Southern Fiji

Powerful Tropical Cyclone Gita hit the most populated islands in Tonga on Monday and moved west to threaten the southernmost islands of Fiji.  Gita brought strong winds and very heavy rain to Tongapatu and Eau on Monday and there were reports of damage from Tonga.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Gita was located at latitude 21.1°S and longitude 178.9°W which put it about 300 miles (480 km) southeast of Suva, Fiji.  Gita was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 140 m.p.h. (220 km/h) and there were wind gusts to 165 m.p.h. (270 km/h).  The minimum surface pressure was 935 mb.  Tropical Cyclone Gita was the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.

Gita remains a powerful tropical cyclone.  There is a 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.  A rainband has wrapped most of the way around the core of Tropical Cyclone Gita and there are indications that a second, concentric eyewall is forming.  Other rainbands are revolving around the core of the circulation.  Storms in the core are producing strong upper level divergence which is pumping away mass and is allowing the tropical cyclone to remain very strong.  Winds to hurricane/typhoon force extend out about 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extend out about 200 miles (320 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Gita is 28.3.  The Hurricane Size Index (HSI) is 20.5 and the Hurricane Wind Intensity Size Index (HWISI) is 48.8.  Those indices indicate that Tropical Cyclone Gita is capable of causing significant damage.

Tropical Cyclone Gita will remain in an environment favorable for strong tropical cyclones for another 24 to 36 hours.  Gita will move over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is not much vertical wind shear.  If a second concentric eyewall forms, then an eyewall replacement cycle could produce a fluctuation in intensity.  Gita could weaken when the inner eyewall dissipates.  The circulation could strengthen again if the outer eyewall remains intact and starts to contract around the center of circulation.

Tropical Cyclone Gita is moving north of a subtropical ridge which is steering the tropical cyclone toward the west.  A general motion toward the west is expected to continue for another 48 to 72 hours.  On its anticipated track Tropical Cyclone Gita could move over the southernmost islands of Fiji on Tuesday.  The strongest part of Gita could affect Vatoa, Ono-i-lau, Tuvana-i-colo and Tuvana-i-ra.  Gita could bring destructive winds, locally heavy rain and storm surges to the southernmost parts of Fiji.  Tropical Cyclone Gita could approach southern Vanuatu and New Caledonia in about three days.

Powerful Tropical Cyclone Gita Threatens Tonga

Powerful Tropical Cyclone Gita posed an increasing threat to Tonga on Sunday night.  At 10:00 p.m. EST the center of Tropical Cyclone Gita was located at latitude 21.7°S and longitude 173.2°W which put it about 120 miles (195 km) east of Nuku’Alofa, Tonga.  Gita was moving toward the west at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (205 km/h).  The minimum surface pressure was 944 mb.  Tropical Cyclone Gita was the equivalent of a major hurricane.

The circulation of Tropical Cyclone Gita is very well organized.  There is a circular eye at the center of circulation.  A ring of strong thunderstorms surrounds the eye and the strongest winds are occurring in that eye.  Bands of showers and thunderstorms are revolving around the core of Tropical Cyclone Gita.  Storms in the core are generating strong upper level divergence which is pumping mass away in all directions.  Winds to hurricane/typhoon force extend out about 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extend out about 165 miles (270 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Gita is 23.6.  The Hurricane Size Index (HSI) is 16.0 and the Hurricane Wind Intensity Size Index (HWISI) is 39.6.  Those indices indicate that Gita will be capable of causing major damage when it moves over Tonga on Monday.

Tropical Cyclone Gita will be moving through an environment favorable for strong tropical cyclones during the next 24 to 48 hours.  Gita will move over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is little vertical wind shear.  The favorable environment could allow Tropical Cyclone Gita to intensify more before it reaches Tonga.

Tropical Cyclone Gita is moving north of a subtropical ridge which is steering the tropical cyclone toward the west.  A general motion toward the west is expected to continue for another two or three days.  On its anticipated track the center of Tropical Cyclone Gita could reach Tonga within 12 hours.  Tropical Cyclone Gita will be capable of causing major wind damage when it reaches Tonga.  Gita will also drop heavy rain and flooding is possible.  Winds blowing the wind toward the coast could also produce significant storm surges in some locations.

Tropical Cyclone Gita Strengthens Near Niue

Tropical Cyclone Gita strengthened on Saturday as it passed just to the east of Niue.  Outer rainbands on the western side of Gita were bringing gusty winds and heavy rain to Niue.  At 4:00 p.m. EST on Saturday the center of Tropical Cyclone Gita was located at latitude 19.2°S and longitude 168.8°W which put it about 85 miles (135 km) east-southeast of Niue.  Gita was moving toward the south at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 969 mb.  Tropical Cyclone Gita was the equivalent of a hurricane/typhoon.

The circulation of Tropical Cyclone Gita became more symmetrical on Saturday.  Several rainbands wrapped completely around the center of circulation.  A clear area appeared at the center of circulation on visible satellite images, which indicated that an eye was forming.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in the ring.  Storms in the core of the circulation were generating upper level divergence which was pumping mass away from the tropical cyclone.  Other rainbands were revolving around the core of Tropical Cyclone Gita.

Tropical Cyclone Gita will move through an area favorable for intensification during the next 24 to 48 hours.  Gita will move over water where the Sea Surface Temperature is near 30°C.  Tropical Cyclone Gita is moving around the eastern end of an upper level low, but the upper level winds are weak and there is not much vertical wind shear.  There is drier air to the southwest of Gita, but it does not seem to be entering the circulation of the tropical cyclone.  Tropical Cyclone Gita will continue to intensify and it could strengthen rapidly.  Gita could strengthen into the equivalent of a major hurricane.

The upper level low is steering Tropical Cyclone Gita toward the south.  Gita will turn toward the southeast in about 12 to 24 hours.  When Gita reaches the southern side of the upper low, it will move toward the west.  On its anticipated track Tropical Cyclone Gita will pass just to the southeast of Niue.  Gita could approach Tonga in about 36 hours and it could the equivalent of a major hurricane at that time.

Tropical Cyclone Gita Forms Near Samoa

Tropical Cyclone Gita formed near Samoa on Friday.  At 10:00 a.m. EST on Friday the center of Tropical Cyclone Gita was located at latitude 14.8°N and longitude 172.3°E which put it about 155 miles (250 km) west of Pago Pago, Samoa.  Gita was moving toward the east at 18 m.p.h. (29 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 989 mb.

Tropical Cyclone Gita was bringing gusty winds and heavy rain to Samoa.  The strongest rainbands were north and east of the center of circulation.  The bands south of the center consisted primarily of showers and low clouds.  There appeared to be drier air in the southern half of the circulation which was inhibiting the development of taller clouds and stronger storms in that part of Gita.  Thunderstorms in the rainbands north of the center of circulation were generating upper level divergence which was pumping mass away to the east of the tropical cyclone.

Tropical Cyclone Gita will be moving through an environment favorable for intensification.  Gita will move over water where the Sea Surface Temperature is near 30°C.  An upper level low south of Gita is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing some vertical wind shear, but the shear does not appear to be strong enough to prevent intensification.  The drier air in southern half of the circulation will inhibit intensification.  However, if some of the rainbands north of the center wrap around the southern side of the center, then they could reduce the effects of the drier air.  Tropical Cyclone Gita is likely to intensify into the equivalent of a hurricane/typhoon during the weekend.

The upper low south of Gita is currently steering the tropical cyclone toward the east.  Gita will approach the eastern end of the upper low during the next 24 hours and it will move more toward the south.  Tropical cyclone Gita will turn back toward the west when it moves south of the upper low.  On its anticipated track Tropical Cyclone Gita will continue to bring gusty winds and heavy rain to Samoa for another 12 to 24 hours.  Gita could pass near Niue in 24 to 48 hours and it could move near Tonga in about three days.