Tag Archives: Samoa

Tropical Cyclone Nat Forms West of Tahiti

Tropical Cyclone Nat formed over the South Pacific Ocean west of Tahiti on Monday. At 1:00 p.m. EST on Monday the center of Tropical Cyclone Nat was located at latitude 15.3°S and longitude 163.6°W which put it about 965 miles (1560 km) west of Pappete, Tahiti. Nat was moving toward the east-southeast at 15 m.p.h. (24 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 996 mb.

A low pressure system over the South Pacific Ocean between Samoa and Tahiti strengthened on Monday and the Fiji Meteorological Service designated the system as Tropical Cyclone Nat. More thunderstorms formed near the center of Tropical Cyclone Nat. Storms near the center of Nat’s circulation generated upper level divergence that pumped mass away to the east of the tropical cyclone. Thunderstorms were also occurring in bands in the northern and eastern parts of Tropical Cyclone Nat. Bands in the western and southern part of Nat’s circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extend out 160 miles (260 km) in the northwest, northeast and southeast quadrants of Tropical Cyclone Nat. Winds to tropical storm force only extended out 25 miles (40 km) in the southwest quadrant of Nat.

Tropical Cyclone Nat will move through an environment somewhat favorable for intensification during the next 24 hours. Nat will move over water where the Sea Surface Temperatures are near 30°C. It will move under the eastern side of an upper level trough over the South Pacific Ocean northeast of New Zealand. The upper level trough will produce northwesterly winds that will blow toward the top of Nat’s circulation. Those winds will cause moderate vertical wind shear. The wind shear will inhibit intensification, but the shear may not be strong enough to prevent intensification. Tropical Cyclone Nat could intensify gradually during the next 24 hours.

The upper level trough northeast of New Zealand will steer Tropical Cyclone Nat toward the east-southeast during the next 24 hours. On its anticipated track, Nat will move closer to Tahiti. The center of Tropical Cyclone Nat is forecast to pass north of Palmerston, Aitutaki and Mauke. The winds blowing around the southern side of Nat’s could bring gusty winds and rough seas to those places during the next 24 hours.

Tropical Cyclone Wasi Brings Wind and Rain to Samoa

Tropical Cyclone Wasi brought wind and rain to Samoa  on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Wasi was located at latitude 16.7°S and longitude 171.3°W which put it about 140 miles (225 km) south-southwest of Pago Pago, American Samoa.  Wasi was moving toward the south-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 996 mb.

The eastern side of Tropical Cyclone Wasi brought wind and rain to parts of Samoa on Saturday.  A weather station in Pago Pago, American Samoa reported a sustained wind speed of 25 m.p.h. (40 km/h) and a wind gust of 43 m.p.h. (69 km/h).  Several inches of rain also fell on parts of Samoa.

Tropical Cyclone Wasi moved under the western side of an upper level ridge over the South Pacific Ocean.  The ridge produce strong northerly winds which blew across the top of Wasi.  Those winds caused strong vertical wind shear and Tropical Cyclone Wasi began to weaken.  Many of the taller thunderstorms dissipated.  Some storms were still occurring in a band south and east of the center of circulation.  Bands in other parts of the circulation consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 75 miles (120 km) from the center of Wasi.

Tropical Cyclone Wasi will move through an environment unfavorable for intensification.  Wasi will move over water where the Sea Surface Temperature is near 28°C.  However, the upper level ridge will continue to cause strong vertical wind shear.  The shear will be strong enough to prevent significant intensification and Tropical Cyclone Wasi could continue to weaken since it has a small circulation.

Tropical Cyclone Wasi will move around the western end of a high pressure system over the South Pacific Ocean.  The high will steer Wasi toward the south.  On its anticipated track Tropical Cyclone Wasi could pass near Niue in about 18 hours.  Wasi will bring gustier winds and rain showers to Niue on Sunday.

Elsewhere over the South Pacific Ocean, Tropical Cyclone Vicky was dissipating south of Niue.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Vicky was located at latitude 22.6°S and longitude 168.6°W which put it about 250 miles (400 km) south-southeast of Niue.  Vicky was moving toward the south at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1004 mb.

Tropical Cyclone Wasi Develops Near Samoa

Tropical Cyclone Wasi developed near Samoa on Friday night.  At 10:00 p.m. EST on Friday the center of Tropical Cyclone Wasi was located at latitude 13.6°S and longitude 172.9°W which put it about 20 miles (35 km) west of Falealupo, Samoa and about 185 miles (300 km) west-northwest of Pago Pago, American Samoa.  Wasi was moving toward the southeast at 11 m.p.h. (17 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 993 mb.

Tropical Cyclone Wasi spun up out of the same elongated trough of low pressure near Samoa that produced Tropical Cyclone Vicky on Thursday.  A small center of low pressure developed west-northwest of Samoa on Friday.  More thunderstorms formed near the center of circulation and the system was classified as Tropical Cyclone Wasi.  Microwave satellite imagery indicated that there was a tight inner core in the tropical cyclone.  Storms near the core were generating upper level divergence which was pumping mass away from Tropical Cyclone Wasi.  The circulation around Wasi was even smaller than the circulation around Tropical Cyclone Vicky.  Winds to tropical storm force only extended out about 50 miles (80 km) from the center of Tropical Cyclone Wasi.

Tropical Cyclone Wasi will move into an environment somewhat favorable for intensification during the next 24 to 36 hours.  Wasi 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 northwesterly winds which will blow toward the top of the tropical cyclone.  Those winds will cause moderate vertical wind shear, but the winds may not be strong enough to prevent intensification.  Tropical Cyclone Wasi could strengthen during the next 24 to 36 hours.  Since the circulation around Wasi is so small, if the tropical cyclone moves into an area where the upper level winds are stronger, it could weaken quickly.

Tropical Cyclone Wasi will move around the western end of a high pressure system over the South Pacific Ocean.  The high will steer Wasi toward the southeast during the next 12 hours.  Wasi will move more toward the south later in the weekend.  On its anticipated track Tropical Cyclone Wasi will bring gust winds and locally heavy rain to portions of Samoa during the next 24 hours.

Elsewhere over the South Pacific Ocean, Tropical Cyclone Vicky weakened as it passed near Niue on Friday.  At 10:00 p.m. EST on Friday the center of Tropical Cyclone Vicky was located at latitude 19.7°S and longitude 168.7°W which put oit about 95 miles (150 km) southeast of Niue.  Vicky was moving toward the south-southeast at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1001 mb.

Tropical Cyclone Vicky Forms Near Samoa

Tropical Cyclone Vicky formed near Samoa on Thursday.  At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Vicky was located at latitude 15.2°S and longitude 170.6°W which put it about 35 miles (55 km) south of Pago Pago, American Samoa.  Vicky was moving toward the southeast at 9 m.p.h. (15 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 small low pressure system developed quickly within a large elongated trough extending east-southeast across Samoa on Thursday.  A small well defined circulation was evident on satellite imagery.  Thunderstorms developed near the center of the low pressure system and it was designated as Tropical Cyclone Vicky.  Storms near the center began to generate upper level divergence which pumped mass away from the tropical cyclone.  Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation.  A weather station at Pago Pago reported a sustained wind speed of 43 m.p.h. (69 km/h) and a wind gust of 75 m.p.h. (120 km/h) when the developing tropical cyclone passed nearby.

Tropical Cyclone Vicky will move through an environment only marginally favorable for intensification during the next several days.  Vicky will move over water where the Sea Surface Temperature is near 28°C.  It will move under the western side of an upper level ridge over the South Pacific Ocean that extends southeast of Samoa.  The ridge will produce strong northwest winds which will cause moderate to strong vertical wind shear.  The wind shear will inhibit intensification and could cause Tropical Cyclone Vicky to weaken.  Since the circulation around Vicky is small, it could weaken rapidly if the wind shear increases.

Tropical Cyclone Vicky will move around the western side of a high pressure system over the South Pacific Ocean southeast of Samoa.  The ridge will steer Vicky toward the south during the next 24 to 48 hours.  On its anticipated track Tropical Cyclone Vicky could approach Niue in about 48 hours.  Vicky could be the equivalent of a tropical storm when it approaches Niue.

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.

Tropical Cyclone Ella Strengthens To Equivalent of a Hurricane Near Wallis & Futuna

Tropical Cyclone Ella strengthened into the equivalent of a hurricane/typhoon as it moved near Wallis and Futuna on Thursday.  Ella brought gusty winds and locally heavy rain to those islands.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Ella was located at latitude 14.0°S and longitude 178.2°W which put it about 20 miles (30 km) north of Wallis and Futuna.  Ella was moving toward the northwest at 5 m.p.h. (8 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. (170 km/h).  The minimum surface pressure was 979 mb.

Tropical Cyclone Ella has a very small circulation, but that circulation is well organized.  There is a very tight inner core.  A ring of strong thunderstorms surrounds a tiny pinhole eye.  The strongest winds are occurring in the tight eyewall.  Additional bands of thunderstorms are forming in the eastern half of the circulation.  There are bands of showers in the western half of the circulation.  Winds to hurricane/typhoon force extend out only about 10 miles (15 km) from the center of circulation.  Winds to tropical storm force extend out about 80 miles (130 km) from the center.

Tropical Cyclone Ella is moving through an environment favorable for intensification.  Ella is moving over water where the Sea Surface Temperature is near 30°C.  It is in an area where the upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Ella could continue to intensify as long as it is in an area where the upper level winds are weak.  However, there are much strong upper level westerly winds flowing just to the south of the tropical cyclone.  If Tropical Cyclone Ella moves into an area where the upper level winds are strong, vertical wind shear could weaken it very quickly because of Ella’s small size.

A subtropical ridge south of Ella is steering the tropical cyclone toward the west and a general westerly motion is expected to continue for several more days.  On its anticipated path Tropical Cyclone Ella will move away from Wallis and Futuna.  Ella could move near the northeastern portion of Fiji in 24 to 36 hours.

Tropical Cyclone Ella Strengthens As It Nears Wallis and Futuna

Tropical Cyclone Ella strengthened on Wednesday as it moved closer to Wallis and Futuna.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Ella was located at latitude 14.4°S and longitude 177.0°W which put it about 75 miles (120 km) east of Wallis and Futuna.  Ella was moving toward the west at 3 m.p.h. (5 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 989 mb.

The circulation of Tropical Cyclone Ella exhibited better organization on Wednesday.  A circular eye with a diameter of 25 miles (40 km) was evident on some microwave satellite images.  A ring of thunderstorms surrounded the eye.  Additional bands of showers and thunderstorms developed in the eastern half of the circulation.  Storms in the core of the circulation generated upper level divergence which pumped out mass and allowed the surface pressure to decrease.  The size of the circulation of Tropical Cyclone Ella is small.  Winds to tropical storm force only extend out about 100 miles (160 km) fro the center of circulation.

Tropical Cyclone Ella will move through an area that will be favorable for intensification.  Ella 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.  Tropical Cyclone Ella could intensify into the equivalent of a hurricane/typhoon on Thursday.  However, because the size of the circulation is small, any future increase in the vertical wind shear could quickly weaken Tropical Cyclone Ella.

Ella is moving around the northern side of a subtropical ridge, which is steering the tropical cyclone toward the west.  Ella is currently moving north of a weaker section of the ridge and the steering winds are weaker.  So, Ella is moving more slowly.  The ridge is expected to steer Tropical Cyclone Ella in a general westerly direction during the next several days.  On its anticipated track Tropical Cyclone Ella could pass near Wallis and Futuna in 12 to 18 hours.  It could be near hurricane/typhoon strength at that time.  Ella could approach the northeastern part of Fiji in two or three days.

Tropical Cyclone 19P Forms Southwest of Samoa

Tropical Cyclone 19P formed southwest of Samoa on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone 19P was located at latitude 15.2°S and longitude 173.3°W which put it about 100 miles (160 km) southwest of Apia, Samoa.  It was moving toward the west-northwest at 6 m.p.h. (10 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.

A small tight center of circulation formed within an area of thunderstorms south of Samoa on Monday.  A thin primary rainband wrapped tightly around the center of circulation.  Additional bands of showers and thunderstorms developed in the east half of the circulation.  The bands of showers in the western part of the tropical cyclone were much weaker.  Thunderstorms in the core of the circulation generated upper level divergence which pumped out mass.  The circulation of Tropical Cyclone 19P is small.  Winds to tropical storm force only extend out about 40 miles (65 km) from the center of circulation.

Tropical Cyclone 19P will be moving through an environment that will be marginally favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  Tropical Cyclone 19P is under the eastern end of an upper level ridge which is producing southerly winds that are blowing toward toward the top of the circulation.  The upper level winds are generating moderate vertical wind shear which is inhibiting upper level divergence to the south of the tropical cyclone.  Given the marginal conditions Tropical Cyclone 19P could maintain its intensity or slowly strengthen.  However, since the circulation is so small, a significant increase in vertical wind shear could also quickly weaken the tropical cyclone.

The same subtropical ridge that steered Tropical Cyclone Donna is also steering Tropical Cyclone 19P toward the west-northwest.  A general westerly motion is expected for the next two or three days.  On its anticipated track Tropical Cyclone 19P could approach Fiji in about 48 hours.