Monthly Archives: December 2019

Weakened Tropical Cyclone Sarai Moves Across Tonga

A weakened Tropical Cyclone Sarai moved across Tonga on Monday.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Sarai was located at latitude 20.6°S and longitude 174.9°W which put it about 30 miles (50 km) northeast of Nuku Alofa, Tonga.  Sarai was moving toward the northeast 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 989 mb.

Tropical Cyclone Sarai moved south of an upper level ridge on Monday.  The upper level ridge produced strong westerly winds which blew across the top of Sarai.  Those winds caused strong vertical wind shear and they blew the tops off of thunderstorms in Tropical Cyclone Sarai.  The circulation in the lower levels of Sarai remained intact, but it consisted of showers and lower clouds.  The wind speed gradually decreased during Monday.

The center of Tropical Cyclone Sarai passed just north of the Tongatapu Group of islands.  Sarai passed over the Ha’apai Group of islands.  Tropical Cyclone Sarai brought winds to tropical storm force and squally weather to parts of Tonga.  Rainfall amounts were relatively light because the wind sheared the tops off of any thunderstorms which started to form.

Tropical Cyclone Sarai will move through an environment unfavorable for intensification.  Sarai will move over water where the Sea Surface Temperature is near 27°C.  The upper level ridge will continue to cause strong vertical winds shear.  The wind shear will make it very difficult for new thunderstorms to form.  Tropical Cyclone Sarai is likely to weaken slowly as the circulation in the lower levels spins down.

Tropical Cyclone Sarai will move south of a subtropical high pressure system over the South Pacific Ocean.  The high will steer Sarai toward the east during the next several days.  On its anticipated track Tropical Cyclone Sarai will move south of the Vava’u Group of Islands during the next 24 hours.  Sarai could reach Niue in less than 30 hours.

Tropical Cyclone Sarai Moves Toward Tonga

Tropical Cyclone Sarai moved toward Tonga on Sunday.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Sarai was located at latitude 20.7°S and longitude 178.3°E which put it about 220 miles (355 km) west of Nuku Alofa, Tonga.  Sarai was moving toward the east-southeast at 4 m.p.h. (6 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.

Tropical Cyclone Sarai weakened on Sunday.  An upper level ridge north of Sarai produced strong westerly winds which blew toward the top of the circulation.  Those winds caused strong vertical wind shear which disturbed the circulation around Tropical Cyclone Sarai.  The inner core became less well organized and there was no evidence of an eye on satellite images.  The stronger thunderstorms were occurring in bands in the eastern half of the circulation.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  The circulation around Tropical Cyclone Sarai was still large.  Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation.

Tropical Cyclone Sarai will continue to move through an environment unfavorable for intensification during the next several days.  Sarai will move over water where the Sea Surface Temperature is near 28°C.  However, the upper level ridge will continue to produce strong westerly winds and vertical wind shear is likely to cause Tropical Cyclone Sarai to weaken further.

Tropical Cyclone Sarai will move south of a subtropical high pressure system over the South Pacific Ocean.  The high pressure system will steer Sarai toward the east during the next several days.  On its anticipated track Tropical Cyclone Sarai will move across Tonga in about 24 hours.  Although Sarai will weaken, it will bring winds to tropical storm force and heavy rain to parts of Tonga.

Tropical Cyclone Calvinia Develops East of Mauritius

Tropical Cyclone Calvinia developed east of Mauritius on Sunday.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Calvinia was located at latitude 20.7°S and longitude 58.7°E which put it about 105 miles (165 km) east-southeast of Port Louis, Mauritius.  Calvinia was moving toward the southwest 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 998 mb.

A distinct low level center of circulation developed in an area of thunderstorms east of Mauritius on Sunday and the system was designated at Tropical Cyclone Calvinia.  The circulation around Tropical Cyclone Calvinia was asymmetrical.  Many of the stronger thunderstorms were occurring in bands on the eastern side of the circulation.  Bands north and west of the center of Calvinia consisted primarily of showers and lower clouds.  The distributions of strong winds around the tropical cyclone was also asymmetrical.  Winds to tropical storm force extended out 200 miles (320 km) on the eastern side of the circulation.  Winds to tropical storm force only extended out 60 miles (95 km) on the western side.

Tropical Cyclone Calvinia will move through an environment marginally favorable for intensification during the next 24 to 36 hours.  Calvinia will move over water where the Sea Surface Temperature is near 27°C.  It will move east of an upper level trough.  The trough will produce northwesterly winds which will blow toward the top of the circulation.  The winds will cause moderate vertical wind shear and they are probably the reason for the asymmetrical structure of Tropical Cyclone Calvinia.  Calvinia could strengthen during the next several days, but the wind shear is likely to prevent significant intensification.

The upper level trough will steer Tropical Cyclone Calvinia toward the southeast.  On its anticipated track Calvinia will move away from Mauritius and La Reunion.  Since Tropical Cyclone Calvinia will be east of Mauritius, the strongest part of the circulation will remain east of Mauritius and La Reunion.

Tropical Cyclone Sarai Moves Across Southern Fiji

Tropical Cyclone Sarai moved across southern parts of Fiji on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Sarai was located at latitude 19.9°S and longitude 179.1°E which put it about 30 miles (50 km) southwest of Matuku, Fiji.  Sarai was moving toward the east at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 95 m.p.h. (155 km/h).  The minimum surface pressure was 976 mb.

Tropical Cyclone Sarai strengthened into the equivalent of a hurricane/typhoon on Saturday as it moved across the southern part of Fiji.  The center of Sarai passed south of Kadavu, but raindbands on the northern side of the circulation brought gusty winds and heavy rain to the island.  A ragged eye appeared intermittently on satellite images.  The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Tropical Cyclone Sarai had a large circulation.  Winds to hurricane/typhoon force extended out 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out 200 miles (320 km) from the center.

Tropical Cyclone Sarai will move into an environment that will become increasingly unfavorable for intensification.  Sarai will move over water where the Sea Surface Temperature is near 28°C.  So, there will be enough energy in the upper ocean to support a strong tropical cyclone.  Tropical Cyclone Sarai will move south of an upper level ridge.  The ridge will produce westerly winds which will get stronger during the next several days.  Those winds will cause moderate vertical wind shear.  When the shear gets stronger, Tropical Cyclone Sarai will start to weaken.

Tropical Cyclone Sarai will move south of a subtropical high pressure system over the South Pacific Ocean.  The high will steer Sarai toward the east during the next 48 hours.  On its anticipated track Tropical Cyclone Sarai will move across Matuku, Fiji during the next few hours.  Sarai will reach the Lau Group of Fiji Islands during the next 24 hours.  Tropical Cyclone Sarai could reach parts of Tonga within 48 hours.  Sarai will bring gusty winds and heavy rain to all of those places during the next 48 hours.

Tropical Cyclone Sarai Brings Wind and Rain to Fiji

Tropical Cyclone Sarai brought wind and rain to Fiji in Friday.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Sarai was located at latitude 19.3°S and longitude 177.0°E which put it about 100 miles (160 km) west-southwest of Kadavu, Fiji.  Sarai was moving toward the southeast at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 983 mb.

The center of Tropical Cyclone Sarai passed west of Nadi, Fiji on Friday, but rainbands in the eastern side of the circulation produced gusty winds and heavy rain.  A surface weather station in Nadi measured a sustained wind speed of 44 m.p.h. (70 km/h) and wind gusts of 67 m.p.h. (107 km/h).

Tropical Cyclone Sarai continued to intensify on Friday.  The inner end of a rainband wrapped much of the way around the center of circulation.  The rainband had not wrapped entirely around the northwestern part of the center,  A clear area at the center began to appear on satellite images, which could be evidence of formation of an eye.  Storms around the center were generating upper level divergence which was pumping mass away to the east of the tropical cyclone.  The circulation around Tropical Cyclone Sarai was large.  Winds to tropical storm force extended out 200 miles (320 km) from the center of Sarai.

Tropical Cyclone Sarai will move through an environment favorable for intensification for another 24 to 36 hours.  Sarai will move over water where the Sea Surface Temperature is near 28°C.  It will move south of an upper level ridge.  The ridge will produce westerly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear.  The wind shear will inhibit intensification, but it will not be strong enough to keep Tropical Cyclone Sarai from strengthening into the equivalent of a hurricane/typhoon.

Tropical Cyclone Sarai will move south of a subtropical high pressure system over the South Pacific Ocean.  The ridge will steer Sarai toward the east.  On its anticipated track the center of Tropical Cyclone Sarai will pass south of Suva, Fiji.  The core of Sarai will pass near Kadavu, Fiji in about 12 to 18 hours.  Tropical Cyclone Sarai will bring gusty winds and locally heavy rain to Kadavu.  Heavy rain could cause flash floods in some locations.

Tropical Cyclone Sarai Forms Northwest of Fiji

Tropical Cyclone Sarai formed northwest of Fiji on Thursday.  At 10:00 a.m. EST on Thursday the center of Tropical Cyclone Sarai was located at latitude 14.9°S and longitude 175.8°E which put it about 220 miles (355 km) north-northwest of Nadi, Fiji.  Sarai was moving toward the south at 14 m.p.h. (22 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 995 mb.

The circulation around a low pressure system northwest of Fiji exhibited greater organization on Thursday and the Fiji Meteorological Service designated the system as Tropical Cyclone Sarai.  The circulation around Tropical Cyclone Sarai was still organizing.  A band of showers and thunderstorms wrapped around the southern and western sides of the center of circulation.  Other bands of showers and thunderstorms were developing and the bands were starting to revolve around the center.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical cyclone.  The circulation around Tropical Cyclone Sarai was large.  Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation.

Tropical Cyclone Sarai will move through an environment favorable for intensification during the next 48 hours.  Sarai 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.  The ridge will produce northerly winds which will blow toward the top of the circulation.  However, there will be northerly winds at most levels of the troposphere, which means that there will not be a lot of vertical wind shear.  Tropical Cyclone Sarai will intensify during the next 36 to 48 hours and it could strengthen into the equivalent of a hurricane/typhoon.

Tropical Cyclone Sarai will move around the western end of a subtropical high pressure system over the South Pacific Ocean.  The high will steer Sarai toward the south during the next 24 hours.  Tropical Cyclone Sarai will turn more toward the east in a day or so when it rounds the end of the ridge.  On its anticipated track the center of Sarai could approach western Fiji in 24 to 36 hours.

Typhoon Phanfone Moves Away from the Philippines

Typhoon Phanfone moved away from the Philippines on Wednesday after bringing wind and rain to the central Philippines.  At 10:00 p.m. EST on Wednesday the center of Typhoon Phanfone was located at latitude 13.2°N and longitude 118.3°E which put it about 190 miles (310 km) west-southwest of Manila, Philippines.  Phanfone was moving toward the west-northwest at 9 m.p.h. (15 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 975 mb.

Typhoon Phanfone weakened earlier on Wednesday.  The core of Phanfone moved over southern Mindoro and the typhoon weakened when the circulation was disrupted by the mountains.  Satellite imagery suggested that the circulation around Typhoon Phanfone might be reorganizing on Wednesday night.  A small circular eye reappeared on visible satellite images.  Thunderstorms in the eyewall were growing taller.  Storms around the core of Phanfone were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out 40 miles (65 km) north of the center of circulation and out 20 miles (30 km) south of the center.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Phanfone.

Typhoon Phanfone will move through an environment capable of supporting a typhoon for another 24 hours.  Phanfone 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.  In about 24 hours Typhoon Phanfone will reach an area where winds near the surface are blowing from the northeast.  Those winds will bring drier air which will get pulled into the circulation around Phanfone.  Typhoon Phanfone will weaken when the drier air enters its circulation.

Typhoon Phanfone will move south of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Phanfone toward the west-northwest.  On its anticipated track Typhoon Phanfone will move across the South China Sea and it will move farther away from the Philippines.

Typhoon Phanfone Hits Panay Island

Typhoon Phanfone hit Panay Island on Tuesday.  At 10:00 p.m. EST on Tuesday the center of Typhoon Phanfone was located at latitude 11.9°N and longitude 121.8°E which put it about 50 miles (80 km) southeast of San Jose, Philippines.  Phanfone was moving toward the west at 12 m.p.h. (19 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. (210 km/h).  The minimum surface pressure was 963 mb.

The eye of Typhoon Phanfone passed over the northern coast of Panay Island on Tuesday.  The southern part of the eyewall affected Roxas City, Kalibo and Ibajay.  Strong winds and heavy rain moved over the northern coast of Panay.  The northern eyewall was over Tablas Island and the northwestern part of the eyewall reached southeastern Mindoro.  Gusty winds may reach Roxas and San Jose on Mindoro.  Heavy rain was falling over over Tablas Island and southeastern Mindoro.

Typhoon Phanfone strengthened slightly even though parts of the eyewall moved over some of the islands in the central Philippines.  The core of Phanfone remained intact and there was a small circular eye at the center of the typhoon.  The strongest winds were occurring in a ring of thunderstorms around the eye.  Winds to typhoon force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 125 miles (200 km).  The Hurricane Intensity Index (HII) for Typhoon Phanfone was 19.2.  The Hurricane Size Index (HSI) was 8.3 and the Hurricane Wind Intensity Size Index (HWISI) was 27.5.

Typhoon Phanfone will move through an environment favorable for intensification during the next 24 to 36 hours.  Phanfone 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.  Typhoon Phanfone could intensify into the equivalent of a major hurricane if the core of the circulation passes south of Mindoro.

Typhoon Phanfone will move south of a subtropical high pressure system over the Western North Pacific Island.  The high will steer Phanfone toward the west-northwest during the next several days.  On its anticipated track the center of Typhoon Phanfone will pass near the southern end of Mindoro during the next few hours.  The center will pass near Busuanga Island and Culion Island before Phanfone moves over the South China Sea.  Typhoon Phanfone will bring strong winds and heavy rain to Roxas, San Jose and Coron.  Heavy rain on Tablas Island, southern Mindoro, Busuanga Island and Culion Island could cause flash floods.  Floods are most likely on southern Mindoro because of the steep slopes near mountains.  Conditions will improve over Panay Island as Phanfone moves farther away.

Strengthening Typhoon Phanfone Makes Landfall in Central Philippines

A strengthening Typhoon Phanfone made landfall in the central Philippines on Tuesday morning.  At 10:00 a.m. EST on Tuesday the center of Typhoon Phanfone was located at latitude 11.6°N and longitude 124.1°E which put it about 30 miles (50 km) southeast of Placer, Philippines.  Phanfone was moving toward the west-northwest at 19 m.p.h. (31 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 966 mb.

Typhoon Phanfone strengthened quickly as it made landfall in the central Philippines.  A small circular eye became more distinct on  satellite imagery.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Winds to typhoon force extended out 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out 120 miles (195 km) from the center.  The Hurricane intensity Index (HII) for Typhoon Phanfone was 17.8.  The Hurricane Size Index (HSI) was 10.8 and the Hurricane Wind intensity Size Index (HWISI) was 28.6.

The center of Typhoon Phanfone made landfall near Guiuan on Samar.  The center of Phanfone passed near Tacloban on Leyte before it moved over the Visayan Sea.  Typhoon Phanfone brought strong winds and heavy rain to Samar and Leyte.  The winds were strong enough to cause serious damage and regional power outages.  The heavy rain could cause flash floods in some locations.

Typhoon Phanfone moved through a favorable environment that allowed to strengthen.  Phanfone moved over water where the Sea Surface Temperature was near 29°C.  It moved through a region where the upper level winds were weak and there was little vertical wind shear.  The core of Phanfone moved quickly over narrow portions of Samar and Leyte and the core remained intact.  Typhoon Phanfone could strengthen while the enter moves across the Visayan Sea and it could intensify into the equivalent of a major hurricane.

Typhoon Phanfone will move south of a subtropical ridge over the Western North Pacific Ocean during the next several days.  The ridge will steer Phanfone toward the west-northwest.  On its anticipated track the center of Typhoon Phanfone will pass near Masbate and the northern end of Panay Island.  Phanfone could be near Mindoro in about 12 hours.  Typhoon Phanfone will bring strong winds and heavy rain to Masbate, the northern end of Panay Island, the northern end of Negros and Mindoro.  Conditions will improve gradually when Phanfone moves away from Samar and Leyte.

Phanfone Strengthens to a Typhoon, Closing in on Central Philippines

Former Tropical Storm Phanfone strengthened to a typhoon as it closed in on the central Philippines on Monday night.  At 10:00 p.m. EST on Monday the center of Typhoon Phanfone was located at latitude 10.9°N and longitude 126.9°E which put it about 80 miles (130 km) east of Guiuan, Philippines.  Phanfone was moving toward the west at 18 m.p.h. (29 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 981 mb.

Typhoon Phanfone strengthened on Monday.  The circulation became more symmetrical and an eye began to form at the center of Phanfone.  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 Phanfone.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.  The circulation around Typhoon Phanfone was relatively small.  Winds to typhoon force extended out 20 miles (30 km) from the center of circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center.

Typhoon Phanfone will move through an environment favorable for intensification during the next few hours.  Phanfone 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 the will be little vertical wind shear.  Typhoon Phanfone will continue to intensify until it makes landfall in the central Philippines.  Phanfone will begin to weaken when the center moves over land.  It could regain some strength while the center passes over the Visayan Sea.

Typhoon Phanfone will move south of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Phanfone toward the west-northwest during the next several days.  On it anticipated track the center of Typhoon Phanfone will pass over southern Samar near Guiuan in a few hours.  The core of Phanfone will also pass near Tacloban and northern Leyte.  Typhoon Phanfone will move over the Visayan Sea before moving near Roxas City and northern Panay Island.

Typhoon Phanfone will bring strong winds to southern Samar, Leyte and northern Panay Island.  Phanfone will drop locally heavy rain and flash floods could occur in some locations.  Typhoon Phanfone could produce a storm surge of six feet (two meters) along portions of the coast where the wind blows the water toward the shore.