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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.

Typhoon Wutip Strengthens to Equivalent of a Category 5 Hurricane

Typhoon Wutip strengthened into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Monday.  At 5:00 a.m. EST on Monday the center of Typhoon Wutip was located at latitude 14.0°N and longitude 140.1°E which put it about 300 miles (480 km) west-northwest of Guam.  Wutip was moving toward the north-northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km.h) and there were wind gusts to 195 m.p.h. (315 km/h).  The minimum surface pressure was 929 mb.

Typhoon Wutip completed an eyewall replacement cycle on Sunday and then it rapidly intensified into the equivalent of a Category 5 hurricane.  The inner eyewall dissipated completely and the outer eyewall contracted around a circular, symmetrical eye.  A ring of strong thunderstorms surrounded the new eye and the strongest winds were occurring in that ring of storms.  Storms near the core of Typhoon Wutip were generating strong upper level divergence which was pumping mass away from the typhoon.  Bands of showers and thunderstorms were revolving around the core of Wutip.

Winds to typhoon force extended out about 45 miles (75 km) from the center of Typhoon Wutip.  Winds to tropical storm force extended out about 160 miles (260 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Wutip was 35.0.  The Hurricane Size Index (HSI) was 16.6 and the Hurricane Wind Intensity Size Index (HWISI) was 51.6.

Typhoon Wutip will remain in an environment capable of supporting a strong typhoon for another 12 to 24 hours.  Wutip 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 be little vertical wind shear.  A band of stronger westerly winds north of the Philippines will approach Typhoon Wutip in another day or so.  Those winds will cause the vertical wind shear to increase and the increased shear will cause Wutip to weaken.

Typhoon Wutip will move southwest of a subtropical ridge over the Western North Pacific Ocean.  The ridge is forecast to steer Wutip in a west-northwesterly direction.  On its forecast track Typhoon Wutip will gradually move farther away from the Northern Marianas.

Powerful Typhoon Wutip Moving West of Guam

Powerful Typhoon Wutip moved west of Guam on Saturday.  At 10:00 p.m. EST on Saturday the center of Typhoon Wutip was located at latitude 12.9°N and longitude 141.9°E which put it about 170 miles (280 km) west-southwest of Guam.  Wutip was moving toward the northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 155 m.p.h. (250 km/h) and there were wind gusts to 190 m.p.h. (305 km/h).  The minimum surface pressure was 924 mb.  Typhoon Wutip was the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.

Visible and microwave satellite imagery  indicated that Typhoon Wutip may have started an eyewall replacement cycle.  An inner rainband wrapped around the original eye and eyewall.  An outer eyewall formed around the original inner eyewall.  The strongest winds were occurring in the inner eyewall.  The eyewall replacement cycle and the formation of an outer eyewall contributed to an increase in the size of Typhoon Wutip.  Winds to typhoon force extended out about 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out about 200 miles (320 km) from the center.

The Hurricane Intensity Index (HII) for Typhoon Wutip was 33.3.  The Hurricane Size Index (HSI) was 21.5 and the Hurricane Wind Intensity Size Index (HWISI) was 54.8.

Typhoon Wutip will move into an environment that will gradually become less favorable for strong typhoons.  Wutip will move over water where the Sea Surface Temperature is near 27°C.  The eyewall replacement cycle will cause Typhoon Wutip to weaken when the inner eyewall starts to dissipate.  Wutip also appears to be moving toward a region of drier air.  Rainbands in the western side of Typhoon Wutip seemed to be weakening as they moved into the region of drier air.  Typhoon Wutip will weaken during the next few days.

Typhoon Wutip will move southwest of a subtropical ridge over the Western North Pacific Ocean.  The ridge will steer Wutip toward the northwest during the next several days.  On its anticipated track Typhoon Wutip will move away from the Marianas.

Typhoon Wutip Strengthens to Equivalent of a Major Hurricane South of Guam

Typhoon Wutip strengthened into the equivalent of a major hurricane south of Guam on Friday.  At 10:00 a.m. EST on Friday the center of Typhoon Wutip was located at latitude 10.1°N and longitude 144.7°E which put it about 240 miles (385 km) south of Guam.  Wutip was moving toward the northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 949 mb.

Tropical Storm Warnings were in effect for Guam, Rota and Faraulep.  Tropical Storm Watches have been issued for Tinian, Saipan, Agrihan and Pagan.

Typhoon Wutip was a very well organized tropical cyclone.  A small eye was at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Wutip.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.

Typhoon Wutip had a large circulation.  Winds to typhoon force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 185 miles (295 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Wutip was 22.1.  The Hurricane Size Index (HSI) was 17.3 and The Hurricane Wind Intensity Size Index (HWISI) was 39.4.  Typhoon Wutip was capable of causing major damage.

Typhoon Wutip may be near its peak intensity.  Wutip will move over water where the Sea Surface Temperature is near 29°C.  So, there is enough energy in the upper ocean to support a strong typhoon.  Typhoon Wutip has been in an area where the upper level winds were weak and there was little vertical wind shear.  The shear will remain small for another 12 to 24 hours.  Then an upper level trough will approach Typhoon Wutip from the west in a day or so.  The trough will bring southwesterly winds and the vertical wind shear will increase.  Wutip will start to weaken when the shear increases.

Typhoon Wutip will move around the western end of a subtropical ridge over the Western North Pacific Ocean.  Wutip will gradually turn more toward the north while it moves around the end of the ridge.  On its anticipated track the core of Typhoon Wutip will pass west of Guam and the Northern Marianas.  Wutip could bring winds to tropical storm force to Guam and some of the other islands, which is why the warnings and watches were issued.

Wutip Intensifies Into a Typhoon Southeast of Guam

Former Tropical Storm Wutip intensified into a typhoon southeast of Guam on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Typhoon Wutip was located at latitude 6.5°N and longitude 150.0°E which put it about 640 miles (1035 km) southeast of Guam.  Wutip was moving toward the west-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 979 mb.

Tropical Storm Watches have been issued for Guam, Rota, Tinian and Saipan.  A Typhoon Warning is in effect for Satawal and Puluwat.  A Tropical Storm Warning and a Typhoon Watch are in effect for Ulul and Faraulep.

Typhoon Wutip continued to exhibit better organization on Wednesday.  A cluster of thunderstorms remained near the center of circulation.  A band of storms wrapped around the southern side of the center, which could indicate the start of the formation of an eyewall.  Other bands of showers and thunderstorms were revolving around the core of Typhoon Wutip.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out about 160 miles (260 km) from the center.

Typhoon Wutip will move through an environment favorable for intensification for several more days.  Wutip will move over water where the Sea Surface Temperature is near 30°C.  Typhoon Wutip will move around 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 create some vertical wind shear, but the wind shear will not be great enough to prevent intensification.  Typhoon Wutip will continue to intensify and it could strengthen into the equivalent of a major hurricane within 36 hours.

The ridge will steer Typhoon Wutip in a northwesterly direction during the next 48 hours.  Wutip is likely to turn more toward the north-northwest when it approaches the western end of the ridge.  On its anticipated track Typhoon Wutip could be south of Guam in 36 to 48 hours.  Wutip could be the equivalent of a major hurricane at that time.

Elsewhere, Tropical Cyclone Oma continued to spin over the Coral Sea between New Caledonia and Australia.  At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Oma was located at latitude 22.7°S and longitude159.8°E which put it about 560 miles (905 km) northeast of Brisbane, Australia.  Oma was moving toward the southwest at 6 m.p.h. (10 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 981 mb.

Tropical Storm Wutip Forms Southeast of Chuuk

Tropical Storm Wutip formed southeast of Chuuk on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Storm Wutip was located at latitude 4.6°N and longitude 155.2°E which put it about 295 miles (475 km) southeast of Chuuk.  Wutip was moving toward the west 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 1000 mb.

A Typhoon Watch was issued for Puluwat and Satawal.  A Tropical Storm Warning was in effect for Nukuoro, Losep, and Chuuk.  A Tropical Storm Watch was issued for Fananu and Ulul.

Thunderstorms developed near the center of a low pressure system southeast of Chuuk on Tuesday and the Japan Meteorological Agency designated the system as Tropical Storm Wutip.  Thunderstorms continued to form near the center of Wutip and those storms were starting to generate upper level divergence.  Bands of showers and thunderstorms formed in the northern and western portions of the circulation.  Bands south and east of the center consisted primarily of showers and lower clouds although there were a few thunderstorms in some of those bands.  Winds to tropical storm force extended out about 150 miles (245 km) from the center of circulation in the northern half of Wutip and out about 100 miles (160 km) in the southern half of the tropical storm.

Tropical Storm Wutip will move through an environment favorable for intensification.  Wutip will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge east of Tropical Storm Wutip will produce easterly winds which will cause some vertical wind shear.  However, the wind shear will not be strong enough to prevent intensification.  Tropical Storm Wutip will intensify during the next several days.  Wutip could strengthen into a typhoon with 24 to 36 hours.  A period of rapid intensification could occur once an inner core becomes more well organized.  Tropical Storm Wutip could strengthen to the equivalent of a major hurricane in three or four days.

Tropical Storm Wutip will move around the western end of a subtropical ridge.  The ridge will steer Wutip toward the northwest during the next few days.  On its anticipated track Tropical Storm Wutip could approach Guam in three days.  Wutip is likely to be a typhoon at that time.

Tropical Storm Sanba Brings Rain to the Southern Philippines

Tropical Storm Sanba brought rain to the southern Philippines on Monday.  At 10:00 p.m. EST on Monday the center of Tropical Storm Sanba located at latitude 9.9°N and longitude 125.1°E which put it about 100 miles (160 km) east of Cebu, Philippines.  Sanba was moving toward the west-northwest at 19 m.p.h. (31 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 Sanba dropped locally heavy rain on parts of northern Mindanao, Siriagao Island, Dinegat Island, Leyte, southern Samar, Bohol and Cebu on Monday.  The circulation of Tropical Storm Sanba was not well organized.  Bands of showers and thunderstorms were occurring to the north and west of the center of circulation.  There were thin bands of showers and low clouds to the south and east of the center.  An upper level ridge to the north of Sanba was producing easterly winds which were blowing over the top of the circulation.  Those winds were causing moderate vertical wind shear which was the primary reason for the asymmetrical distribution of thunderstorms.

Tropical Storm Sanba will move through an environment marginal for intensification.  Sanba will move over water where the Sea Surface Temperature is near 28°C.  The upper level ridge will continue to produce moderate vertical wind shear, which will inhibit intensification.  In addition, the center of circulation will move across Cebu and Negros.  Increased friction caused by the and could weaken Tropical Storm Sanba.  Sanba could intensify a little when the center moves over the Sulu Sea.

A ridge north of Sanba is steering the tropical storm toward the west.  A general motion toward the west is expected to continue for another 24 to 36 hours.  After that time Sanba could move a little more toward the west-northwest.  On its anticipated track Tropical Storm Sanba is forecast to move over Cebu and Negros during the next 12 to 18 hours.  Sanba will move across the Sulu Sea toward Palawan and over the South China Sea.  Tropical Storm Sanba could drop locally heavy rain over Cebu, Negros, Panay and Palawan.  Prolonged heavy rain could cause flooding in some places.

Tropical Storm Sanba Develops Near Palau

Tropical Storm Sanba developed near Palau on Sunday.  At 10:00 a.m. EST on Sunday the center of Tropical Storm Sanba was located at latitude 7.2°N and longitude 133.5°E which put it about 20 miles (35 km) south-southwest of Koror, Palau.  Sanba was moving toward the west at 19 m.p.h. (31 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.

Thunderstorms developed closer to the center of circulation of former Tropical Depression 02W and the Japan Meteorological Agency classified the system as Tropical Storm Sanba.  The distribution of storms was asymmetrical.  The stronger thunderstorms were occurring in bands west of the center of circulation.  The bands in the eastern half of the circulation consisted primarily of showers and lower clouds.  Sanba is moving south of a strong upper level ridge.  The ridge is producing easterly winds which are causing moderate vertical wind shear.  The wind shear is causing the asymmetrical distribution of thunderstorms.

Tropical Storm Sanba will move through an environment marginally favorable for intensification.  Sanba will move over water where the Sea Surface Temperature is near 29°C.  So, there is sufficient energy in the upper ocean to support intensification.  However, the upper level ridge will continue to generate moderate vertical wind shear which will inhibit intensification.  Tropical Storm Sanba could get a little stronger during the next 24 to 36 hours.

The ridge is steering Tropical Storm Sanba toward the west and a general westerly motion is expected to continue.  On its anticipated track Tropical Storm Sanba could approach Mindanao in the southern Philippines in about 36 hours.  Sanba could bring gusty winds and locally heavy rain to parts of the southern Philippines.  Locally heavy rain could cause flash floods.

Tropical Depression 02W Forms East of the Philippines

Tropical Depression 02W formed east of the Philippines on Friday.  At 11:00 a.m. EDT on Friday the center of Tropical Depression 02W was located at latitude 10.7°N and longitude 128.1°E which put it about 190 miles (305 km) east-southeast of Dolores, Philippines.  Tropical Depression 02W was moving toward the west-northwest at 13 m.p.h. (21 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.

The circulation of Tropical Depression 02W is organizing around a low level center east of Samar and Leyte.  Thunderstorms were developing near the center of circulation and several spiral bands were developing farther away from the center.  The thunderstorms near the center of circulation were just beginning to generate upper level divergence.

Tropical Depression 02W will move through an environment that will be favorable for intensification during the next 18 to 24 hours.  It will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge located east of Tropical Depression 02W is producing easterly winds that are blowing toward the depression, but the vertical wind shear is minimal.  The combination of warm SSTs and little vertical wind shear could allow Tropical Depression 02W to organize quickly and it could become a tropical storm before it reaches the Philippines.

A subtropical ridge is steering Tropical Depression 02W toward the west-northwest and that general motion is expected to continue for the next several days.  On its anticipated track Tropical Depression 02W will move across the Central Philippines during the weekend.  Tropical Depression 02W could bring gusty winds and heavy rain to portions of Samar, Leyte, Cebu, Panay, Mindoro and southern Luzon.  Heavy rain could create a risk for mudslides in some areas.