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Powerful Typhoon Maria Spins East of Taiwan

Powerful Typhoon Maria spun east of Taiwan on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Maria was located at latitude 19.4°N and longitude 138.3°E which put it about 950 miles (1530 km) east-southeast of Okinawa.  Maria was moving toward the northwest at 13 m.p.h. (10 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h).  The minimum surface pressure was 925 mb.

Typhoon Maria appeared to complete an eyewall replacement cycle on Saturday.  The completion of the cycle resulted in a  larger circulation.   There was an eye which had a diameter of 24 miles (38 km).  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of the circulation.  The rainbands northwest in the northwestern quadrant of Typhoon Maria were a little weaker than the bands in the other parts of the circulation.  Storms in the core of Maria were generating upper level divergence which was pumping mass away to the northeast of the typhoon.

Winds to typhoon force extended out about 70 miles (110 km/h) 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 Maria was 37.9.  The Hurricane Size Index (HSI) was 24.5 and the Hurricane Wind Intensity Size Index (HWISI) was 62.4.

Typhoon Maria will move through an environment mostly favorable for powerful typhoons on Sunday.   Maria will move over water where the Sea Surface Temperature is near 30°C.  It will move through an environment where the upper level winds are weak and there will be little vertical wind shear.  There appears to be some sinking motion and drier air northwest of Maria and that may be the reason why the rainbands were weaker in that part of the typhoon.  The drier air could inhibit further strengthening.  Typhoon Maria is likely to remain strong for another 24 to 48 hours.

Typhoon Maria was moving around the southern portion of a subtropical ridge over the Western North Pacific.  The ridge was steering Maria toward the northwest.  The ridge is forecast to strengthen and it will steer Typhoon Maria more toward the west-northwest.  On its anticipated track Typhoon Maria could approach the southern Ryukyu Islands in about 48 hours.  Maria could be near the northern end of Taiwan in about 60 hours.

Typhoon Maria Rapidly Intensifies Into Equivalent of Major Hurricane

Typhoon Maria rapidly intensified Thursday into the equivalent of a major hurricane as it moved west of the Mariana Islands.  At 5:00 p.m. EDT on Thursday the center of Typhoon Maria was located at latitude 15.7°N and longitude 142.1°E which put it about 210 miles (340 km) northwest of Guam.  Maria was moving toward the northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 125 m.p.h. (205 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 950 mb.

After striking Guam as a tropical storm on Wednesday Maria rapidly intensified into a strong typhoon on Thursday.  A circular eye was evident on satellite imagery.  The eye was surrounded by a ring of strong thunderstorms.  Several bands of showers and thunderstorms were revolving around the core of the circulation.  Storm in the core were generating strong upper level divergence which was pumping mass away from the typhoon in all directions.  Winds to typhoon force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out about 155 miles (250 km) from the center.

The Hurricane Intensity Index (HII) for Typhoon Maria was 23.6.  The Hurricane Size Index (HSI) was 14.1 and the Hurricane Wind Intensity Size Index (HWISI) was 37.7.

Typhoon Maria will continue to move through an environment favorable for intensification for another day or two.  Maria will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region of weaker winds between an upper level low to the west and an upper level low to the east.  There will be little vertical wind shear.  Typhoon Maria is likely to intensify more on Friday and it could become the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.  An eyewall replacement cycle could occur if one of the rainbands wraps around existing eye and eyewall.  If an eyewall replacement cycle starts, it will cause Typhoon Maria to weaken at least temporarily.

Typhoon Maria was moving south of a subtropical ridge over the Western North Pacific Ocean.  The ridge was steering Maria toward the northwest.  A general motion toward the northwest is expected to continue for another day or two.  The ridge is forecast to strengthen after that time and it will steer Typhoon Maria more toward the west-northwest.  On its anticipated track Maria will pass south of Iwo To.  Typhoon Maria could approach Okinawa and the Ryukyu Islands in four or five days.

Strengthening Tropical Storm Maria Brings Wind and Rain to Guam

Tropical Storm Maria strengthened quickly on Wednesday and it brought gusty winds and heavy rain to Guam.  The weather station at Andersen Air Force Base on Guam reported sustained winds to 44 m.p.h. (71 km/h) and wind gusts to 72 m.p.h. (116 km/h).  At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Maria was located at latitude 13.9°N and longitude 144.7°E which put it about 5 miles (10 km/h) south of Andersen Air Force Base.  Maria was moving toward the north-northwest at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 987 mb.  Tropical Storm Warnings remained in effect for Guam and Rota.  Tropical Storm Watches were in effect for Saipan and Tinian.

The circulation of Tropical Storm Maria organized quickly on Wednesday.  A tight center of circulation contracted at the center of Maria.  A partial ring of thunderstorms formed on the east side of the center.  Numerous bands of showers and thunderstorms were revolving around the core of the circulation.  Storms around the core generated well developed upper level divergence which pumped mass away in all directions from the tropical storm.  Winds to tropical storm force extended out about 95 miles (155 km) from the center of circulation.

Tropical Storm Maria will move through an environment very favorable for intensification.  Maria will move over water where the Sea Surface Temperature is near 30°C.  Tropical Storm Maria will move under the western portion of an upper level ridge where the upper level winds are weak.  There will little vertical wind shear.  Upper level lows east and west of the ridge will enhance the upper level divergence.  Tropical Storm Maria will strengthen into a typhoon on Thursday.  Maria could intensify rapidly and it is likely to become the equivalent of a major hurricane.

Tropical Storm Maria was moving around the western end of a subtropical ridge which was steering Maria toward the north-northwest.  The ridge is forecast to steer Maria toward the northwest during the next few days.  On its anticipated track Tropical Storm Maria will move away from the Marianas and toward the Ryukyu Islands.  Tropical Storm Maria will continue to cause gusty winds and drop locally heavy rain on the southern Marianas for a few more hours.  Conditions will improve on Thursday when Maria moves away the Marianas.

Tropical Storm Maria Prompts Warning for Guam

Tropical Depression 10W strengthened into Tropical Storm Maria on Wednesday and a Tropical Storm Warning was issued for Guam.  At 5:00 a.m. EDT on Wednesday the center of Tropical Storm Maria was located at latitude 12.7°N and longitude 145.9°E which put it about 95 miles (155 km) southeast of Guam.  Maria was moving toward the north-northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1000 mb.  Tropical Storm Warnings were in effect for Guam and Rota.  Tropical Storm Watches were in effect for Saipan and Tinian.

The center of circulation in former Tropical Depression 10W became more well organized on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Maria.  The circulation was still increasing in organization.  There was a distinct low level center of circulation.  Numerous bands of showers and thunderstorms were revolving around the center of circulation.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Maria will move through an environment very favorable for intensification during the next few days.  Maria will move over water where the Sea Surface Temperature is near 30°C.  Tropical Storm Maria will move under the western end of an upper level ridge that is between two upper level lows which are east and west of the ridge.  The upper level winds will be relatively weak and there will be little vertical wind shear.  The combination of the ridge and two upper level lows will increase the upper level divergence.  Tropical Storm Maria will continue to strengthen.  Maria will become a typhoon later this week.  It could intensify rapidly once an eye forms and the inner core is well developed.

Tropical Storm Maria is moving around the western end of a subtropical ridge which is steering Maria toward the north-northwest.  On its anticipated track the center of Tropical Storm Maria will move near Guam and Rota later today.  A general motion toward the northwest is forecast for the next several days.  Maria could move in the direction of the Ryukyu Islands at the end of the week.

Tropical Storm Maria will bring gusty winds and heavy rain to the southern Mariana Islands.  The strongest winds and heaviest rain will affect Guam and Rota.  Gusty winds and heavy rain will also affect Saipan and Tinian.  Heavy rain could produce flash floods.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Prapiroon was moving over the Sea of Japan.  Prapiroon was bringing wind and rain to the northern Islands of Japan including Hokkaido and Honshu.  At 5:00 a.m. EDT on Wednesday the center of Tropical Storm Prapiroon was located at latitude 39.6°N and longitude 135.6°E which put it about 360 miles (585 km) west-southwest of Misawa, Japan.  Prapiroon was moving toward the northeast at 25 m.p.h. (40 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were winds gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 987 mb.

Maliksi Strengthens Into a Typhoon East of Okinawa

Former Tropical Storm Maliksi strengthened into a typhoon east of Okinawa near Minami Daito Jima late on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Maliksi was located at latitude 25.7°N and longitude 131.7°E which put it about 210 miles (335 km) east of Okinawa.  Maliksi was moving toward the northeast at 24 m.p.h. (39 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 970 mb.

The circulation of Typhoon Maliksi became more organized on Saturday.  An inner rainband wrapped around the center of circulation and an eye was apparent on satellite images.  There were intermittent breaks in the rings of thunderstorms around the eye.  Several bands of showers and thunderstorms in the eastern half of the circulation were revolving around the core of the typhoon.  Bands west of the center consisted primarily of showers and low clouds.  Storms near the core of Maliksi were generating upper level divergence which was pumping mass away to the northeast of the typhoon.  The circulation of Typhoon Maliksi was large and winds to tropical storm force extended out about 250 miles (400 km) from the center of circulation.

Typhoon Maliksi will move through an environment favorable for intensification during the next 12 to 24 hours.  Maliksi will move over water where the Sea Surface Temperature is near 30°C.  An upper level trough to the west of Maliksi will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will produce some vertical wind shear, but the shear will not be strong enough to prevent intensification on Sunday.  The shear will increase after 18 to 24 hours and that will likely cause Maliksi to start to weaken.

The upper level trough is steering Maliksi toward the northeast and that general motion is expected to continue for another two or three days.  Typhoon Maliksi will speed past Minami Daito Jima during the next few hours.  On its anticipated track Maliksi will reach some of the islands south of Honshu in about 24 hours.  Typhoon Maliksi will produce gusty winds and locally heavy rain.

Tropical Depression 04W Forms East of the Northern Marianas

Tropical Depression 04W formed east of the Northern Marianas very late on Friday.  At 11:00 p.m. EDT on Friday the center of Tropical Depression 04W was located at latitude 18.8°N and longitude 148.5°E which put it about 185 miles (300 km) east of Agrihan.  It was moving toward the northwest at 11 m.p.h. (17 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 1003 mb.

An area of showers and thunderstorms persisted for much of the past week east of the Northern Marianas.  Several smaller centers of circulation formed within the area of showers and storms, but those centers ran into strong upper level winds and weakened because strong vertical wind shear and they dissipated.  Another center formed on Friday, but the upper level winds were a little weaker and the center persisted.  An upper level trough south of Japan was still producing southwesterly winds which were blowing toward the top of the circulation.  Those winds were producing moderate vertical wind shear, but the center of circulation persisted.  Most of the thunderstorms were occurring in bands east of the center of circulation.  The bands west of the center consisted primarily of low clouds and showers.

Tropical Depression will move through an area marginally favorable for intensification during the next 24 hours.  it will move over water where the Sea Surface Temperatures are near 28°C.  So, there will be enough energy in the upper ocean to support some intensification.  The upper level trough south of Japan will continue to cause moderate vertical wind shear, but the upper level winds could be weak enough to allow for further intensification.  Tropical Depression 04W could strengthen into a tropical storm on Saturday.

Tropical Depression 04W is moving near the southwestern part of a ridge over the North Pacific Ocean.  The ridge is steering the depression toward the northwest and that general motion is expected to continue for another day or two.  On its anticipated track Tropical Depression 04W is expected to pass near the northernmost Mariana Islands.  It could pass near Asuncion Island, the Maug Islands, Supply Reef and Farallon de Pajaros.  Tropical Depression 04W could bring gust winds, locally heavy rain and higher waves to those places.

Tropical Storm Jelawat Weakens Rapidly Over the Northern Marianas

Tropical Storm Jelawat weakened rapidly over the Northern Marianas on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Jelawat was located at latitude 19.3°N and longitude 145.5°E which put it about 50 miles (80 km) north-northwest of Agrihan.  Jelawat was moving toward the east-northeast 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 993 mb.

Former Typhoon Jelawat moved into an area where there were upper level westerly winds blowing at 50 m.p.h. (80 km/h).  Those strong upper level winds created enough vertical wind shear to blow the upper two thirds of the circulation east of the lower part of the circulation.  The remaining strong thunderstorms were weakening well to the east of the lower level circulation.  Tropical Storm Jelawat consisted primarily of narrow bands of showers and low clouds that were revolving around the center of circulation.  Jelawat may bring brief gusty winds and showers to the northernmost islands in the Marianas.

Typhoon Jelawat Rapidly Intensifies Into Equivalent of Major Hurricane

Typhoon Jelawat intensified rapidly on Friday into the equivalent of a major hurricane.  At 11:00 a.m. EDT on Friday the center of Typhoon Jelawat was located at latitude 17.1°N and longitude 139.5°E which put it about 440 miles (710 km) northwest of Guam.  Jelawat was moving toward the east-northeast at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h).  The minimum surface pressure was 926 mb.

Typhoon Jelawat intensified rapidly on Friday.  There was a small circular eye at the center of circulation.  A ring of very strong storms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several spiral bands were revolving around the core of the circulation.  Storms near the core were generating well developed upper level divergence which was pumping large quantities of mass away to the east of the typhoon.  The removal of mass allowed the surface pressure to decrease rapidly and that produced a a rapid increase in wind speed.

Winds to typhoon force extend out about 45 miles (75 km) from the center of Typhoon Jelawat.  Winds to tropical storm force extend out about 175 miles (280 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Typhoon Jelawat is 31.6.  The Hurricane Size Index (HSI) is 17.7 and the Hurricane Wind Intensity Size Index (HWISI) is 49.3.

Typhoon Jelawat is in an environment favorable for strong typhoons, but it may be near its peak in intensity.  Jelawat will move over water where the Sea Surface Temperature is near 28°C.  Typhoon Jelwat has moved around the western end of an upper level ridge which is producing easterly winds that are blowing toward the top of the circulation.  The winds are causing some vertical wind shear, but the shear has not inhibited intensification.  When Typhoon Jelawat moves farther to the northeast it will move under stronger easterly and the wind shear will increase.  More shear will cause Jelawat to weaken during the next few days.

A subtropical ridge to the east of Typhoon Jelawat is steering the typhoon toward the east-northeast.  A general motion toward the east-northeast is expected to continue for several more days.  On its anticipated track Typhoon Jelawat could approach the northernmost islands in the Marianas in about 48 hours.

Typhoon Jelawat Strengthens West-Northwest of Guam

Former Tropical Storm Jelawat strengthened into a typhoon as it moved west-northwest of Guam on Thursday.  At 11:00 p.m. EDT on Thursday the center of Typhoon Jelawat was located at latitude 15.9°N and longitude 137.7°E which put it about 520 miles (840 km) west-northwest of Guam.  Jelawat was moving toward the east-northeast at 7 m.p.h. (11 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 972 mb.

Typhoon Jelawat strengthened quickly on Thursday night.  A small eye developed at the center of circulation.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Typhoon Jelawat.  Storms in the core of the circulation were generating upper level divergence which was pumping mass away to the northeast of the typhoon.  Winds to typhoon force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 145 miles (230 km) from the center.

Typhoon Jelawat will move through an area favorable for intensification on Friday.  Jelawat will move over water where the Sea Surface Temperature is near 28°C.  Typhoon Jelawat has moved around the western end of an upper level ridge which is producing southwesterly winds which are blowing toward the top of the circulation.  Those winds are producing some vertical wind shear, but the wind shear is not strong enough to prevent intensification.   Typhoon Jelwat is likely to intensify further on Friday.

The upper level ridge is steering Typhoon Jelawat toward the east-northeast and that general motion is expected to continue for several more days.  On its anticipated track Typhoon Jelawat is expected to pass northwest of Guam.  Jelawat could approach the northernmost islands in the Marianas in about two or three days.

Tropical Storm Jelawat Strengthens West of Guam

Tropical Storm Jelawat strengthened west of Guam late on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Jelawat was located at latitude 12.3°N and longitude 135.5°E which put it about 230 miles (375 km) northwest of Yap and about 600 miles (970 km) west of Guam.  Jelawat was moving toward the north at 10 m.p.h. (16 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.

After being affected by strong vertical wind shear for about 36 hours, Tropical Storm Jelawat began to strengthen late on Tuesday.  Many more thunderstorms formed near the center of circulation.  The circulation became much more symmetrical.  Bands of showers and thunderstorms formed in all parts of the circulation.  The storms near the center of circulation started to generate upper level divergence which pumped mass away from the tropical storm.

Tropical Storm Jelawat will be moving through an environment favorable for intensification during the next several days.  Jelawat will move over water where the Sea Surface Temperature is near 28°C.  Tropical Storm Jelawat is moving around the western end of an upper level ridge.  The ridge is producing southerly winds which are blowing toward the tropical storm.  The winds are producing some vertical wind shear, but the shear is not as strong as it has been.  Tropical Storm Jelawat will intensify during the next day or two and it could strengthen into a typhoon.

The ridge is steering Tropical Storm Jelawat toward the north and the northerly motion is expected to continue for another 12 to 24 hours.  Jelawat will move more toward the northeast in a day or so after it rounds the western end of the ridge.  On its anticipated track Tropical Storm Jelawat will move away from Yap and it will remain west of Guam.