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Typhoon Fengshen Brings Wind and Rain to Northern Marianas

Typhoon Fengshen brought wind and rain to the Northern Marianas on Thursday.  At 10:00 p.m. EST on Thursday the center of Typhoon Fengshen was located at latitude 19.6°N and longitude 143.3°E which put it about 385 miles (620 km) south-southeast of Iwo To.  Fengshen was moving toward the northwest at 18 m.p.h. (30 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 974 mb.

Typhoon Fengshen intensified rapidly into a typhoon on Thursday as it moved over the Northern Marianas.  Fengshen brought strong, gusty winds and heavy rain to Alamagan, Agrihan and Pagan.  There was a small circular eye at the center of Typhoon Fengshen.  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 Fengshen.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out 30 miles from the center of circulation.  Winds to tropical storm force extended out 85 miles (135 km) from the center.

Typhoon Fengshen will move through an environment favorable for intensification during the next day or so.  Fengshen 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 Fengshen could strengthen into the equivalent of a major hurricane on Friday.

Typhoon Fengshen will move around the western end of a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Fengshen toward the north during the next 24 hours.  The typhoon will move toward the northeast on Saturday after it moves around the end of the ridge.  On its anticipated track Typhoon Fengshen will be south of Iwo To in about 24 hours.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Kalmaegi move closer to northern Luzon.  At 10:00 p.m. EST on Thursday the center of Tropical Storm Kalmaegi was located at latitude 16.6°N and longitude 125.0°E which put it about 250 miles (400 km) southeast of Aparri, Philippines.  Kalmaegi was moving toward the west-northwest at 12 m.p.h. (19 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 1002 mb.

Tropical Storm Fengshen Prompts Typhoon Warning for Northern Marianas

Tropical Storm Fengshen prompted the National Weather Service Office in Guam to issue a Typhoon Warning for portions of the Northern Marianas on Wednesday night.  At 10:00 a.m. EST on Wednesday the center of Tropical Storm Fengshen was located at latitude 17.2°N and longitude 149.0°E which put it about 265 miles (430 km) east of Alamagan.  Fengshen was moving toward west at 18 m.p.h. (30 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. (129 km/h).  The minimum surface pressure was 991 mb.

A Typhoon Warning was in effect for Alamagan, Pagan and Agrihan.

Tropical Storm Fengshen strengthened slowly on Wednesday, although the thunderstorm activity fluctuated during the day.  More thunderstorms developed near the center of circulation on Wednesday night.  Those thunderstorms were generating some upper level divergence which was pumping mass away to the west of the tropical storm.  The strongest rainbands were in the southern and eastern parts of Fengshen.  Bands in the northern wand western parts of the circulations consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

The circulation around Tropical Storm Fengshen may have pulled drier air into the tropical storm.  The drier air may have mixed into rainbands in the northern and western parts of Fengshen and caused the thunderstorms in those parts of the tropical storm to weaken.  Tropical Storm Fengshen will move through an environment favorable for intensification during the next several days.  Fengshen will move over water where the Sea Surface Temperature is near 29°C.  It will move south of an upper level ridge centered south of Japan.  The ridge will produce northeasterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear.  The wind shear and drier air will slow the rate of intensification.  Tropical Storm Fengshen could strengthen into a typhoon within 24 hours.

The ridge south of Japan will steer Tropical Storm Fengshen toward the west for another 12 to 24 hours.  Fengshen will start to move toward the north when it reaches the western end of the ridge.  On its anticipated track Tropical Storm Fengshen could reach Alamagan, Pagan and Agrihan in about 12 hours.  Fengshen could be a typhoon at that time.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Kalmaegi moved slowly toward northern Luzon.  At 10:00 p.m. EST on Wednesday the center of Tropical Storm Kalmaegi was located at latitude 14.3°N and longitude 127.2°E which put it about 425 miles (685 km) east-southeast of Baler, Philippines.  Kalmaegi was moving toward northwest at 12 m.p.h. (19 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 1002 mb.

Tropical Storm Kalmaegi Forms East of Luzon

Tropical Storm Kalmaegi formed east of Luzon on Tuesday night.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm Kalmaegi was located at latitude 12.9°N and longitude 128.8°E which put it about 350 miles (565 km) east of Legaspi, Philippines.  Kalmaegi was moving toward the west-northwest 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 1002 mb.

The Japan Meteorological Agency determined that former Tropical Depression 27W strengthened into Tropical Storm Kalmaegi on Tuesday night.  The circulation Kalmaegi was not well organized.  There was a large, broad area of low pressure, but there were few thunderstorms near the center of circulation.  Most of the stronger thunderstorms were occurring in bands in the northwestern part of Tropical Storm Kalmaegi.  Bands in the other portions of the circulation consisted primarily of showers and lower clouds.

Tropical Storm Kalmaegi will move through an environment marginally favorable for intensification.  Kalmaegi will move over water where the Sea Surface Temperature is near 29°C.  So, there is plenty of energy in the upper layer of the Western North Pacific Ocean to support intensification.  However, Tropical Storm Kalmaegi will move around the southwestern part of an upper level ridge centered south of Japan on Wednesday.  The ridge will produce northeasterly winds which will blow across the eastern part of the tropical storm.  Those winds will cause moderate vertical wind shear and they will inhibit intensification.  In 12 to 24 hours Kalmaegi will move closer to the western end of the ridge and the upper level winds will blow from the south.  The wind shear could decrease when the wind direction changes, which may allow the tropical storm to strengthen.

The ridge south of Japan will steer Tropical Storm Kalmaegi toward the northwest during the next 48 hours.  On its anticipated track Tropical Storm Kalmaegi could approach northeastern Luzon in 48 to 72 hours.  Since the strongest thunderstorms are in the northwestern part of Kalmaegi, the tropical storm could drop locally heavy rain over Luzon even if the center does not make landfall.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Fengshen continued to organize east of the Northern Marianas.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm Fengshen was located at latitude 17.4°N and longitude 155.3°E which put it about 690 miles (1115 km) east-northeast of Saipan.  Fengshen was moving toward the west-northwest at 21 m.p.h. (34 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 1002 mb.

Tropical Storm Fengshen Forms East of Northern Marianas

Tropical Storm Fengshen formed east of the Northern Marianas on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Storm Fengshen was located at latitude 17.1°N and longitude 157.1°E which put it about 805 miles (1300 km) east of Saipan.  Fengshen was moving toward the west-northwest at 18 m.p.h. (30 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 1000 mb.

More thunderstorms developed near the center of a cluster of thunderstorms east of the Northern Marianas on Tuesday and the Japan Meteorological Society designated the system as Tropical Storm Fengshen.  The distribution of thunderstorms around Tropical Storm Fengshen was asymmetrical.  Stronger thunderstorms were occurring in bands in the western half of the circulation.  Bands in the eastern half of the tropical storm consisted primarily of showers and lower clouds.  Fengshen was moving south of an upper level ridge over the Western North Pacific Ocean.  The ridge was producing easterly winds which were causing moderate vertical wind shear.  The wind shear was contributing to the asymmetrical distribution of thunderstorms.

Tropical Storm Fenshen will move through an environment favorable for intensification during the next several days.  Fengshen will move over water where the Sea Surface Temperature is near 29°C.  The upper level ridge will continue to cause vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be strong enough to prevent intensification.  Tropical Storm Fengshen will intensify gradually and it could strengthen into a typhoon during the next two to three days.

Tropical Storm Fengshen will move around the western end of the ridge over the Western North Pacific.  The ridge will steer Fengshen toward the west-northwest during the next 24 to 36 hours.  Tropical Storm Fengshen will move more toward the north in about 36 hours when it reaches the western end of the ridge.  On its anticipated track Fengshen will pass northeast of the Northern Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 27W developed east of Luzon.  At 4:00 p.m. EST on Tuesday the center of Tropical Depression 27W was located at latitude 12.1°N and longitude 130.9°E which put it about 315 miles (510 km) east of Laoang, Philippines.  The depression was moving toward the west at 12 m.p.h. (19 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 1004 mb.

Typhoon Mangkhut Strengthens Into Equivalent of Cat. 5 Hurricane

Typhoon Mangkhut strengthened into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of Typhoon Mangkhut was located at latitude 13.7°N and longitude 138.0°E which put it about 290 miles (470 km) north of Yap.  Mangkhut was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 190 m.p.h. (305 km/h).  The minimum surface pressure was 915 mb.

Typhoon Mangkhut is strong and well organized.  It has a symmetrical circulation with a circular eye at the center.  A ring of strong thunderstorms surround the eye and the strongest winds are occurring in the ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Typhoon Mangkhut.  Storms near the core were generating strong upper level divergence which was pumping large quantities of mass away from the typhoon in all directions.

Typhoon Mangkhut has a large circulation.  Winds to typhoon force extend out about 65 miles (105 km) from the center of circulation.  Winds to tropical storm force extend out about 210 miles (375 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Mangkhut is 35.0.  The Hurricane Size Index (HSI) is 22.1 and the Hurricane Wind Intensity Size Index (HWISI) is 57.1.  Typhoon Mangkhut is capable of causing extensive catastrophic damage.

Typhoon Mangkhut will be moving through an environment very favorable for powerful typhoons.  Mangkhut will be moving over water where the Sea Surface Temperature is near 30°C.  It will move through an area were the upper level winds are weak and there will be little vertical wind shear.  Typhoon Mangkhut could maintain its intensity for several more days unless eyewall replacement cycles cause fluctuations in the wind speed.

Typhoon Mangkhut is moving south a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Mangkhut in a general west-northwesterly direction during the next few days.  On its anticipated track Typhoon Mangkhut could approach northern Luzon in about three days.  Mangkhut could be near Hong Kong in about five days.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Barijat was moving southeast of Hong Kong.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Barijat was located at latitude 20.5°N and longitude 116.5°E which put it about 215 miles (345 km) southeast of Hong Kong.  Barijat was moving toward the west-southwest at 12 m.p.h. (19 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 Saola Speeding Toward Tokyo

Tropical Storm Saola sped toward Tokyo, Japan on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Saola was located at latitude 32.4°N and longitude 134.4°E which put it about 370 miles (595 km) west-southwest of Tokyo.  Saola was moving toward the northeast at 24 m.p.h. (39 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 979 mb.

Tropical Storm Saola was weakening and making a transition to an extratropical cyclone.  A primary band of showers and thunderstorms wrapped around the eastern side of the circulation.  There were other thinner bands of showers revolving around the core of the circulation.  Strong westerly winds in the upper levels were causing significant vertical wind shear which was tilting the upper part of the circulation toward the northeast.  Cooler drier air appeared to be flowing toward the western part of the circulation.

Westerly winds in the middle latitudes were steering Tropical Storm Saola quickly toward the northeast.  The center of Saola will pass south of Shikoku.  On its anticipated track the center of Tropical Storm Saola will pass near Tokyo in about 12 hours.  Tropical Storm Saola will bring gusty winds and locally heavy rain to Shikoku and central Honshu.  The heavy rain could cause flash floods in some locations.

Typhoon Saola Near Okinawa

The core of Typhoon Saola moved near Okinawa on Friday night.  At 11:00 p.m. EDT on Friday the center of Typhoon Saola was near latitude 26.2°N and longitude 128.2°E which put it about 70 miles (110 km) south of Okinawa.  Saola was moving toward the north at 14 m.p.h. (22 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.

The circulation of Typhoon Saola became more well organized on Friday.   The primary rainband wrapped most of the way around the center of circulation.  A large eye was surrounded by a broken ring of showers and thunderstorms.  Low clouds and showers were scattered throughout the large eye.  Several other bands of showers and storms were revolving around the core of Typhoon Saola.  The rainbands were weaker on the northwestern side of Typhoon Saola and there appeared to be cooler, drier air on that side of the typhoon.  Winds to typhoon force extended out about 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out about 200 miles (320 km) from the center.

Typhoon Saola could be near its maximum intensity.  Saola will move over water where the Sea Surface Temperature is near 29°C.  However Typhoon Saola is near the upper level westerly winds in the middle latitudes and the vertical wind shear will increase on Saturday.  Typhoon Saola could strengthen a little more during the next six to twelve hours, but it will start to weaken when the vertical wind shear increases.

Typhoon Saola is moving around the western end of a ridge which is steering Saola toward the north.  When Typhoon Saola reaches the westerly winds of the middle latitudes, those winds will turn Saola toward the east-northeast.  On its anticipated track Typhoon Saola will bring strong winds and heavy rain to Okinawa and the Ryukyu Islands.  The center of Typhoon Saola will be near southern Kyushu in about 12 hours and the center could pass near Tokyo in about 24 hours.

Tropical Storm Saola Strengthens, Moves Toward Okinawa

Tropical Storm strengthened on Thursday as it moved closer to Okinawa.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Saola was located at latitude 22.2°N and longitude 129.4°E which put it about 350 miles (570 km) south-southeast of Okinawa.  Saola was moving toward the north-northwest at 17 m.p.h. (27 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 987 mb.

The circulation of Tropical Storm Saola exhibited more organization in recent hours.  For much of the past several days many of the showers and thunderstorms were in a single primary rainband that wrapped around the outer part of the circulation.  There were few showers or storms near and to the north of the center of circulation.  A broken ring of showers and thunderstorms began to develop around the center during the past few hours.  The ring could represent the initial formation of an eyewall.  Additional bands of showers and thunderstorms also began to form outside the core of Tropical Storm Saola.

Tropical Storm Saola will be moving through an environment that will be favorable for intensification during the next 24 hours.  Saola will move over water where the Sea Surface Temperature is near 29°C.  The winds will be similar in all levels of the atmosphere and there will be little vertical wind shear.  Tropical Storm Saola will intensify on Friday and it could become a typhoon.  After about 24 hours Tropical Storm Saola will reach the upper level westerly winds in the middle latitudes and the vertical wind shear will increase.  More wind shear will start to weaken Saola.

Tropical Storm Saola was moving the western end of a ridge which is steering the tropical storm toward the north-northwest and that general motion is expected to continue for about another 24 hours.  On its anticipated track Tropical Storm Saola will approach Okinawa in about 24 hours.  When Saola nears Okinawa, it will encounter the westerly winds in the middle latitudes.  Those winds will turn Saola toward the northeast.  Tropical Storm Saola will bring gusty winds and locally heavy rain to Okinawa and the Ryukyu Islands.

Tropical Storm Saola Develops West of Guam

Tropical Storm Saola developed west of Guam on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Saola was located at latitude 14.8°N and longitude 134.8°E which put it about 375 miles (605 km) northwest of Yap.  Saola was moving toward the west-northwest at 24 m.p.h. (39 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 997 mb.

The core of the circulation of Tropical Storm Saola became more well organized on Tuesday.  The center of circulation strengthened and more thunderstorms developed close to the center  Bands of showers and thunderstorms formed outside the core of Tropical Storm Saola.  Many of the showers and storms formed southwest of the center.  There were fewer showers and storms northeast of the center.  The storms near the core of Saola began to produce upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Saola will move through an environment that will be somewhat favorable for intensification.  Saola will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge north of Tropical Storm Saola is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing moderate vertical wind shear which is inhibiting the intensification of Tropical Storm Saola.  The upper level winds are forecast to weaken which would cause the wind shear to decrease.  The decreased wind shear should allow Tropical Storm Saola to intensify during the next several days and it could eventually strengthen into a typhoon.

The upper level ridge has been steering Tropical Storm Saola toward the west-northwest.  An upper level trough east of Asia is forecast to weaken the ridge.  When the ridge weakens,Tropical Storm Saola will turn more the north.  On its anticipated track Tropical Storm Saola will remain east of the Philippines and Taiwan.  Tropical Storm Saola could approach Okinawa in about 72 hours.  Saola could be a typhoon when it approaches Okinawa.

Typhoon Lan Brings Wind and Rain to Japan

Typhoon Lan brought wind and rain to parts of Japan on Sunday.  At 5:00 p.m. EDT on Sunday the center of Typhoon Lan was located at latitude 35.2°N and longitude 139.1°E which put it about 50 miles southwest of Tokyo, Japan.  Lan was moving toward the northeast at 37 m.p.h. (60 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 960 mb.

Typhoon Lan weakened significantly before it reached Japan.  Lan moved over cooler water south of Japan.  Strong upper level westerly winds caused strong vertical wind shear.  The circulation of Lan pulled drier air into the western half of the circulation.  The combination of cooler water, strong shear and drier air caused the significant weakening.  In addition the shear was strong enough to push the heavier rain to the northeast of the center of Typhoon Lan.

Lan was still a typhoon when it made landfall in Honshu despite the unfavorable environment.  A weather station at the Tokyo International Airport reported a wind speed of 56 m.p.h. (90 km/h).  Some areas in eastern Honshu experienced periods of heavy rain and gusty winds.  The drier air will limit the rainfall after the center of the typhoon passes a given location.

The strong westerly winds will steer Typhoon Lan rapidly toward the northeast.  Lan will move east of Honshu in a few hours.  The strong vertical wind shear and cooler, drier air will cause Typhoon Lan to transition to a strong extratropical cyclone east of Japan.

While Typhoon Lan races across eastern Japan, Tropical Depression 27W organized southeast of Guam.  At 5:00 p.m. EDT on Sunday the center of Tropical Depression 27W was located at latitude 9.3°N and longitude 147.4°E which put it about 360 miles (580 km) southeast of Guam.  It was moving toward west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gust to 45 m.p.h.  The minimum surface pressure was 1004 mb.

Tropical Depression 27W will move through an environment that will be somewhat favorable for development during the next several days.  It will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge centered northeast of the Marianas is producing easterly winds which are blowing over the top of the depression.  Those winds are causing moderate vertical wind shear.  The shear is inhibiting the organization of the circulation and it is slowing the development of the depression.  The shear is forecast to decrease during the next several days and the depression could strengthen into a tropical storm if a distinct low level center forms.

Tropical Depression 27W is near the southwestern end of the ridge to its northeast.  The ridge is currently steering the depression toward the west.  It is forecast to move around the end of the ridge and turn more toward the north during the next few days.  On its anticipated track the depression could be near Guam in about 24 hours.  It could be a tropical storm at that time.