Monthly Archives: August 2018

Tropical Storm Cimaron Prompts Warnings for Northern Marianas, Soulik Strengthens West of Iwo To

Tropical Storm Cimaron developed east of the Northern Marianas on Saturday and it prompted Typhoon Warnings for some of the islands, while Typhoon Soulik strengthened west of Iwo To.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Cimaron was located at latitude 15.5°N and longitude 151.6°E which put it about 420 miles (675 km) east of Saipan.  Cimaron was moving toward the northwest 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 997 mb.  A Typhoon Warning was in effect for Agrihan, Pagan and Almagan.

A distinct center of circulation developed in an area of thunderstorms east of the Northern Marianas on Saturday and the Japan Meteorological Agency designated the system as Tropical Storm Cimaron.  Numerous bands of showers and thunderstorms developed around the circulation of Tropical Storm Cimaron.  The rainbands west and south of the center of circulation were stronger than the bands east and north of the center.  An inner bands of thunderstorms started to wrap around the south side of the center.  Storms near the center began to generate upper level divergence.

Tropical Storm Cimaron will move through an environment favorable for intensification during the next several days.  Cimaron will move over water where the Sea Surface Temperature is near 29°C.  Tropical Storm Cimaron will move through an area where it will be near the upper level divergence from Typhoon Soulik.  Tropical Storm Cimaron is forecast to stay just southeast of the divergence from Soulik.  If it does that, Cimaron will strengthen into a typhoon during the next few days.  However, if Cimaron moves under the upper level divergence from Typhoon Soulik, then the vertical wind shear will keep Cimaron from strengthening.

Typhoon Soulik strengthened into the equivalent of a major hurricane west of Iwo To on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Soulik was located at latitude 25.2°N and longitude 138.8°E which put it about 145 miles (235 km) west-northwest of Iwo To.  Soulik was moving toward the west-northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 135 m.p.h. (215 km/h).  The minimum surface pressure was 952 mb.

Typhoon Soulik is well organized.  There is a circular eye at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds are occurring in that ring of storms.  Several bands of showers and thunderstorms are revolving around the core of Soulik.  Storms near the core are generating strong upper level divergence which is pumping mass away in all directions.  Winds to typhoon force extend out about 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extend out about 170 miles (280 km) from the center.

Typhoon Soulik will move through an area favorable for strong typhoons.  Soulik 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.  Soulik could maintain its intensity for another 24 to 48 hours.

Typhoon Soulik will move around the western end of a ridge in the middle troposphere.  The ridge will steer Soulik in a general northwesterly direction.  On it anticipated track Typhoon Soulik will move toward the Ryukyu Islands.  Tropical Storm Cimaron will move around the western end of a subtropical ridge over the Western North Pacific Ocean.  On its anticipated track, Cimaron will move near the northern Marianas in 24 to 36 hours.  Tropical Storm Cimaron could approach Iwo To in about three days.

Lane Intensifies Into a Major Hurricane on Way to Central Pacific

Hurricane Lane intensified into a major hurricane on it way toward the Central Pacific Ocean on Friday night.  At 11:00 p.m. EDT on Friday the center of Hurricane Lane was located at latitude 11.8°N and longitude 135.6°W which put it about 1405 miles (2260 km) east-southeast of Hilo, Hawaii.  Lane was moving toward the west at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 140 m.p.h. (225 km/h).  The minimum surface pressure was 964 mb.

Hurricane Lane exhibited the structure of a major hurricane on satellite imagery.  There was a circular eye 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 spiral bands were revolving around the core of the circulation.  Storms around the core were generating strong upper level divergence which was pumping mass away from the hurricane in all directions.  Winds to hurricane force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center.

Hurricane Lane will be moving through an environment favorable for intensification on Saturday.  Lane 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 is little vertical wind shear.  Lane is likely to intensify more during the next 24 hours.  If one of the rainbands wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause a weakening of Hurricane Lane.

Hurricane Lane will move south of the subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Lane in a general westerly direction during the next few days.  On its anticipated track Hurricane Lane could be southeast of Hawaii in about four days.

Typhoon Soulik Strengthens Near Iwo To

Typhoon Soulik strengthened near Iwo To on Friday.  At 5:00 p.m. EDT on Friday the center of Typhoon Soulik was located at latitude 24.4°N and longitude 140.0°E which put it about 90 miles (145 km) west-southwest of Iwo To.  Soulik was moving toward the north at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 963 mb.

Typhoon Soulik strengthened quickly on Friday.  An eye appeared at the center of circulation on satellite imagery.  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 the circulation.  The strongest rainbands were occurring in the eastern half of Typhoon Soulik.  Storms around the core were generating strong upper level divergence which was pumping large quantities of mass away from the typhoon.  Winds to typhoon force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 150 miles (240 km) from the center.

Typhoon Soulik will move through an environment favorable for intensification during the next 48 hours.  Soulik 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 Soulik will continue to intensify and it will become the equivalent of a major hurricane during the weekend.

Typhoon Soulik will be in an area where the winds at steering level are weak during next 12 to 24 hours.  Soulik is likely to move slowly northward during that time.  A subtropical ridge northeast of Typhoon Soulik is forecast to strengthen in a day or so.  When that happens, the ridge will steer Soulik in a general northwesterly direction.  On its anticipated track Typhoon Soulik will slowly away from Iwo To on Saturday.  Soulik will continue to produce gusty winds and to drop heavy rain over Iwo To until it moves away.  Typhoon Soulik will move in the general direction of Kyushu and the Ryukyu Islands during the next several days.

Lane Strengthens Into a Hurricane

Former Tropical Storm Lane strengthened into a hurricane on Thursday night.  At 11:00 p.m. EDT on Thursday the center of Hurricane Lane was located at latitude 11.2°N and longitude 129.8°W which put it about 1780 miles (2865 km) east-southeast of Hilo, Hawaii.  Lane was moving toward the west-northwest at 15 m.p.h. (24 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 992 mb.

The circulation of Hurricane Lane became much better organized.  A primary rainband wrapped most of the way around the center of circulation and it could become an eyewall.  Several bands of showers and thunderstorms in the southern and eastern parts of the circulation were revolving around the core of Hurricane Lane.  Storms near the core were generating strong upper level divergence which was pumping mass away from the hurricane in all directions.  Winds to hurricane force extended out about 20 miles (30 km) from the center of circulation.  Winds to tropical storm force extended out about 60 miles (95 km) from the center.

Hurricane Lane will be moving through an environment that will be favorable for intensification during the next several days.  Lane 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.  Hurricane Lane will intensify during the next 36 to 48 hours and it could intensify rapidly once a well developed eye forms.

Hurricane Lane will move south of the subtropical high over the Eastern North Pacific Ocean.  The high will steer Lane in a general west-northwesterly direction during the next few days.  On its anticipated track Hurricane Lane could be southeast of Hawaii by early next week.

Tropical Storm Rumbia Makes Landfall Near Shanghai, Bebinca Hits Vietnam

Tropical Storm Rumbia made landfall on the east coast of China just south of Shanghai on Thursday, and Tropical Storm Babinca hit Vietnam.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Rumbia was located at latitude 30.5°N and longitude 121.0°E which put it about 60 miles (95 km) southwest of Shanghai, China.  Rumbia was moving toward the west at 14 m.p.h. (22 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.

Tropical Storm Rumbia strengthened before it made landfall.  Thunderstorms developed near the center of circulation and a band wrapped around the center.  The circulation became more circular and storms near the center began to generate upper level divergence.  In the western half off the circulation where the winds were blowing toward the land, increased friction enhanced rising motion and heavier rain fell.

Tropical Storm Rumbia caused some gusty winds near the coast, but the greater risks were the locally heavy rain and the potential for floods.  Tropical Storm Rumbia is forecast to move slightly north of due west as it moves inland over eastern China.  Rumbia will drop locally heavy rain over the area around Shanghai, and over parts Zhejiang, Jiangsu and Anhui provinces.  Some of those regions have received heavy rain from previous storms and the potential for serious flooding exists.

Tropical Storm Bebinca made landfall on the coast of Vietnam on Thursday.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Bebinca was located at latitude 19.9°N and longitude 106.3°E which put it about 70 miles (110 km) southeast of Ninh Binh, Vietnam.  Bebinca was moving toward the west-southwest at 8 m.p.h. (13 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 979 mb.

Tropical Storm Bebinca also strengthened before it made landfall.  An eye started to form at the center of circulation and Bebinca was on the threshold of becoming a typhoon when it made landfall.  Tropical Storm Bebinca produced gusty winds and a storm surge near the coast.  However, the greatest risks are locally heavy rain and the potential for floods.  Tropical Storm Bebinca is forecast to move in a general westerly direction.  Bebinca will drop locally heavy rain over parts of Vietnam, northern Laos and extreme northern Thailand.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Soulik moved quickly toward Iwo To and strengthened.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Soulik was located at latitude 20.9°N and longitude 141.3°E which put it about 315 miles (510 km) south of Iwo To.  Soulik was moving toward the north at 20 m.p.h. (32 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 981 mb.

Ernesto Makes Transition to Tropical Storm

Former Subtropical Storm Ernesto made a transition to a tropical storm on Thursday afternoon.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Ernesto was located at latitude 43.0°N and longitude 41.0°W which put it about 645 miles (1035 km) east-southeast of Cape Race, Newfoundland.  Ernesto was moving toward the northeast 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 1007 mb.

Even though now Tropical Storm Ernesto moved over water where the Sea Surface Temperature was between 24°C and 25°C, there was enough energy in the upper ocean to cause more thunderstorms to develop.  In addition, many of the thunderstorms developed close to the center of circulation.  The inner bands of showers and thunderstorms became stronger and the bands in the outer parts of the circulation weakened.  Ernesto exhibited a structure like a tropical cyclone and the National Hurricane Center classified the system as a tropical storm in the 5:00 p.m. EDT advisory.

Tropical Storm Ernesto will move over much cooler water during the next 24 hours.  It is likely to make a transition to an extratropical cyclone when it moves over the cooler water.  Ernesto could strengthen when colder air is pulled into the western half of the circulation and a cold front forms south of the center.  The development of the cold front and upper level divergence could strengthen the pressure gradient force which would give the air a stronger push.  An upper level trough east of the U.S. is forecast to steer Ernesto in the general direction of Ireland and the United Kingdom.

Tropical Storm Rumbia Nears Shanghai, Bebinca Strengthens East of Vietnam

Tropical Storm Rumbia moved closer to Shanghai on Wednesday, while Tropical Storm Bebinca strengthened east of Vietnam and Tropical Storm Soulik formed west of Guam.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Rumbia was located at latitude 30.1°N and longitude 124.2°E which put it about 160 miles (260 km) southeast of Shanghai, China.  Rumbia was moving toward the west-northwest at 7 m.p.h. (11 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 999 mb.

Tropical Storm Rumbia has about 12 to 18 hours before it makes landfall near Shanghai.  It will move through an environment somewhat favorable for intensification.  Rumbia will move over water where the Sea Surface Temperature is near 28°C.  The circulation of Rumbia is broad.  There is a distinct center of circulation, but there are few thunderstorms close to the center.  Most of the stronger thunderstorms were occurring in rainbands revolving around the center of Rumbia.  The broad circulation will limit the potential for intensification, but Tropical Storm Rumbia could get stronger before it reaches the east coast of China on Thursday.

Tropical Storm Bebinca strengthened on Wednesday while it moved south of China.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Bebinca was located at latitude 19.9°N and longitude 108.2°E which put it about 125 miles (200 km) east-southeast of Hai Phong, Vietnam.  Bebinca was moving toward the west-southwest at 15 m.p.h. (24 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 980 mb.

Tropical Storm Bebinca intensified quickly on Wednesday after it moved west of Hainan Island.  A primary rainband wrapped around the center of circulation and an eye appeared to be forming.  Several bands of showers and thunderstorms were revolving around the core of Bebinca.  Tropical Storm Bebinca has about 18 hours before it reaches the coast of Vietnam.  It will move through an environment favorable for intensification.  Bebinca will move over water where the Sea Surface Temperature is near 29°C.  It will move through an area where the upper level winds are weak and there is little vertical wind shear.  Bebinca could strengthen into a typhoon before it reaches Vietnam.

Tropical Storm Bebinca could make landfall on the coast of  Vietnam between Hai Phong and Vinh within 24 hours.  It could be a typhoon when it makes landfall.  Bebinca will bring strong winds capable of causing damage.  it could generate a storm surge of 6 to 9 feet (2 to 3 meters) at the coast.  Bebinca will drop heavy rain over parts of Vietnam and it could cause serious flooding.

Tropical Storm Soulik formed west of Guam on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Soulik was located at latitude 15.9°N and longitude 142.7°E which put it about 165 miles (265 km) northwest of Guam.  Soulik was moving toward the north-northwest at 20 m.p.h. (32 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 999 mb.

Tropical Storm Soulik will move through an environment favorable for intensification.  Soulik will move over water where the Sea Surface Temperature is near 29°C.  It will move east of an upper level low that will produce southerly winds.  Those winds will move blow toward the top of the circulation and they will cause some vertical wind shear, but they will not be strong enough to prevent intensification.  Soulik could strengthen into a typhoon within 48 hours.  The upper low will pull Tropical Storm Soulik toward Iwo To.

Tropical Storm Lane Forms Southwest of Baja Califonia

Tropical Storm Lane formed southwest of Baja California on Wednesday morning.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Lane was located at latitude 10.7°N and longitude 123.6°E which put it about 1235 miles (1990 km) southwest of the southern tip of Baja California.  Lane was loving toward the west at 14 m.p.h. (22 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 1006 mb.

A distinct low level center of circulation formed on Wednesday morning within a tropical wave southwest of Baja California.  The National Hurricane Center designated the system as Tropical Storm Lane when more thunderstorms formed near the center of circulation.  The circulation of Tropical Storm Lane was organizing quickly.  Thunderstorms were developing around the center of circulation.  Bands of showers and thunderstorms began to form and to revolve around the core of Tropical Storm Lane.  Storms in the core started to generate upper level divergence which was pumping mass away from the tropical storm in all directions.

Tropical Storm Lane will move through an environment very favorable for intensification.  Lane will move over water where the Sea Surface Temperature is near 28°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Lane will intensify and it could become a hurricane within 36 hours.  When an eye forms and the core of the circulation is well established, Lane could intensify rapidly and it could strengthen into a major hurricane by the weekend.

Tropical Storm Lane will move south of the subtropical ridge over the Eastern North Pacific.  The ridge will steer Lane westward.  On its anticipated track Tropical Storm Lane will move farther away from Baja California and in the general direction of Hawaii.

Subtropical Storm Ernesto Forms West of the Azores

Subtropical Storm Ernesto formed west of the Azores on Wednesday morning.  At 11:00 a.m. EDT on Wednesday the center of Subtropical Storm Ernesto was located at latitude 38.1°N and longitude 46.0°W which put it about 695 miles (1120 km) southeast of Cape Race, Newfoundland.  Ernesto was moving toward the north 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 1008 mb.

More thunderstorms formed closer to the center of a low pressure system west of the Azores on Wednesday morning and the National Hurricane Center designated the system as Subtropical Storm Ernesto.  Several bands of showers and thunderstorms wrapped around the eastern and northern portions of the circulation.  Bands northwest of the center of Ernesto consisted primarily of showers and lower clouds.  The circulation may have been transporting some cooler, drier, more stable air into that part of the circulation.  Showers and thunderstorms around the center of Ernesto were generating upper level divergence which was pumping mass away to the northeast of the subtropical storm.

Subtropical Storm Ernesto will move through an environment that could support some intensification during the next day or so.  Ernesto will move over water where the Sea Surface Temperature is near 26°C.  It will move through a region where the upper level winds are not too strong and there will not be much vertical wind shear.  Subtropical Storm Ernesto could strengthen during the next 12 to 24 hours.  Ernesto will move over cooler water later on Thursday and it will start to weaken.  An upper level trough east of the U.S. will approach Subtropical Storm Ernesto from the west.  Southwesterly winds ahead of the trough will cause more vertical wind shear and Ernesto could make a transition to an extratropical cyclone.

The southwesterly winds ahead of the upper level trough will steer Subtropical Storm Ernesto in a general northeasterly direction.  On its anticipated track Subtropical Ernesto will pass between the Azores and Greenland.

Tropical Storm Leepi Approaches Kyushu

Tropical Storm Leepi approached Kyushu late on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Leepi was located at latitude 29.8°N and longitude 135.3°E which put it about 335 miles (545 km) east-southeast of Kagoshima, Japan.  Leepi was moving toward the northwest at 17 m.p.h. (28 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 circulation of Tropical Storm Leepi became much better organized on Monday.  A large circular clear area formed at the center of circulation, which represented the formation of an eye.  A primary band of showers and thunderstorms wrapped most of the way around the formative eye and the strongest winds were occurring in that band of storms.  Several bands of showers and thunderstorms in the eastern half of the circulation were revolving around the core of Tropical Storm Leepi.  Bands northwest of the center consisted mostly of showers and lower clouds.  Winds to tropical storm force extend out about 110 miles (170 km) from the center of circulation.  Storms around the center of Tropical Storm Leepi were generating upper level divergence that was pumping mass away from the tropical storm.

Tropical Storm Leepi will move through an environment that will become less favorable on Tuesday.  Leepi will move over water where the Sea Surface Temperature is near 28°C which means there will be enough energy to support a strong tropical storm.  However, an upper level ridge northwest of Japan will produce northeasterly winds which will cause significant vertical wind shear.  The wind shear will cause Tropical Storm Leepi to start to weaken when it nears Japan.

The ridge northwest of Japan will steer Tropical Storm Leepi toward the northwest on Tuesday.  On its anticipated track the center of Tropical Storm Leepi will reach southeastern Kyushu in about 18 hours.  Leepi will bring gusty winds and locally heavy rain to Kyushu late on Tuesday.  The locally heavy rain could create the potential for flash floods.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Bebinca meandered southwest of Hong Kong and Tropical Storm Hector move westward across the International Date Line.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Bebinca was located at latitude 21.1°N and longitude 113.8°E which put it about 100 miles (160 km) south-southwest of Hong Kong.  Bebinca was moving toward the north-northeast at 5 m.p.h. (8 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. (95km/h).  The minimum surface pressure was 989 mb.

At 11:00 p.m. EDT on Monday the center of Tropical Storm Hector was located at latitude 26.2°N and longitude 176.2°E which put it about 760 miles (1225 km) east-northeast of Wake Island.  Hector was moving toward the west at 18 m.p.h. (29 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 1003 mb.