Tag Archives: Japan

Tropical Storm Meranti Forms West of Guam

A center of circulation developed within an area of thunderstorms west of Guam on Saturday and the system was designated as Tropical Storm Meranti.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Meranti was located at latitude 16.0°N and longitude 135.8°E which put it about 1070 miles (1725 km) east-southeast of Taiwan.  Meranti was moving toward the west at 13 m.p.h. (20 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 991 mb.

The circulation of Tropical Storm Meranti is still organizing and the distribution of thunderstorms is asymmetrical.  Most of the thunderstorms are occurring east of the center of circulation.  There is a cluster of the thunderstorms just to the east of the center.  There are also two well formed rainbands east of the core of Tropical Storm Meranti.  Additional spiral bands are located in all parts of the tropical storm.  The thunderstorms near the center are generating upper level divergence which is pumping out mass in all directions.

Tropical Storm Meranti is moving through an environment which is favorable for further intensification.  It is moving over water where the Sea Surface Temperature is near 31°C.  An upper level ridge located to the northwest of Meranti is producing northeasterly winds which are blowing across the western portion of the tropical storm.  The upper level winds are weaker over the eastern half of the circulation and the vertical wind shear is only slowing the intensification.  Although there may be some drier air in the western half of the circulation, Tropical Storm Meranti could intensify into a typhoon on Sunday.  Meranti could become a strong typhoon in two or three days.

A subtropical ridge north of Tropical Storm Meranti is steering it toward the west.  The subtropical ridge is forecast to steer Meranti in a general west-northwesterly direction during the next two or three days.  On its anticipated track Tropical Storm Meranti is expected to approach the area of northern Luzon, Taiwan and the southern Ryukyu Islands in about three days.  It could be a strong typhoon at that time.

Tropical Storm Namtheun Bringing Wind and Rain to Southwest Kyushu

Tropical Storm Namtheun brought wind and rain to southwestern Kyushu on Saturday as the center moved just west of the coast.  At 8:00 p.m. EDT on Saturday the center of Tropical Storm Namtheun was located at latitude 31.4°N and longitude 129.6°E which put it about 85 miles (135 km) south of Nagasaki, Japan.  Namtheun was moving toward the north-northwest 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 985 mb.

Tropical Storm Namtheun has a small, but well organized circulation.  There is the remnant of the eye that existed when Namtheun was a typhoon.  A broken ring of thunderstorms surrounds the remnant eye.  Several spiral rainbands are rotating around just outside the small core of Namtheun.  Winds to tropical storm force extend out about 60 miles (95 km) from the center of circulation.

Tropical Storm Namtheun is moving through an environment that is marginally favorable for a tropical storm.  It is moving over water where the Sea Surface Temperature (SST) is near 29°C.  A large upper level trough is producing southerly winds which are blowing across the top of Tropical Storm Namtheun.  Those winds are generating moderate vertical wind shear and they are inhibiting the upper level divergence to the south of the tropical storm.  The marginally favorable environment could allow Tropical Storm Namtheun to maintain its intensity for another 12 to 24 hours.  After that time it will move over cooler SSTs and start to weaken faster.

The upper level trough is steering Tropical Storm Namtheun toward the north and that general motion is expected to continue for another 12 hours or so.  After that time, southwesterly winds are expected to turn Tropical Storm Namtheun more toward the northeast.  On its anticipated track Tropical Storm Namtheun will move close to Nagasaki, Fukuoka, Kitakyushu and the southwestern portion of Honshu.

Tropical Storm Namtheun’s small size should keep the wind damage minimal.  It could cause locally heavy rainfall and the potential for flooding, but the areal extent of any floods should be limited.

Typhoon Namtheun Heads for Southern Japan

Typhoon Namtheun spun up quickly on Thursday and moved steadily toward Kyushu in southern Japan.  At 11:00 p.m. EDT on Thursday the center of Typhoon Namtheun was located at latitude 26.6°N and longitude 130.8°E which put it about 335 miles (540 km) south of Kagoshima, Japan.  Namtheun was moving toward the north at 7 m.p.h. (11 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 975 mb.

Typhoon Namtheun developed quickly from a low pressure system along a surface trough.  Namtheun has a small but very well organized circulation.  It has a tiny pinhole eye surrounded by a ring of strong thunderstorms.  Several other rainbands are spiraling around the ring of strong thunderstorms.  The thunderstorms are generating upper level divergence which is pumping out mass in all directions.  The upper level divergence is slightly less to the west of the center of circulation.

Typhoon Namtheun is in an environment favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  Although there is a large upper level trough over eastern Asia which contains strong southwesterly winds, Typhoon Namtheun developed east of those strong winds.  It is in an area where the upper level winds are weaker and there is little vertical wind shear.  Namtheun is likely to intensify more during the next day or two.  However, Namtheun’s small circulation means that it will respond very rapidly to positive or negative changes in its surrounding environment.

A ridge to the east of Namtheun is steering the typhoon toward the north and that general motion is expected to continue for several more days.  On its anticipated track Typhoon Namtheun could be very near the southern tip of Kyushu within 48 hours.  It could bring strong winds and heavy rain to parts of southern Japan.

Typhoon Lionrock Nearing Landfall in Japan

An upper level low is pulling Typhoon Lionrock toward a landfall in northern Japan.  At 8:00 p.m. EDT on Monday the center of Typhoon Lionrock was located at latitude 36.1°N and longitude 142.5°E which put it about 150 miles (240 km) south-southeast of Sendai, Japan.  Lionrock was moving toward the north-northwest 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 965 mb.

An upper level low west of Japan was pulling Typhoon Lionrock back toward the west-northwest.  At its current track and speed Typhoon Lionrock would make landfall on the northeastern coast of Honshu near Sendai in about six hours.

The structure of Typhoon Lionrock is changing as a result of cooler Sea Surface Temperatures and more vertical wind shear.  Lionrock is making a transition of a tropical cyclone to an extratropical cyclone.  The circulation is becoming more elongated and the typhoon is pulling cooler drier air into the western half of the circulation.  The wind field will tend to expand as the typhoon becomes extratropical.

Typhoon Lionrock will be capable of producing minor wind damage along its path.  It could also cause locally heavy rainfall and flash floods over northern Honshu.  It will pass over some of the same areas recently affected by Typhoon Mindulle.

Large Typhoon Lionrock Moves Closer to Japan

Large Typhoon Lionrock moved closer to Japan on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Lionrock was located at latitude 31.1°N and longitude 142.1°W which put it about 385 miles (620 km) south-southeast of Tokyo, Japan.  Lionrock was moving toward the northeast at 19 m.p.h. (31 km/h).  The maximum sustained wind speed was 110 m.p.h. (180 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 952 mb.

Typhoon Lionrock retains a large symmetrical circulation.  Winds to typhoon force extend out about 40 miles (65 km) from the center.  Microwave satellite images suggest that there could be two eyewalls.  The inner eyewall is weaker on the western side and the larger outer eyewall has fewer thunderstorms on the northwestern side.  Other spiral bands are rotating around outside the outer eyewall.  Thunderstorms near the core of the circulation are generating upper level divergence which is pumping out mass primarily to the east of the typhoon.

The environment around Typhoon Lionrock would be marginally favorable for intensification.  Lionrock is moving over water where the Sea Surface Temperature (SSTs) is near 28°C.  An upper level trough west of Lionrock is generating southwesterly winds which are affecting the upper level divergence on the western side of the typhoon.  However, the vertical wind shear is not too significant.  On the other hand, concentric eyewalls often produce weakening as the inner eye wall dissipates and the stronger winds occur in the outer eyewall.  So, Lionrock could maintain a steady intensity or weaken slowly during the next 24 hours.  After that time is will move over cooler SSTs and it could weaken more.

The upper level trough is steering Typhoon Lionrock toward the northeast and that general motion is expect to continue for another 24 hours.  After that time, the upper trough will turn Lionrock back toward the northwest.  On its anticipated track Typhoon Lionrock will make landfall on northeast Honshu north of Tokyo in about 36 hours.  It could cause some wind damage.  Heavy rainfall and flash floods will also pose serious risks since Lionrock will move over some of the same areas affected by Typhoon Mindulle.

Typhoon Lionrock Turns in the Direction of Japan

After meandering southeast of Okinawa for several days Typhoon Lionrock started moving northeast toward Japan on Friday.  At 5:00 p.m. EDT on Friday the center of Typhoon Lionrock was located at latitude 23.7°N and longitude 133.0°E which put it about 920 miles (1485 km) south-southwest of Tokyo, Japan.  Lionrockk was moving toward the northeast at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 953 mb.

Typhoon Lionrock is very well organized.  It has a circular eye surrounded by a ring of strong thunderstorms.  Additional well formed spiral bands are rotating around outside the core of Lionrock.  Thunderstorms in the eyewall and spiral bands are generating upper level divergence which are pumping out mass in all directions.  The upper level divergence is inhibited a little on the far northern edge of the circulation by northerly winds impinging on Typhoon Lionrock.  Even so, there is enough upper level divergence to compensate for the strong inflow of mass near the surface and Typhoon Lionrock has been in a nearly steady state during recent hours.

Typhoon Lionrock is moving through an environment that should allow for it to maintain its intensity during the next severall days.  It is moving over water where the Sea Surface Temperature (SST) is near 30°C.  An upper level high over China is generating northerly winds which are effecting the extreme northern edge of the outflow from Lionrock.  However, the vertical wind shear is not very strong and it should have a minimal effect on the intensity of the typhoon in the short term.  Eventually, Typhoon Lionrock will move over cooler SSTs and into a region where the upper level winds are stronger and it will start to weaken before it reaches Japan.

Typhoon Lionrock is moving around the western end of a subtropical ridge and that ridge is beginning to steer it toward the northeast.  That general motion is expected to continue for the next several days.  Eventually Lionrock is forecast to turn more toward the northwest.  On its anticipated track Typhoon Lionrock could approach the eastern coast of Honshu in three or four days.  Lionrock could still be a typhoon at that time.

If Lionrock makes landfall in Honshu as a typhoon it will be strong enough to cause some wind damage.  In addition, Typhoon Lionrock could move over some of the same areas affected by Typhoon Mindulle.  Heavy rain caused by Lionrock could create the potential for additional flash flooding and mudslides.

Lionrock Becomes a Typhoon East of Okinawa

Tropical Storm Lionrock intensified into a typhoon east of Okinawa on Tuesday.  At 8:00 p.m. EDT on Tuesday the center of Typhoon Lionrock was located at latitude 25.3°N and longitude 132.8°E which put it about 340 miles (550 km) east-southeast of Okinawa.  Lionrock was moving toward the south-southwest at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 965 mb.

Lionrock is a fairly small typhoon.  Winds to tropical storm force only extend out about 150 miles (240 km) from the center.  The circulation of Typhoon Lionrock is very well organized.  A small distinct eye is visible on satellite imagery.  The eye is surrounded by a ring of strong thunderstorms.  Additional spiral rainbands are rotating around the core of Lionrock.  The thunderstorms around the eye are generating upper level divergence which is pumping out mass in all directions.

Typhoon Lionrock is in an environment that is favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30.5°C.  The upper level winds are weak and there is little vertical wind shear.  A small typhoon like Lionrock can intensify very quickly and it appears to be doing so.

An upper level ridge over China is steering Typhoon Lionrock slowly toward the south-southwest and that general motion is expected to continue for another day or two.  Lionrock could move into an area where the steering winds are weak and it could stall for a period of time.  Eventually, an upper level trough is expected to approach the area from the west and begin to pull Lionrock toward the north.

Typhoon Mindulle Nearing Japan

Typhoon Mindulle moved steadily toward the coast of Japan on Sunday.  At 2:00 p.m. EDT on Sunday the center of Typhoon Mindulle was located at latitude 32.9°N and longitude 139.4°E which put it about 185 miles (305 km) south of Tokyo, Japan.  Mindulle was moving toward the north at 19 m.p.h. (31 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 975 mb.

The circulation of Typhoon is reasonably well organized.  A primary rainband wraps most of the way around the northern and eastern sides of the center of circulation.  There is evidence of a partial eyewall north of the center.  Additional bands of thunderstorms are occurring in the northern half of the circulation.  The thunderstorms near the core of Mindulle are generating upper level divergence which is pumping away mass to the east of the typhoon.  However, there are fewer thunderstorms west of the center of circulation which may indicate the presence of dry air in that area.

Typhoon Mindulle is moving through an environment that is only marginal for further intensification.  It is currently moving over water where the Sea Surface Temperature is near 29°C, but Mindulle will move over cooler water when it approaches the coast of Japan.  An upper level trough located to the west of Japan is generating southwesterly winds which are blowing across the top of Mindulle.  The moderate vertical wind shear is preventing upper level divergence to the west of the typhoon and the shear may also be partially responsible for the asymmetric distribution of thunderstorms.  It is also possible that Mindulle is pulling in some drier air located northwest of the typhoon.

The upper level trough is steering Mindulle toward the north and that general motion is expected to continue.  On its anticipated track the center of Typhoon Mindulle will reach the coast near Tokyo in 10-12 hours.  Heavy rain in some of the bands of thunderstorms north of the center could reach the coast at any time.  Since Mindulle is a typhoon, it is capable of causing minor wind damage.  A greater risk is the potential for locally heavy rainfall and flash flooding.

Tropical Storms Lionrock and Kompasu Spin Up Near Japan

A large cyclonic atmospheric gyre near Japan spun up two more tropical storms at the end of the week.  The Japan Meteorological Agency named two smaller circulations within the larger gyre Tropical Storm Lionrock and Tropical Storm Kompasu.

At 2:00 p.m. EDT on Saturday the center of Tropical Storm Kompasu was located at latitude 37.8°N and longitude 142.3°E which put it about 75 miles (120 km) east of Sendai, Japan.  Kompasu was moving toward the northwest at 26 m.p.h. (42 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 996 mb.

At 2:00 p.m. EDT on Saturday the center of Tropical Storm Lionrock was located at latitude 30.6°N and longitude 135.7°E which put it about 530 miles (860 km) east-northeast of Okinawa.  Lionrock was moving toward the west-southwest 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 994 mb.

Tropical Storm Kompasu is located farther north and it is beginning to make a transition into an extratropical cyclone.  Kompasu is moving over water where the Sea Surface Temperature (SST) is near 26°C, but it is moving rapidly toward cooler SSTs.  Most of the thunderstorms are in a single primary rainband that wraps around the southern part of the circulation.  An upper level trough west of Japan is pulling southwesterly winds across the top of Tropical Storm Kompasu and the vertical wind shear is increasing.

The upper level trough is expected to turn Tropical Storm Kompasu toward the northeast.  On its anticipated track Tropical Storm Kompasu will move across Hokkaido in about 18 hours.  It will bring locally heavy rain and some wind.

Tropical Storm Lionrock is more well organized.  Several spiral bands of thunderstorms are wrapping around the southern and east sides of the center of circulation.  There is drier air in the western portion of the circulation and there are few thunderstorms in that part of Lionrock.  The thunderstorms east of the center are generating upper level divergence that is pumping mass toward the northeast away from core of Tropical Storm Lionrock.

Tropical Storm Lionrock is in an environment that is somewhat favorable for additional intensification.  It is moving over water where the SST is near 30°C.  The upper level trough west of Japan is generating some vertical wind shear.  The drier air in the western part of the circulation will also inhibit intensification, but Lionrock could gradually get better organized.  Upper level outflow from stronger Tropical Storm Mindulle, which is southwest of Lionrock, could produce enough vertical wind shear to weaken Lionrock at times.

The large atmospheric gyre is steering Tropical Storm Lionrock toward the west-southwest.  Lionrock could be pulled more toward the south as the larger, stronger Tropical Storm Mindulle passes east of it.  Tropical Storm Lionrock is expected to remain south of Japan during the next several days.  An alternative scenario would be for Tropical Storm Mindulle to intensify into a typhoon and grow large enough to absorb the circulation of Lionrock.

Tropical Storm Mindulle Forms Northwest of Guam

A smaller center of circulation consolidated within a much larger cyclonic gyre that extends from the Marianas north to Japan and west to China and the system has been designated Tropical Storm Mindulle.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Mindulle was located at latitude 19.5°N and longitude 141.0°E which put it about 410 miles (655 km) south of Iwo To.  Mindule was moving toward the north-northwest at 11 m.p.h.  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 992 mb.

The circulation around Tropical Storm Mindulle is still organizing.  A primary rainband is wrapping about three quarters of the way around the broad center of circulation.  There are few thunderstorms close to the core of tropical storm.  Scattered thunderstorms are forming in broken bands outside the primary rainband.  The thunderstorms in the primary rainband are generating some upper level divergence which is mainly pumping mass to the southwest of the center of circulation.

Tropical Storm Mindulle is in an environment that is favorable for slow intensification.  It is moving over water where the Sea Surface Temperature is near 31°C.  The upper level pattern near Mindulle is quite complex with a number of different features.  A narrow upper level ridge is just north of Mindulle and it is producing northeasterly winds that are blowing across the top of the tropical storm.  The northeasterly winds are contributing to the fact that most of the thunderstorms are west of the center of circulation and they are causing moderate vertical wind shear.  The vertical wind shear is inhibiting intensification.  Tropical Storm Mindulle is expected to extract enough energy from the ocean to intensify.  However, intensification will be slow while the core of the circulation organizes.

Tropical Storm Mindule is moving around the eastern portion of the large cyclonic gyre mentioned above.  That gyre is steering Mindulle toward the north-northwest and a general motion toward the north is expected to continue.  On its anticipated track Tropical Storm Mindulle could pass near Iwo To in about 24 hours.  Mindulle could be near Tokyo, Japan in about three days.