Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Tropical Storm Kirogi Forms West of the Philippines

Tropical Storm Kirogi formed west of the Philippines on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Storm Kirogi was located at latitude 10.9°N and longitude 115.7°E which put it about 465 miles (745 km) east of Nha Trang, Vietnam.  Kirogi was moving toward the west-northwest at 18 m.p.h. (30 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1000 mb.

A low level center of circulation developed near the eastern edge of an area of showers and thunderstorms west of the Philippines on Friday and the Japan Meteorological Agency designated the system as Tropical Storm Kirogi.  The distribution of showers and thunderstorms in Kirogi was asymmetrical.  A primary rainband wrapped around the western side of the center of circulations and most of the stronger storms were west of the center.  There were only bands of low clouds and showers east of the center of Kirogi.  An upper level ridge north of Kirogi was producing easterly winds which were blowing across the top of the tropical storm.  The vertical wind shear created by those winds was causing the asymmetrical distribution of showers and thunderstorms.

Tropical Storm Kirogi will move through an environment that will be somewhat favorable for intensification.  Kirogi 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 shear may be strong enough to slow intensification, but it may not strong enough to prevent Tropical Storm Kirogi from strengthening.  The forecast is for Tropical Storm Kirogi to intensify during the next 24 to 36 hours.

The ridge is steering Tropical Storm Kirogi toward the west-northwest and a general westerly motion is expected to continue.  On its anticipated track Tropical Storm Kirogi will move across the South China Sea toward Vietnam.  Kirogi could reach the coast of Vietnam near Nha Trang in about 36 hours.  Kirogi will bring gusty winds and locally heavy rain when it reaches the coast.  The locally heavy rain could cause flash floods.  There could also be a storm surge of 3 to 6 feet (1 to 2 meters) where the wind blows water toward the coast of Vietnam.

Remnants of Tropical Storm Haikui Make Landfall in Vietnam

The remnants of Tropical Storm Haikui made landfall near Da Nang, Vietnam late on Monday.  At 10:00 p.m. EDT on Monday the center of Tropical Depression Haikui were located at latitude 17.0°N and longitude 108.2°E which put it about 20 miles (30 km/h) north of Da Nang, Vietnam.  Haikui was moving toward the west at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 25 m.p.h. (40 km/h) and there were wind gusts to 35 m.p.h. (55 km/h).  The minimum surface pressure was 1003 mb.

The remnants of Tropical Storm Haikui consists of primarily of a low level counterclockwise circulation.  There are several thin bands of low clouds and showers.  Stronger thunderstorms were forming near the core of the circulation.  It appeared that winds blowing toward the coast were converging due to increased friction caused by the land.  The convergence was causing stronger rising motion which was contributing to the development of strong thunderstorms near and to the west of the center of circulation.

The remnants of Tropical Storm Haikui will move inland before significant intensification can occur.  The remnants of Haikui could drop locally heavy rainfall over portions of Vietnam, southern Laos and northeastern Thailand.  Locally heavy rainfall could cause flooding in some places.

Tropical Storm Haikui Weakens Southeast of Hainan Island

Tropical Storm Haikui weakened as it moved southeast of Hainan Island on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Storm Haikui was located at latitude 17.6°N and longitude 112.6°E which put it about 290 miles (470 km) east of Da Nang, Vietnam.  Haikui was moving toward the west-southwest at 6 m.p.h. (10 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.

A combination of drier air and strong vertical wind shear weakened Tropical Storm Haikui on Saturday.  Strong northeasterly winds transported colder drier air from eastern Asia into the circulation of Tropical Storm Haikui.  The drier air reached the core of the circulation and it prevented the formation of new thunderstorms around the center of circulation.  Strong westerly winds in the upper levels were blowing over the top of the circulation.  The combination of northeasterly winds in the lower levels and westerly winds in the upper levels produced strong vertical wind shear.  The wind shear blew the upper portion of the circulation to the east of the low level core of Tropical Storm Haikui.  The core of Tropical Storm Haikui consists of a circular rotation of showers and low clouds.  The only thunderstorms are occurring in a rainband on the northeastern periphery of the circulation.

The strong wind vertical wind shear and drier air should continue to weaken Tropical Storm Haikui.  Haikui is likely to weaken to a tropical depression on Sunday.  Since the circulation exists primarily in the lower levels, it will be steered by the winds closer to the surface of the Earth.  The northeasterly winds in the lower levels will steer Tropical Storm Haikui toward the west- southwest.  On its anticipated track Tropical Storm Haikui will pass south of Hainan Island.  Haikui or its remnants could reach the coast of Vietnam in 36 to 48 hours.

Tropical Storm Haikui Moves Across South China Sea

Tropical Storm Haikui moved across the South China Sea on Friday.  At 10:00 p.m. EST on Friday the center of Tropical Storm Haikui was located at latitude 17.8°N and longitude 115.4°E which put it about 485 miles (785 km) east of Da Nang, Vietnam.  Haikui was moving toward the west-northwest at 8 m.p.h. (13 km/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 994 mb.

Tropical Storm Haikui strengthened slightly on Friday, but the circulation remained asymmetrical.  Most of the stronger thunderstorms were occurring east of the center of circulation.  A short primary rainband wrapped around the eastern side of the center.  Several other broken bands of showers and thunderstorms formed to the east of the primary rainband.  Bands of showers and storms were also located south of the center of circulation.  Storms near the core of Tropical Storm Haikui were generating some upper level divergence which was pumping mass away to the east of the tropical storm.  The bands in the western half of the circulation consisted primarily of low clouds and showers.

Tropical Storm Haikui will move through an environment marginally favorable for intensification during the next 24 to 36 hours.  Haikui will move over water where the Sea Surface Temperature is near 29°C.  Colder, drier air over eastern Asia was flowing toward the western side of Tropical Storm Haikui.  The upper level westerly winds of the middle latitudes were blowing just to the northwest of Tropical Storm Haikui.  Those winds were causing moderate vertical shear over the northwestern periphery of Haikui.  The winds over the core of Tropical Storm Haikui were weaker.  If Tropical Storm Haikui remains south of the stronger westerly winds, it could intensify a little more during the next 24 hours.

A ridge to the north of Haikui is steering the tropical storm toward the west-northwest.  The ridge is forecast to strengthen and Tropical Storm Haikui is likely to move more toward the west during the next several days.  On its anticipated track Tropical Storm Haikui will pass south of Hainan Island in about 48 hours.  Tropical Storm Haikui could reach the coast of Vietnam in less than three days.

Tropical Storm Haikui Develops Over the Philippines

Tropical Storm Haikui developed over the Philippines on Thursday.  At 4:00 p.m. EST on Thursday the center of Tropical Storm Haikui was located at latitude 14.6°N and longitude 119.8°E which put it about 50 miles (80 km) west-southwest of Manila, Philippines.  Haikui was moving toward the west-northwest at 13 m.p.h. (21 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).  Thee minimum surface pressure was 998 mb.

A center of circulation developed within an area of showers and thunderstorms over the Philippines and the Japan Meteorological Agency designated the system as Tropical Storm Haikui.  The circulation of Tropical Storm Haikui is still organizing.  Several areas of showers and thunderstorms are east and south of the center of circulation.  Broken bands of showers and storms are beginning to form farther away from the center.  There are fewer showers and thunderstorms in the western half of the circulation.

Tropical Storm Haikui will be moving through an environment that is somewhat favorable for intensification.  Haikui will move over water where the Sea Surface Temperature is near 29°C.  An upper level ridge centered northeast of the Philippines is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing moderate vertical wind shear.  Tropical Storm Haikui will move toward the western end of the ridge and the winds will blow from the southwest at that point.  So, the direction of the wind shear will change.  If Haikui stays far enough south, it will pass south of the stronger upper level winds and the tropical storm could intensify.

The ridge northeast of the Philippines is steering Tropical Storm Haikui toward the west-northwest and that general motion is expected to continue for several more days.  On its anticipated track Tropical Storm Haikui will move away from the Philippines across the South China Sea.  Haikui could approach Hainan Island in a few days.

Typhoon Damrey Makes Landfall in Vietnam

Typhoon Damrey made landfall in Vietnam late on Friday.  At 5:00 p.m. EDT on Friday the center of Typhoon Damrey was located at latitude 12.9°N and longitude 109.7°E which put it about 100 miles (160 km) east-northeast of Nha Trang, Vietnam.  Damrey was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/hr) and there were wind gusts to 125 m.p.h. (205 km/h).  The minimum surface pressure was 960 mb.

Typhoon Damrey strengthened until it made landfall on the coast of Vietnam.  A small eye formed at the center of circulation.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring that ring.  Multiple bands of showers and thunderstorms were revolving around the core of Typhoon Damrey.  Winds to typhoon force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center.

A ridge north of Damrey steered the typhoon steadily westward across the South China Sea.  The center of Typhoon Damrey made landfall on the coast of Vietnam north of Nha Trang.  The ridge is forecast to continue to steer Damrey toward the west.  Typhoon Damrey will move across southern Vietnam, southern Laos, Cambodia and Thailand during the next several days.

Typhoon Damrey brought strong winds and heavy rain to the coast of Vietnam.  Damrey was capable of causing serious wind damage.  Typhoon Damrey was also capable of generating a storm surge of 9 to 12 feet (3 to 4 meters) where the winds blew the water toward the coast.  Damrey will weaken as it moves inland over Southeast Asia, but it will drop locally heavy rain.  The locally heavy rain could produce serious floods in parts of Vietnam, Laos, Cambodia and Thailand.

Typhoon Damrey Strengthens As It Approaches Vietnam

Typhoon Damrey strengthened as it approached Vietnam on Thursday.  At 11:00 p.m. EDT on Thursday the center of Typhoon Damrey was located at latitude 12.6°N and longitude 113.1°E which put it about 185 miles (300 km) east-northeast of Nha Trang, Vietnam.  Damrey was moving toward the west at 10 m.p.h. (16 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 Tropical Storm Damrey became much more well organized on Thursday and it strengthened in a typhoon.  A small circular eye developed at the center of Typhoon Damrey.  A broken ring of thunderstorms surrounded the eye.  Numerous bands of showers and thunderstorms were revolving around the core of the symmetrical circulation of Typhoon Damrey.  The storms generated well developed upper level divergence which pumped mass away from the typhoon and allowed the surface pressure to decrease.

Typhoon Damrey will move through an environment favorable for intensification for about another 18 hours.  Damrey will move over water where the Sea Surface Temperature is near 28°C.  An upper level ridge to the north of Damrey is producing easterly winds which are blowing toward the top of the circulation.  However, there are also easterly winds in the lower and middle of the troposphere.  So, there is not a lot of vertical wind shear.  Typhoon Damrey will continue to intensify on Friday and there could be a period of more rapid intensification.  Typhoon Damrey will begin to weaken after the center makes landfall in Vietnam.

The ridge to the north of Damrey is steering the typhoon toward the west and that general motion is expected to continue for several more days.  On its anticipated track the center of Typhoon Damrey will reach the coast of Vietnam in 18 to 24 hours.  The center could make landfall between Cam Ranh and Quy Nhon.

Typhoon Damrey will bring strong winds to southern Vietnam.  Damrey cold produce a storm surface of 6 to 12 feet (2 to 4 meters) near where the center makes landfall on the coast.  Typhoon Damrey will also drop very heavy rain over parts of southern Vietnam, southern Laos, Cambodia and Thailand.  The heavy rain could cause flooding in those areas.

Tropical Storm Damrey Forms West of the Philippines

Tropical Storm Damrey formed west of the Philippines on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Damrey was located at latitude 12.8°N and longitude 116.4°E which put it about 615 miles (990 km) east-southeast of Da Nang, Vietnam.  Damrey was moving toward the west-northwest at 13 m.p.h. (21 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.

An area of low pressure slowly organized as it moved through the Philippines during the past several days.  A center of circulation developed and bands of showers and thunderstorms formed and started to revolve around the core of the low pressure system.  The Japan Meteorological Agency designated the system as Tropical Storm Damrey.

The circulation of Tropical Storm Damrey is still organizing.  More thunderstorms formed near the center of circulation.  A primary rainband wrapped around the western and southern sides of the center.  Additional bands of showers and thunderstorms formed outside the core of the circulation.  Storms in the core of Damrey began to generate upper level divergence which pumped mass away from the tropical storm and allowed the surface pressure to decrease.

Tropical Storm Damrey will be moving through an environment that will be favorable for intensification.  Damrey will move over water where the Sea Surface Temperature will be near 28°C.  An upper level ridge north of Tropical Storm Damrey is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing some vertical wind shear, but the shear is not strong enough to prevent intensification.  Tropical Storm Damrey will continue to intensify and it could become a typhoon in 24 to 36 hours.

The upper level ridge north of Damrey is steering the tropical storm toward the west-northwest and a general westerly motion is forecast.  On its anticipated track Tropical Storm Damrey will move toward Vietnam.  Damrey could approach the coast of Vietnam in less than 48 hours.  Damrey could be a typhoon when it gets to Vietnam.

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.