Tag Archives: Indonesia

Typhoon Tembin Nears Southern Vietnam

Typhoon Tembin moved nearer to southern Vietnam on Sunday.  At 10:00 p.m. EST on Sunday the center of Typhoon Tembin was located at latitude 8.0°N and longitude 109.3°E which put it about 290 miles (470 km) southeast of Ho Chi Minh City, Vietnam.  Tembin was moving toward the west at 13 m.p.h. (21 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.

Typhoon Tembin weakened during the past 12 hours as it moved over the South China Sea.  An upper level ridge north of Tembin generated stronger easterly winds on Sunday which increased the vertical wind shear.  The strong upper level winds weakened the rainbands in the eastern half of the circulation of Typhoon Tembin.  Those winds also tilted the upper portion of the circulation toward the west.  The low level circulation of Typhoon Tembin remained well organized, but the storms around the center weakened.  The strongest thunderstorms were occurring in bands west of the core of Tembin.  Winds to typhoon force extended out about 40 miles (65 km) from the center in the northern half of the circulation and about 25 miles (40 km) in the southern half.  Winds to tropical storm force extended out about 155 miles (250 km) from the center.

Typhoon Tembin is likely to continue to weaken on Monday.  Typhoon Tembin will move over water where the Sea Surface Temperature is near 29°C.  However, the upper level ridge is likely to continue to generate strong easterly winds and the significant vertical wind shear will make it difficult for tall thunderstorms to develop around much of the circulation.  The wind shear will probably weaken Tembin to a tropical storm on Monday.

The ridge north of Tembin is steering the typhoon toward the west and a general westerly motion is expected to continue for several more days.  On its anticipated track the center of Typhoon Tembin will pass near the southern tip of Vietnam in about 24 hours.  Tembin will likely move into the Gulf of Thailand as a tropical storm or tropical depression.

The heavy rain with Typhoon Tembin is occurring in bands west of the core of the typhoon.  So, the heavy rain will begin to fall before the center of circulation reaches places.  The heaviest rain will fall over the Mouths of the Mekong River and the part of Vietnam south of that area.  The rain could be heavy enough to cause floods in some locations.  Gusty winds could produce isolated damage as well in the southern part of Vietnam.

Tembin Strengthens to a Typhoon Over South China Sea

Tropical Storm Tembin strengthened into a typhoon on Saturday as it moved over the South China Sea.  At 10:00 p.m. EST on Saturday the center of Typhoon Tembin was located at latitude 8.2°N and longitude 113.6°E which put it about 540 miles (880 km) east of Ho Chi Minh City, Vietnam.  Tembin was moving toward the west at 18 m.p.h. (29 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. (170 km/h).  The minimum surface pressure was 976 mb.

Typhoon Tembin became much better organized on Saturday.  A primary rainband wrapped around the center of circulation and an eye became apparent on microwave satellite imagery.  Several other rainbands strengthened outside the core of Typhoon Tembin.  Storms near the core of the circulation generated strong upper level divergence which pumped mass away to the west and northeast of the typhoon.  The removal of mass allowed the surface pressure to decrease and the wind speed to increase.  Winds to typhoon force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 155 miles (250 km) from the center.

Typhoon Tembin will move through an environment favorable for intensification during the next 24 hours.  Tembin will move over water where the Sea Surface Temperature is near 29°C.  An upper level ridge north of Tempin is producing easterly winds which are blowing toward the typhoon.  However, the easterly winds are blowing at most levels of the atmosphere and there is not a lot of vertical wind shear.  Typhoon Tembin is likely to continue to intensify on Sunday.

The subtropical ridge north of Tembin is steering the typhoon quickly toward the west.  A general motion toward the west is expected to continue.  On its anticipated track Typhoon Tembin could approach the southern part of Vietnam in about 36 hours.  Tembin has the potential to bring strong winds, heavy rain and a storm surge to the southern coast of Vietnam.

Tropical Storm Tembin Strengthens Over the Sulu Sea

Tropical Storm Tembin moved west of Mindanao and it strengthened over the Sulu Sea on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Storm Tembin was located at latitude 8.0°N and longitude 120.8°E which put it about 200 miles (320 km) southeast of Puerto Princesa, Philippines.  Tembin was moving toward the west at 8 m.p.h. (13 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 992 mb.

Tropical Storm Tembin weakened when the center moved across Mindanao.  The center is back over water in the Sulu Sea and the circulation of Tembin is strengthening again.  There is a distinct low level center of circulation, but the distribution of thunderstorms is asymmetrical.  Most of the strong thunderstorms are occurring in bands in the western half of the circulation.  Bands in the eastern half of the circulation consist primarily of low clouds and showers.  The storms west of the center are generating upper level divergence which is pumping mass away to the west of the tropical storm.  The removal of mass has caused the surface pressure to decrease and the wind speeds have started to increase.

Tropical Storm Tembin will be moving through an environment that is favorable for intensification.  Tembin will move over water where the Sea Surface Temperature is near 29°C.  An upper level ridge north of Tropical Storm Tembin is producing easterly winds which are blowing toward the top of the circulation.   Those winds are causing vertical wind shear, which is probably the reason for the asymmetrical distribution of thunderstorms.  However, the shear is not strong enough to prevent Tropical Storm Tembin from intensifying.  Tembin could strengthen into a typhoon during the next day or two while is moves over the South China Sea.

The subtropical ridge north of Tembin is steering the tropical storm toward the west.  A general motion toward the west-northwest west is forecast for the next two or three days.  On its anticipated track Tropical Storm Tembin will move across Palawan in about 18 hours.  Tembin could reach the southern coast of Vietnam in about three days.  Tembin will bring gusty winds and heavy rain to Palawan.  Tembin could be a typhoon when it approaches southern Vietnam.

Elsewhere over the western North Pacific Ocean Tropical Depression Kai-tak is approaching the east coast of Malaysia.  At 4:00 p.m. EST on Friday the center of Tropical Depression Kai-tak was located at latitude 4.0°N and longitude 104.4°E which put it about 175 miles (285 km) north-northeast of Singapore.  Kai-tak was moving toward the southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1005 mb.  Tropical Depression Kai-tak will drop locally heavy rain over portions of Malaysia, which could cause floods and mudslides.

Tropical Storm Tembin Drops Heavy Rain on Mindanao

Tropical Storm Tembin dropped heavy rain on Mindanao on Thursday.  At 4:00 p.m. EST on Thursday the center of Tropical Storm Tembin was located at latitude 7.9°N and longitude 126.1°E which put it near Monkayo, Philippines.  Tembin was moving toward the west-southwest at 12 m.p.h. (19 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 990 mb.

Tropical Storm Tembin intensified on Thursday before it made landfall on Mindanao.  More thunderstorms developed near the core of the circulation and those storms generated stronger upper level divergence which pumped mass away from the tropical storm.  The removal of mass allowed the surface pressure to decrease and the wind speed to increase.  Although the circulation became much better organized, the distribution of thunderstorms was still asymmetrical.  There were far fewer thunderstorms forming in the eastern half of the circulation.

The center of Tropical Storm Tembin will be moving across Mindanao for another day or so.  The mountains on the island will disrupt the lower levels of the circulation and increased friction will slow the wind speed.  Tropical Storm Tembin will weaken while the center is over Mindanao.  However, the middle and upper parts of the circulation are likely to remain intact, and Tropical Storm Tembin will move through a favorable environment when it reaches the Sulu Sea.  Tembin will move over water where the Sea Surface Temperature is near 29°C.  An upper level ridge north of Tropical Storm Tembin is producing easterly winds which are blowing toward the top of the circulation.  The winds in the middle and lower levels are also blowing from the east and the vertical wind shear will not be strong enough to prevent intensification of Tropical Storm Tembin once the center gets back over water.  Temping could strengthen into a typhoon when it reaches the South China Sea.

The ridge north of Tembin is steering the tropical storm toward the west-southwest.  A general motion toward the west is expected during the next two to three days.  On its anticipated track Tropical Storm Tembin will move east to west over Mindanao during the next 24 hours.  Afterwards, Tropical Storm Tembin will move across the Sulu Sea toward Palawan.  Tembin could be near Palawan in about 48 hours and it could be over the South China Sea shortly thereafter.

Tropical Storm Tembin represents a serious hazard for Mindanao and nearby locations in the southern Philippines.  Tembin is dropping heavy rain and it has the potential to cause serious floods.  Water levels could rise quickly and flash floods could develop.  Saturated soils could result in mudslides in areas of steeper terrain.

Farther to the west, Tropical Storm Kai-tak continued to move across the South China Sea.  At 4:00 p.m. EST on Thursday the center of Tropical Storm Kai-tak was located at latitude 5.7°N and longitude 106.9°E which put it about 250 miles (400 km) east of Kuala Terengganu, Malaysia.  Kai-tak was moving toward the west-southwest at 5 m.p.h. (8 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 Tembin Forms East of the Philippines

Tropical Storm Tembin formed east of the Philippines on Wednesday.  At 1:00 p.m. EST on Wednesday the center of Tropical Storm Tembin was located at latitude 9.0°N and longitude 130.7°E which put it about 270 miles (435 km) east of Mindanao.  Tembin was moving toward the west at 12 m.p.h. (20 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 more well organized center of circulation developed on the eastern edge of a cluster of thunderstorms east of the Philippines and the Japan Meteorological Agency classified the system as Tropical Storm Tembin.  The distribution of thunderstorms in Tembin is asymmetrical.  Most of the storms are forming in bands north and west of the center of circulation.  Those storms are generating upper level divergence which is pumping mass away from the core of Tembin.  There are a few thunderstorms in bands on the eastern periphery of the circulation, but most of the bands in the eastern half of Tropical Storm Tembin contain only low clouds and showers.

Tropical Storm Tembin will be moving through an environment favorable for intensification during the next several days.  Tembin will move over water where the Sea Surface Temperature is near 29°C.  An upper level ridge north of Tembin is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing moderate vertical wind shear and they are probably the reason why most of the thunderstorms are developing west of the center of circulation.  However, the shear has not been enough to prevent Tembin from organizing and Tembin is likely to strengthen during the next 24 hours.  The center of Tembin will move over Mindanao later on Thursday and it will weaken while the center is over land.  Tropical Storm Tembin will likely intensify once the center moves west of Mindanao.

A subtropical ridge north of Tembin is steering the tropical storm toward the west and a general westerly motion is expected to continue for several more days.  On its anticipated track the center of Tropical Storm Tembin could approach Mindanao in about 24 hours.  Tembin is then forecast to move over the Bohol Sea and Sulu Sea and on toward Palawan.  It currently looks like Tropical Storm Tembin will take a track a little to the south of the track taken by Tropical Storm Kai-tak across the Philippines last week.

Tropical Storm Tembin will drop heavy rain over parts of Mindanao, southern Leyte, Bohol, Cebu, Negros, Siargao, and Dinagat.  The heavy rain could cause floods and mudslides.  The northern part of Tropical Storm Tembin could drop heavy rain in some of the places affected by Tropical Storm Kai-tak last week.  Any additional rain in those locations would hamper efforts to recover from floods and mudslides caused by Kai-tak.

Tropical Storm Kai-Tak continue to move southwest over the South China Sea.  At 4:00 p.m. EST on Wednesday the center of Tropical Storm Kai-tak was located at latitude 6.4°N and longitude 111.1°E which put it about 440 miles (710 km) southeast of Ho Chi Minh City, Vietnam.  Kai-tak was moving toward the southwest at 7 m.p.h. (11 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 998 mb.

Tropical Storm Kai-tak Moves Over South China Sea

Tropical Storm Kai-tak moved west of the Philippines and over the South China Sea on Tuesday.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm Kai-tak was located at latitude 8.2°N and longitude 112.0°E which put it about 425 miles (685 km) east-southeast of Ho Chi Minh City, Vietnam.  Kai-tak 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.

The organization of the circulation of Tropical Storm Kai-tak improved on Tuesday.  More thunderstorms developed near the center of circulation.  The two stronger rainbands were north and west of the center.  However, thunderstorms also developed in a couple of bands southeast of the center of circulation.  These storms were the first to form in the eastern half of the circulation in several days.  The distribution of the rainbands was still asymmetrical, but storms were occurring in more quadrants of Kai-tak.  The storms in the two stronger rainbands were generating some upper level divergence which was pumping mass away to the west of the tropical storm.

Tropical Storm Kai-tak will be moving through an environment somewhat favorable for intensification during the next day or two.  Kai-tak will move over water where the Sea Surface Temperature is near 29°C.  Kai-tak is moving near the southwestern portion of a subtropical ridge.  The ridge is producing easterly winds which are blowing toward the top of the circulation.  The easterly winds are causing moderate vertical wind shear, but they have weakened somewhat during the past 24 hours.  Less wind shear has allowed Tropical Storm Kai-tak to become better organized.  Tropical Storm Kai-tak could strengthen during the next 24 to 36 hours.

The western end of the subtropical ridge is strengthening and the ridge is steering Tropical Storm Kai-tak toward the west-southwest.  A general motion toward the west-southwest is expected to continue for the next two or three days.  On its anticipated track the center of Tropical Storm Kai-tak is expected to pass south of the southern tip of Vietnam.  Kai-tak is forecast to stay north of Borneo.  The center of Tropical Storm Kai-tak could approach the region near the border between Thailand and Malaysia in about 72 hours.

Tropical Cyclone Dahlia Forms Southwest of Indonesia

Tropical Cyclone Dahlia formed southwest of Indonesia on Wednesday.  At 10:00 a.m. EST on Wednesday the center of Tropical Cyclone Dahlia was located at latitude 8.4°S and longitude 101.5°E which put it about 320 miles (520 km) west-northwest of Christmas Island.  Dahlia was moving toward the east at 5 m.p.h. (8 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 center of circulation developed in a cluster of thunderstorms previously designated as Invest 96S and the Australian Bureau of Meteorology named the system Tropical Cyclone Dahlia.  The circulation of Dahlia is still organizing.  A primary rainband wrapped around the southern and western sides of the center.  Additional bands of showers and thunderstorms formed in the western half of the circulation.  Fewer thunderstorms formed in the eastern half of Dahlia.  The thunderstorms near and to the west of the center were generating upper level divergence which was pumping mass away to the west of the tropical cyclone.

Tropical Cyclone Dahlia will be moving through an environment favorable for intensification during the next several days.  Dahlia will move over water where the Sea Surface Temperature is near 29°C.  Dahlia is underneath the northern part of an upper level ridge.  The ridge is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing moderate vertical wind shear, which may be the reason why most of the thunderstorms are west of the center of circulation.  The shear is strong enough to slow the intensification of Dahlia, but it is not strong enough to prevent the tropical cyclone from strengthening.  Tropical Cyclone Dahlia is likely to likely to intensify during the next 24 to 48 hours.

The steering winds around Dahlia are relatively weak and the tropical cyclone is moving slowly toward the east.  The upper level ridge is forecast to shift north and stronger westerly winds are likely to steer Tropical Cyclone Dahlia toward the east at a faster speed.  When Dahlia reaches the southern portion of the upper level ridge in a couple of days, northerly winds diverging from the ridge are likely to steer the tropical cyclone toward the south.

Tropical Cyclone Cempaka Develops South of Java

The organization of a small area of low pressure (also known as Invest 95S) south of Java increased early on Monday and the Badan Meteorologi Klimatologi Dan Geofisika (BMKG) Tropical Cyclone Warning Center in Jakarta designated the system as Tropical Cyclone Cempaka.  At 7:00 a.m. EST on Monday the center of Tropical Cyclone Cempaka was located at latitude 8.8°S and longitude 110.8°E which put it about 70 miles (115 km) south-southeast of Yokyakarta, Indonesia.  Cempaka was moving toward the east- northeast at 5 m.p.h. (8 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 997 mb.

Tropical Cyclone Cempaka has a small but well developed center of circulation.  Radar images from BKMG showed an eyelike feature at the center of circulation.  The strongest winds are occurring in a ring of showers and thunderstorms that surrounds the center.  The stronger storms are in the eastern half of the ring.  Other narrow rainbands are developing outside the core of Cempaka.  Thunderstorms around the center are generating some upper level divergence which is pumping mass away from the tropical cyclone.  Winds to tropical storm force extend out about 40 miles (65 km) from the center of circulation.

Tropical Cyclone Cempaka will be in an environment somewhat favorable for intensification during the next 24 to 48 hours.  Cempaka will move over water where the Sea Surface Temperature is near 29°C.  Tropical Cyclone Cempaka is under an upper level ridge and the upper level winds are weak.  There is little vertical wind shear over the tropical cyclone.  The core of Tropical Cyclone Cempaka is near Java.  Part of the circulation is flowing over Java and nearby islands and friction from those islands is slowing the winds.  Interaction with land is the primary factor inhibiting intensification.  If the center of Tropical Cyclone Cempaka remains south of Java, then it has a chance to intensify.  If Cempaka moves closer to Java, then it could weaken.  Also, since Cempaka is a very small tropical cyclone, an increase in the speed of the upper level winds could blow the top off of the circulation.

Since Tropical Cyclone Cempaka is underneath an upper level ridge, the steering winds are weak.  Cempaka is south of the center of the ridge and weak westerly winds are steering the tropical cyclone slowly toward the east-northeast.  Tropical Cyclone Cempaka is forecast to meander south of Java for several more days because of the weak stearing winds.

Tropical Cyclone Cempaka is producing locally heavy rain over parts of Java, Bali and nearby islands.  The locally heavy rain could cause flash floods as Cempaka meanders south of Java during the next day or two.

Low Pressure System Forms South of Java

A small, but well organized area of low pressure developed just to the south of Java on Sunday.  The low pressure system is currently designated as Invest 95S, but it could become a tropical cyclone during the next several days.  At 10:00 p.m. EST on Sunday the center of Invest 95S was located at latitude 8.9°S and longitude 109.8°E which put it about 100 miles (160 km) southwest of Yogyakarta, Indonesia.  It was moving toward the northeast at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 998 mb.

The circulation of Invest 95S is small but well formed.  There is a distinct low level center of circulation.  Two well formed narrow rainbands wrapped around the southern and northeastern sides of the center.  Other rainbands developed just outside the core of the circulation.  Storms near the center of circulation were generating some upper level divergence which was pumping out mass and allowing the surface pressure to decrease.

Invest 95S will move through an environment that is mostly favorable for intensification.  It will move over water where the Sea Surface Temperature is near 29°C.  Invest 95S is near the center of an upper level ridge.  The upper level winds blowing over the top of the low pressure system are weak and there is not a lot of vertical wind shear.  The proximity of the circulation to Java is the only factor likely to inhibit intensification.  If the center of circulation remains south of Java, then there is a good chance it could intensify into a tropical cyclone.

The ridge north of Invest 95S is steering the system slowly toward the northeast and a general easterly motion is expected to continue during the next 24 hours.  Guidance from numerical models diverges in a day or so.  Some models to suggest the northeasterly motion will continue and the low pressure system will move across Java.  Other models predict a turn toward the south in a day or so.  There is a high degree of uncertainty about the future track of Invest 95S.

Tropical Cyclone Ernie Forms Northwest of Australia

Tropical Cyclone Ernie formed northwest of Australia on Thursday.  At 2:00 p.m. EDT on Thursday the center of Tropical Cyclone Ernie was located at latitude 14.1°S and longitude 110.9°E which put it about 580 miles (940 km) north-northwest of Exmouth, Australia.  Ernie was moving toward the south-southwest at 5 m.p.h. (7 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. (100 km/h).  The minimum surface pressure was 995 mb.

Thunderstorms developed around a small area of low pressure south of Indonesia during the past several days.  The storms consolidated near the center of circulation on Thursday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Ernie.  Ernie does have a well organized low level center of circulation, but many of the thunderstorms are occurring just to the west of the center of circulation.  There are also several bands of showers and thunderstorms in the southeastern quadrant of the circulation.  The thunderstorms near the center are generating upper level divergence which is pumping out mass to the south and southeast of Tropical Cyclone Ernie.

Tropical Cyclone Ernie is in an environment that is favorable for intensification.  It is moving over water where the Sea Surface Temperature (SST) is near 30°C.  An upper level ridge southeast of Ernie is generating northerly winds which are cause some vertical wind shear over the tropical cyclone.  However, the vertical wind shear is not strong enough to prevent further intensification of Tropical Cyclone Ernie.  Ernie should intensify during the next 24 hours and it could intensify rapidly during that time.  Tropical Cyclone Ernie will move into an unfavorable environment in a day or two.  Ernie will move over cooler SSTs and into a region where stronger upper level winds will produce more vertical wind shear.  The tropical cyclone will weaken at that time.

A subtropical ridge centered southeast of Ernie is steering the tropical cyclone slowly toward the south-southwest.  The ridge is forecast to strengthen and extend farther to the west.  When the ridge extends westward, it will steer Tropical Cyclone Ernie more toward the west.  On its anticipated track Tropical Cyclone Ernie currently poses no threat to land.