Monthly Archives: November 2018

Tropical Storm Usagi Makes Landfall South of Ho Chi Minh City

Tropical Storm Usagi made landfall south of Ho Chi Minh City, Vietnam on Saturday night.  At 10:00 p.m. EST on Saturday the center of Tropical Storm Usagi was located at latitude 10.2°N and longitude 107.1°E which put it about 60 miles (995 km) south-southeast of Ho Chi Minh City, Vietnam.  Usagi was moving toward the west at 5 m.p.h. (8 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 984 mb.

Former Typhoon Usagi weakened as it approached the coast of southern Vietnam.  Moderate vertical wind shear caused by upper level winds blowing from the east caused Usagi to weaken slowly.  The core of Tropical Storm Usagi was still relatively intact.  A ring of strong thunderstorms surrounded the remnants of the small eye.  The strongest winds were occurring in that ring of storms.  Heavy rain was falling just to the southwest of the center of circulation.  Thunderstorms were also dropping heavy rain in a couple of bands on the northeastern periphery of the circulation.

Tropical Storm Usagi will bring gusty winds to the areas south and west of Ho Chi Minh City.  Some places in southern Vietnam and Cambodia will receive locally heavy rainfall and flash floods could occur in those areas.  Usagi will weaken slowly as it move inland over southern Vietnam.

Elsewhere over the Western North Pacific Ocean, Typhoon Man-yi was meandering slowly southeast of Okinawa.  At 10:00 p.m. EST on Saturday the center of Typhoon Man-yi was located at latitude 18.4°N and longitude 135.8°E which put it about 770 miles (1245 km) southeast of Okinawa.  Man-yi was moving toward the west at 2 m.p.h. (3 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 969 mb.

Usagi Strengthens to a Typhoon East of Southern Vietnam

Former Tropical Storm Usagi strengthened into a typhoon east of southern Vietnam on Friday night.  At 10:00 p.m. EST on Friday the center of Typhoon Usagi was located at latitude 9.6°N and longitude 109.2°E which put it about 205 miles (335 km) east-southeast of Ho Chi Minh City, Vietnam.  Usagi was moving toward the west-southwest at 10 m.p.h. (16 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 977 mb.

A small circular eye was visible at the center of Typhoon Usagi on both conventional and microwave satellite imagery.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Typhoon Usagi.  The strongest rain bands were in the western half of the typhoon.  Storms near the core of Usagi were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out about 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out about 125 miles (200 km) from the center.

Typhoon Usagi will move through an environment favorable for intensification during the next 24 hours.  Usagi will move over water where the Sea Surface Temperature is near 29°C.  It will move south of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, which will reduce the rate of intensification.  Typhoon Usagi will strengthen on Saturday.

The ridge north of Typhoon Usagi will steer the typhoon a little to the south of due west.  On its anticipated track the center of Typhoon Usagi will approach the Mouths of the Mekong River in about 24 hours.  Usagi will bring strong winds and drop heavy rain on southern Vietnam.  Winds to tropical storm force could affect Ho Chi Minh City.  There could be a storm surge of 6 to 9 feet (2 to 3 meters) along the coast.  Locally heavy rain could cause floods over portions of southern Vietnam and Cambodia.

Elsewhere over the Western North Pacific Typhoon Man-yi started to weaken southeast of Okinawa.  At 10:00 p.m. EST on Friday the center of Typhoon Man-yi was located at latitude 18.1°N and longitude 135.4°E which put it about 760 miles (1230 km) southeast of Okinawa.  Man-yi was moving toward the north at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 969 mb.

Tropical Storm Usagi Forms East of Vietnam

Tropical Storm Usagi formed over the South China Sea east of Vietnam on Thursday.  At 10:00 a.m. EST on Thursday the center of Tropical Storm Usagi was located at latitude 11.2°N and longitude 113.7°E which put it about 350 miles (565 km) east of Lien Huong, Vietnam.  Usagi 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 1001 mb.

More thunderstorms developed near the center of former Tropical Depression 33W and the Japan Meteorological Agency designated the system as Tropical Storm Usagi.  Satellite imagery indicated that the inner end of a rainband was wrapping around the center of circulation.  Several other bands of showers and thunderstorms were in the western half of Tropical Storm Usagi.  Bands in the eastern half of the circulation consisted primarily of showers and low clouds.  An upper level ridge north Usagi was producing southeasterly winds which were blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and they were the reason why the stronger thunderstorms were developing west of the center of circulation.  Storms near the center were producing upper level divergence which was pumping mass away to the west of the tropical storm.

Tropical Storm Usagi will move through an environment favorable for intensification during the next 24 to 36 hours.  Usagi will move over water where the Sea Surface Temperature is near 29°C.  It will continue to move south of an upper level ridge and moderate vertical wind shear will continue to affect Tropical Storm Usagi.  The wind shear will slow intensification, but Usagi will strengthen during the next day or so.  It could intensify into a typhoon during the next 36 hours.

The ridge north of Tropical Storm Usagi will steer the tropical storm on a track a little to the south of due west.  On its anticipated track the center of Tropical Storm Usagi will approach the coast of southern Vietnam in about 36 hours.  Usagi could make landfall on the portion of the coast between Cam Ranh and Vung Tau.  Tropical Storm Usagi will bring gusty winds and it could drop locally heavy rain over southern Vietnam and Cambodia.  Heavy rain could cause flash foods in some locations.

Elsewhere over the Western North Pacific, Typhoon Man-yi was moving away from the Marianas after causing power outages in southern Guam.  At 10:00 a.m. EST on Thursday the center of Typhoon Man-yi was located at latitude 13.5°N and longitude 137.8°E which put it about 1155 miles (1860 km) southeast of Okinawa.  Man-yi was moving toward the northwest at 21 m.p.h. (34 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 969 mb.

Man-yi Strengthens to a Typhoon Southwest of Guam

Former Tropical Storm Man-yi strengthened to a typhoon southwest of Guam on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Typhoon Man-yi was located at latitude 11.1°N and longitude 141.1°E which put it about 300 miles (485 km) southwest of Guam.  Man-yi was moving toward the west-northwest at 27 m.p.h. (44 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 973 mb.

Typhoon Man-yi strengthened quickly on Wednesday.  An inner band of thunderstorms wrapped around the center of circulation.  A small eye appeared intermittently on satellite imagery.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Other bands of showers and thunderstorms were revolving around the core of Typhoon Man-yi.  Storms near the core were generating upper level divergence which was pumping 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 145 miles (230 km) from the center.

Typhoon Man-yi will move through an environment somewhat favorable for intensification on Thursday.  Man-yi will move over water where the Sea Surface Temperature is near 29°C.  So, there will be enough energy in the upper ocean to support further intensification.  Typhoon Man-yi will move south of an upper level ridge.  The ridge will produce strong east-southeasterly winds which will blow toward the top of the circulation.  Those winds will produce moderate vertical wind shear.  The wind shear will inhibit upper level outflow to the east of the typhoon and they will slow the rate of intensification.  Despite the moderate vertical wind shear, Typhoon Man-yi is likely to strengthen during the next 24 hours and it could become the equivalent of a major hurricane.

The ridge will steer Typhoon Man-yi rapidly toward the northwest during the next 24 to 36 hours.  On its anticipated track Typhoon Man-yi will move quickly away from Guam and the Marianas.  Man-yi could move southeast of Okinawa this weekend.

Elsewhere over the rest of the Western North Pacific Ocean, Tropical Depression 33W was moving quickly westward over the South China Sea.  At 10:00 p.m. EDT on Wednesday the center of Tropical Depression 33W was located at latitude 11.1°N and longitude 116.2°E which put it about 505 miles (815 km) east of Cam Ranh, Vietnam.  It was moving toward the west at 25 m.p.h. (40 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1004 mb.

Tropical Storm Man-yi Forms Southeast of Chuuk

Tropical Storm Man-yi formed southeast of Chuuk on Tuesday.  At 7:00 a.m. EST on Tuesday the center of Tropical Storm Man-yi was located at latitude 4.8°N and longitude 154.2°E which put it about 245 miles (395 km) southeast of Chuuk.  Man-yi was moving toward the west at 11 m.p.h. (17 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 Tropical Storm Watch was issued for Guam and Rota.  Tropical Storm Warnings were in effect for Chuuk Lagoon, Lukunor, Losap, Fananu, Ulul, Pulawat and Satawal.  Typhoon Watches were issued for Faraulep and Pulawat.

Tropical Depression 34W exhibited greater organization on satellite imagery and the Japan Meteorological Agency designated the system as Tropical Storm Man-yi.  More thunderstorms developed near the center of circulation.  The strongest thunderstorms were occurring in a band west of the center.  Other bands of showers and thunderstorms were developing around Tropical Storm Man-yi.  Storms near the center of circulation were generating upper level divergence which was pumping mass away to the west of the tropical storm.

Tropical Storm Man-yi will move through an environment favorable for intensification.  Man-yi will move over water where the Sea Surface Temperature is near 29°C.  It will move south of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Storm Man-yi will intensify and it could strengthen into a typhoon in a day or two.

The upper level ridge will steer Tropical Storm Man-yi toward the west-northwest during the next 12 to 24 hours.  A weakness is forecast to develop in the ridge, which would allow Man-yi to move more toward the northwest.  On its anticipated track Tropical Storm Man-yi will move near Chuuk in 12 to 24 hours.  It will bring gusty winds and drop heavy rain.  Man-yi could be southeast of Guam in 36 to 48 hours.

Elsewhere over the Western North Pacific Ocean Tropical Depression 33W was dropping rain over parts of the central Philippines and Tropical Depression Toraji was moving over the Gulf of Thailand.  At 4:00 a.m. EST on Tuesday the center of Tropical Depression 33W was located at latitude 10.9°N and longitude 126.8°E which put it about 160 miles (260 km) east-southeast of Tacloban, Philippines.  It was moving toward the west-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1004 mb.

At 4:00 a.m. EDT the center of Tropical Depression Toraji was located at latitude 8.1°N and longitude 101.1°E which put it about 100 miles (160 km) east of Hua Sai, Malaysia.  Toraji was moving toward the west-southwest at 5 m.p.h. (8 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 1002 mb.

Tropical Storm Teraji Develops East of Vietnam

Tropical Storm Teraji developed east of Vietnam on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Storm Teraji was located at latitude 11.1°N and longitude 110.1°E which put it about 100 miles (160 km) east of Lien Huong, Vietnam.  Teraji was moving toward the west 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 1004 mb.

A distinct low level center of circulation developed in an area of thunderstorms over the South China Sea east of southern Vietnam on Saturday and the Japan Meteorological Agency designated the system as Tropical Storm Teraji.  The circulation around Teraji was exhibiting evidence of vertical wind shear.  The center of circulation was on the eastern edge of a cluster of thunderstorms.  Tropical Storm Teraji was south of an upper level ridge.  The ridge was producing easterly winds which were causing moderate vertical wind shear.  The stronger thunderstorms were occurring in bands west of the center of circulation, which was likely an effect of the wind shear.

The ridge north of Tropical Storm Teraji will steer the tropical storm westward into southern Vietnam.  On its anticipated track Teraji will move over southern Vietnam on Sunday.  Tropical Storm Teraji will move across southern Cambodia early next week.  Thunderstorms in rainbands in the western half of Teraji could drop locally heavy and floods could occur in some locations.

Elsewhere over the Western North Pacific Ocean Tropical Depression 34W formed southeast of Palau.  At 10:00 p.m. EST on Saturday the center of Tropical Depression 34W was located at latitude 6.6°N and longitude 135.5°E which put it about 90 miles (145 km) southeast of Palau.  It was moving toward the west-southwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts tot 45 m.p.h. (75 km/h).  The minimum surface pressure was 1004 mb.

Tropical Cyclone Gaja Makes Landfall in Southern India

Tropical Cyclone Gaja made landfall on the coast of southern India just south of Nagappattinam on Thursday.  At 4:00 p.m. EST on Thursday the center of Tropical Storm Gaja was located at latitude 10.5°N and longitude 79.7°E which put it about 10 miles (15 km) south of Nagappattinam, India.  Gaja was moving toward the west-southwest at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 974 mb.

Tropical Cyclone Gaja strengthened rapidly into the equivalent of a hurricane/typhoon while it approached the coast of Southern India.  A small circular eye formed 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 bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Gaja.  The circulation of Gaja was small, which allowed it to strengthen quickly before landfall.  Winds to hurricane/typhoon force only extended out about 10 miles (15 km) from the center of circulation.  Winds to tropical storm force only extended out about 65 miles (105 km) from the center.

Tropical Cyclone Gaja produced winds strong enough to cause damage in the area near Nagappattinam.  Those winds could bring a storm surge of 5 to 8 feet (1.5 to 2.5 meters) near where the center made landfall.  The small size of Tropical Cyclone Gaja and the fact it did not intensify until it neared the coast will limit the magnitude of the storm surge.  Gaja is forecast to move westward across southern India.  Tropical Cyclone Gaja will weaken when it moves inland but it will drop locally heavy rain over Tamil Nadu, Kerala and southern Karnataka.  The heavy rain could cause flash flooding in those regions.

Tropical Cyclone Gaja will weaken while it moves across southern India.  The small size of the circulation and mountains in that area will contribute to a fairly rapid weakening.  The circulation in the lower levels could be seriously disrupted when it moves over the mountains, but the circulation in the middle levels may persist.  Some numerical models are forecasting that Tropical Cyclone Gaja could strengthen back into the equivalent of a tropical storm when it moves over the Arabian Sea.

Tropical Cyclone Gaja Moves Closer to Southern India

Tropical Cyclone Gaja moved closer to southern India and strengthened on Wednesday.  At 4:00 p.m. EST on Wednesday the center of Tropical Cyclone Gaja was located at latitude 11.7°N and longitude 83.6°E which put it about 260 miles (420 km) east of Cuddalore, India.  Gaja was moving toward the southwest at 10 m.p.h. (16 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 996 mb.

Tropical Cyclone Gaja strengthened on Wednesday.  More thunderstorms developed near the center of circulation.  Some microwave images exhibited the appearance of an eyelike feature in the lower levels.  The inner end of a rainband appeared to be wrapping around the center of Gaja.  There were several bands of stronger thunderstorms in the western half of Tropical Cyclone Gaja.  Rainbands in the eastern half of the tropical cyclone consisted primarily of showers and lower clouds.  The storms around the center of circulation were generating strong upper level divergence which was pumping mass away to the northeast of Gaja.  The circulation around Tropical Cyclone Gaja was relatively small.  Winds to tropical storm force only extended out about 65 miles (105 km) from the center of circulation.

Tropical Cyclone Gaja will move through an environment favorable for intensification during the next 24 hours.  Gaja will move over water where the Sea Surface Temperature is near 29°C.  It will move southwest of an upper level ridge.  The ridge will produce southeasterly winds which will blow toward the top of the circulation.  Those winds will restrict upper level divergence to the southeast of Gaja.  They will also cause moderate vertical wind shear, which is probably the reason why most of the stronger thunderstorms are occurring in the western half of the circulation.  The wind shear will slow intensification, but Tropical Cyclone Gaja will strengthen during the next 24 hours.  Gaja could intensify to the equivalent of a hurricane/typhoon.

Tropical Cyclone Gaja will move south of a ridge in the middle troposphere during the next 48 hours.  The ridge will steer Gaja on a track that is a little south of straight westward.  On its anticipated track Tropical Cyclone Gaja will approach the coast of southern India in about 24 hours.  Gaja will make landfall in Tamil Nadu between Cuddalore and Nagappattinam in a little over a day.  It could be the equivalent of a hurricane/typhoon when it makes landfall.  Gaja will bring strong winds and it could cause a storm surge of 5 to 8 feet (1.5 to 2.5 metres) at the coast.  Tropical Cyclone Gaja will drop locally heavy rain over portions of Tamil Nadu, Karnataka and Kerala.  Heavy rain could cause flash floods in some locations.

Tropical Cyclone Gaja Forms Over Bay of Bengal

Tropical Cyclone Gaja formed over the Bay of Bengal on Sunday.  At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Gaja was located at latitude 12.9°N and longitude 86.7°E which put it about 500 miles (805 km) east of Chennai, India.  Gaja 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 1002 mb.

An area of low pressure moving over the Bay of Bengal strengthened on Sunday and the India Meteorological Department classified the system as Tropical Cyclone Gaja.  The circulation around Tropical Cyclone Gaja is still organizing.  There is a distinct low level center of circulation.  A short band of thunderstorms is west and north of the center.  Several other bands of showers and thunderstorms are developing in other parts of Tropical Cyclone Gaja.  One stronger band is east of the center of circulation and another stronger band is southeast of the center.  Storms near the center are beginning to generate upper level divergence which will pump mass away from the tropical cyclone.

Tropical Cyclone Gaja will move through an environment somewhat favorable for intensification during the next 48 hours.  Gaja will move over water where the Sea Surface Temperature is near 29°C.  It will move south of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of the circulation.  The winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Cyclone Gaja will intensify and it could be nearly equivalent to a hurricane/typhoon in two or three days.

The upper level ridge will steer Tropical Cyclone Gaja in a generally west-southwesterly direction.  On its anticipated track Tropical Cyclone Gaja will approach the coast of southern India in about 72 hours.  Gaja could be nearly the equivalent of a hurricane/typhoon at that time.

Elsewhere, over the South Indian Ocean Tropical Cyclone Alcide still was moving slowly east of the northern end of Madgascar and Tropical Cyclone Bouchra developed between Diego Garcia and Cocos Island.  At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Alcide was located at latitude 12.3°N and longitude 51.9°E which put it about 170 miles (275 km) east of Antisiranana, Madagascar.  Alcide was moving toward the northwest at 4 m.p.h. (6 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.

At 4:00 p.m. EDT on Sunday the center of Tropical Cyclone Bouchra was located at latitude 5.4°S and longitude 89.1°E which put it about 700 miles (1130 km) northwest of Cocos Island, Australia.  Bouchra was moving toward the east at 2 m.p.h. (3 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 999 mb.

Tropical Cyclone Alcide Stalls East of Madgascar

Tropical Cyclone Alcide stalled east of northern Madagascar on Friday.  At 4:00 p.m. EDT on Friday the center of Tropical Cyclone Alcide was located at latitude 13.4°N and longitude 53.1°E which put it about 250 miles (400 km) east of Antisiranana, Madagascar.  Alcide was moving toward the south at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 95 m.p.h. (155 km/h).  The minimum surface pressure was 978 mb.

Tropical Cyclone Alcide weakened during the past 36 hours.  An eye is no longer apparent on visible satellite images, although an eyelike feature persists on microwave satellite images.  There are breaks in the ring of thunderstorms surrounding the eye.  Winds to hurricane/typhoon force are occurring in the broken ring of storms.  Alcide moved very slowly during the past day or so.  Its slow movement may have allowed its winds to mix cooler water to the surface of the ocean.  If there is cooler water at the surface, then there is less energy available to support the circulation of Tropical Cyclone Alcide.  The circulation of Alcide remains relatively small.  Winds to tropical storm force extend out about 100 miles (160 km) from the center of circulation.

Tropical Cyclone Alcide is in an area where the steering currents are weak.  Alcide could meander over the same area for another day or so.  If it remains over the same cooler water, then Alcide will slowly weaken further.  As the circulation gets weaker, thunderstorms will not rise as high into the atmosphere and Tropical Cyclone Alcide will be steered by winds at lower levels.  If Alcide eventually moves over warmer water, and the upper level winds are not too strong, then new thunderstorms could develop.

Tropical Cyclone Alcide is not forecast to move much during the next 24 hours.  In a day or so the winds in the lower and middle troposphere are forecast to begin to steer Alcide in a more westerly direction.  On its anticipated track Tropical Cyclone Alcide could move closer to northern Madagascar on Sunday.