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Dangerous Typhoon Koppu Making Landfall in Northern Luzon

Typhoon Koppu intensified rapidly during the past 12 hours and it is making landfall near Baler in northern Luzon as the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.  At 11:00 a.m. EDT on Saturday the center of Typhoon Koppu was located at latitude 16.0°N and longitude 122.9°E which put it about 170 miles (275 km) east-northeast of Manila, Philippines.  Koppu was moving toward the west-northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h).  The minimum surface pressure was 918 mb.  Typhoon Koppu has a Hurricane Intensity Index (HII) of 31.6, a Hurricane Size Index (HSI) of 17.5 and a Hurricane Wind Intensity Size Index (HWISI) of 49.1, which means it is capable of producing regional significant wind damage.  In addition the slow movement of Koppu means it will produce very heavy rainfall which will create the potential for serious flooding and landslides.

Koppu will continue to move toward the west-northwest for another 12 to 24 hours.  Then it will reach the western end of the subtropical ridge that has been steering it and start to move toward the north.  Although Typhoon Koppu will weaken as it moves across northern Luzon, it will be over that area for 36 to 48 hours.  Koppu has the potential to cause widespread damage due to winds, floods and landslides.

Typhoon Koppu Continues to Intensify and Threaten Luzon

Typhoon Koppu continued to intensify on Friday and it maintained its steady course toward northern Luzon.  At 5:00 p.m. EDT on Friday the center of Typhoon Koppu was located at latitude 15.8°N and longitude 124.5°E which put it about 270 miles (435 km) east-northeast of Manila, Philippines.  Koppu was moving toward the west at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 947 mb.

Typhoon Koppu is evolving into a large well organized typhoon.  An eye has formed at the center of the circulation and multiple rain bands spiral around the core of the typhoon.  Upper level divergence is pumping mass away from the center of circulation.  Koppu is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are light and there is not much vertical wind shear.  Koppu is likely to continue to intensify until it begins to interact with northern Luzon.

A subtropical ridge is steering Koppu toward the west and that steering pattern is expected to continue for another 24 to 36 hours.  On its anticipated track the center of Typhoon Koppu will be very near the northeastern coast of Luzon in about 24 hours.  Koppu will bring strong winds, heavy rain and a storm surge to northern Luzon.  The large size of Koppu and its relatively slow movement means that it could produce very heavy rainfall.  Serious flooding and numerous mudslides are possible across northern Luzon.

Intensifying Typhoon Koppu Moving Toward Northern Luzon

Typhoon Koppu intensified on Thursday as it continued to move steadily toward Northern Luzon.  At 11:00 p.m. EDT the center of Typhoon Koppu was located at latitude 15.6°N and longitude 126.9°E which put it about 425 miles (685 km) east of Manila, Philippines.  Koppu was moving toward the west at 8 m.p.h. (13 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.

Typhoon Koppu is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds lessened on Thursday which decreased the vertical wind shear and allowed Koppu to intensify more quickly.  The core of the circulation consolidated and there are suggestions that an eyewall may be forming.  Koppu is expected to move through a favorable environment until it reaches northern Luzon and further intensification is very likely.

A subtropical ridge is steering Koppu toward the west and that general steering pattern is expected to continue for another 36 to 48 hours.  On its anticipated track, Typhoon Koppu will approach northern Luzon in 36 to 42 hours.  It could bring strong winds, heavy rain and a storm surge when it reaches that area.  The heavy rain could produce floods and mudslides as Koppu moves over northern Luzon.

Tropical Storm Koppu Forms North of Yap

In spite of significant vertical wind shear a surface circulation has been consolidating inside an area of thunderstorms north of Yap.  The system has been designated Tropical Storm Koppu.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Koppu was located at latitude 15.7°N and longitude 137.1°E which put it about 430 miles (690 km) north of Yap.  Koppu was moving toward the west at 14 m.p.h. (23 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 993 mb.

Significant vertical wind shear is inhibiting the organization of Tropical Storm Koppu.  An upper level ridge north of Koppu is generating strong northeasterly winds over the top of the tropical storm.  The vertical wind shear is causing most of the strong thunderstorms to be located southwest of the center of circulation.  The only other deep convection is occurring in a band that is west of the core of the circulation.

Koppu is over water where the Sea Surface Temperature is near 30°C and so there is plenty of energy in the upper ocean.  The wind shear will inhibit intensification for another 24 to 48 hours before it starts to subside.  Koppu could intensify much more quickly later this week when it moves into an area where the upper level winds are lighter.  Koppu could become a typhoon withing 36 to 48 hours and it could be a strong typhoon by the end of the week.

A subtropical ridge is steering Tropical Storm Koppu quickly to the west.  That general motion is expected to continue for the rest of the week.  On its anticipated track Koppu could be approaching northern Luzon in about three or four days.  It could be a significant typhoon by that time.

Typhoon Dujan Making Landfall in China

Typhoon Dujuan moved across Taiwan on Monday and it is currently making another landfall on the east coast of China.  At 11:00 p.m. EDT the center of Typhoon Dujuan was located at latitude 25.3°N and longitude 118.6°E which put it near Putian, China.  Dujuan was moving toward the northwest at 13 m.p.h.  The maximum sustained wind speed was 85 m.p.h. (135 m.p.h.) and there were wind gusts to 105 m.p.h. (170 km/h).  The minimum surface pressure was 976 mb.

Dujuan brought strong winds and heavy rain when it moved across Taiwan.  It weakened as the center moved over the mountains on Taiwan, but its large size and intensity allow Dujuan to survive.  Dujuan was still a typhoon as it moved into the coast of eastern China near Putian.  It could produce heavy rainfall and flooding as it moves inland.  Dujuan should spin down gradually during the next few days as it moves farther into eastern China.

Large Dangerous Typhoon Dujuan Nearing Taiwan

Large and dangerous Typhoon Dujuan is nearing Taiwan.  At 11:00 p.m. EDT on Sunday the center of Typhoon Dujuan was located at latitude 23.5°N and longitude 123.2°W which put it about 185 miles (300 km) southeast of Taipei, Taiwan.  Dujuan was moving toward the west-northwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 145 m.p.h. (235 km/h) and there were wind gusts to 170 m.p.h. (275 km/h).  The minimum surface pressure was 912 mb.

Typhoon Dujuan is a very symmetrical storm with a large eye.  Winds to hurricane force extend out 60 miles from the center.  A weather station on Ishigaki Jima, Japan has reported winds over 54 m.p.h. (87 km/h) for the past five hours even though the center is passing south of that island.  The upper level winds around the typhoon are light and upper level divergence is pumping out mass in all directions  Typhoon Dujuan is likely to maintain its intensify until it makes landfall in Taiwan.  When the core of the typhoon moves over the mountains on Taiwan it will weaken.  However, given Dujuan’s size and intensity, it is likely to still be a typhoon when it moves west of Taiwan.

A subtropical ridge north of Dujuan is steering the typhoon toward the west-northwest and that general steering pattern is expected to continue.  On its anticipated track Dujuan will make landfall in northeastern Taiwan in less than 12 hours.  It will move across Taiwan and the center could reform northwest of that island.  Dujuan could make a landfall in China between Xiamen and Fuzhou in less than 24 hours.

Dujuan has the potential to be a very destructive typhoon.  It has a Hurricane Intensity Index of 29.9 and a Hurricane Size Index of 21.3.  Those numbers produce a Hurricane Wind Intensity Size Index of 51.2.  Those Indices suggest it is capable of producing widespread significant damage.  In addition to wind damage, Dujuan is capable of producing very heavy rainfall and floods.

Powerful Typhoon Dujuan Heads Toward Taiwan

Powerful Typhoon Dujuan turned west on Saturday and headed for Taiwan.  At 11:00 p.m. EDT on Saturday the center of Typhoon Dujuan was located at latitude 22.3°N and longitude 127.0°E which put it about 380 miles (610 km) east-southeast of Taipei, Taiwan and about 300 miles (480 km) south of Okinawa.  Dujuan was moving toward the west at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 925 mb.

Dujuan continued to intensify on Saturday and it is a powerful well organized typhoon.  Dujuan has a large symmetrical eye which is surrounded by strong thunderstorms.  Upper level divergence is pumping out mass and the surface pressure is decreasing.  Dujuan is over warm Sea Surface Temperatures and there is not much vertical wind shear.  Further intensification is possible, although if concentric eyewalls form, it could disrupt the intensification trend.

An upper level ridge north of Dujuan steered the typhoon a little north of due west on Saturday.  That general motion is expected to continue for another day or two.  On its anticipated track Dujuan will pass near the southwestern Ryukyu Islands in about 24 hours.  It will approach Taiwan in about 30 hours and it could reach China in less than two days.  Dujuan is a large powerful typhoon and it will bring strong winds and heavy rain.  It could produce flooding in parts of Taiwan and eastern China.

Dujuan Reaches Typhoon Intensity South of Okinawa

Tropical Storm Dujuan continued to strengthen on Thursday and it reached typhoon intensity.  At 11:00 p.m. EDT on Thursday the center of Typhoon Dujuan was located at latitude 19.4°N and longitude 132.1°E which put it about 575 miles (930 km) south-southeast of Okinawa.  Dujuan was moving toward the north-northwest 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 90 m.p.h. (145 km/h).  The minimum surface pressure was 980 mb.

The circulation around Typhoon Dujuan is becoming increasingly well organized.  A spiral band wrapped entirely around the center of circulation creating a large eye in the middle of the typhoon.  Additional spiral bands are forming, especially in the southern half of the circulation.  Thunderstorms in the eyewall are generating upper level divergence which is increasing with time.  Recent satellite images suggest that they eye may be contracting which would be another sign of intensification.

Dujuan is in an environment that favors intensification.  The Sea Surface Temperatures are warm and the speed of the upper level winds is decreasing.  An upper level ridge west of Dujuan is producing some northerly winds over the top of the typhoon, but the vertical wind shear is decreasing.  Intensification is likely and a period of rapid intensification is possible.  Dujuan could become the equivalent of a major hurricane in 24 to 48 hours.

Typhoon Dujuan is between a subtropical ridge to its northeast and another ridge to its northwest.  As a result, it moved slowly toward the northwest on Thursday.  Dujuan is expected to continue to move in a general northwesterly direction for another day or two.  The ridge west of Dujuan is expected to extend north of the typhoon during the weekend.  When the ridge extends north of Dujuan, it will steer the typhoon more toward the west.

On its anticipated track Typhoon Dujuan could approach the southwestern Ryukyu Islands including Ishigaki JIma in 60 to 72 hours.  Dujuan could be near Taiwan in about three and a half days and it could reach the coast of China in less than five days.  Dujuan could be a large and powerful typhoon capable of bringing strong winds and heavy rain by the time it reaches those areas.

Tropical Storm Dujuan Intensifying Southeast of Okinawa

After several days where vertical wind shear pushed most of the thunderstorms west of the core of the circulation, Tropical Storm Dujuan began to intensify on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Dujuan was located at latitude 18.9°N and longitude 132.7°E which put it about 620 miles (1000 km) southeast of Okinawa.  Dujuan was moving toward the west-northwest at 10 m.p.h. (16 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 988 mb.

The circulation near the core of Tropical Storm Dujuan is showing more organization.  Thunderstorms are developing closer to the center of circulation, although most of the stronger storms are still south and southwest of the center.  The distribution of thunderstorms is an indication that an upper level ridge west of Dujuan is still generating northeasterly winds over the top of the tropical storm.  Some of the storms closer to the center of circulation are starting to generate upper level divergence.

Dujuan is over water where the Sea Surface Temperatures are near 30°C.  Intensification is likely but vertical wind shear could limit the rate of intensification in the short term.  The wind shear is likely to decrease in a day or two as Dujuan moves into an area where the upper level winds are lighter.  Dujuan could become a typhoon within 24 to 36 hours and it could reach the equivalent of a major hurricane during the weekend.

Tropical Storm Dujuan is being steered toward the west-northwest by a subtropical ridge located to its northeast,  That general steering patter is expected to continue for another 24 to 36 hours.  At that time Dujuan will be between the ridge to its east and another upper level ridge to its west, and it could turn toward the northwest for a day or so.  The western ridge is expected to build north of Dujuan and turn it more toward the west in three or four days.  On its anticipated track Dujuan could approach the southern islands of Japan in three or four days.  It could be near Taiwan in five days.  Dujuan could be a strong typhoon by that time.

Typhoon Goni Heading Toward Western Japan

Typhoon Goni turned north-northeastward and began moving toward western Japan on Saturday.  At 5:00 p.m. EDT on Saturday the center of Typhoon Goni was located at latitude 22.7°N and longitude 123.4°E which put it about 270 miles (435 km) southeast of Taipei, Taiwan and about 410 miles (660 km) southwest of Okinawa.  Goni was moving toward the north-northeast at 11 m.p.h. (18 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 967 mb.

The circulation of Typhoon Goni continues to be well organized.  It has a small eye with a fairly continuous eyewall surrounding it.  There are multiple spiral bands and the strongest band is about 60 miles east of the center of circulation.  There is upper level divergence pumping out mass.  Goni is moving over warm Sea Surface Temperatures and the upper level winds are relatively light.  The environment is favorable for intensification and modest intensification is possible during the next day or so.

Goni is moving around the western end of a subtropical ridge which is steering it toward the north-northeast.  That steering pattern is expected to continue for another two or three days.  On its anticipated track Goni will be near Ishigaki Jima in about 12 hours.  It could be just west of Okinawa in about 30 hours and it could be approaching Kyushu in about 48 hours.  Goni will bring strong winds and heavy rains to any places in its path.