Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Typhoon Meari Passing Northwest of the Marianas

Typhoon Meari moved northwest of the Marianas on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Meari was located at latitude 20.2°N and longitude 143.2°E which put it about 240 miles (390 km) west-northwest of Agrihan.  Meari was moving toward the northeast at 13 m.p.h. (21 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. (205 km/h).  The minimum surface pressure was 963 mb.

Typhoon Meari strengthened on Saturday.  An eye appeared on visible satellite imagery.  The eyewall is thicker on the southwestern side and thinner on the northeastern side.  There are also more rainbands in the southwestern part of the circulation.  Winds to typhoon force extend out about 70 miles (110 km) from the center of circulation.  Thunderstorms around the core of Typhoon Meari are generating upper level divergence which is pumping out mass.

Typhoon Meari will be moving through a favorable environment for another 12 to 24 hours.  Meari is moving over water where the Sea Surface Temperature is near 30°C.  The typhoon is moving along the transition zone between an upper level trough to its west and an upper level ridge to its east.  There are southwesterly winds blowing across the western side of Typhoon Meari, but those winds are actually enhancing the upper level divergence.  Vertical wind shear will increase when the upper level trough moves closer to the typhoon and Meari will start to weaken early next week.

The upper level trough is steering Typhoon Meari toward the northeast and that general motion is expected to continue for the next several days.  On its anticipated track the center of Typhoon Meari will pass northwest of the northernmost Marianas.  Meari will pass southeast of Iwo To as it moves toward the northern Pacific.

Tropical Storm Meari Intensifies Into a Typhoon

A well organized core developed at the center of Tropical Storm Meari on Friday and it intensified into a typhoon.  At 5:00 p.m. EDT on Friday the center of Typhoon Meari was located at latitude 17.0°N and longitude 140.0°E which put it about 425 miles (685 km) west-northwest of Saipan.  Meari was moving toward the north-northeast 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.

A strong center of circulation finally developed within a broader area of low pressure that contained Tropical Storm Meari.  An inner rainband wrapped around the center and an eye appeared on microwave satellite imagery.  The formation of a tight inner core allowed Meari to strengthen into a typhoon.  There are some rainbands east of the center of Typhoon Meari, but most of the stronger thunderstorms are occurring in bands south and west of the center.  Thunderstorms in the core of Typhoon Meari are now generating upper level divergence which is pumping out mass.  Typhoon Meari is now a well organized tropical cyclone.

Typhoon Meari is moving through an environment that is favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  An upper level ridge is over Meari which is resulting in light winds in the upper levels and little vertical wind shear.  In fact the upper level ridge is enhancing the divergence generated by the typhoon.  Typhoon Meari should continue to strengthen during the next 24 hours.  Since a well formed core now exists at the center, a period of rapid intensification is quite possible.

Typhoon Meari is moving around the western end of a subtropical ridge which is steering it toward the north-northeast.  That general motion is expected to continue for another day or so.  When Typhoon Meari gets farther north, westerly winds from the middle latitudes will push it toward the northeast more quickly.  On its anticipated track, Typhoon Meari could be near the northernmost Marianas in about 36 hours.  Meari could be a strong typhoon at that time.  Although no warnings are currently in effect, people on Alamagan, Pagan and Agrihan need to monitor the movement of Typhoon Meari.

Tropical Storm Meari Reorganizes West of Guam

The circulation designated as Tropical Storm Meari reorganized west of Guam on Thursday.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Meari was located at latitude 15.0°N and longitude 139.0°E which put it about 415 miles (670 km) west of Guam.  Meari was moving toward the north-northeast at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 990 mb.

Tropical Storm Meari initially formed as a smaller counterclockwise circulation within a much broader cyclonic circulation that stretched from the Northern Mariana Islands toward the Philippines.  The initial surface center weakened on Thursday and a new center of circulation organized northeast of the original center.  A primary rainband began to wrap around the southern and east side of the low level center.  Numerous other bands of showers and thunderstorms were forming within the broader cyclonic circulation.  More bands of showers and thunderstorms were developing southwest of the new center and fewer bands were northeast of the center.  The new center of circulation is still consolidating and Tropical Storm Meari still does not have a well developed core.

Although Meari is still not well organized, the tropical storm is moving through an environment that is favorable for intensification.  Tropical Storm Meari is moving over water where the Sea Surface Temperature is near 30°C.  An upper level ridge is located over Tropical Storm Meari and the upper level winds are weak.  So, there is little vertical wind shear.  Warm water and little shear should allow Tropical Storm Meari to continue to intensify.  The lack of a well formed inner core and the large broad cyclonic circulation will slow the rate of strengthening.

The reformation of the center of circulation farther toward the northeast caused the forecast track guidance from numerical models to shift to a more northeasterly track.  If the current center of Tropical Storm Meari persists, it is located near the western end of a subtropical ridge.  Meari is expected to move toward the northeast around the western end of the ridge.  When Meari moves farther north, westerly winds in the middle latitudes will accelerate the tropical storm toward the northeast.

Tropical Storm Meari Forms East of the Philippines

Tropical Storm Meari formed east of the Philippines on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Meari was located at latitude 13.0°N and longitude 136.4°E which put it about 1045 miles (1685 km) east of Manila, Philippines.  Meari was moving toward the west at 10 m.p.h. (16 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.

A distinct center of circulation began to consolidate inside a broad area of low pressure located between Guam and the Philippines on Wednesday.  The center acquired enough characteristics of a tropical cyclone to be classified as Tropical Storm Meari by the Japan Meteorological Agency.  The low level center is still consolidating, but multiple spiral rainbands are forming.  More thunderstorms are forming south and west of the center and there are fewer storms north and east of center.

Tropical Storm Meari formed in an environment that is favorable for further intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  Meari is organizing beneath an upper level ridge which is an area of weaker winds.  There is little vertical wind shear and the upper level ridge is providing some upper level divergence.  Meari is likely to strengthen slowly while the core of the circulation organizes, but it could intensify more quickly once a well formed center exists.  Tropical Storm Meari could eventually strengthen into a typhoon.

A subtropical ridge located north of Meari is slowly steering the tropical storm toward the west.  That general motion is expected to continue during the next few days.  On its anticipated track Tropical Storm Meari will move gradually closer to the Philippines.

Typhoon Haima Brings Gusty Winds and Rain to China

The large eye of Typhoon Haima neared the coast of China on Thursday and the typhoon was bringing gusty winds and heavy rain to the area near Hong Kong.  At 11:00 p.m. EDT on Thursday the center of Typhoon Haima was located at latitude 22.6°N and longitude 115.6°E which put it about 105 miles (170 km) east of Hong Kong.  Haima was moving toward the northwest at 18 m.p.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.

After the center of Typhoon Haima moved northwest of Luzon, a large eye reformed at the center of the typhoon.  The diameter of the eye is about 60 miles (95 km).  The eye is surrounded by a thin ring of thunderstorms and multiple rainbands.  Haima is a large typhoon.  Winds to typhoon force extend out about 70 miles (110 km) from the center and winds to tropical storm force extend out about 240 miles (390 km) from the center.

Typhoon Haima is moving around the western end of a subtropical ridge which is steering it toward the northwest.  Haima is expected to turn more toward the north when it reaches the coast of China.  An upper level trough over eastern Asia will begin to steer Haima toward the northeast on Friday.  On its anticipated track the eye of Typhoon Haima will make landfall on the coast of China near Haifeng and Lufeng.

The Hurricane Intensity Index (HII) for Typhoon Haima is 13.9.  The Hurricane Size Index (HSI) is 27.0 and the Hurricane Wind Intensity Size Index (HWISI) is 40.9.  These indices indicate that Typhoon Haima is capable of causing widespread serious wind damage.  Typhoon Haima will also generate a serious storm surge north of where the eye makes landfall and the wind blows the water toward the coast.  Haima will also bring heavy rain and a threat of floods to Guangdong, Jiangxi and Fujian provinces when it moves inland.

Typhoon Haima Producing Strong Winds and Heavy Rain Over Northern Luzon

Typhoon Haima was producing strong winds and heavy rain as it moved across northern Luzon on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Haima was located at latitude 18.2°N and longitude 120.8°E which put it about 10 miles (15 km) east of Laoag, Philippines.  Haima was moving toward the west-northwest at 20 m.p.h. (32 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (235 km/h).  The minimum surface pressure was 946 mb.

The center of Typhoon Haima moved quickly across northern Luzon on Wednesday.  Haima made landfall on northeastern Luzon east of Tuguegarao.  As it moved toward the west-northwest the center of Typhoon Haima passed near Tuao and Dingras.  The center also passed over the Cordillera Central, where it produced very heavy rain in places where the wind was blowing up the slopes of the mountains.

Movement across the mountain ranges in northern Luzon weakened Typhoon Haima and an eye is no longer evident on satellite images.  However, Haima is still a large, powerful typhoon.  Winds to typhoon force extend out 65 miles (105 km) from the center of circulation.  Winds to tropical storm force extend out about 240 miles (390 km) from the center.  The Hurricane Intensity Index (HII) for Haima is 20.6.  The Hurricane Size Index (HSI) is 25.6 and the Hurricane Wind Intensity Size Index (HWISI) is 46.2.  The indices indicate that Typhoon Haima is capable of causing widespread major wind damage.

The core of Typhoon Haima is not as well organized as it was before the typhoon made landfall in Luzon.   Some reorganization of the core could occur when Typhoon Haima moves over the South China Sea.  Haima will move over water where the Sea Surface Temperature is near 29°C.  The upper level winds are weak and Typhoon Haima is still producing strong upper level divergence which is pumping mass away in all directions.  Typhoon Haima could restrengthen somewhat or maintain its intensity after the center moves northwest of the Philippines.  When Haima nears the coast of China, it will approach an upper level trough and vertical wind shear will increase.  So, Typhoon Haima is likely to be on a weakening trend when it makes landfall in China.

Typhoon Haima is moving around the western end of subtropical ridge which is steering it toward the west-northwest.  Typhoon Haima is likely to move more toward the northwest after it leaves Luzon and reaches the end of the ridge.  When Typhoon Haima nears the coast of China, it will move under southwesterly winds caused by an upper level trough over China.  Those winds will turn Haima more toward the north.  On its anticipated track Typhoon Haima could make a landfall in China northeast of Hong Kong in about 36 hours.

Typhoon Haima will continue to produce strong winds and heavy rains over parts of northern Luzon for a few more hours until the core of the typhoon moves northwest of that region.  The heavy rain has the potential to cause floods and mudslides.  Although Typhoon Haima is likely to be weakening when it reaches the coast of China, it will still be capable of producing strong winds, heavy rain, floods and a storm surge along the coast.

Typhoon Haima Equal to Cat. 5 Hurricane, Threatens Luzon

Typhoon Haima intensified into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of Typhoon Haima was located at latitude 15.9°N and longitude 128.4°E which put it about 400 miles (640 km) east of northern Luzon.  Haima was moving toward the west-northwest at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h).  The minimum surface pressure was 919 mb.

Typhoon Haima completed an eyewall replacement cycle and it intensified as the outer eyewall contracted.  Haima is a very well organized, symmetrical typhoon.  Haima has a clear circular eye surrounded by a ring of very strong thunderstorms.  Thunderstorms in the core of Typhoon Haima are generating strong upper level divergence which is pumping away large quantities of mass in all directions.  Winds to typhoon force extend out about 65 miles (105 km) from the center.

Typhoon Haima is moving through a very favorable environment.  It is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is very little vertical wind shear.  Typhoon Haima is moving on a track that is a little to the north of the track taken by Typhoon Sarika.  This means that the core of Haima is moving north of cooler water mixed to the surface by Typhoon Sarika.  Typhoon Haima could intensify more during the next 12 to 24 hours.  However, if another eyewall replacement cycle occurs, then there could be fluctuations in intensity.

A subtropical ridge is steering Typhoon Haima toward the west-northwest and that general motion is expected to continue for several more days.  On its anticipated track the core of Typhoon Haima will approach northern Luzon in about 24 hours.  After Haima moves across Luzon it will reach the western end of the ridge and turn more toward the northwest.  Typhoon Haima could be near the coast of China in 72 hours.

Haima is an extremely dangerous typhoon.  The Hurricane Intensity Index (HII) for Haima is 35.0.  The Hurricane Size Index (HSI) is 21.2 and the Hurricane Wind Intensity Size Index (HWISI) is 56.2.  The indices indicate that Typhoon Haima is capable of causing widespread catastrophic wind damage.  In addition Typhoon Haima will produce very heavy rain over northern Luzon including over some locations hit by Typhoon Sarika a few days ago.  The heavy rain will create the potential for flash floods and mudslides.  Haima will also generate a significant storm surge in locations where the wind pushes the water toward the coast.

Typhoon Sarika Making Landfall on Hainan Island

The center of Typhoon Sarika is making landfall on Hainan Island near Qionghai and Wanning.  At 11:00 p.m. EDT on Monday the center of Typhoon Sarika was located at latitude 19.1°N and longitude 110.4°E which put it near Qionghai, China.  Sarika was moving toward the west-northwest at 11 m.p.h. (18 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 976 mb.

The structure of Typhoon Sarika changed after it moved across the Philippines.  It developed a larger eye and more of the thunderstorms occurred in a primary rainband that wrapped around the western and southern parts of the circulation.  Sarika maintained that structure as it made landfall on Hainan Island, although were some indications in satellite imagery that they eye was contracting just prior to landfall.

Typhoon Sarika will weaken while the center passes over Hainan Island.  Sarika could be a tropical storm by the time the center emerges over the Gulf of Tongking.  The Sea Surface Temperature in the Gulf of Tongking is near 31°C.  So, evaporation could provide another source of energy and moisture while the center is over water.

Typhoon Sarika is being steered toward the west-northwest by a subtropical ridge and that general motion is expected to continue for another day or so.  On its anticipated track Typhoon Sarika will spend the next few hours moving across Hainan Island.  Sarika could make another landfall over northern Vietnam and southern China in about 24 to 30 hours.

The Hurricane Intensity Index (HII) was 11.5 for Typhoon Sarika.  The Hurricane Size Index (HSI) was 13.2 and the Hurricane Wind Intensity Size Index (HWISI) was 24.7.  These indices indicate that Typhoon Sarika is capable of causing regional, minor wind damage.  Sarika will also bring locally heavy which could cause floods over Hainan Island and parts of northern Vietnam and southern China.

Typhoons Sarika and Haima Churning Over Western North Pacific

Typhoons Sarika and Haima churned across the western North Pacific Ocean on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Sarika was located at latitude 17.3°N and longitude 113.7°E which put it about 240 miles (390 km) east-southeast of Hainan Island.  Sarika was moving toward the west at 17 m.p.h. (27 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 970 mb.

At 11:00 p.m. EDT on Sunday the center of Typhoon Haima was located at latitude 13.2°N and longitude 135.9°E which put it about 935 miles (1505 km) east-southeast of Luzon.  Haima was moving toward the west-northwest at 17 m.p.h. (27 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 956 mb.

The circulation of Typhoon Sarika was disrupted somewhat when it crossed northern Luzon.  Thunderstorms around the eye weakened and breaks developed in the eyewall.  More and stronger thunderstorms developed around the center of circulation today and an eye has become more apparent on satellite imagery.  Numerous rainbands are rotating around the rest of the circulation.  Upper level divergence is increasing, which will increase the removal of mass from the core of Typhoon Sarika.

Typhoon Sarika is moving through an environment that is favorable for intensification.  Sarika is moving over water where the Sea Surface Temperature is above 30°C.  The upper level winds are weak and there is little vertical wind shear.  Typhoon Sarika is likely to intensify during the next 24 hours and it could intensify quickly if the eye finishes reforming.

A subtropical ridge is steering Typhoon Sarika toward the west .  Sarika is nearing the western end of the ridge and the typhoon is expected to turn more toward the northwest.  On its anticipated track Typhoon Sarika could be near Hainan Island in about 24 hours.  After it crosses Hainan Island, Marika could approach the coast of northern Vietnam in about two days.  Typhoon Sarika will bring strong winds and very heavy rain to Hainan.  It will weaken when it moves across Hainan, but Sarika could also bring gusty winds and heavy rain to northern Vietnam and parts of southeastern China.

Typhoon Haima is developing into a very strong and dangerous typhoon.  Haima has a small eye at the center of circulation.  The eye is surrounded by a ring of very strong thunderstorms.  Rainbands are rotating around the core of the circulation.  Thunderstorms in the core of Typhoon Haima are generating upper level divergence which is pumping out mass in all directions.

Typhoon Haima is moving through an environment that is favorable for continued intensification.  It is moving over water where the Sea Surface Temperature is 30°C.  The upper level winds are weak and there is little vertical wind shear.  Typhoon Haima is likely to continue to intensify and it could reach super typhoon status.

A subtropical ridge is steering Typhoon Haima toward the west-northwest and that general motion is expected to continue for several more days.  On its anticipated track Typhoon Haima could be near the northern end of Luzon in about three days.  It could be a very powerful typhoon at that time.

Powerful Typhoon Sarika Makes Landfall in Luzon

Powerful Typhoon Sarika made landfall in Luzon near Baler on Saturday.  At 11:00 a.m. EDT on Saturday the center of Typhoon Sarika was located at latitude 15.3°N and longitude 122.3°E which put it near Baler, Philippines and about 130 miles (210 km) east-northeast of Manila.  Sarika was moving toward the west-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 941 mb.

Sarika is a powerful, well organized typhoon.  It has a circular eye surrounded by a ring of strong thunderstorms.  Additional rainbands are rotating around the core of Sarika.  The core of Typhoon Sarika is generating well developed upper level divergence which is pumping out mass in all directions.  Typhoon Sarika was intensifying rapidly until it made landfall.

The Hurricane Intensity Index (HII) for Typhoon Sarika is 20.6.  The Hurricane Size Index (HSI) is 17.0 and the Hurricane Wind Intensity Size Index (HWISI) is 37.6.  These indices indicate that Typhoon Sarika is capable of causing regional major wind damage.  Typhoon Sarika will also generate a storm surge along the coast of Luzon north of the eye where the wind will push water toward the coast.  Sarika will also produce heavy rain over northern Luzon which will create a risk of flash flooding and mudslides.

A subtropical ridge is steering Typhoon Marika toward the west-northwest and that general motion is expected to continue for several more days.  On its anticipated track across Luzon the center of Typhoon Sarika will pass near San Jose City,  Baguio and Dagupan.  The center of Sarika could emerge over the South China Sea near the Lingayen Gulf.  The core of Typhoon Sarika will move across the Sierra Madre Mountains and the Cordillera Central.  Where winds blow up the slopes of the mountains, rising motion will be stronger and the rainfall will be heavier.  The mountains will also disrupt the airflow in the lower part of Sarika’s circulation and the typhoon will weaken.

It could take the center of Typhoon Sarika about 12 hours to move across Luzon.  The environment of the Sea China Sea will  be favorable for intensification.  The Sea Surface Temperature is warm and there will be little vertical wind shear.  If the core of the circulation remains reasonably intact, then Typhoon Sarika could intensify again while it moves across the South China Sea.  Sarika could eventually move near Hainan Island and into northern Vietnam in a few days.