Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Tropical Storm Prapiroon Brings Wind and Rain to Hainan

Tropical Storm Prapiroon brought wind and rain to Hainan on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Prapiroon was located at latitude 19.1°N and longitude 109.9°E which put the center about 65 miles (105 km) south-southwest of Haikou, China.  Prapiroon was moving toward the northwest at 13 m.p.h. (21 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 Prapiroon intensified on Sunday before the center moved over Hainan.  Microwave satellite images indicated that an eye was in the process of forming at the center of Prapiroon’s circulation as the tropical storm made landfall in Hainan.  The formative eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Tropical Storm Prapiroon.

Winds to tropical storm force extended out 70 miles (110 km) from the center of Tropical Storm Prapiroon.

The center of Tropical Storm Prapiroon made landfall on the south coast of Hainan near Lingshui.  The core of Prapiroon’s circulation moved across the center of Hainan.  Storms near the center of Tropical Storm Prapiroon brought heavy rain and strong winds to much of Hainan.  Bands in the northern part of Hainan’s circulation were also bringing gusty winds and heavy rain to parts of southern China.

Tropical Storm Prapiroon will move around the southern side of a high pressure system over southern China.  The high pressure system will steer Prapiroon toward the northwest during the next 24 hours.  On its anticipated track Tropical Storm Prapiroon will move over the Gulf of Tonkin on Monday.  The center of Prapiroon’s circulation could approach the southern coast of China in 24 hours.

Tropical Storm Prapiroon will continue to cause strong winds and locally heavy rain in Hainan during the next few hours.  Heavy rain could cause flash floods in some locations.  Prapiroon will also bring gusty winds and heavy rain to parts of southern China and northeastern Vietnam.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Gaemi strengthened east of Luzon.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Gaemi was located at latitude 17.2°N and longitude 125.7°E which put the center about 525 miles (845 km) south of Ishigakijima, Japan.  Gaemi was moving toward the north-northwest at 3 m.p.h. (5 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 992 mb.

Tropical Storm Prapiroon Forms Over South China Sea

Tropical Storm Prapiroon formed over the South China Sea on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Prapiroon was located at latitude 16.3°N and longitude 111.2°E which put the center about 260 miles (460 km) south-southeast of Haikou, China.  Prapiroon 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 998 mb.

Former Tropical Depression 04W strengthened on Saturday night and the Japan Meteorological Agency designated the system as Tropical Storm Prapiroon.  The circulation around Tropical Storm Prapiroon was exhibiting a little more organization.  There were not a lot of thunderstorms near the center of Prapiroon’s circulation.  Thunderstorms were occurring in bands revolving around the center of Tropical Storm Prapiroon.

Although the circulation around Tropical Storm Prapiroon was large, the area of stronger winds was relatively small.  Winds to tropical storm force extended out 60 miles (95 km) from the center of Prapiroon’s circulation.

Tropical Storm Prapiroon will move through an environment somewhat favorable for intensification during the next 24 hours.  Prapiroon will move over water where the Sea Surface Temperatures are near 30°C.   It will move under the southeastern part of an upper level ridge over China.  The upper level ridge will produce northeasterly winds that will blow toward the top of Prapiroon’s circulation.  Those winds will cause moderate vertical wind shear.  The wind shear will inhibit intensification but the shear may not be strong enough to prevent some strengthening.  Tropical Storm Prapiroon could intensify a little during the next 24 hours.

Tropical Storm Prapiroon will move around the southern part of a high pressure system over eastern China.  The high pressure system will steer Prapiroon toward the northeast during the next 24 hours.  On its anticipated track Tropical Storm Prapiroon will move toward Hainan.

Tropical Storm Prapiroon will bring gusty winds and heavy rain to Hainan during the next 24 hours.  Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Gaemi strengthened gradually east of the Philippines.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Gaemi was located at latitude 17.0°N and longitude 125.5°E which put the center about 485 miles (780 km) south of Ishigakijima, Japan.  Gaemi was moving toward the west-northwest at 9 m.p.h. (15 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 Storm Gaemi Forms East of the Philippines

Tropical Storm Gaemi formed over the Western North Pacific Ocean east of the Philippines early on Saturday.   At 5:00 a.m. EDT on Saturday the center of Tropical Storm Gaemi was located at latitude 16.1°N and longitude 128.2°E which put the center about 520 miles (840 km) south-southeast of Ishigakijima, Japan.  Gaemi was moving toward the northwest at 14 m.p.h. (22 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.

A low pressure system over the Western North Pacific Ocean east of the Philippines strengthened early on Saturday and the Japan Meteorological Agency designated the system as Tropical Storm Gaemi.  The circulation around Tropical Storm Gaemi was starting to exhibit more organization.  More thunderstorms were forming near the center of Gaemi’s circulation.  Thunderstorms were also developing in bands revolving around the center of Tropical Storm Gaemi.  Storms near the center of Gaemi started to generate upper level divergence that pumped mass away from the tropical storm.

Tropical Storm Gaemi will move through an environment favorable for intensification during the next 24 hours.  Gaemi will move over water where the Sea Surface Temperatures are near 30°C.   It will move under the western part of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce southeasterly winds that will blow toward the top of Gaemi’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Gaemi is likely to intensify gradually during the next 24 hours.  Gaemi could strengthen to a typhoon by early next week.

Tropical Storm Gaemi will move around the western part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Gaemi toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Gaemi will move toward the southern Ryukyu Islands.  Gaemi could be a typhoon when it approaches the southern Ryukyu Islands early next week.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 04W formed over the South China Sea.  At 5:00 a.m. EDT on Saturday the center of Tropical Depression 04W was located at latitude 16.1°N and longitude 113.8°E which put the center about 360 miles (580 km) southeast of Haikou, China.   The tropical depression was moving toward the northwest 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 to 45 m.p.h. (75 km/h).   The minimum surface pressure was 999 mb.

Maliksi Drops Rain on Southeastern China

Former Tropical Storm Maliksi dropped rain on parts of southeastern China on Saturday. At 5:00 p.m. EDT on Saturday the center of Tropical Depression Maliksi was located at latitude 23.0°N and longitude 112.0°E which put it about 125 miles (200 km) west of Guangzhou, China. Maliksi was moving toward the north-northeast at 12 m.p.h. (19 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 1002 mb.

Former Tropical Storm Maliksi weakened to a tropical depression after it made landfall on the coast of southern China west of Hong Kong late on Friday. Thunderstorms were still occurring in bands in the eastern and southern parts of Maliksi’s circulation. Some of those thunderstorms were dropping heavy rain on parts of southeastern China. Heavy rain was falling in parts of Guangdong. Prolonged heavy rain could cause floods in some locations.

The circulation around Tropical Depression Maliksi will continue to weaken as it moves over southeastern China. Maliksi could dissipate by the end of the weekend.

Tropical Storm Maliksi Forms Southwest of Hong Kong

Tropical Storm Maliksi formed over the South China Sea southwest of Hong Kong on Friday. At 11:00 a.m. EDT on Friday the center of Tropical Storm Maliksi was located at latitude 21.4°N and longitude 111.6°E which put it about 185 miles (300 km) west-southwest of Hong Kong. Maliksi was moving toward the north-northwest 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 998 mb.

A low pressure system over the South China Sea southwest of Hong Kong strengthened on Friday and the Japan Meteorological Agency designated the system as Tropical Storm Maliksi. The distribution of thunderstorms in Tropical Storm Maliksi was asymmetrical. Thunderstorms were occurring in bands in the southern half of Maliksi’s circulation. Bands in the northern half of the circulation consisted primarily of showers and lower clouds. Storms near the center of circulation generated upper level divergence that pumped mass away to the south of the tropical storm.

The distribution of wind speeds around Tropical Storm Maliksi was also asymmetrical. Winds to tropical storm force extended out 120 miles (195 km) in the southeastern part of Maliksi’s circulation. Winds to tropical storm force only extended out 60 miles (95 km) in the northwestern side of Maliksi.

Tropical Storm Maliksi will move through an environment somewhat favorable for intensification during the next few hours. Maliksi will move over water where the Sea Surface Temperatures are near 29°C. It will move under the eastern part of an upper level ridge over China. The ridge will produce northerly winds that will blow toward the top of Maliksi’s circulation. Those winds will also cause moderate vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Maliksi could intensify a little during the next few hours.

Tropical Storm Maliksi will move around the western side of a high pressure system over the Western North Pacific Ocean. The high pressure will steer Maliksi toward the north during the next 24 hours. On its anticipated track, Tropical Storm Maliksi will make landfall in southern China in a few hours. Maliksi will drop heavy rain over parts of southern China. Heavy rain could cause floods in some locations.

Tropical Storm Ewiniar Weakens South of Japan

Tropical Storm Ewiniar weakened south of Japan on Thursday. At 11:00 a.m. EDT on Thursday the center of Tropical Storm Ewiniar was located at latitude 30.8°N and longitude 137.7°E which put it about 400 miles (645 km) south-southwest of Tokyo, Japan. Ewiniar was moving toward the northeast at 17 m.p.h. (28 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 995 mb.

Strong vertical wind shear and cooler Sea Surface Temperatures caused Tropical Storm Ewiniar to weaken south of Japan on Thursday. No thunderstorms were occurring in Tropical Storm Ewiniar. Bands revolving around the center of Ewiniar’s circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 90 miles (145 km) from the center of Ewiniar.

Tropical Storm Ewiniar will move through an environment that will be unfavorable for intensification during the next 24 hours. Ewiniar will move over water where the Sea Surface Temperatures are near 24°C. An upper level trough northwest of Japan will produce strong westerly winds that will blow across the top of Ewiniar’s circulation. Those winds will cause strong vertical wind shear. The cooler water and strong vertical wind shear will cause Tropical Storm Ewiniar to continue to weaken during the next 24 hours.

Tropical Storm Ewiniar will move around the northern side of a high pressure system over the Western North Pacific Ocean. The high pressure system and the upper level trough northwest of Japan will steer Ewiniar toward the northeast during the next 24 hours. On its anticipated track, Tropical Storm Ewiniar will remain south of Japan. Ewiniar will pass south of Tokyo in 12 hours.

Ewiniar Weakens to a Tropical Storm

Former Typhoon Ewiniar weakened to a tropical storm south of Japan on Wednesday. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Ewiniar was located at latitude 26.9°N and longitude 133.5°E which put it about 120 miles (195 km) northeast of Minamidaitojima, Japan. Ewiniar was moving toward the northeast at 18 m.p.h. (30 km/h). The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h). The minimum surface pressure was 981 mb.

After bringing strong winds and heavy rain to Minamidaitojima, former Typhoon Ewiniar weakened to a tropical storm on Wednesday. An upper level trough northwest of Japan was producing strong southwesterly winds that were blowing toward the top of Ewiniar’s circulation. Those winds were causing strong vertical wind shear. The wind shear caused former Typhoon Ewiniar to weaken.

The strong vertical wind shear was also affecting the structure of Tropical Storm Ewiniar. The strong upper level southwesterly winds were causing the upper part of Ewinar’s circulation to tilt toward the northeast. Thunderstorms were still occurring in bands in the northern and eastern parts of Tropical Storm Ewiniar. Bands in the southern and western parts of Ewiniar consisted primarily of showers and lower clouds.

The circulation around Typhoon Ewiniar was still small. Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

Tropical Storm Ewiniar will move through an environment that will be unfavorable for intensification during the next 24 hours. Ewiniar will move over water where the Sea Surface Temperatures are near 25°C. The upper level trough northwest of Japan will continue to cause strong vertical wind shear. The cooler water and strong vertical wind shear will cause Tropical Storm Ewiniar to weaken during the next 24 hours. If the upper level winds get stronger, they could blow the top off of Ewiniar’s circulation. The cooler water and strong vertical wind shear will also cause Tropical Storm Ewiniar to begin to make a transition to an extratropical cyclone.

Tropical Storm Ewiniar will move around the northern side of a high pressure system over the Western North Pacific Ocean. The high pressure system and the upper level trough northwest of Japan will steer Ewiniar toward the northeast during the next 24 hours. On its anticipated track, Tropical Storm Ewiniar will remain south of Japan.

Typhoon Ewiniar Passes South of Okinawa

Typhoon Ewiniar passed south of Okinawa on Tuesday. At 11:00 a.m. EDT on Tuesday the center of Typhoon Ewiniar was located at latitude 22.1°N and longitude 128.6°E which put it about 350 miles (565 km) south of Okinawa. Ewiniar was moving toward the northeast at 22 m.p.h. (35 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.

Typhoon Ewiniar was weakening as it passed south of Okinawa on Tuesday. An upper level trough west of Japan was producing southwesterly winds that were blowing toward the top of Ewiniar’s circulation. Those winds were causing moderate vertical wind shear. The wind shear was causing Typhoon Ewiniar to weaken.

The vertical wind shear was also affecting the structure of Typhoon Ewiniar. An eye was no longer visible at the center of Ewiniar’s circulation. Thunderstorms were occurring in a band that wrapped around the southern and eastern sides of the center of circulation. Bands in the other parts of Typhoon Ewiniar consisted primarily of showers and lower clouds. Storms near the center of Ewiniar still generated upper level divergence that pumped mass away from the typhoon.

The circulation around Typhoon Ewiniar was still small. Winds to typhoon force extended out 25 miles (40 km) from the center of Ewiniar’s circulation. Winds to tropical storm force extended out 90 miles (145 km) from the center of circulation.

Typhoon Ewiniar will move through an environment that will be unfavorable for intensification during the next 24 hours. Ewiniar will move over water where the Sea Surface Temperatures are near 28°C. The upper level trough west of Japan will continue to cause moderate vertical wind shear. Since the circulation around Ewiniar is small, the wind shear will cause Typhoon Ewiniar to weaken during the next 24 hours.

Typhoon Ewiniar will move around the northern side of a high pressure system over the Western North Pacific Ocean. The high pressure system and the upper level trough west coast of Japan will steer Ewiniar toward the northeast during the next 24 hours. On its anticipated track, Typhoon Ewiniar will pass near Minamidaitojoma in 12 to 18 hours. Ewiniar will bring strong winds and locally heavy rain to Minamidaitojima.

Typhoon Ewiniar Moves Away From Luzon

Typhoon Ewiniar moved away from Luzon on Monday. At 11:00 a.m. EDT on Monday the center of Typhoon Ewiniar was located at latitude 17.4°N and longitude 124.3°E which put it about 185 miles (300 km) east of Tuguegarao, Philippines. Ewiniar was moving toward the northeast at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h). The minimum surface pressure was 966 mb.

After intensifying rapidly on Sunday, Typhoon Ewiniar showed signs of weakening on Monday. A small eye with a diameter of 5 miles (8 km) was still present at the center of Ewiniar’s circulation. However, there were breaks in the ring of thunderstorms surrounding the eye. Storms near the center of Ewiniar still were generating upper level divergence that was pumping mass away from the typhoon. Bands of showers and thunderstorms were revolving around the center of Typhoon Ewiniar.

The circulation around Typhoon Ewiniar was small. Winds to typhoon force extended out 20 miles (30 km) from the center of Ewiniar’s circulation. Winds to tropical storm force extended out 75 miles (120 km) from the center of circulation.

Typhoon Ewiniar will move through an environment that will become less favorable for intensification during the next 24 hours. Ewiniar will move over water where the Sea Surface Temperatures are near 30°C. An upper level trough near the east coast of China will produce southwesterly winds that will blow toward the top of Ewiniar’s circulation. Those winds will cause the vertical wind shear to increase. Since the circulation around Ewiniar is small, an increase in wind shear will have a larger effect on the typhoon. Typhoon Ewiniar is likely to weaken during the next 24 hours when the vertical wind shear increases.

Typhoon Ewiniar will move around the northwestern part of a high pressure system over the Western North Pacific Ocean. The high pressure system and the upper level trough near the east coast of China will steer Ewiniar toward the northeast during the next 24 hours. On its anticipated track, Typhoon Ewiniar will continue to move farther away from Luzon. Ewiniar will pass southeast of the Ryukyu Islands during the next few days.

Elsewhere, Tropical Cyclone Remal continued to drop heavy rain on Bangladesh. There were reports that Remal caused fatalities in Bangladesh. At 5:00 a.m. EDT on Monday the center of Tropical Cyclone Remal was located at latitude 23.1°N and longitude 89.2°E which put it about 85 miles (140 km) southwest of Dhaka, Bangladesh. Remal was moving toward the north-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 979 mb.

Ewiniar Rapidly Intensifies to a Typhoon East of Luzon

Former Tropical Storm Ewiniar rapidly intensified to a typhoon east of Luzon on Sunday. At 11:00 a.m. EDT on Sunday the center of Typhoon Ewiniar was located at latitude 15.2°N and longitude 122.5°E which put it about 125 miles (200 km) east-northeast of Manila, Philippines. Ewiniar was moving toward the northeast at 7 m.p.h. (11 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 966 mb.

Former Tropical Storm Ewiniar rapidly intensified to a typhoon after it moved east of Luzon on Sunday. A very small eye with a diameter of 5 miles (8 km) formed at the center of Typhoon Ewiniar. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms revolved around the center of Ewiniar’s circulation. Storms near the center generated upper level divergence that pumped mass away from the typhoon. The removal of mass caused the surface pressure to decrease rapidly.

The circulation around Typhoon Ewiniar was small. Winds to typhoon force extended out 20 miles (30 km) from the center of Ewiniar’s circulation. Winds to tropical storm force extended out 60 miles (95 km) from the center of circulation.

Typhoon Ewiniar will move through an environment that will be very favorable for intensification during the next 24 hours. Ewiniar will move over water where the Sea Surface Temperatures are near 31°C. It will move under the western part of an upper level ridge over the Western North Pacific Ocean. The upper level ridge will produce southwesterly winds that will blow toward the top of Ewiniar’s circulation. The winds in the lower levels of the atmosphere will also blow from the southwest and there will be little vertical wind shear. Typhoon Ewiniar is likely to intensify during the next 24 hours. Ewiniar could continue to intensify rapidly. If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could interrupt the intensification.

Typhoon Ewiniar will move around the western end of a high pressure system that is east of the Philippines. The high pressure system will steer Ewiniar toward the northeast during the next 24 hours. On its anticipated track, Typhoon Ewiniar will move farther away from Luzon during the next 24 hours. Ewiniar will pass southeast of the Ryukyu Islands during the early part of next week.

Typhoon Ewiniar will continue to produce strong winds and locally heavy rain in Luzon until it moves farther to the northeast. Heavy rain is likely to cause flash floods in some locations.