Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Typhoon Surigae Moves away from the Philippines

Typhoon Surigae started to move away from the Philippines on Wednesday. At 5:00 p.m. EDT on Wednesday the center of Typhoon Surigae was located at latitude 19.6°N and longitude 124.9°E which put it about 240 miles (385 km) east-northeast of Aparri, Philippines. Surigae was moving toward the north at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h). The minimum surface pressure was 952 mb.

Typhoon Surigae weakened slowly on Wednesday as it started to move farther away from the Philippines. A large circular eye with a diameter of 70 miles (110 km) was present at the center of Surigae. The eye was surrounded by a ring of strong thunderstorms and the stronger winds were occurring in that ring of storms. Several bands of showers and thunderstorms were revolving around the core of Typhoon Surigae. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

Typhoon Surigae still had a large circulation on Wednesday. Winds to typhoon force extended out 60 miles (95 km) from the center of Surigae. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Surigae was 22.1. The Hurricane Size Index (HSI) was 22.1 and the Hurricane Wind Intensity Size Index (HWISI) was 44.2. Surigae was still the equivalent of a major hurricane.

Typhoon Surigae will move into an environment that will become less favorable for a strong typhoon during the next several days. Surigae will move over cooler water northeast of the Philippines where the Sea Surface Temperatures is near 26°C. In addition, an upper level trough over China will move toward Typhoon Surigae. The trough will produce westerly winds which will blow toward the top of the typhoon. Those winds will cause the vertical wind shear to increase. The combination of cooler water and more wind shear will cause Typhoon Surigae to weaken during the next 48 hours.

The upper level trough will steer Typhoon Surigae toward the east-northeast during the next several days. On its anticipated track Surigae will move away from the Philippines and it will stay southeast of Taiwan and the Ryukyu Islands. Surigae could approach Iwo To by the end of the weekend.

Typhoon Surigae Stalls East of Luzon

Typhoon Surigae stalled east of Luzon on Monday. At 11:00 p.m. EDT on Monday the center of Typhoon Surigae was located at latitude 15.6°N and longitude 126.1°E which put it about 310 miles (500 km) east of Baler, Philippines. Surigae was moving toward the north-northwest at 4 m.p.h. (6 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 944 mb.

Typhoon Surigae completed an eyewall replacement cycle on Monday. The inner eyewall weakened to a swirl of low clouds. There was a large circular eye at the center of Surigae. The eye had a diameter of 60 miles (95 km). The large 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 core of Surigae. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

The eyewall replacement cycle left Typhoon Surigae with a symmetrical circulation. Winds to typhoon force extended out 65 miles (105 km) from the center of Surigae. Winds to tropical storm force extended out 180 miles (290 km) from the center. The Hurricane Intensity Index (HII) for Typhoon Surigae was 25.1. The Hurricane Size Index (HSI) was 23.9 and the Hurricane Wind Intensity Size Index (HWISI) was 49.0.

Typhoon Surigae will move through an environment capable of supporting a strong typhoon during the next 24 hours. Surigae will be over water where the Sea Surface Temperatures will be near 29°C. It will move under the western part of an upper level ridge over the Western North Pacific Ocean. The upper level winds are weak near the end of the ridge and there will be little vertical wind shear. Typhoon Surigae will be moving slowly and it could mix cooler water to the surface. The cooler water could cause Surigae to weaken gradually.

Typhoon Surigae will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next 36 hours. The high will steer Surigae toward the north-northwest during the next 36 hours. After that time Typhoon Surigae will approach the westerly winds in the middle latitudes. Those winds will turn Surigae toward the east. On its anticipated track, the core Typhoon Surigae with the strongest winds will remain east of Luzon.

Typhoon Surigae Spins East of the Philippines

Typhoon Surigae spun east of the Philippines on Sunday. At 5:00 p.m. EDT on Sunday the center of Typhoon Surigae was located at latitude 14.2°N and longitude 126.4°E which put it about 260 miles (420 km) east of Daet, Philippines. Surigae was moving toward the northwest at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (275 km/h). The minimum surface pressure was 934 mb.

An eyewall replacement cycle was underway in the core of Typhoon Surigae and the typhoon was weakening. The inner part of a rainband wrapped around the original eye and eyewall and a much larger outer eyewall formed. The low level winds converged into the outer eyewall and the inner eyewall weakened. The fastest wind speeds were in the inner eyewall. So, the maximum wind speed decreased when the inner eyewall weakened. There were still remnants of the original inner eyewall inside the outer eyewall, but the strongest wind speeds were occurring in the outer eyewall.

Typhoon Surigae was still large and powerful. Winds to typhoon force extended out 60 miles (95 km) from the center of Surigae. Winds to tropical storm force extended out 195 miles (315 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Surigae was 28.3. The Hurricane Size Index (HSI) was 16.9 and the Hurricane Wind Intensity Size Index (HWISI) was 45.2.

Typhoon Surigae will move through an environment capable of supporting a powerful typhoon during the next 24 hours. Surigae will be over water where the Sea Surface Temperatures will be near 29°C. It will move under the western part of an upper level ridge over the Western North Pacific Ocean. The ridge will produce southerly winds which will blow toward the top of the circulation. However, the winds at lower levels in the atmosphere will also blow from the south and there will be little vertical wind shear. Typhoon Surigae will likely weaken gradually as the eyewall replacement cycle is completed.

Typhoon Surigae will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next 48 hours. The high will steer Surigae toward the north-northwest during the next 48 hours. After that time Typhoon Surigae will approach the westerly winds in the middle latitudes. Those winds will turn Surigae toward the northeast. On its anticipated track, the core Typhoon Surigae with the strongest winds will remain east of Luzon.

Typhoon Surigae Rapidly Intensifies to Equivalent of Cat. 5 Hurricane

Typhoon Surigae rapidly intensified to the equivalent of a Category 5 hurricane on the Saffir-Simspson Scale on Saturday. At 11:00 a.m. EDT on Saturday the center of Typhoon Surigae was located at latitude 12.3°N and longitude 128.8°E which put it about 275 miles (445 km) east-southeast of Laoang, Philippines. Surigae was moving toward the northwest at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 180 m.p.h. (290 km/h) and there were wind gusts to 215 m.p.h. (345 km/h). The minimum surface pressure was 900 mb.

Typhoon Surigae continued to intensify rapidly on Saturday. There was a circular eye with a diameter of 20 miles (32 km) at the center of Surigae. The 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 core of Typhoon Surigae. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the typhoon in all directions.

Typhoon Surigae was a large and powerful typhoon. Winds to typhoon force extended out 65 miles (105 km) from the center of Surigae. Winds to tropical storm force extended out 215 miles (345 km) from the center. The Hurricane Intensity Index (HII) for Typhoon Surigae was 42.2. The Hurricane Size Index (HSI) was 23.7 and the Hurricane Wind Intensity Size Index (HWISI) was 65.9.

Typhoon Surigae will move through an environment capable of supporting a powerful typhoon during the next 24 hours. Surigae will be over water where the Sea Surface Temperatures will be near 30°C. It will move under the western part of an upper level ridge over the Western North Pacific Ocean. The ridge will produce southeasterly winds which will blow toward the top of the circulation. However, the winds at lower levels in the atmosphere will also blow from the southeast and there will be little vertical wind shear. Typhoon Surigae may have attained its maximum intensity even though it will move through a very favorable environment. If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Surigae to weaken.

Typhoon Surigae will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next several days. The high will steer Surigae toward the north-northwest during the next 24 hours. After that time Typhoon Surigae will move more toward the north. On its anticipated track the core Typhoon Surigae with the strongest winds is forecast to pass east of the Philippines.

Typhoon Surigae Rapidly Intensifies to Equivalent of Major Hurricane

Typhoon Surigae rapidly intensified to the equivalent of a major hurricane on Friday. At 5:00 p.m. EDT on Friday the center of Typhoon Surigae was located at latitude 10.3°N and longitude 131.6°E which put it about 220 miles (330 km) northwest of Palau. Surigae was moving toward the west-northwest at 10 m.p.h. (16 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 944 mb.

Typhoon Surigae rapidly intensified on Friday as it moved farther away from Palau. A small circular eye was present at the center of circulation. The 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 core of Typhoon Surigae. Storms near the core generated strong upper level divergence that pumped mass away from the typhoon in all directions. The removal of mass allowed the pressure to decrease rapidly.

The circulation around Typhoon Surigae increased in size on Friday. Winds to typhoon force extended out 50 miles (80 km) from the center of Surigae. Winds to tropical storm force extended out 180 miles (290 km) from the center. The Hurricane Intensity Index (HII) for Typhoon Surigae was 25.1. The Hurricane Size Index (HSI) was 18.8 and the Hurricane Wind Intensity Size Index (HWISI) was 43.9. Surigae was a large, dangerous typhoon capable of causing major damage.

Typhoon Surigae will move through an environment favorable for intensification during the next 24 hours. Surigae will be over water where the Sea Surface Temperatures will be near 30°C. It will move under the southwestern part of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds which will blow toward the top of the circulation. However, the winds at lower levels in the atmosphere will also blow from the east and there will be little vertical wind shear. Typhoon Surigae will likely continue to intensify during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Surigae to weaken.

Typhoon Surigae will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next several days. The high will steer Surigae toward the northwest during the next 24 hours. After that time Typhoon Surigae will move more toward the north when it moves around the western end of the high pressure system. On its anticipated track Typhoon Surigae could be east of the Philippines in 36 hours.

Surigae Strengthens to Typhoon North of Palau

Former Tropical Storm Surigae strengthened to a typhoon north of Palau on Thursday night. At 11:00 p.m. EDT on Thursday the center of Typhoon Surigae was located at latitude 8.9°N and longitude 134.2°E which put it about 50 miles (80 km) north of Palau. Surigae was moving toward the west-northwest at 7 m.p.h. (11 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. (165 km/h). The minimum surface pressure was 973 mb. A weather station at the international airport on Palau reported a sustained wind speed of 46 m.p.h. (74 km/h) and a wind gust of 74 m.p.h. (118 km/h). There were reports of trees down and of wind damage on Palau.

Typhoon Surigae was intensifying more rapidly on Thursday night. Microwave satellite images showed an eye forming at the center of Surigae. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. The strongest rainbands were still in the western half of Typhoon Surigae, but more thunderstorms were developing in bands in the eastern half of the circulation. Storms near the center of Surigae were producing strong upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 30 miles (50 km) from the center of Typhoon Surigae. Winds to tropical storm force extended out 160 miles (260 km) from the center.

Typhoon Surigae will move through an environment favorable for intensification during the next 48 hours. Surigae will be over water where the Sea Surface Temperatures will be near 30°C. It will move under the southwestern part of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds which will blow toward the top of the circulation. However, the winds at lower levels in the atmosphere will also blow from the east and there will be little vertical wind shear. Typhoon Surigae will continue to intensify and it could strengthen rapidly once an inner core is fully formed. Surigae could intensify to the equivalent of a major hurricane in 24 hours.

Typhoon Surigae will move around the southwestern part of a subtropical high pressure system over the Western North Pacific Ocean during the next few days. The high will steer Surigae toward the west-northwest during the next two days. After that time Typhoon Surigae will move more toward the north when it moves around the western end of the high pressure system. On its anticipated track Typhoon Surigae could be east of the Philippines in 48 hours. Conditions on Palau will improve gradually on Friday when Surigae moves farther away.

Tropical Storm Surigae Strengthens Northeast of Palau

Tropical Storm Surigae strengthened northeast of Palau on Wednesday. At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Surigae was located at latitude 9.1°N and longitude 136.2°E which put it about 120 miles (195 km) west-southwest of Yap. Serigae was moving toward the west-northwest at 5 m.p.h. (8 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 around Tropical Storm Surigae strengthened on Wednesday, but the distribution of thunderstorms was still asymmetrical. The strongest thunderstorms were occurring in bands in the western half of Surigae. Bands in the eastern half of the circulation consisted primarily of showers and lower clouds. Thunderstorms west of the center of circulation generated upper level divergence that pumped mass away to the west of the tropical storm. Winds to tropical storm force extended out 140 miles (220 km) from the center of Tropical Cyclone Surigae.

Tropical Storm Surigae will move through an environment favorable for intensification during the next several days. Surigae will be over water where the Sea Surface Temperatures will be near 30°C. It will move under the southwestern part of an upper level ridge over the Western North Pacific Ocean. 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 Surigae will continue to intensify and it could strengthen to a typhoon within 24 hours.

Tropical Storm Surigae will move around the southwestern part of a subtropical high pressure system over the Western North Pacific Ocean during the next few days. The high will steer Surigae toward the west-northwest during the next few days. On its anticipated track Tropical Storm Surigae will pass north of Palau during the next 36 hours. Surigae could be east of the Philippines by late this week.

Tropical Storm Surigae Develops Southwest of Yap

Tropical Storm Surigae developed southwest of Yap on Tuesday. At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Surigae was located at latitude 8.2°N and longitude 137.1°E which put it about 35 miles (55 km) west-southwest of Ngulu. Serigae 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 1000 mb.

Former Tropical Depression 02W strengthened southwest of Yap on Tuesday and the Japan Meteorological Agency designated the system as Tropical Storm Surigae. The circulation around Tropical Storm Surigae exhibited more organization on satellite images. Thunderstorms developed near the center of circulation. More thunderstorms also formed in bands revolving around the center of Surigae. Storms near the center of circulation began to generate upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 50 miles (80 km) from the center.

Tropical Storm Surigae will be in an environment favorable for intensification during the next several days. Surigae will be over water where the Sea Surface Temperatures will be near 30°C. It will be under the axis of an upper level ridge over the Western North Pacific Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. The circulation around Tropical Storm Surigae will continue to get better organized. Surigae will intensify and it could strengthen to a typhoon within 48 hours.

Tropical Storm Surigae will move around the southwestern part of a subtropical high pressure system over the Western North Pacific Ocean during the next few days. The high will steer Surigae toward the northwest during the next few days. On its anticipated track Tropical Storm Surigae will pass north of Palau. Bands on the eastern side of Tropical Storm Surigae could bring gusty winds and locally heavy rain to Yap. Persistent heavy rain could cause flash floods. Surigae could be east of the Philippines by late this week.

Tropical Depression Forms Southeast of Yap

A tropical depression formed southeast of Yap on Monday night. At 8:00 p.m. EDT on Monday the center of the tropical depression was located at latitude 7.1°N and longitude 139.9°E which put it about 200 miles (320 km) southeast of Yap. The tropical depression was nearly stationary. 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 1006 mb.

An area of low pressure exhibited more organization on Monday night and the Japan Meteorological Agency designated the system as a tropical depression. The circulation around the tropical depression was in the early stages of organization. There was a broad center of low pressure, but there were not a lot of thunderstorms near the center of circulation. Many of the stronger thunderstorms were occurring in two bands on the periphery of the tropical depression. The strongest rainband was north of the broad center of the depression. Another strong rainband was on the southern periphery of the circulation.

The tropical depression will be in an environment favorable for intensification during the next several days. The depression will be over water where the Sea Surface Temperatures will be near 30°C. It will be under the center of an upper level ridge over the Western North Pacific Ocean. The upper level winds are weak in the center of the ridge and there will be little vertical wind shear. The circulation around the tropical depression is forecast to gradually get better organized and it could strengthen to a tropical storm during the next 24 hours. The depression is forecast to intensify into a typhoon later this week.

The tropical depression will be in an area where the steering winds are weak during the next several days. It will remain nearly stationary during that time period. A subtropical high pressure system over the Western North Pacific Ocean will begin to steer the tropical depression toward the northwest later this week. On its anticipated track the tropical depression will pass near Yap. It will bring gusty winds and locally heavy rain. Persistent heavy rain could cause flash floods.

Dujuan Weakens to a Tropical Depression

Former Tropical Storm Dujuan weakened to a tropical depression on Saturday. At 10:00 a.m. EST on Saturday the center of Tropical Depression Dujuan was located at latitude 8.4°N and longitude 129.6°E which put it about 210 miles (335 km) east of Hinatuan, Philippines. Dujuan was moving toward the west-northwest at 5 m.p.h. (8 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 1003 mb.

Strong easterly winds in the upper troposphere blew the top off of former Tropical Storm Dujuan on Friday night. The circulation in the lower levels gradually weakened and Dujuan was classified as a tropical depression on Saturday. The low level circulation consisted almost entirely of showers and lower clouds during much of Saturday. A few thunderstorms developed northeast of the center of Tropical Depression Dujuan on Saturday night, but it was not clear that the thunderstorms would persist.

Tropical Depression Dujuan will move through an environment unfavorable for intensification during the next 48 hours. Dujuan will move over water where the Sea Surface Temperature is near 28°C. So, there will be enough energy in the upper ocean to support intensification. However, Tropical Depression Dujuan will move under the southern part of an upper level ridge over the Western North Pacific Ocean. The ridge will continue to produce strong easterly winds which will blow toward the top of Dujuan. In addition, a surface high pressure system over eastern Asia will produce strong northeasterly winds in the lower levels. Those winds will transport drier air over the Philippines. The combination of vertical wind shear and drier air will likely prevent intensification of Tropical Depression Dujuan.

Tropical Depression Dujuan will move south of a high pressure system over the Western North Pacific Ocean. The high will steer Dujuan toward the west-northwest during the next several days. On its anticipated track Tropical Depression Dujuan could approach northern Mindano, southern Samar and Cebu in 18 hours. Dujuan will bring gusty winds and locally heavy rain to parts of the central Philippines.