Tag Archives: Leyte

Tropical Storm Penha Brings Wind and Rain to Southern Philippines

Tropical Storm Penha brought wind and rain to the southern Philippines on Thursday.  At 10:00 a.m. EST on Thursday the center of Tropical Storm Penha was located at latitude 8.7°N and longitude 126.4°E which put the center about 20 miles (30 km) east of Lianga, Philippines.  Penha was moving toward the west-northwest at 11 m.p.h. (17 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 1001 mb.

Tropical Storm Penha brought wind and rain to the southern Philippines on Thursday.  Bands in the western side of Penha’s circulation were dropping rain on northern Mindanao, Leyte, Samar, Bohol, Cebu, and Negros.  Heavy rain could cause flash floods in some locations.

The area of strongest winds in Tropical Storm Penha was relatively small.  Winds to tropical storm force extended out 65 miles (105 km) from the center of Penha’s circulation.

Tropical Storm Penha will move around the southern part of the high pressure system that is south of Japan.  The high pressure system will steer Penha toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Penha will move across northern Mindanao during the next few hours.  Penha will reach the Bohol Sea in 12 hours.  Tropical Storm Penha will be over the northern Sulu Sea in 24 hours.

Tropical Storm Penha will move into an environment that will be unfavorable for intensification during the next 24 hours. Tropical Storm Penha will weaken while the center moves over northern Mindanao.   Penha will then move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southwestern part of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce strong southeasterly winds that will blow toward the top of Penha’s circulation.  The winds will cause strong vertical wind shear.  In addition, Penha will move into a region of drier air by the time it reaches the northern part of the Sulu Sea.  The strong vertical wind shear and the drier air will cause Tropical Storm Penha to continue to weaken even when the center gets back of water.

 

Typhoon Kalmaegi Brings Wind and Rain to the Philippines

Typhoon Kalmaegi brought wind and rain to parts of the Philippines on Monday.  At 10:00 a.m. EST on Monday the center of Typhoon Kalmaegi was located at latitude 10.6°N and longitude 125.6°E which put the center about 50 miles (80 km) east of Abuyog, Philippines.  Kalmaegi was moving toward the west at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 968 mb.

Typhoon Kalmaegi continued to strengthen as it approached the central Philippines on Monday.  A small circular eye developed at the center of Kalmaegi’s circulation.  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 were revolving around the core of Typhoon Kalmaegi.  Storms neat the center of Kalmaegi generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speeds around Typhoon Kalmaegi was symmetrical.  Winds to typhoon force extended out 35 miles (55 km) from the center of Kalmaegi’s circulation.  Winds to tropical storm force extended out 125 miles (200 km) from the center of Typhoon Kalmaegi.

The Hurricane Intensity Index (HII) for Typhoon Kalmaegi was 17.8.  The Hurricane Size Index (HSI) was 13.7 and the Hurricane Wind Intensity Size Index (HWISI) was 31.5.  Typhoon Kalmaegi was similar in size and intensity to Hurricane Sally when Sally hit South Alabama in 2020.

Typhoon Kalmaegi will weaken when the center of circulation passes over the central Philippines.  Kalmaegi will move into an environment favorable for intensification when it reaches the Sulu Sea on Tuesday.  Kalmaegi will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Kalmaegi’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Typhoon Kalmaegi will start to intensify again when it reaches the Sulu Sea.

Typhoon Kalmaegi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Kalmaegi toward the west during the next 24 hours.  On its anticipated track, Typhoon Kalmaegi will move through the central Philippines during the next 24 hours.  The center of Kalmaegi will pass near southern Leyte, Bohol, Cebu, northern Negros, and Panay Island.  Typhoon Kalmaegi will pass near northern Palawan on Tuesday.

Typhoon Kalmaegi will bring strong winds and heavy rain to the central Philippines.  The strongest winds and heaviest rain will occur at Dinagat Island, southern Leyte, Bohol, Cebu, northern Negros, Panay Island, and northern Palawan.  Heavy rain is likely to cause flash floods in some locations.  Typhoon Kalmaegi could also cause a storm surge of up to 10 feet (3 meters) along the coast.

Kalmaegi Strengthens to a Typhoon

Former Tropical Storm Kalmaegi strengthened to a typhoon east of the Philippines on Sunday.  At 10:00 p.m. EST on Sunday the center of Typhoon Kalmaegi was located at latitude 10.5°N and longitude 128.3°E which put the center about 190 miles (305 km) east-northeast of Dinagat, Philippines.  Kalmaegi was moving toward the west-southwest at 15 m.p.h. (24 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 985 mb.

Former Tropical Storm Kalmaegi strengthened to a typhoon east of the Philippines on Sunday.  The inner end of a rainband wrapped around the center of Kalmaegi’s circulation.  Conventional and microwave satellite images indicated that a small eye was forming at the center of Typhoon Kalmaegi.  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 were revolving around the core of Typhoon Kalmaegi.  Storms neat the center of Kalmaegi generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon Kalmaegi was small.  Winds to typhoon force extended out 20 miles (30 km) from the center of Kalmaegi’s circulation.  Winds to tropical storm force extended out 110 miles (175 km) from the center of Typhoon Kalmaegi.

Typhoon Kalmaegi will move through an environment favorable for intensification during the next 12 hours.  Kalmaegi will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southern part of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Kalmaegi’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Typhoon Kalmaegi will intensify during the next 12 hours.  Kalmaegi will weaken when it passes over the Philippines.

Typhoon Kalmaegi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Kalmaegi toward the west during the next 24 hours.  On its anticipated track, Typhoon Kalmaegi will reach the Philippines in 12 hours.  The center of Kalmaegi will pass near Dinagat Island, southern Leyte, Bohol, Cebu, northern Negros, and Panay Island.

Typhoon Kalmaegi will bring strong winds and heavy rain to the central Philippines.  The strongest winds and heaviest rain will occur at Dinagat Island, southern Leyte, Bohol, Cebu, northern Negros, and Panay Island.  Heavy rain is likely to cause flash floods in some locations.  Typhoon Kalmaegi could also cause a storm surge of up to 10 feet (3 meters) along the coast.

Tropical Storm Malakas Passes Between Guam and Yap

Tropical Storm Malakas passed between Guam and Yap on Saturday night. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Malakas was located at latitude 12.0°N and longitude 139.7°E which put it about 345 miles (555 km) west of Guam. Malakas was moving toward the northwest at 29 m.p.h (46 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 982 mb.

Tropical Storm Malakas brought gusty winds and heavy rain to Fais on Saturday night as it passed between Guam and Yap. The circulation around Malakas strengthened on Saturday. The heaviest rain was occurring in a band that was wrapping around the southern side of the center of Tropical Storm Malakas. Other bands of showers and thunderstorms were revolving around the center of Malakas. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 130 miles (210 km) from the center of Malakas.

Tropical Storm Malakas will move through an environment mostly favorable for intensification during the next 36 hours. Malakas will move over water where the Sea Surface Temperatures are near 29˚C. It will move under the southwestern part of an upper level ridge over the Western North Pacific Ocean. The ridge will produce southeasterly winds that will blow toward the top of Malakas’ circulation. Those winds will cause moderate vertical wind shear. The wind shear will inhibit intensification, but the shear will not be large enough to prevent strengthening. Tropical Storm Malakas will intensify during the next 36 hours. Malakas could strengthen to a typhoon during the next 24 hours.

Tropical Storm Malakas will move around the western part of a high pressure system over the Western North Pacific Ocean during the next several days. The high pressure system will steer Malakas toward the northwest during the next 24 hours. On its anticipated track Tropical Storm Malakas will remain west of the Marianas during the next several days. Malakas will move more toward the north when it reaches the western end of the high pressure system. Malakas could approach Iwo To in four days.

Elsewhere over the Western North Pacific Ocean, former Tropical Depression 03W strengthened to Tropical Storm Megi near the Philippines. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Megi was located at latitude 11.3°N and longitude 125.9°E which put it about 25 miles (40 km) east of Guiuan, Philippines. Megi was moving toward the northwest 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. Tropical Storm Megi could drop heavy rain over Samar and Leyte. Locally heavy rain could cause flash floods in some locations.

Typhoon Rai Brings Wind and Rain to the Southern Philippines

Typhoon Rai brought wind and rain to the southern Philippines on Thursday. At 10:00 p.m. EST on Thursday the center of Typhoon Rai was located at latitude 10.0°N and longitude 120.4°E which put it about 140 miles (225 km) east of Puerto Princesa, Philippines. Rai was moving toward the west at 16 m.p.h. (26 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.

Typhoon Rai brought strong winds and heavy rain as it moved across the southern Philippines on Thursday. The core of Typhoon Rai affected Siarago Island, Dinagat Island, northern Mindanao, southern Leyte, Bohol, Cebu, Negros and southern Panay Island. There were reports of wind damage, power outages and flash floods across the southern Philippines.

Typhoon Rai moved over the Sulu Sea on Thursday night and its structure remained well organized. A circular eye was present at the center of Rai’s circulation. The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Rai. Storms near the core of Rai generated upper level divergence that pumped mass away to the west and north of the typhoon.

Winds to typhoon force extended out 45 miles (75 km) from the center of Typhoon Rai. Winds to tropical storm force extended out 155 miles (245 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 20.6. The Hurricane Size Index (HSI) was 13.9 and the Hurricane Wind intensity Size Index (HWISI) was 34.5. Rai was capable of causing regional major damage.

Although Typhoon Rai weakened when the center passed over the islands of the southern Philippines, it will move through an environment capable of supporting a strong typhoon as it moves over the Sulu Sea. Rai will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the southern side of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Typhoon Rai’s circulation. Those winds will cause some vertical wind shear but the wind shear will be too small to cause much weakening. Typhoon Rai is likely to maintain its intensity during the next 24 hours. Rai could strengthen when it moves over the South China Sea during the weekend.

Typhoon Rai will move south of a surface high pressure system over the Western North Pacific Ocean. The high pressure system will steer Rai toward the west during the next 24 hours. On its anticipated track the core of Typhoon Rai will move across Palawan during the next 12 hours. Rai will be capable of causing major damage. It will bring strong winds and heavy rain to Palawan on Friday. Typhoon Rai will move over the South China Sea during the weekend. Rai could approach Vietnam by the end of the weekend.

Typhoon Rai Hits the Southern Philippines

Powerful Typhoon Rai hit the southern Philippines on Thursday morning. At 4:00 a.m. EST on Thursday the center of Typhoon Rai was located at latitude 10.0°N and longitude 125.3°E which put it about 25 miles (40 km) southeast of Maasin, Philippines. Rai was moving toward the west at 17 m.p.h. (28 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 927 mb.

The center of powerful Typhoon Rai made landfall on Siargao Island on Thursday morning. The core of Rai’s circulation moved over Dinagat Island and northern Mindanao. The center of Typhoon Rai was over the Bohol Sea just to the south of Leyte. The inner end of a rainband wrapped around the original eye and eyewall of Typhoon Rai as it hit the southern Philippines. Microwave satellite images indicated that concentric eyewalls formed, which increased the size of the core of Rai. Winds to typhoon force extended out 60 miles (95 km) from the center of Typhoon Rai. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 31.6. The Hurricane Size Index (HSI) was 18.9 and the Hurricane Wind intensity Size Index (HWISI) was 50.5. Rai was capable of causing regional severe damage.

Typhoon Rai will weaken when the center is over land, but it will move through an environment capable of supporting a strong typhoon as it moves over the southern Philippines. Rai will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the southern side of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Typhoon Rai’s circulation. Those winds will cause some vertical wind shear but the wind shear will be too small to cause much weakening. Typhoon Rai weaken gradually when the center passes over land.

Typhoon Rai will move south of a surface high pressure system over the Western North Pacific Ocean. The high pressure system will steer Rai toward the west-northwest during the next 36 hours. On its anticipated track the core of Typhoon Rai will pass over southern Leyte, northern Bohol, Cebu, northern Negros, southern Panay Island, northern Palawan, Linapacan Island, Culion Island and Busuanga Island. Typhoon Rai will weaken when the center passes over land, but it will be the equivalent of a major hurricane as it moves across the southern Philippines. Typhoon Rai will bring very strong winds and locally heavy rain to northern Mindanao, Leyte, Samar, Cebu, Negros, Bohol, Panay Island, Palawan, Linacapan Island, Culion Island and Busuanga Island. Heavy rain could cause flash floods in some locations. Rai will cause a significant storm surge along coasts where the wind blows the water toward the shore. Typhoon Rai could cause severe damage in locations that experience the inner core of the circulation.

Typhoon Rai Rapidly Intensifies to Equivalent of Cat. 5 Hurricane

Typhoon Rai rapidly intensified to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Wednesday night. At 10:00 p.m. EST on Wednesday the center of Typhoon Rai was located at latitude 9.8°N and longitude 126.3°E which put it about 90 miles (145 km) east of Dinagat, Philippines. Rai was moving toward the west at 16 m.p.h. (26 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 915 mb.

Typhoon Rai continued to intensify very rapidly during Wednesday evening and it strengthened to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale. A small circular eye with a diameter of 8 miles (13 km) was at the center of Rai’s 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 Rai. Storms near the core of Rai generated strong upper level divergence that pumped large quantities of mass away to the west and north of the typhoon. The continued rapid removal of mass allowed the surface pressure to decrease very rapidly.

The circulation around Typhoon Rai exhibited more symmetry as it rapidly intensified. Winds to typhoon force extended out 50 miles (80 km) from the center of Rai. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 35.0. The Hurricane Size Index (HSI) was 17.5 and the Hurricane Wind Intensity Size Index (HWISI) was 52.5. Typhoon Rai was capable of doing regional catastrophic damage.

Typhoon Rai will move through an environment favorable for intensification during the next few hours. Rai will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the southern side of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Typhoon Rai’s circulation. Those winds will cause some vertical wind shear but the wind shear will be too small to prevent intensification. Typhoon Rai could continue to strengthen until the center makes landfall in southern Philippines in a few hours. Rai will weaken when the center passes over land.

Typhoon Rai will move south of a surface high pressure system over the Western North Pacific Ocean. The high pressure system will steer Rai toward the west-northwest during the next 36 hours. On its anticipated track the center of Typhoon Rai will pass over Siargao Island in a few hours. The core of Rai will pass over Dinagat Island, southern Leyte, northern Bohol, Cebu, northern Negros and southern Panay Island. Typhoon Rai will weaken when the center passes over land, but it will be the equivalent of a major hurricane when it moves across the southern Philippines. Typhoon Rai will bring very strong winds and locally heavy rain to northern Mindanao, Siargao Island, Dinagat Island, Samar, Leyte, Cebu, Negros, Bohol and Panay Island. Heavy rain could cause flash floods in some locations. Rai will cause a significant storm surge along coasts where the wind blows the water toward the shore. Typhoon Rai could cause catastrophic damage in locations that experience the inner core of the circulation.

Typhoon Rai Rapidly Intensifies to Equivalent of a Major Hurricane

Typhoon Rai rapidly intensified to the equivalent of a major hurricane on Wednesday. At 4:00 p.m. EST on Wednesday the center of Typhoon Rai was located at latitude 9.5°N and longitude 128.3°E which put it about 190 miles (305 km) east of Dinagat, Philippines. Rai was moving toward the west at 13 m.p.h. (20 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 942 mb.

Typhoon Rai intensified very rapidly during Wednesday afternoon and it reached the equivalent of a major hurricane. . A small circular eye with a diameter of 8 miles (13 km) was at the center of Rai’s 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 Rai. Storms near the core of Rai generated strong upper level divergence that pumped large quantities of mass away to the west and north of the typhoon. The removal of mass allowed the surface pressure to decrease rapidly.

The circulation around Typhoon Rai increased in size as it rapidly intensified. Winds to typhoon force extended out 45 miles (75 km) from the center of Rai. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 25.1. The Hurricane Size Index (HSI) was 17.1 and the Hurricane Wind Intensity Size Index (HWISI) was 42.2. Typhoon Rai was capable of doing regional severe damage.

Typhoon Rai will move through an environment favorable for intensification during the next 12 hours. Rai will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the southern side of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Typhoon Rai’s circulation. Those winds will cause some vertical wind shear but the wind shear will be too small to prevent intensification. Typhoon Rai will continue to strengthen during the next 12 hours. Rai could continue to rapidly intensify during the next few hours.

Typhoon Rai will move south of a surface high pressure system over the Western North Pacific Ocean. The high pressure system will steer Rai toward the west-northwest during the next 48 hours. On its anticipated track the center of Typhoon Rai could approach northern Mindanao in 12 hours. Rai will be the equivalent of a major hurricane when it reaches the Philippines. Typhoon Rai will bring very strong winds and locally heavy rain to northern Mindanao, Siargao Island, Dinagat Island, Samar, Leyte, Cebu, Negros, Bohol and Panay Island. Heavy rain could cause flash floods in some locations. Rai will cause a significant storm surge along coasts where the wind blows the water toward the shore.

Typhoon Rai Strengthens East of Mindanao

Typhoon Rai strengthened east of Mindanao on Wednesday morning. At 10:00 a.m. EST on Wednesday the center of Typhoon Rai was located at latitude 9.5°N and longitude 129.3°E which put it about 260 miles (415 km) east of Dinagat, Philippines. Rai was moving toward the west at 12 m.p.h. (19 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 Rai continued to intensify during Tuesday night and Wednesday morning. A small circular eye was at the center of Rai’s 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 Rai. The strongest rainbands were in the western and southern parts of the typhoon. Storms near the core of Rai generated upper level divergence that pumped mass away to the west and north of the typhoon.

The circulation around Typhoon Rai tightened as it intensified. Winds to typhoon force extended out 40 miles (65 km) from the center of Rai. Winds to tropical storm force extended out 125 miles (200 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 13.9. The Hurricane Size Index (HSI) was 10.0 and the Hurricane Wind Intensity Size Index (HWISI) was 23.9. Typhoon Rai was capable of doing regional serious damage.

Typhoon Rai will move through an environment favorable for intensification during the next 18 hours. Rai will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the southern side of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Typhoon Rai’s circulation. Those winds will cause some vertical wind shear but the wind shear will be too small to prevent intensification. Typhoon Rai will continue to strengthen during the next 18 hours. Rai could undergo a period of rapid intensification

Typhoon Rai will move south of a surface high pressure system over the Western North Pacific Ocean. The high pressure system will steer Rai toward the west-northwest during the next 48 hours. On its anticipated track the center of Typhoon Rai could approach northern Mindanao in 18 hours. Rai will be a typhoon when it reaches the Philippines. Typhoon Rai will bring strong winds and locally heavy rain to northern Mindanao, Siargao Island, Dinagat Island, Samar, Leyte, Cebu, Negros, Bohol and Panay Island. Heavy rain could cause flash floods in some locations. Rai will cause a significant storm surge along coasts where the wind blows the water toward the shore.

Rai Intensifies to a Typhoon East of the Philippines

Former Tropical Storm Rai intensified to a typhoon east of the Philippines on Tuesday night. At 10:00 p.m. EST on Tuesday the center of Typhoon Rai was located at latitude 9.0°N and longitude 131.7°E which put it about 180 miles (290 km) northwest of Koror, Palau. Rai was moving toward the west at 12 m.p.h. (19 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 981 mb.

Former Tropical Storm Rai intensified steadily on Tuesday over the Western North Pacific Ocean and it reached typhoon intensity on Tuesday night. A small circular eye formed at the center of Rai. 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 Rai. Storms near the core generated upper level divergence that pumped mass away to the west and north of the typhoon. Winds to typhoon force extended out 45 miles (75 km) from the center of Rai’s circulation. Winds to tropical storm force extended out 180 miles (290 km) from the center.

Typhoon Rai will move through an environment favorable for intensification during the next 24 hours. Rai will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the southern side of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Typhoon Rai’s circulation. Those winds will cause some vertical wind shear but the wind shear will be too small to prevent intensification. Typhoon Rai will continue to strengthen. Rai could intensify more rapidly now that an inner core with an eye and an eyewall has formed.

Typhoon Rai will move south of a surface high pressure system over the Western North Pacific Ocean. The high pressure system will steer Rai toward the west-northwest during the next several days. On its anticipated track the center of Typhoon Rai could approach northern Mindanao in 24 hours. Rai will be a typhoon when it reaches the Philippines. Typhoon Rai will bring strong winds and locally heavy rain to northern Mindanao, Siargao Island, Dinegat Island, Samar, Leyte, Cebu, Negros, Bohol and Panay Island. Rai will cause a significant storm surge along coasts where the wind blows the water toward the shore.