Tag Archives: HWISI

Typhoon Muifa Intensifies to Equivalent of a Major Hurricane

Typhoon Muifa intensified to the equivalent of a major hurricane south of the southern Ryukyu Islands on Saturday afternoon. At 5:00 p.m. EDT on Saturday the center of Typhoon Muifa was located at latitude 22.4°N and longitude 124.9°E which put it about 140 miles (230 km) south-southeast of Ishigaki, Japan. Muifa was moving toward the northwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 135 m.p.h. (230 km/h). The minimum surface pressure was 956 mb.

Typhoon Muifa intensified rapidly to the equivalent of a major hurricane over the Western North Pacific Ocean south of the southern Ryukyu Islands on Saturday. A circular eye with a diameter of 30 miles (50 km) was present at the center of Muifa’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 Muifa. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

The circulation around Typhoon Muifa increased in size when it intensified. Winds to typhoon force extended out 35 miles (55 km/h) from the center of Muifa. Winds to tropical storm force extended out 130 miles (210 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Muifa was 20.6. The Hurricane Size Index (HSI) was 12.6 and the Hurricane Wind Intensity Size Index (HWISI) was 33.2. Typhoon Muifa was capable of causing regional major damage.

Typhoon Muifa will move through an environment favorable for intensification during the next 24 hours. Muifa will move over water where the Sea Surface Temperatures are near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Typhoon Muifa is likely to intensify during the next 24 hours.

Typhoon Muifa will move around the western part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Muifa toward the north-northwest during the next 36 hours. On its anticipated track, the center of Typhoon Muifa could be near Ishigakijima within 36 hours. Muifa is likely to be the equivalent of a major hurricane when it approaches the southern Ryukyu Islands. The center of Typhoon Muifa could pass directly over Ishigakijima. Muifa will produce strong, damaging winds and locally heavy rain. Heavy rain is likely to cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 15W formed west-northwest of Wake Island. At 5:00 p.m. EDT on Saturday the center of Tropical Depression 15W was located at latitude 21.0°N and longitude 160.0°E which put it about 455 miles (735 km) west-southwest of Wake Island. The tropical depression was moving toward the northeast 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 1003 mb.

Hurricane Earl Speeds Northeast

Hurricane Earl sped toward the east over the North Atlantic Ocean south of Newfoundland on Saturday morning. At 5:00 a.m. EDT on Saturday the center of Hurricane Earl was located at latitude 41.2°N and longitude 53.5°W which put it about 380 miles (610 km) south of Cape Race, Newfoundland. Earl was moving toward the northeast at 35 m.p.h. (56 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 955 mb.

Hurricane Earl was making a transition to an extratropical cyclone on Saturday morning. An upper level trough over eastern Canada was producing strong southwesterly winds that were blowing toward the top of Earl’s circulation. Those winds were causing strong vertical wind shear. The wind shear was causing the eyewall around the eye at the center of Hurricane Earl to become fragmented. The eyewall was broken on the southwestern side of the eye. There were still thunderstorms in the northeastern remnant of the eyewall. Bands of showers and thunderstorms in the northeastern part of Earl’s circulation revolved around the center of Earl. Bands in the southwestern part of Hurricane Earl consisted primarily of showers and lower clouds.

Hurricane Earl was almost as large as Hurricane Sandy was in 2012. Winds to hurricane force extended out 90 miles (145 km) from the center of Earl’s circulation. Winds to tropical storm force extended out 415 miles (675 km) from the center of circulation. The Hurricane Intensity Index (HII) was 17.8. The Hurricane Size Index (HSI) was 32.4 and the Hurricane Wind Intensity Size Index (HWISI) was 50.2.

Hurricane Earl will complete the transition to a strong extratropical cyclone during the next 24 hours. Earl will move over water where the Sea Surface Temperatures are colder than 26˚C. The trough over eastern Canada will continue to cause strong vertical wind shear. The colder water and strong vertical wind shear will cause Earl’s structure to compete the transition to an extratropical cyclone.

The westerly winds in the middle latitudes will steer the extratropical cyclone toward the east during the next few days. The extratropical cyclone will weaken gradually over the North Atlantic Ocean south of Greenland during the next week.

Hurricane Kay Strengthens to Cat. 2

Hurricane Kay strengthened to Category 2 on the Saffir-Simpson Scale over the Eastern North Pacific Ocean southwest of Baja California on Wednesday morning. At 8:00 a.m. EDT on Wednesday the center of Hurricane Kay was located at latitude 20.6°N and longitude 112.3°W which put it about 220 miles (355 km) southwest of the southern tip of Baja California. Kay was moving toward the north-northwest at 12 m.p.h. (19 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 975 mb.

A Hurricane Warning was in effect for the portion of the coast from Punta Abreojos to San Jose De Las Palmas, Mexico. A Hurricane Watch was in effect for the portion of the coast from Punta Abreojos to Puerto Cortes, Mexico. A Tropical Storm Warning was in effect for the portion of the coast from Punta Abreojos to Bahia De Los Angeles, Mexico. The Tropical Storm Warning included Cabo San Lucas. A Tropical Storm Watch was in effect for the portion of the coast from Bahia De Los Angeles to San Felipe, Mexico. A Tropical Storm Watch was in effect for the portion of the coast from San Jose De Las Palmas to Cabo San Quintin, Mexico.

Hurricane Kay continue to strengthen on Wednesday morning. A circular eye was present at the center of Kay’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 Hurricane Kay. Storms near the core generated upper level divergence that pumped mass away from the hurricane in all directions.

The circulation around Hurricane Kay was large. Winds to hurricane force extended out 30 miles (50 km) from the center of Kay’s circulation. Winds to tropical storm force extended out 230 miles (370 km) from the center. The Hurricane Intensity Index (HII) for Hurricane Kay was 16.5. The Hurricane Size Index (HSI) was 11.3 and the Hurricane Wind Intensity Size Index (HWISI) was 27.8. Kay was capable of causing regional serious damage.

Hurricane Kay will move through an environment favorable for intensification during the next 18 hours. Kay will move over water where the Sea Surface Temperatures are near 28˚C. It will move through a region where the upper level winds are weak and there will be little wind shear. Hurricane Kay will intensify during the next 18 hours. Kay could strengthen to a major hurricane.

Hurricane Kay will move around the southwestern part of a high pressure system over Mexico. The high pressure system will steer Kay toward the north-northwest during the next 24 hours. On its anticipated track, Hurricane Kay will approach the west coast of Baja California south of Punta Eugenia on Thursday morning. Kay will bring strong winds to the portion of the coast near Punta Eugenia. Bands on the eastern side of Hurricane Kay will drop locally heavy rain over much of Baja California. Heavy rain is likely to cause flash floods in some locations. Widespread outages of electricity could occur in Baja California.

Powerful Typhoon Hinnamnor Heads Toward South Korea

Powerful Typhoon Hinnamnor headed toward South Korea on Sunday night. At 11:00 p.m. EDT on Sunday the center of Typhoon Hinnamnor was located at latitude 30.5°N and longitude 125.3°E which put it about 440 miles (710 km) southwest of Busan, South Korea. Hinnamnor was moving toward the north at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 947 mb.

Typhoon Hinnamnor was a large and dangerous storm as it headed toward South Korea on Sunday night. Winds to typhoon force extended out 80 miles (130 km) from the center of Hinnamnor’s circulation. Winds to tropical storm force extended out 260 miles (420 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Hinnamnor was 23.6. The Hurricane Size Index (HSI) was 29.4 and the Hurricane Wind Intensity Size Index (HWISI) was 53.0. Typhoon Hinnamnor was capable of causing widespread major damage.

The circulation around Typhoon Hinnamnor was very well organized. A small eye with a diameter of 12 miles (19 km) was at the center of Hinnamnor’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 Hinnamnor. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

Typhoon Hinnamnor will move into an environment less favorable for a strong typhoon during the next 24 hours. Hinnamnor will move over water where the Sea Surface Temperatures are 28˚C. An upper level trough over China will produce southwesterly winds that will blow toward the top of Hinnamnor’s circulation. Those winds will cause the vertical wind shear to increase during the next 24 hours. Typhoon Hinnamnor will start to weaken when the wind shear increases.

The upper level trough over China will steer Typhoon Hinnamnor toward the northeast during the next 24 hours. On its anticipated track, the center of Typhoon Hinnamnor will be near Jeju Island in 12 hours. Hinnamnor will approach the coast of South Korea near Busan in 18 hours. Although Typhoon Hinnamnor will weaken as it approaches South Korea, it will still be a large, powerful typhoon. Hinnamnor will bring strong gusty winds and locally heavy rain to South Korea. Heavy rain could cause flash floods in some locations. Typhoon Hinnamnor could also bring gusty winds and locally heavy rain to parts of Japan.

Typhoon Hinnamnor Intensifies Back to Equivalent of a Major Hurricane

Typhoon Hinnamnor intensified back to the equivalent of a major hurricane west of Okinawa on Saturday night. At 11:00 p.m. EDT on Saturday the center of Typhoon Hinnamnor was located at latitude 26.6°N and longitude 124.4°E which put it about 205 miles (330 km) west of Okinawa. Hinnamnor was moving toward the north at 12 m.p.h. (19 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 951 mb.

Typhoon Hinnamnor strengthened back to the equivalent of a major hurricane over the East China Sea west of Okinawa on Saturday night. Two concentric eyewalls appeared to have formed in the middle of Typhoon Hinnamnor. A small inner eye with a diameter of 12 miles (19 km) was that the center of Hinnamnor’s circulation. The inner eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. A much larger, outer eyewall with a diameter of 100 miles (160 km) surrounded the inner eye and eyewall.

The formation of concentric eyewalls caused the size of the circulation around Typhoon Hinnamnor to increase. Winds to typhoon force extended out 70 miles (110 km) from the center of Hinnamnor. Winds to tropical storm force extended out 270 miles (435 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Hinnamnor was 22.1. The Hurricane Size Index (HSI) was 29.3 and the Hurricane Wind Intensity Size Index (HWISI) was 51.4. Typhoon Hinnamnor was capable of causing widespread major damage.

Typhoon Hinnamnor will move through an environment favorable for intensification during the next 24 hours. Hinnamnor will move over water where the Sea Surface Temperatures are 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Typhoon Hinnamnor could intensify until the inner eyewall starts to weaken and an eyewall replacement cycle begins. Hinnamnor will move closer to the upper level westerly winds in the middle latitudes on Monday. The vertical wind shear will increase when that happens and Hinnamnor will weaken.

Typhoon Hinnamnor will move around the western end of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Hinnamnor toward the north during the next 24 hours. Hinnamnor will move toward northeast when it reaches the westerly winds in the middle latitudes. On its anticipated track Typhoon Hinnamnor will move east of Shanghai in 24 hours. Hinnamnor could approach South Korea in 36 hours.

Typhoon Hinnamnor Brings Wind and Rain to Southern Ryukyu Islands

Typhoon Hinnamnor brought wind and rain to the southern Ryukyu Islands on Saturday morning. At 5:00 a.m. EDT on Saturday the center of Typhoon Hinnamnor was located at latitude 24.1°N and longitude 124.6°E which put it about 35 miles (55 km) east-southeast of Ishigaki, Japan. Hinnamnor was moving toward the north at 7 m.p.h. (11 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 967 mb.

Typhoon Hinnamnor strengthened as it moved slowly through the southern Ryukyu Islands on Saturday morning. A small circular eye formed at the center of Hinnamnor’s circulation. The eye was east of Ishigakijima and southwest of Miyakojima. 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 Hinnamnor. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

Typhoon Hinnamnor had a large circulation. Winds to typhoon force extended out 70 miles (110 km) from the center of Hinnamnor. Winds to tropical storm force extended out 225 miles (360 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Hinnamnor was 16.4. The Hurricane Size Index (HSI) was 22.3 and the Hurricane Wind Intensity Size Index (HWISI) was 38.7. Typhoon Hinnamnor was capable of causing widespread serious damage.

Typhoon Hinnamnor will produce strong gusty winds and locally heavy rain over the southern Ryukyu Islands during the next 12 hours. The eastern side of the eyewall could pass over or close to Miyakojima. Strong winds will be capable of causing serious damage. Heavy rain could cause flash floods in some locations. The winds will not be as strong on Ishigakijima because the western side of the eyewall will pass to the east. Weather conditions will improve gradually when Typhoon Hinnamnor moves farther to the north.

Typhoon Hinnamnor will move through an environment favorable for intensification during the next 24 hours. Hinnamnor will move over water where the Sea Surface Temperatures are 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Typhoon Hinnamnor will intensity during the next 24 hours. Hinnamnor could strengthen to the equivalent of a major hurricane.

Typhoon Hinnamnor will move around the western end of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Hinnamnor toward the north during the next 36 hours. On its anticipated track Typhoon Hinnamnor will move across the southern Ryukyu Islands during the next 12 hours. The center of Hinnamnor will be west of Okinawa in 24 hours. Typhoon Hinnamnor could be southeast of Shanghai in 36 hours.

Typhoon Hinnamnor Stalls near Southern Ryukyu Islands

Typhoon Hinnamnor stalled near the southern Ryukyu Islands on Thursday. At 11:00 p.m. EDT on Thursday the center of Typhoon Hinnamnor was located at latitude 21.7°N and longitude 125.3°E which put it about 200 miles (320 km) south-southeast of Ishigaki, Japan. Hinnamnor was moving toward the northwest at 2 m.p.h. (3 km/h). The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h). The minimum surface pressure was 960 mb.

Typhoon Hinnamnor stalled and weakened southeast of the southern Ryukyu Islands on Thursday. When Hinnamnor stalled, strong winds in the lower levels of the atmosphere mixed cooler water to the surface of the Western North Pacific. Typhoon Hinnamnor was unable to extract enough energy from the upper ocean to maintain its intensity and it weakened. The northern and western parts of the eyewall weakened. Most of the thunderstorms were occurring in bands in the eastern and southern parts of Hinnamnor’s circulation. Bands in the northern and western parts of the circulation consisted primarily of showers and lower clouds. Storms near the center of Hinnamnor still generated upper level divergence that pumped mass away from the typhoon.

The size of the circulation around Typhoon Hinnamnor increased on Thursday when the typhoon weakened. Winds to typhoon force extended out 35 miles (55 km) from the center of Hinnamnor. Winds to tropical storm force extended out 230 miles (370 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Hinnamnor was 19.2. The Hurricane Size Index (HSI) was 13.8 and the Hurricane Wind Intensity Size Index (HWISI) was 33.0. Typhoon Hinnamnor was capable of causing regional serious damage.

A high pressure system over the Western North Pacific Ocean will start to steer Typhoon Hinnamnor toward the north during the next 24 hours. On its anticipated track Typhoon Hinnamnor will approach the southern Ryukyu Islands in 24 hours. Hinnamnor will bring strong winds and locally heavy rain to the southern Ryukyu Islands. Heavy rain could cause flash floods in some locations.

Typhoon Hinnamnor will move through an environment unfavorable for intensification during the next 24 hours. The core of Hinnamnor will still be over cooler water that was mixed to the surface for much of Friday. An upper level ridge over China will produce northerly winds that will blow toward the top of Hinnamnor’s circulation. Those winds will cause vertical wind shear which will inhibit intensification. Typhoon Hinnamnor could weaken further during the next 24 hours. Hinnamnor will move over water where the Sea Surface Temperatures are 30˚C during the weekend, when it moves north of the cooler water that has been mixed to the surface. Typhoon Hinnamnor could strengthen again when it moves over warmer water..

Typhoon Hinnamnor Strengthens Back to Equivalent of Cat. 5 Hurricane

Typhoon Hinnamnor strengthened back to the equivalent of a Category 5 hurricane on the Saffir-Simpson southeast of the southern Ryukyu Islands on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Typhoon Hinnamnor was located at latitude 22.4°N and longitude 125.7°E which put it about 165 miles (270 km) southeast of Ishigaki, Japan. Hinnamnor was moving toward the south-southwest at 17 m.p.h. (28 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 Hinnamnor intensified back to the equivalent of a Category 5 hurricane after the completion of an eyewall replacement cycle southeast of the southern Ryukyu Islands. A circular eye with a diameter of 20 miles (32 km) was at the center of Hinnamnor. 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 Hinnamnor. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the typhoon.

The circulation around Typhoon Hinnamnor began to contract again after the completion of the eyewall replacement cycle. Winds to typhoon force extended out 45 miles (75 km) from the center of Hinnamnor. Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Hinnamnor was 35.0. The Hurricane Size Index (HSI) was 15.1 and the Hurricane Wind Intensity Size Index (HWISI) was 50.1. Hinnamnor was capable of causing regional catastrophic damage.

Typhoon Hinnamnor will move through an environment capable of supporting a strong typhoon during the next 24 hours. Hinnamnor will move over water where the Sea Surface Temperatures are 30˚C. It will move through region where the upper level winds are weak and there there will be little vertical wind shear. Typhoon Hinnamnor could maintain its intensity during the next 24 hours unless concentric eyewalls form again.

Typhoon Hinnamnor will finish absorbing the circulation of Tropical Depression 13W that is located southeast of Okinawa during the next 24 hours. At 11:00 p.m. EDT on Wednesday the center of Tropical Depression 13W was located at at latitude 24.5°N and longitude 129.0°E which put it about 185 miles (300 km) southeast of Okinawa. The tropical depression was moving toward the northwest at 17 m.p.h. (28 km/h). The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h). The minimum surface pressure was 1003 mb.

Typhoon Hinnamnor will moved toward the southwest during the next 24 hours as it finishes the absorption of Tropical Depression 13W. On its anticipated track, Typhoon Hinnamnor will move south of the southern Ryukyu Islands during the next 24 hours. Hinnamnor could be in an area where the steering winds are weak after it absorbs the tropical depression. Typhoon Hinnamnor could start to move toward the north back toward the southern Ryukyu Islands on Friday.

Typhoon Hinnamnor Moves South of Okinawa

Typhoon Hinnamnor moved south of Okinawa on Wednesday. At 11:00 a.m. EDT on Wednesday the center of Typhoon Hinnamnor was located at latitude 24.4°N and longitude 127.3°E which put it about 115 miles (185 km) south of Okinawa. Hinnamnor was moving toward the west-southwest at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 175 m.p.h. (280 km/h). The minimum surface pressure was 929 mb.

Concentric eyewalls developed at the center of Typhoon Hinnamnor on Tuesday night. The original eye with a diameter of 10 miles (16 km) was still present at the center of Hinnamnor. The inner end of a rainband wrapped around the original eye and eyewall. An outer eye with a diameter of 60 miles (95 km) surrounded the original eye and eyewall. Typhoon Hinnamnor weakened slightly as the winds in the inner eyewall decreased slightly. The core of Hinnamnor still generated strong upper level divergence that pumped mass away from the typhoon.

The size of the circulation around Typhoon Hinnamnor increased when the concentric eyewalls developed. Winds to typhoon force extended out 35 miles (55 km) from the center of Hinnamnor. Winds to tropical storm force extended out 120 miles (195 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Hinnamnor was 29.9. The Hurricane Size Index (HSI) was 13.4 and the Hurricane Wind Intensity Size Index (HWISI) was 43.3. Hinnamnor was capable of causing regional severe damage.

Typhoon Hinnamnor will move through an environment capable of supporting a strong typhoon during the next 24 hours. Hinnamnor will move over water where the Sea Surface Temperatures are 30˚C. It will move through region where the winds at all levels of the troposphere are blowing from the east. Since the winds at different levels are blowing from the same direction, there will be little vertical wind shear. Even though it will be in a favorable environment, Typhoon Hinnamnor will weaken as the inner eyewall weakens because of the eyewall replacement cycle. More of the low level inflow will become concentrated in the outer eyewall. Hinnamnor could strengthen again after the eyewall replacement cycle is completed.

Typhoon Hinnamnor will interact with Tropical Depression 13W that is located southeast of Okinawa during the next 24 hours. At 11:00 a.m. EDT on Wednesday morning center of Tropical Depression 13W was located at at latitude 22.6°N and longitude 131.6°E which put it about 400 miles (640 km) southeast of Okinawa. The tropical depression was moving toward the north-northwest at 14 m.p.h. (22 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 1000 mb.

Typhoon Hinnamnor will moved toward the southwest during the next 24 hours as it moves around the western side of Tropical Depression 13W. On its anticipated track, Typhoon Hinnamnor will move south of the southern Ryukyu Islands. The much stronger circulation around Typhoon Hinnamnor will eventually absorb the weaker tropical depression. Hinnamnor could be in an area where the steering winds are weak after it absorbs the tropical depression. Typhoon Hinnamnor could meander near the southern Ryukyu Islands later this week.

Typhoon Hinnamnor Intensifies to Equivalent of Cat. 5 Hurricane

Typhoon Hinnamnor intensified to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale over the Western North Pacific Ocean near Minami Daito Jima on Tuesday afternoon. At 5:00 p.m. EDT on Tuesday the center of Typhoon Hinnamnor was located at latitude 26.1°N and longitude 131.2°E which put it about 55 miles (90 km) east-northeast of Minami Daito Jima and about 255 miles (410 km) east of Okinawa. Hinnamnor was moving toward the west 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 915 mb.

Powerful Typhoon Hinnamnor was the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Tuesday afternoon. A circular eye with a diameter of 10 miles (16 km) was at the center of Hinnamnor’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 Hinnamnor. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the typhoon. The removal of large quantities of mass allowed the surface pressure to decrease.

The circulation around Typhoon Hinnamnor contracted in size when the typhoon intensified to Category 5. Winds to typhoon force extended out 25 miles (40 km) from the center of Hinnamnor. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Hinnamnor was 35.0. The Hurricane Size Index (HSI) was 8.8 and the Hurricane Wind Intensity Size Index (HWISI) was 43.8. Hinnamnor was capable of causing regional catastrophic damage.

Typhoon Hinnamnor will move through an environment capable of supporting a strong typhoon during the next 24 hours. Hinnamnor will move over water where the Sea Surface Temperatures are 30˚C. It will move through region where the winds at all levels of the troposphere are blowing from the east. Since the winds at different levels are blowing from the same direction, there will be little vertical wind shear. Typhoon Hinnamnor could maintain much of its intensity during the next 24 hours, if the inner end of rainband does not wrap around the existing eye and eyewall. If concentric eyewalls form, then an eyewall replacement cycle could cause Typhoon Hinnamnor could to weaken temporarily.

Typhoon Hinnamnor will interact with Tropical Depression 13W that formed southeast of Okinawa during the next 24 hours. At 5:00 p.m. EDT on Tuesday morning center of Tropical Depression 13W was located at at latitude 20.5°N and longitude 133.0°E which put it about 555 miles (895 km) southeast of Okinawa. The tropical depression was moving toward the north 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 1000 mb.

Typhoon Hinnamnor will move toward the west-southwest during the next 24 hours when its circulation interacts with the tropical depression. On its anticipated track the core of Typhoon Hinnamnor will be near Minami Daito Jima in a few hours. Hinnamnor could cause catastrophic wind damage on Minami Daito Jima. Very heavy rain could cause flash floods. Typhoon Hinnamnor will also cause a significant storm surge along the coast of Minami Daito Jima. Widespread electrical outages are likely. The center of Hinnamnor could be southeast of Okinawa in 12 hours.

Typhoon Hinnamnor will eventually absorb the circulation around the tropical depression. Hinnamnor could move slowly around the southern Ryukyu Islands while it absorbs the depression. A prolonged period of strong winds and heavy rain could affect the southern Ryukyu Islands later this week.