Nanmadol Strengthens to a Typhoon South of Japan

Former Tropical Storm Nanmadol strengthened to a typhoon south of Japan on Thursday morning. At 5:00 a.m. EDT on Thursday the center of Typhoon Nanmadol was located at latitude 23.6°N and longitude 137.5°E which put it about 660 miles (1065 km) east-southeast of Okinawa. Nanmadol was moving toward the west-northwest at 9 m.p.h. (15 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 Nanmadol intensified to a typhoon over the Western North Pacific Ocean south of Japan on Thursday morning. A circular eye formed at the center of Nanmadol’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 Nanmadol. Storms near the core generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 30 miles (50 km) from the center of circulation in the northern side of Nanmadol. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation.

Typhoon Nanmadol will move through an environment favorable for intensification during the next 36 hours. Nanmadol will move over water where the Sea Surface Temperatures are near 29˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Typhoon Nanmadol will intensify during the next 36 hours. It is likely to strengthen to the equivalent of a major hurricane.

Typhoon Nanmadol will move around the southwestern part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Nanmadol toward then northwest during the next 36 hours. On its anticipated track Typhoon Nanmadol could approach the northern Ryukyu Islands in 48 hours. Nanmadol is likely to be a large, dangerous typhoon when it moves near the north Ryukyu Islands.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Muifa weakened over the Yellow Sea and Typhoon Merbok was transitioning to a powerful extratropical cyclone south of the western Aleutian Islands. At 5:00 a.m. EDT on Thursday the center of Tropical Storm Muifa was located at latitude 34.6°N and longitude 120.3°E which put it about 100 miles (160 km) south-southwest of Qingdao, China. Muifa was moving toward the north-northwest at 16 m.p.h. (26 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 994 mb.

At 5:00 a.m. EDT on Thursday the center of Typhoon Merbok was located at latitude 41.0°N and longitude 166.0°E which put it about 890 miles (1435 km) south-southwest of Kiska, Alaska. Merbok was moving toward the north-northeast at 45 m.p.h. (75 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 960 mb.

TD 7 Strengthens to Tropical Storm Fiona, Watches Issued for Leeward Islands

Former Tropical Depression Seven strengthened to Tropical Storm Fiona on Wednesday evening and Tropical Storm Watches were issued for the Leeward Islands. At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Fiona was located at latitude 16.7°N and longitude 52.0°W which put it about 650 miles (1045 km) east of the Leeward Islands. Fiona was moving toward the west at 16 m.p.h. (26 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 1002 mb.

Tropical Storm Watches were in effect for Saba, St. Eustatius, St. Maarten, Antigua, Barbuda, St. Kitts, Nevis, Montserrat and Anguilla.

Remotely sensed data gathered by satellites indicated that the circulation around former Tropical Depression Seven had strengthened on Wednesday evening and the National Hurricane Center upgraded the system to Tropical Storm Fiona. The distribution of thunderstorms in Tropical Storm Fiona was asymmetric. Almost all of the thunderstorms were occurring in bands in the eastern half of Fiona’s circulation. Bands in the western half of the circulation consisted primarily of showers and lower clouds. Storms in the eastern half of the circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 140 miles (220 km) on the eastern side of Tropical Storm Fiona. The winds in the western half of the circulation were blowing at less than tropical storm force.

Tropical Storm Fiona will move through an environment somewhat favorable for intensification during the next 36 hours. Fiona will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western part of an upper level ridge over the tropical Atlantic Ocean. The ridge will produce southwesterly winds that will blow toward the top of Fiona’s circulation. Those winds will cause some vertical wind shear and the wind shear will inhibit intensification. Tropical Storm Fiona could intensify if the upper level winds weaken.

Tropical Storm Fiona will move around the southern side of the subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Fiona toward the west during the next 48 hours. On its anticipated track Tropical Storm Fiona could approach the Leeward Islands on Friday afternoon. Fiona could bring gusty winds and locally heavy rain to the northern Leeward Islands.

Typhoon Muifa Brings Wind and Rain to Eastern China

Typhoon Muifa brought wind and rain to eastern China on Wednesday afternoon. At 5:00 p.m. EDT on Wednesday the center of Typhoon Muifa was located at latitude 31.8°N and longitude 121.5°E which put it about 20 miles (30 km) east of Shanghai, China. Muifa was moving toward the north-northwest at 16 m.p.h. (26 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 978 mb.

Typhoon Muifa brought strong winds and heavy rain to parts of eastern China near Shanghai on Wednesday afternoon. The center of Typhoon Muifa made an initial landfall on the east coast of China southeast of Shanghai near Ningbo. Although Muifa was weakening at the time it made landfall, the northern part of the eyewall was still intact. The strongest winds and heaviest rain were occurring in that part of the eyewall. Bands of showers and thunderstorms were also revolving around the center of Typhoon Muifa. Winds to typhoon force extended out 30 miles (50 km) from the center of Muifa’s circulation. Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

Typhoon Muifa will move around the western side of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Muifa toward the north during the next 24 hours. On its anticipated track Typhoon Muifa will move along the east coast of China. Muifa will continue to bring strong winds and locally heavy rain as it moves along the coast. Heavy rain could fall over coastal areas of Jiangsu and Shandong. Heavy could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Typhoon Merbok was moving quickly toward the far western Aleutian Islands and Tropical Storm Nanmadol was strengthening southwest of Iwo To. At 5:00 p.m. EDT on Wednesday the center of Typhoon Merbok was located at latitude 35.5N and longitude 163.2°E which put it about 1355 miles (2185 km) south-southwest of Kiska, Alaska. Merbok was moving toward the north at 23 m.p.h. (37 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.

At 5:00 p.m. EDT on Wednesday the center of Tropical Strm Nanmadol was located at latitude 23.2°N and longitude 139.4°E which put it about 150 miles (240 km) southwest of Iwo To. Nanmadol was moving toward the west-northwest at 6 m.p.h. (10 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 984 mb.

Tropical Depression Seven Forms East of the Leeward Islands

Tropical Depression Seven formed east of the Leeward Islands on Wednesday morning. At 11:00 a.m. EDT on Wednesday the center of Tropical Depression Seven was located at latitude 16.6°N and longitude 49.6°W which put it about 805 miles (1300 km) east of the Leeward Islands. The tropical depression was moving toward the west at 14 m.p.h. (13 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 1009 mb.

A low pressure system over the Atlantic Ocean east of the Leeward Islands strengthened on Wednesday morning and the National Hurricane Center designated the system as Tropical Depression Seven. The distribution of thunderstorms in Tropical Depression Seven was asymmetric. Many of the thunderstorms were occurring in bands in the eastern half of the tropical depression. Bands in the western half of the circulation consisted primarily of showers and lower clouds. Storms in the eastern half of the circulation generated upper level divergence that pumped mass away from the tropical depression.

Tropical Depression Seven will move through an environment somewhat favorable for intensification during the next 36 hours. The tropical depression will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western part of an upper level ridge over the tropical Atlantic Ocean. The ridge will produce southerly winds that will blow toward the top of the tropical depression. Those winds will cause some vertical wind shear. The wind shear will inhibit intensification, but Tropical Depression Seven is likely to strengthen to a tropical storm.

Tropical Depression Seven will move around the southern side of the subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer the tropical depression toward the west during the next few days. On its anticipated track Tropical Depression Seven could approach the Leeward Islands on Friday afternoon. It could be a tropical storm when it approaches those islands.

Typhoon Muifa Moves Toward Eastern China

Typhoon Muifa moved toward eastern China on Tuesday morning. At 11:00 a.m. EDT on Tuesday the center of Typhoon Muifa was located at latitude 27.2°N and longitude 123.7°E which put it about 280 miles (450 km) south-southeast of Shanghai, China. Muifa was moving toward the north-northwest at 8 m.p.h. (13 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 964 mb.

The circulation around Typhoon Mauifa exhibited good organization on Tuesday morning. A circular eye was present at the center of Muifa. 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 wind field around Typhoon Muifa way very symmetrical. Winds to typhoon force extended out 40 miles (65 km) from the center of Muifa. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Muifa was 17.8. The Hurricane Size Index (HSI) was 17.1 and the Hurricane Wind Intensity Size Index (HWISI) was 34.9. Typhoon Muifa was capable of causing regional serious damage.

Typhoon Muifa will move through an environment that will be unfavorable for intensification during the next 24 hours. Muifa will move over water where the Sea Surface Temperatures are near 27˚C. An upper level trough over China will produce southwesterly winds that will blow toward the top of Muifa’s circulation. Those winds will cause the vertical wind shear to increase during the next 24 hours. The increase in wind shear and cooler water will cause Typhoon Muifa to weaken gradually.

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 24 hours. On its anticipated track Typhoon Muifa will make landfall on the east coast of China south of Shanghai in 18 hours. The center of Muifa could make landfall near Ningbo. Typhoon Muifa will bring strong winds and locally heavy rain to the region around Shanghai. Heavy rain could cause flash floods in some locations in eastern China.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Merbok strengthened north-northwest of Wake Island and Tropical Depression 16W also strengthened southwest of Iwo To. At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Merbok was located at latitude 26.2N and longitude 162.7°E which put it about 500 miles (805 km) north-northwest of Wake Island. Merbok was moving toward the north-northwest at 10 m.p.h. (16 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 984 mb.

At 11:00 a.m. EDT on Tuesday the center of Tropical Depression 16W was located at latitude 22.6N and longitude 139.6°E which put it about 190 miles (310 km) southwest of Iwo To. The tropical depression was moving toward the northeast at 6 m.p.h. (10 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 Muifa Brings Wind and Rain to Southern Ryukyu Islands

Typhoon Muifa brought wind and rain to the southern Ryukyu Islands on Monday. At 11:00 a.m. EDT on Monday the center of Typhoon Muifa was located at latitude 25.2°N and longitude 124.0°E which put it about 55 miles (90 km) north of Ishigaki, Japan. Muifa was moving toward the north-northwest at 5 m.p.h. (8 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 Muifa continued to bring wind and rain to the southern Ryukyu Islands on Monday. The center of Typhoon Muifa was moving slowly away from Ishigakijima. The strongest winds were measured in Ishigakijima after the eye passed over. A weather station on Ishigakijima measured a sustained wind speed of 68 m.p.h. (109 km/h). The same weather station measured a surface pressure of 968.3 mb when the eye of Typhoon Muifa passed over it. The weather station measured 11.71 inches (297.5 mm) of rain during the passage of Muifa. Bands in the eastern side of Muifa’s circulation also dropped heavy rain over Miyakojima.

The circulation around Typhoon Muifa remained well organized on Monday. A circular eye was present at the center of Muifa’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 Muifa. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

Winds to typhoon force extended out 45 miles (75 km) from the center of Typhoon Muifa. Winds to tropical storm force extended out 110 miles (175 km) from the center of Muifa. The Hurricane Intensity Index (HII) for Typhoon Muifa was 16.5. The Hurricane Size Index (HSI) was 15.4 and the Hurricane Wind Intensity Size Index (HWISI) was 31.9. Muifa was capable of causing regional serious damage.

Typhoon Muifa will move through an environment that will become unfavorable for intensification during the next 36 hours. Muifa will move over water where the Sea Surface Temperatures are near 30˚C. However, an upper level trough over China will produce southwesterly winds that will blow toward the top of Muifa’s circulation. Those winds will cause the vertical wind shear to increase during the next 36 hours. The increase in wind shear will cause Typhoon Muifa to start to weaken.

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 slowly toward the north-northwest during the next 36 hours. The strong winds and locally heavy rain in the southern Ryukyu Islands will gradually diminish during the next 24 hours as Typhoon Muifa moves farther away. On its anticipated track Typhoon Muifa could approach the east coast of China south of Shanghai in 36 hours.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Merbok continued to strengthen northwest of Wake Island. At 11:00 a.m. EDT on Monday the center of Tropical Storm Merbok was located at latitude 22.9°N and longitude 162.8°E which put it about 350 miles (565 km) northwest of Wake Island. Merbok was moving toward the northeast at 10 m.p.h. (16 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 994 mb.

Eye of Typhoon Muifa Passes over Ishigakijima

The eye of Typhoon Muifa passed directly over Ishigakijima on Sunday night. A weather station on Ishigakijima measured a surface pressure of 968.3 mb. At 11:00 p.m. EDT on Sunday the center of Typhoon Muifa was located at latitude 24.4°N and longitude 124.2°E which put it about 5 miles (10 km) east of Ishigaki, Japan. Muifa was moving toward the north-northwest at 5 m.p.h. (8 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 Muifa developed two concentric eyewalls and began an eyewall replacement cycle as it slowly approached Ishigakijima on Sunday. The inner end of rainband wrapped around the existing eye and eyewall and a larger outer eyewall surrounded them. Low level convergence became concentrated in the outer eyewall and the thunderstorms in the inner eyewall weakened. The remnants of the inner eyewall were visible on satellite images as a ring of showers and lower clouds. The outer eyewall had a diameter of 60 miles (95 km). The strongest winds were occurring in the outer eyewall. 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 eyewall replacement cycle caused Typhoon Muifa to weaken as it approached Ishigakijima. Winds to typhoon force extended out 35 miles (55 km) from the center of Typhoon Muifa. Winds to tropical storm force extended out 120 miles (195 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Muifa was 16.5. The Hurricane Size Index (HSI) was 13.9 and the Hurricane Wind Intensity Size Index (HWISI) was 30.4. Typhoon Muifa was capable causing regional serious 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 could intensify during the next 24 hours after the inner eyewall completely dissipates. Since Typhoon Muifa will move slowly, its winds could mix cooler water up to the surface of the ocean. Cooler water would limit potential intensification.

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 slowly toward the north-northwest during the next 36 hours. Typhoon Muifa will continue to produce strong winds and locally heavy rain in the southern Ryukyu Islands during the next 24 hours. The strongest winds and heaviest rain are likely to affect Ishigakijima. Gusty winds and locally heavy rain could also affect Miyakojima. On its anticipated track Typhoon Muifa could approach the east coast of China near Shanghai in 60 hours.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Merbok was slowly strengthening west-northwest of Wake Island. At 11:00 p.m. EDT on Sunday the center of Tropical Storm Merbok was located at latitude 21.6°N and longitude 161.6°E which put it about 365 miles (595 km) west-northwest of Wake Island. Merbok was moving toward the east-northeast at 6 m.p.h. (10 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.

Powerful Typhoon Muifa Nears Ishigakijima

Powerful Typhoon Muifa neared Ishigakijima on Sunday morning. At 5:00 a.m. EDT on Sunday the center of Typhoon Muifa was located at latitude 23.1°N and longitude 124.2°E which put it about 85 miles (135 km) south of Ishigaki, Japan. Muifa was moving toward the north-northwest at 5 m.p.h. (8 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 Muifa was the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale as it approached Ishigakijima from the south of Sunday. morning. A small circular eye 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. The inner end of a rainband wrapped part of the way around the eye and eyewall. A second concentric eyewall may be in the process of developing. Other bands of showers and thunderstorms were revolving around the core of Typhoon Muifa’s circulation. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

Winds to typhoon force extended out 40 miles (65 km) from the center of Typhoon Muifa. Winds to tropical storm force extended out 140 miles (225 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Muifa was 25.1. The Hurricane Size Index (HSI) was 15.1 and the Hurricane Wind Intensity Size Index (HWISI) was 40.2. Typhoon Muifa was capable causing regional severe 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. However, two factors could prevent Typhoon Muifa from intensifying even though it will be in a favorable environment. First, if concentric eyewalls develop, then Muifa could weaken when an eyewall replacement cycle occurs. Second, Typhoon Muifa will move slowly and its winds could mix cooler water up to the surface of the ocean. Typhoon Muifa could intensify a little more during the next 12 hours, but it is likely to slowly weaken after that time.

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 slowly toward the north-northwest during the next 36 hours. On its anticipated track, the center of Typhoon Muifa could be over Ishigakijima within 24 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. Ishigakijima is already reporting heavy rain. The wind speeds will increase steadily as the center of Muifa approaches. Typhoon Muifa is capable of causing severe damage. Heavy rain is likely to cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 15W was spinning west-northwest of Wake Island. At 5:00 a.m. EDT on Sunday the center of Tropical Depression 15W was located at latitude 21.4°N and longitude 160.0°E which put it about 460 miles (745 km) west-northwest of Wake Island. The tropical depression was moving toward the east-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.

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.