Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Tropical Storm Nanmadol Brings Wind and Rain to Japan

Tropical Storm Nanmadol brought wind and rain to Japan on Sunday. At 11:00 p.m. EDT on Sunday the center of Tropical Storm Nanmadol was located at latitude 34.5°N and longitude 131.9°E which put it about 30 miles (50 km) west of Hiroshima, Japan. Nanmadol was moving toward the north-northeast at 13 m.p.h. (20 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 976 mb.

Former Typhoon Nanmadol weakened to a strong tropical storm as it moved inland over Kyushu on Sunday. The circulation around Tropical Storm Nanmadol was still large. Winds to tropical storm force extended out 275 miles (445 km) from the center of Nanmadol. The strongest winds and heaviest rain were occurring in band in the eastern and northern parts of Nanmadol. Bands in the southern and western parts of Tropical Storm Nanmadol consisted primarily of showers and lower clouds.

The eye of then Typhoon Nanmadol moved over Kagoshima earlier on Sunday. A weather station in Kagoshima measured a surface pressure of 940.8 mb. The same weather station also measured 7.10 inches (180 mm) of rain. Heavy rain fell over many other locations in Kyushu and there were reports of flash floods in some locations.

An upper level trough northwest of Japan will steer Tropical Storm Nanmadol quickly toward the northeast during the next 36 hours. On its anticipated track Tropical Storm Nanmadol will move over much of Honshu. Nanmadol will bring gusty winds and locally heavy rain to Shikoku and Honshu. Heavy rain could cause flash floods in some locations.

Typhoon Nanmadol Brings Strong Wind and Heavy Rain to Kyushu

Typhoon Nanmadol brought strong winds and heavy rain to Kyushu on Sunday morning. At 5:00 a.m. EDT on Sunday the center of Typhoon Nanmadol was located at latitude 31.1°N and longitude 130.6°E which put it about 40 miles (65 km) south of Kagoshima, Japan. Nanmadol was moving toward the north-northwest at 12 m.p.h. (19 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 969 mb.

The center of Typhoon Nanmadol was moving inland over Kyushu on Sunday morning. Nanmadol was a large an powerful typhoon. Winds to typhoon force extended out 75 miles (120 km) from the center of Nanmadol. Winds to tropical storm force extended out 250 miles (400 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Nanmadol was 19.2. The Hurricane Size Index (HSI) was 30.2 and the Hurricane Wind Intensity Size Index (HWISI) was 51.1. Typhoon Nanmadol was capable of causing extensive serious damage.

Typhoon Nanmadol will move around the western end of a high pressure system over the Western North Pacific Ocean during the next 12 hours. The high pressure system will steer Nanmadol toward the north during that time. On its anticipated track the center of Typhoon Nanmadol will continue to move farther inland over Kyushu. Nanmadol will continue to produce strong gusty winds and locally heavy rain to Kyushu. Heavy rain is likely to cause flash floods in some locations. The westerly winds in the middle latitudes will Nanmadol toward the northeast later today. Typhoon Nanmadol will move over Honshu tomorrow. Nanmadol will bring strong winds and heavy rain to much of Honshu and Shikoku, when it moves northeastward.

Typhoon Nanmadol Near Yakushima

The center of Typhoon Nanmadol was near Yakushima on Saturday night. At 11:00 p.m. EDT on Saturday the center of Typhoon Nanmadol was located at latitude 30.2°N and longitude 130.8°E which put it about 90 miles (145 km) south of Kagoshima, Japan. Nanmadol was moving toward the north-northwest at 14 m.p.h. (22 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.

The eye of Typhoon Nanmadol was just southeast of Yakushima on Saturday night. The northwestern part of the eyewall was over Yakushima. Bands on the northern side of Typhoon Nanmadol were producing gusty winds and locally heavy rain over Kyushu.

Nanmadol was a large typhoon. Winds to typhoon force extended out 70 miles (110 km) from the center of Typhoon Nanmadol. Winds to tropical storm force extended out 275 miles (445 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Nanmadol was 22.1. The Hurricane Size Index (HSI) was 29.0 and the Hurricane Wind Intensity Size Index (HWISI) was 51.1. Typhoon Nanmadol was capable of causing widespread serious damage.

Typhoon Nanmadol will move around the western end of a high pressure system over the Western North Pacific Ocean during the next 24 hours. The high pressure system will steer Nanmadol toward the north during the next 24 hours. On its anticipated track the center of Typhoon Nanmadol will reach southwestern Kyushu in a few hours. Nanmadol will bring strong gusty winds and locally heavy rain to Kyushu. Heavy rain is likely to cause flash floods in some locations. The westerly winds in the middle latitudes will Nanmadol toward the northeast in a day or so. Typhoon Nanmadol will move over Honshu early next week. Nanmadol will bring strong winds and heavy rain to Honshu and Shikoku.

Powerful Typhoon Nanmadol Is East of Okinawa

Powerful Typhoon Nanamadol was east of Okinawa on Friday night. At 11:00 p.m. EDT on Friday the center of Typhoon Nanmadol was located at latitude 26.4°N and longitude 132.7°E which put it about 330 miles (530 km) east of Okinawa. Nanmadol was moving toward the northwest at 9 m.p.h. (15 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 926 mb.

Powerful Typhoon Nanmadol was churning over the Western North Pacific Ocean east of Okinawa on Friday night. A circular eye with a diameter of 23 miles (37 km) was present at the center of Nanmadol. 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 in all directions.

The size of the circulation around Typhoon Nanmadol increased on Friday when Nanmadol intensified. Winds to typhoon force extended out 100 miles (160 km) from the center of Nanmadol. Winds to tropical storm force extended out 260 miles (420 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Nanmadol was 31.6. The Hurricane Size Index (HSI) was 28.0 and the Hurricane Wind Intensity Size Index (HWISI) was 59.6. Typhoon Nanmadol was capable of causing widespread severe damage.

Typhoon Nanmadol will move through an environment capable of supporting a powerful typhoon during the next 24 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 could maintain much of its intensity during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then concentric eyewalls could form. That would be the start of an eyewall replacement cycle that would cause Nanmadol to weaken.

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 the northwest during the next 24 hours. On its anticipated track the center of Typhoon Nanmadol will be east of Minami Daito Jima within 12 hours. Nanmadol could be east of Amami Oshima in 24 hours. Typhoon Nanmadol will bring strong, gusty winds and heavy rain to parts of the northern Ryukyu Islands during the weekend. Nanmadol could be near western Kyushu in 36 hours.

Typhoon Nanmadol Rapidly Intensifies to Equivalent of a Major Hurricane

Typhoon Nanmadol rapidly intensified to the equivalent of a major hurricane south of Japan during Thursday night. At 11:00 p.m. EDT on Thursday the center of Typhoon Nanmadol was located at latitude 24.1°N and longitude 135.4°E which put it about 535 miles (860 km) east-southeast of Okinawa. Nanmadol was moving toward the northwest at 8 m.p.h. (13 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 Nanmadol rapidly intensified to the equivalent of a major hurricane over the Western North Pacific Ocean south of Japan during Thursday night. A well formed circular eye was present 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 strong upper level divergence that pumped mass away from the typhoon in all directions.

The circulation around Typhoon Nanmadol was symmetrical. Winds to typhoon force extended out 60 miles (95 km) from the center of Nanmadol. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Nanmadol was 23.6. The Hurricane Size Index (HSI) was 20.6 and the Hurricane Wind Intensity Size Index (HWISI) was 44.2. Typhoon Nanmadol was capable of causing widespread major damage.

Typhoon Nanmadol will move through an environment favorable for intensification during the next 24 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 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then concentric eyewalls could form. That would be the start of an eyewall replacement cycle that would cause Nanmadol to weaken.

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 the center of Typhoon Nanmadol will be east of Minami Daito Jima within 24 hours. Nanmadol could be east of Amami Oshima in 36 hours. Typhoon Nanmadol will bring strong, gusty winds and heavy rain to parts of the northern Ryukyu Islands during the weekend.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Muifa weakened over the northern Yellow Sea. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Muifa was located at latitude 38.5°N and longitude 121.8°E which put it about 50 miles (80 km) northeast of Yantai, China. Muifa was moving toward the north-northeast at 16 m.p.h. (26 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.

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.

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.

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.