Tag Archives: Ishigakijima

Muifa Intensifies to a Typhoon

Former Tropical Storm Muifa intensified to a typhoon over the Western North Pacific Ocean south of the Ryukyu Islands on Friday night. At 11:00 p.m. EDT on Friday the center of Typhoon Muifa was located at latitude 20.9°N and longitude 125.8°E which put it about 260 miles (420 km) south-southeast of Ishigaki, Japan. Muifa was moving toward the northwest at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 95 m.p.h. (150 km/h). The minimum surface pressure was 976 mb.

Former Tropical Storm Muifa strengthened over the warm water in the Western North Pacific Ocean on Friday and it intensified to a typhoon south of the southern Ryukyu Islands. The inner end of a rainband wrapped around the western and southern sides of the center of circulation. A small eye appeared to be developing at the center of Typhoon Muifa. Bands of showers and thunderstorms were revolving around the core of Muifa’s circulation. Storms near the core generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extend out 25 miles (40 km) from the center of Muifa. Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

Typhoon Muifa will move through an environment favorable for intensification during the next 36 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 will intensify during the next 36 hours and it could strengthen to the equivalent of a major hurricane.

Typhoon Muifa will move around the southwestern part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Muifa toward the northwest during the next 36 hours. On its anticipated track Typhoon Muifa could be south of Ishigakijima in 36 hours. Muifa could be the equivalent of a major hurricane when it approaches the southern Ryukyu Islands.

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 Lekima Moves Through Southern Ryukyu Islands

Powerful Typhoon Lekima moved through the southern Ryukyu Islands on Thursday.  At 5:00 p.m. EDT on Thursday the center of Typhoon Lekima was located at latitude 25.8°N and longitude 124.2°E which put it about 405 miles (655 km) south-southeast of Shanghai, China.  Lekima was moving toward the north-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (270 km/h).  The minimum surface pressure was 935 mb.

An inner rainband wrapped around the original eye and eyewall of Typhoon Lekima and a larger outer eye formed around the original eye.  The inner eye remained intact and the strongest winds were occurring in a small ring of thunderstorms around the inner eye.  The diameter of the outer eye was about 60 miles (95 km).  Additional bands of showers and thunderstorms were revolving around the two concentric eyewalls.

The formation of two concentric eyewalls increased the size of the circulation around Typhoon Lekima.  Winds to typhoon force extended out about 80 miles (130 km) from the center of circulation.  Winds to tropical storm force extended out about 275 miles (445 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Lekima was 28.3.  The Hurricane Size Index (HSI) was 28.1 and the Hurricane Wind Intensity Size Index (HWISI) was 56.4.  Those indices indicated that Typhoon Lekima was capable of causing widespread significant damage.

The inner eye of Typhoon Lekima wobbled between Ishigakijima and Miyakojima on Thursday.  The inner eyewall appeared to pass over Taramajima and Minnajima.  No reports were available from a weather station on Taramajima.  Stations on Ishigakijima and Miyakojima reports winds to tropical storm force, but the strong inner eye passed between those two islands.

The formation of the larger outer eye probably indicates that an eyewall replacement cycle will occur.  Typhoon Lekima will weaken when the inner eyewall dissipates.  However, the circulation will remain large.  Typhoon Lekima will be in an environment favorable for strong typhoons during the next 24 hours.  Lekima will move over water where the Sea Surface Temperature is near 28.5°C.  It will move through a region where the upper level winds are not strong and there will not be a lot of vertical wind shear.  Typhoon Lekima will weaken because of an eyewall replacement cycle, but it will remain a large, powerful typhoon.

Typhoon Lekima will move around the western end of a subtropical ridge over the Western North Pacific Ocean.  The ridge will steer Lekima toward the north-northwest during the next several days.  On its anticipated track Typhoon Lekima could approach the coast of China south of Shanghai in about 24 hours.  It is likely to be a large typhoon at that time.

Elsewhere around the Western North Pacific Ocean, Typhoon Krosa was nearly stationary south of Iwo To on Thursday.  At 5:00 p.m. EDT on Thursday the center of Typhoon Krosa was located at latitude 22.1°N and longitude 141.0°E which put it about 195 miles (315 km) south of Iwo To.  Krosa was nearly stationary.  The maximum sustained wind speed was 110 m.p.h. (180 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 950 mb.

The circulation around Typhoon Krosa was also large.  Winds to typhoon force extended out about 75 miles (120 km) from the center of circulation.  Winds to tropical storm force extended out about 250 miles (405 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Krosa was 19.2.  The Hurricane Size Index (HSI) was 28.4 and the Hurricane Wind Intensity Size Index (HWISI) was 47.6.

Typhoon Krosa is forecast to move slowly north toward Iwo To on Friday.  On its anticipated track Krosa could approach Iwo To in about 36 hours.  It will be a large typhoon capable of causing serious damage at that time.