Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Typhoon Mekkhala Strengthens to Equivalent of Cat. 4 Hurricane

Typhoon Mekkhala strengthened to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Monday as it moved over the Western North Pacific Ocean east of northern Luzon.  At 11:00 a.m. EDT on Monday the center of Typhoon Mekkhala was located at latitude 18.3°N and longitude 125.9°E which put the center about 305 miles (490 km) east of Aparri, Philippines.  Mekkhala was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 145 m.p.h. (235 km/h) and there were wind gusts to 175 m.p.h. (280 km/h).  The minimum surface pressure was 937 mb.

Typhoon Mekkhala strengthened to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Monday.  A circular eye with a diameter of 25 miles (40 km) was present at the center of Typhoon Mekkhala.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Mekkhala’s circulation.  Storms near the center of Mekkhala generated strong upper level divergence that pumped mass away from the typhoon.  The removal of large amounts of mass caused the surface pressure to decrease.

The distribution of winds speeds in Typhoon Mekkhala was fairly symmetrical.  Winds to typhoon force extended out 25 miles (40 km) from the center of Mekkhala’s circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center of Typhoon Mekkhala.

The Hurricane Intensity Index (HII) for Typhoon Mekkhala is 29.9. The Hurricane Size Index (HSI) is 10.0 and the Hurricane Wind Intensity Size Index (HWISI) is 39.9.  Typhoon Mekkhala is similar in intensity to Hurricane Charley when Charley hit Southwest Florida in 2004.  Mekkhala is a little larger than Charley was.

Typhoon Mekkhala will move through an environment favorable for intensification during the next 24 hours.  Mekkhala will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge that is southwest of Japan. The upper level winds are weak in the middle of the ridge and there will be little vertical wind shear.  Typhoon Mekhala could intensify during the next 24 hours unless the inner end of a rainband wraps around the existing eye and eyewall.  If concentric eyewalls form, then an eyewall replacement cycle would cause Mekkhala to weaken.  Typhoon Mekkhala could strengthen to the equivalent of a Category 5 hurricane, if there is no eyewall replacement cycle.

Typhoon Mekkhala will move around the southwestern part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Mekkhala toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Mekkhala will move toward the southern Ryukyu Islands.  Mekkhala could approach the southern Ryukyu Islands in 60 hours.

Typhoon Mekkhala Rapidly Intensifies to Equivalent of Major Hurricane

Typhoon Mekkhala rapidly intensified to the equivalent of a major hurricane on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Mekkhala was located at latitude 17.7°N and longitude 127.4°E which put the center about 415 miles (670 km) east-southeast of Aparri, Philippines.  Mekkhala was moving toward the west at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 961 mb.

Typhoon Mekkhala rapidly intensified to the equivalent of a major hurricane.  The inner end of a rainband wrapped around the center of Mekkhala’s circulation.  A circular eye with a diameter of 25 miles (40 km) formed at the center of Typhoon Mekkhala.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Mekkhala’s circulation.  Storms near the center of Mekkhala generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The distribution of winds speeds in Typhoon Mekkhala became more symmetrical on Sunday.  Winds to typhoon force extended out 25 miles (40 km) from the center of Mekkhala’s circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center of Typhoon Mekkhala.

The Hurricane Intensity Index (HII) for Typhoon Mekkhala is 20.6.  The Hurricane Size Index (HSI) is 10.0 and the Hurricane Wind Intensity Size Index (HWISI) is 30.6.  Typhoon Mekkhala is similar in intensity to Hurricane Delta when Delta hit Southwest Louisiana in 2020.  Mekkhala is a little smaller than Delta was.

Typhoon Mekkhala will move through an environment favorable for intensification during the next 24 hours.  Mekkhala will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge that is southwest of Japan.  The upper level winds are weak in the middle of the ridge and there will be little vertical wind shear.  Typhoon Mekhala will intensify during the next 24 hours.  Mekkhala could continue to intensify rapidly during the next few hours.

Typhoon Mekkhala will move around the southwestern part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Mekkhala toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Mekkhala will move closer to northern Luzon. Mekkhala is likely to move more slowly in a couple of days when it reaches the western end of the high pressure system.  Typhoon Mekkhala is also likely to move toward the north when it reaches the western end of the high pressure system

Mekkhala Strengthens to a Typhoon

Former Tropical Storm Mekkhala strengthened to a typhoon over the Western North Pacific Ocean east of Luzon on Saturday night.  At 5:00 a.m. EDT on Sunday the center of Typhoon Mekkhala was located at latitude 16.4°N and longitude 131.3°E which put the center about 710 miles (1145 km) east-southeast of Aparri, Philippines.  Mekkhala was moving toward the northwest at 14 m.p.h. (22 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 988 mb.

Former Tropical Storm Mekkhala strengthened to a typhoon on Saturday night.  The inner end of a rainband wrapped around the southern side of Mekkhala’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Typhoon Mekkhala.  Storms near the center of Mekkhala generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The strongest winds were occurring in the northern side of Typhoon Mekkhala.  Winds to typhoon force extended out 25 miles (40 km) in the northern half of Mekkhala’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) in the northern side of Typhoon Mekkhala.  Winds to tropical storm force only extended out 40 miles (65 km) in the southern half of Mekkhala’s circulation.

Typhoon Mekkhala will move through an environment favorable for intensification during the next 24 hours.  Mekkhala will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southern part of an upper level ridge that is southwest of Japan. The upper level ridge will produce easterly winds that will blow toward the top of Mekkhala’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Typhoon Mekhala will intensify during the next 24 hours.  Mekkhala could strengthen to the equivalent of a major hurricane during the next few days.

Typhoon Mekkhala will move around the southwestern part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Mekkhala toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Mekkhala will move toward northern Luzon.  Mekkhala is likely to move more slowly in a couple of days when it reaches the western end of the high pressure system.

Tropical Storm Mekkhala Develops North of Yap

Tropical Storm Mekkhala developed over the Western North Pacific Ocean north of Yap on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Mekkhala was located at latitude 14.2°N and longitude 138.0°E which put the center about 315 miles (510 km) north of Yap. Mekkhala was moving toward the west-northwest at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1000 mb.

Former Tropical Depression 07W strengthened north of Yap on Friday and the Japan Meteorological Agency designated it as Tropical Storm Mekkhala.

More thunderstorms developed near the center of Tropical Storm Mekkhala on Friday.  More thunderstorms also formed in the bands revolving around the center of Mekkhala’s circulation.  Storms near the center of Mekkhala generated more upper level divergence that pumped mass away from the tropical storm.  The removal of more mass caused the surface pressure to decrease.

Despite the fact that Tropical Storm Mekkhala strengthened on Friday, the distribution of wind speeds was very asymmetrical.  Winds to tropical storm force extended out 115 miles (185 km) in the northern side of Mekkhala’s circulation.  Winds to tropical storm force extended out only 25 miles (40 km) in the southern side of Tropical Storm Mekkhala.

Tropical Storm Mekkhala will move through an environment favorable for intensification during the next 24 hours.  Mekkhala will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southern part of an upper level ridge that is southwest of Japan.  The upper level ridge will produce northeasterly winds that will blow toward the top of Mekkhala’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Storm Mekhala will intensify during the next 24 hours.  Mekkhala is likely to strengthen to a typhoon during the weekend.

Tropical Storm Mekkhala will move around the southwestern part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Mekkhala toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Mekkhala will move away from Yap.

Tropical Depression Forms West of Guam

Tropical Depression 07W formed over the Western North Pacific Ocean west-southwest of Guam on Thursday night.  At 11:00 p.m. EDT on Thursday the center of Tropical Depression 07W was located at latitude 13.1°N and longitude 142.5°E which put the center about 150 miles (240 km) west-southwest of Guam.  Tropical Depression 07W was moving toward the west-northwest at 17 m.p.h. (28 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 1005 mb.

A low pressure system over the Western North Pacific Ocean west-southwest of Guam strengthened on Thursday night and both the Japan Meteorological Agency and the U.S. Joint Typhoon Warning Center classified the system as a tropical depression.

The distribution of thunderstorms in Tropical Depression 07W was asymmetrical.  Thunderstorms were occurring in bands in the southern half of the tropical depression.  Bands in the northern half of Tropical Depression 07W consisted primarily of showers and lower clouds.  Storms near the center of circulation began to generate upper level divergence that pumped mass away to the west of the tropical depression.  The removal of mass caused the surface pressure to decrease.

Tropical Depression 07W will move through an environment mostly favorable for intensification during the next 24 hours.  The tropical depression will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southern part of an upper level ridge that is southwest of Japan.  The upper level ridge will produce northeasterly winds that will blow toward the top of the tropical depression.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Depression 07W is likely to intensify to a tropical storm during the next 24 hours.  It could strengthen to a typhoon during the weekend.

Tropical Depression 07W will move around the southwestern part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer the tropical depression toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Depression 07W will move away from the Marianas.

Tropical Storm Jangmi Brings Wind and Rain to Japan

Tropical Storm Jangmi brought wind and rain to parts of Japan on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Jangmi was located at latitude 32.8°N and longitude 134.3°E which put the center about 135 miles (215 km) southwest of Osaka, Japan.  Jangmi was moving toward the northeast at 29 m.p.h. (46 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 984 mb.

Tropical Storm Jangmi was bringing wind and rain to parts of Honshu on Tuesday.  A weather station at Kansai International Airport in Osaka (RJBB) reported a sustained wind speed of 43 m.p.h. (68 km/h) and a wind gust of 55 m.p.h. (89 km/h).

Tropical Storm Jangmi was making a transition to an extratropical cyclone on Tuesday.  The circulation around Jangmi was interacting with a stationary front that was just south of Japan.  The interaction with the front was causing the distribution of thunderstorms in Tropical Storm Jangmi to become more asymmetrical.  Thunderstorms were occurring in bands in the eastern and northern parts of Jangmi’s circulation.  Bands in the western and southern parts of Tropical Storm Jangmi consisted primarily of showers and lower clouds.

The circulation around Tropical Storm Jangmi was still large. Winds to tropical storm force extended out 240 miles (390 km) from the center of Jangmi’s circulation.

Tropical Storm Jangmi will move through an environment that will be unfavorable for intensification of a tropical cyclone during the next 24 hours.  Jangmi will move over water where the Sea Surface Temperatures are near 23°C.  It will move under the eastern part of an upper level trough that is over South Korea.  The upper level trough will produce strong southwesterly winds that will blow toward the top of Jangmi’s circulation.  Those winds will cause strong vertical wind shear.  The cool Sea Surface Temperature and the strong vertical wind shear will cause Tropical Storm Jangmi to continue to make a transition to an extratropical cyclone during the next 24 hours.

The upper level trough over South Korea will steer Tropical Storm Jangmi toward the east-northeast during the next 24 hours.  On its anticipated track, the center of Tropical Storm Jangmi will pass near Tokyo in 18 hours.

Tropical Storm Jangmi will continue to bring strong winds and locally heavy rain to parts of Honshu.  Heavy rain could cause flash floods in some locations.

Jangmi Brings Wind and Rain to Okinawa

Tropical Storm Jangmi brought wind and rain to Okinawa on Monday.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Jangmi was located at latitude 27.3°N and longitude 128.0°E which put the center about 25 miles (40 km) northwest of Okinawa.  Jangmi was moving toward the north at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 85 m.p.h. (130 km/h).  The minimum surface pressure was 982 mb.

Tropical Storm Jangmi brought wind and rain to Okinawa on Monday.  A weather station at Kadena Air Force Base in Okinawa (RODN) reported a sustained wind speed of 52 m.p.h. (84 km/h) and a wind gust of 71 m.p.h. (115 km/h).

Former Typhoon Jangmi weakened back to a tropical storm Monday.  A large eye with a diameter of 60 miles (95 km) was still present at the center of Tropical Storm Jangmi.  The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms.

The circulation around Tropical Storm Jangmi was pulling drier air around the western and southern parts of Jangmi’s circulation.  Thunderstorms were still occurring in bands in the eastern and northern parts of Tropical Storm Jangmi.  Bands in the western and southern sides of Jangmi’s circulation consisted primarily of showers and lower clouds.

Storms near the center of Jangmi generated upper level divergence that pumped mass away to the northeast of the tropical storm.  However, the removal of mass in the upper levels of the atmosphere was less than the convergence of mass in the lower levels.  So, the surface pressure increased gradually.

The circulation around Tropical Storm Jangmi was still large.  Winds to tropical storm force extended out 205 miles (330 km) from the center of Jangmi’s circulation.

Tropical Storm Jangmi will move through an environment that will be unfavorable for intensification during the next 24 hours.  Jangmi will move over water where the Sea Surface Temperatures are near 26°C. It will move under the eastern part of an upper level trough that is over the east coast of China.  The upper level trough will produce southwesterly winds that will blow toward the top of Jangmi’s circulation.  Those winds will cause the moderate vertical wind shear. Tropical Storm Jangmi will continue to weaken slowly during the next 24 hours.

The upper level trough over the east coast of China will steer Tropical Storm Jangmi toward the northeast during the next 24 hours.  On its anticipated track, the center of Jangmi will move over the northern Ryukyu Islands.  The center of Tropical Storm Jangmi will be southeast of Kyushu in 18 hours.

Tropical Storm Jangmi will bring strong winds and locally heavy rain to the northern Ryukyu Islands.  Heavy rain could cause flash floods in some locations. Jangmi will also bring strong winds and heavy rain to parts of Kyushu, Shikoku, and Honshu.

Typhoon Jangmi Approaches Okinawa

Typhoon Jangmi was approaching Okinawa on Sunday.  At 11:00 a.m. EDT on Sunday the center of Typhoon Jangmi was located at latitude 23.3°N and longitude 127.7°E which put the center about 255 miles (410 km) south of Okinawa.  Jangmi was moving toward the north at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 973 mb.

The northern part of Typhoon Jangmi was already affecting Okinawa on Sunday morning.  A weather station at Kadena Air Force Base (RODN) was reporting a sustained wind speed of 25 m.p.h. (40 km/h) and a wind gusts of 35 m.p.h. (55 km/h) even though the center of Jangmi was 255 miles (410 km) south of the station.

Typhoon Jangmi continued to intensify slowly during Saturday night.   A very large circular eye was at the center of Typhoon Jangmi.  The eye had a diameter of 80 miles (130 km).  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 center Jangmi’s circulation.  Storms near the center of Jangmi generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon Jangmi was large.  Winds to typhoon force extended out 90 miles (145 km) from the center of Jangmi’s circulation.  Winds to tropical storm force extended out 230 miles (370 km) from the center of Typhoon Jangmi.

The Hurricane Intensity Index (HII) for Typhoon Jangmi was 12.7.  The Hurricane Size Index (HSI) was 29.7 and the Hurricane Wind Intensity Size Index (HWISI) was 42.4.

Typhoon Jangmi will move into an environment that will become unfavorable for intensification during the next 24 hours.  Jangmi will move over water where the Sea Surface Temperatures are near 26°C.  It will move under the eastern part of an upper level trough that is over the east coast of China.  The upper level trough will produce southwesterly winds that will blow toward the top of Jangmi’s circulation.  Those winds will cause the vertical wind shear to increase.  Typhoon Jangmi will start to weaken slowly when the vertical wind shear increases.

Typhoon Jangmi will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Jangmi toward the north during the next 24 hours.  On its anticipated track, the center of Typhoon Jangmi will reach Okinawa in 18 hours.

Typhoon Jangmi will bring strong winds and locally heavy rain to the Ryukyu Islands including Okinawa.  Heavy rain is could cause flash floods in some locations.  Typhoon Jangmi could also cause a storm surge of up to 10 feet (3 meters) along portions of the coasts of the Ryukyu Islands.

 

Jangmi Strengthens to a Typhoon

Former Tropical Storm Jangmi strengthened to a typhoon on Saturday.  At 11:00 a.m. EDT on Saturday the center of Typhoon Jangmi was located at latitude 19.7°N and longitude 128.8°E which put the center about 500 miles (805 km) south of Okinawa.  Jangmi was moving toward the north-northwest at 14 m.p.h. (22 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 979 mb.

Former Tropical Storm Jangmi strengthened to a typhoon south of Okinawa on Saturday.  A very large circular eye formed at the center of Typhoon Jangmi.  The eye had a diameter of 70 miles (110 km).  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 center Jangmi’s circulation.  Storms near the center of Jangmi generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon Jangmi was large.  Winds to typhoon force extended out 90 miles (145 km) from the center of Jangmi’s circulation.  Winds to tropical storm force extended out 205 miles (335 km) from the center of Typhoon Jangmi.

Typhoon Jangmi will move through an environment favorable for intensification during the next 24 hours.  Jangmi will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge that is southwest of Japan.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear. Typhoon Jangmi will intensify during the next 24 hours.

Typhoon Jangmi will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Jangmi toward the north-northwest during the next 24 hours.  On its anticipated track, Typhoon Jangmi will approach Okinawa in 36 hours.

Typhoon Jangmi will bring strong winds and locally heavy rain to the Ryukyu Islands including Okinawa.  Heavy rain is could cause flash floods in some locations.  Typhoon Jangmi could also cause a storm surge of up to 10 feet (3 meters) along portions of the coasts of the Ryukyu Islands.

Tropical Storm Jangmi Continues to Intensify

Tropical Storm Jangmi continued to intensify over the Western North Pacific Ocean on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Jangmi was located at latitude 17.0°N and longitude 130.4°E which put the center about 705 miles (1135 km) south-southeast of Okinawa.  Jangmi was moving toward the west-northwest at 12 m.p.h. (19 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 989 mb.

Tropical Storm Jangmi continued to intensify as it moved over the Western North Pacific Ocean south-southeast of the Ryukyu Islands on Friday.  The inner end of a rainband wrapped around the center of Jangmi’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Tropical Storm Jangmi.  Storms near the center of Jangmi generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Storm Jangmi was large.  Winds to tropical storm force extended out 185 miles (295 km) from the center of Jangmi’s circulation.

Tropical Storm Jangmi will move through an environment favorable for intensification during the next 24 hours.  Jangmi will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge that is south of Japan. The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Storm Jangmi will intensify during the next 24 hours.  Jangmi is likely strengthen to a typhoon.

Tropical Storm Jangmi will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Jangmi toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Jangmi will approach the southern Ryukyu Islands in 48 hours.

Tropical Storm Jangmi is likely to be a typhoon when it approaches the southern Ryukyu Islands.  Jangmi will bring strong winds and locally heavy rain to the Ryukyu Islands.  Heavy rain is could cause flash floods in some locations.