Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Kajiki Strengthens to a Typhoon

Former Tropical Storm Kajiki strengthened to a typhoon over the South China Sea southeast of Hainan on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Typhoon Kajiki was located at latitude 17.3°N and longitude 110.6°E which put the center about 85 miles (135 km) south-southeast of Lingshui, China.  Kajiki was moving toward the west at 13 m.p.h. (21 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 985 mb.

Former Tropical Storm Kajiki strengthened to a typhoon on Saturday night. The inner end of a rainband wrapped around the center of Typhoon Kajiki.  A small circular eye was visible at the center of Kajiki’s circulation.  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 Typhoon Kajiki.  Storms near the center of Kajiki generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The size of the circulation around Typhoon Kajiki increased as Kajiki strengthened on Saturday.  Winds to typhoon force extended out 40 miles (65 km) from the center of Kajiki’s circulation.  Winds to tropical storm force extended out 145 miles (235 km) from the center of Typhoon Kajiki.

Typhoon Kajiki will move through an environment that is favorable for intensification during the next 24 hours.  Kajiki will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level ridge over China.  The upper level ridge will produce northeasterly winds that will blow toward the top of Kajiki’s circulation.  The winds in the lower levels of the atmosphere will also blow from the northeast.  So, there will be little vertical wind shear.  Typhoon Kajiki will intensify during the next 24 hours as long as the center passes south of Hainan.

Typhoom Kajiki will move around the southern side of a high pressure system over China.  The high pressure system will steer Kajiki toward the west during the next 24 hours.  On its anticipated track, the center of Typhoon Kajiki will pass south of Hainan during the next 12 hours.  Kajiki will approach northern Vietnam in 24 hours.

Typhoon Kajiki will bring strong winds and heavy rain to Hainan.  Heavy rain is likely to cause flash floods in some locations.

Typhoon Kajiki will also bring strong winds and heavy rain to northern Vietnam.  Heavy rain is likely to cause flash floods there as well.  Typhoon Kajiki could cause a storm surge of up to 8 feet (2.4 meters) along the coast of northern Vietnam.

Tropical Storm Kajiki Forms Over South China Sea

Tropical Storm Kajiki formed over the South China Sea on Friday night.  At 11:00 p.m. EDT on Friday the center of Tropical Storm Kajiki was located at latitude 17.6°N and longitude 115.9°E which put the center about 365 miles (590 km) south-southeast of Hong Kong.  Kajiki was moving toward the west-northwest at 12 m.p.h. (19 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.

A low pressure system over the South China Sea strengthened on Friday evening and the Japan Meteorological Agency designated the system as Tropical Storm Kajiki.

The circulation around Tropical Storm Kajiki exhibited much more organization on Friday night.  Numerous thunderstorms were forming around the center of Kajiki’s circulation.  Thunderstorms also developed in bands revolving around the center of Tropical Storm Kajiki.  Storms near the center of Kajiki generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speeds around Tropical Storm Kajiki was asymmetrical.  Winds to tropical storm force extended out 130 miles (210 km) in the northwestern quadrant of Kajiki’s circulation.  Winds to tropical storm force extended out 80 miles (130 km) in the other parts of Tropical Storm Kajiki.

Tropical Storm Kajiki will move through an environment that is favorable for intensification during the next 24 hours.  Kajiki will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level ridge over China.  The upper level ridge will produce easterly winds that will blow toward the top of Kajiki’s circulation.  The winds in the lower levels of the atmosphere will also blow from the east.  So, there will be little vertical wind shear.  Tropical Storm Kajiki will intensify during the next 24 hours.  Kajiki could strengthen to a typhoon during the weekend.

Tropical Storm Kajiki will move around the southern side of a high pressure system over China.  The high pressure system will steer Kajiki toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Kajiki will approach southern Hainan in 24 hours.

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

Typhoon Podul Nears Taiwan

Typhoon Podul was nearing southern Taiwan on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Typhoon Podul was located at latitude 22.3°N and longitude 122.6°E which put the center about 100 miles (160 km) east-southeast of Taitung, Taiwan.  Podul was moving toward the west-northwest at 17 m.p.h. (28 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 970 mb.

Typhoon Podul was intensifying as it approached southern Taiwan on Tuesday.  A circular eye with a diameter of 30 miles (48 km) was at the center of Podul’s circulation.  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 Typhoon Podul.  Storms near the center generated upper level divergence that pumped mass away to the south and west of the typhoon.  The removal of mass caused the surface pressure to decrease.

The size of the circulation around Typhoon Podul increased as Podul intensified on Tuesday.  Winds to typhoon force extended out 60 miles (95 km) from the center of Podul’s circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Typhoon Podul.

The Hurricane Intensity Index (HII) for Typhoon Podul is 16.5.  The Hurricane Size Index (HSI) is 16.7 and the Hurricane Wind Intensity Size Index (HWISI) is 33.2.  Typhoon Podul is similar in intensity to Hurricane Idalia when Idalia hit Florida in 2023.  Typhoon Podul is much larger than Idalia was.

Typhoon Podul will move through an environment that will be mostly favorable for intensification during the next few hours.  Podul will move over water where the Sea Surface Temperatures are near 29°C.  An upper level ridge over eastern China will produce northeasterly winds that will blow toward the top of Podul’s circulation.  Those winds will cause moderate vertical wind shear. The vertical wind shear will inhibit intensification, but the shear may not be enough to prevent intensification.  Typhoon Podul could continue to intensify during the next few hours.

Typhoon Podul will move around the southern side of a high pressure system that is south of Japan.  The high pressure system will steer Podul toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Podul will make landfall in southeastern Taiwan in a few hours.

Typhoon Podul will bring strong gusty winds and heavy rain to Taiwan.  The heaviest rain will fall in southern Taiwan and on the eastern slopes of mountains in eastern Taiwan.  Heavy rain is likely to cause flash floods in some locations.

The Taiwan Central Weather Administration has issued a Land Typhoon Warning for much of Taiwan.  A Sea Typhoon Warning is in effect for much of the waters surrounding Taiwan.

The Taiwan Central Weather Administration has issued an Extremely Heavy Rain Advisory for much of southern and eastern Taiwan.

Typhoon Podul could also cause a storm surge of up to 10 feet (3 meters) along parts of the east coast of Taiwan.

Podul Strengthens to a Typhoon

Former Tropical Storm Podul strengthened to a typhoon over the Western North Pacific Ocean east-southeast of Taiwan on Monday.  At 5:00 p.m. EDT on Monday the center of Typhoon Podul was located at latitude 20.8°N and longitude 128.6°E which put the center about 510 miles (825 km) east-southeast of Taipei, Taiwan.  Podul was moving toward the west at 16 m.p.h. (26 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 984 mb.

The circulation around Typhoon Podul became more symmetrical on Monday.  A circular eye appeared at the center of Podul’s circulation.  The eye was surrounded by a broken ring of thunderstorms.  The strongest winds were occurring in that broken ring of storms.  Bands of showers and thunderstorms were revolving around the center of Typhoon Podul.  Storms near the center of Podul 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 eastern side of Typhoon Podul.  Winds to typhoon force extended out 35 miles (55 km) in the eastern side of Podul’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Typhoon Podul.

Typhoon Podul will move through an environment that will be somewhat favorable for intensification during the next 24 hours.  Podul will move over water where the Sea Surface Temperatures are near 29°C.  However, an upper level ridge over eastern China and Japan will produce northeasterly winds that will blow toward the top of Podul’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the shear may not be enough to prevent intensification.  Typhoon Podul could intensify during the next 24 hours if the wind shear does not get any stronger.

Typhoon Podul will move around the southern side of a high pressure system that is south of Japan.  The high pressure system will steer Podul toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Podul will approach Taiwan in 24 hours.

Typhoon Podul will bring strong winds and heavy rain to Taiwan.  Heavy rain is likely to cause flash floods in some locations.

Tropical Storm Podul Churns Westward

Tropical Storm Podul churned westward over the Western North Pacific Ocean on Sunday.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Podul was located at latitude 21.2°N and longitude 132.7°E which put the center about 510 miles (820 km) southeast of Okinawa.  Podul was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 990 mb.

The structure of Tropical Storm Podul did not change much on Sunday.  An upper level ridge over China and Japan continue to produce northeasterly winds that blew toward the top of Podul’s circulation.  Those winds caused moderate vertical wind shear.  The wind shear was caused the distribution of thunderstorms in Tropical Storm Podul to be asymmetrical.  Thunderstorms were occurring in bands in the southern half of Podul’s circulation.  Bands in the northern side of Tropical Storm Podul consisted primarily of showers and lower clouds.

The circulation around Tropical Storm Podul was small.  Winds to tropical storm force extended out 75 miles (120 km) from the center of Podul’s circulation.

Tropical Storm Podul will move through an environment that will be somewhat favorable for intensification during the next 24 hours.  Podul will move over water where the Sea Surface Temperatures are near 29°C.  However, the upper level ridge over China and Japan will continue to cause vertical wind shear.  The vertical wind shear will continue to  inhibit intensification.  Tropical Storm Podul could intensify slowly during the next 24 hours if the wind shear does not get any stronger.  Podul could strengthen to a typhoon on Monday.

Tropical Storm Podul will move around the southern side of a high pressure system that is south of Japan. The high pressure system will steer Podul toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Podul will approach the southern Ryukyu Islands in 36 hours.  Podul could approach Taiwan in 48 hours.

Tropical Storm Podul Passes South of Iwo To

Tropical Storm Podul passes south of Iwo To on Saturday.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Podul was located at latitude 21.6°N and longitude 140.4°E which put the center about 230 miles (370 km) south of Iwo To.  Podul was moving toward the west at 9 m.p.h. (17 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 998 mb.

Tropical Storm Podul was maintaining its intensity on Saturday as it passed south of Iwo To.  An upper level ridge over China and Japan was producing northeasterly winds that were blowing toward the top of Podul’s circulation.  Those winds were causing moderate vertical wind shear.  The wind shear was causing the distribution of thunderstorms in Tropical Storm Podul to be asymmetrical.  Thunderstorms were occurring in bands in the southern half of Podul’s circulation.  Bands in the northern side of Tropical Storm Podul consisted primarily of showers and lower clouds.

The circulation around Tropical Storm Podul was small.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Podul’s circulation.

Tropical Storm Podul will move through an environment that will be somewhat favorable for intensification during the next 24 hours.  Podul will move over water where the Sea Surface Temperatures are near 29°C.  However, the upper level ridge over China and Japan will continue to cause moderate vertical wind shear.  The wind shear will inhibit intensification.  Tropical Storm Podul could intensify slowly during the next 24 hours if the wind shear does not get any stronger.

Tropical Storm Podul will move around the southern side of a high pressure system over Japan.  The high pressure system will steer Podul toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Podul will move toward the southern Ryukyu Islands.

Tropical Storm Podul Forms North of Saipan

Tropical Storm Podul formed over the Western North Pacific Ocean north of Saipan on Thursday.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Podul was located at latitude 19.7°N and longitude 145.9°E which put the center about 290 miles (470 km) north of Saipan.  Podul was moving toward the northwest at 11 m.p.h. (17 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 1003 mb.

A low pressure system over the Western North Pacific Ocean north of Saipan strengthened on Thursday and the Japan Meteorological Agency designated the system as Tropical Storm Podul.

The circulation around Tropical Storm Podul was small.  Thunderstorms were occurring in bands south and east of the center of Podul’s circulation.  Bands in the rest of Tropical Storm Podul consisted primarily of showers and lower clouds.  Storms near the center of Podul started to generate upper level divergence that was beginning to pump mass away from the tropical storm.

The strongest winds in Tropical Storm Podul were occurring in the thunderstorms southeast of the center of circulation.  Winds to tropical storm force extended out 60 miles (95 km) in the southeastern quadrant of Podul’s circulation.  The winds in the other parts of Tropical Storm Podul were blowing at less than tropical storm force.

Tropical Storm Podul will move through an environment favorable for intensification during the next 24 hours.  Podul will move over water where the Sea Surface Temperatures are near 29°C.   It will move under the southern side of an upper level ridge that is south of Japan.  The upper level ridge will produce easterly winds that will blow toward the top of Podul’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Podul will intensify during the next 24 hours.  Podul is likely to strengthen to a typhoon during the weekend.

Tropical Storm Podul will move around the southern side of a high pressure system that is south of Japan.  The high pressure system will steer Podul toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Podul will move away from the Marianas.  Podul could approach Taiwan in a few days.

Tropical Storm Bailu Forms South of Japan

Tropical Storm Bailu formed over the Western North Pacific Ocean south of Japan on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Bailu was located at latitude 33.9°N and longitude 142.6°E which put the center about 185 miles (295 km) south of Tokyo, Japan.  Bailu was moving toward the north-northeast at 29 m.p.h. (46 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 998 mb.

A low pressure system over the Western North Pacific Ocean strengthened on Saturday and the Japan Meteorological Agency designated the system as Tropical Storm Bailu.

The distribution of thunderstorms in Tropical Storm Bailu was asymmetrical.  Thunderstorms were occurring in bands in the northern part of Bailu’s circulation.  Thunderstorms were also occurring in bands in the southwestern part of Tropical Storm Bailu.  Bands in the other parts of Bailu’s circulation consisted primarily of showers and lower clouds.

The distribution of wind speeds in Tropical Storm Bailu was also asymmetrical.  Winds to tropical storm force extended out 175 miles (280 km) in the southern half of Bailu’s circulation.  The winds in the northern side of Tropical Storm Bailu were blowing at less than tropical storm force.

Tropical Storm Bailu will move through an environment marginally favorable for intensification during the next 24 hours.  Bailu will move over water where the Sea Surface Temperatures are near 27°C.  It will move under the eastern side of an upper level trough that is north of Japan.  The upper level trough will produce southwesterly winds that will blow toward the top of Bailu’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification.  Tropical Storm Bailu could intensify during the next 24 hours, if the vertical wind shear does not increase.

The upper level trough north of Japan will steer Tropical Storm Bailu quickly toward the east-northeast during the next 24 hours.  On its anticipated track, Tropical Storm Bailu will move quickly away from Honshu on Sunday.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Krosa was moving rapidly away from Japan.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Krosa was located at latitude 40.2°N and longitude 152.2°E which put the center about 505 miles (820 km) east of Misawa, Japan.  Krosa was moving toward the east-northeast at 28 m.p.h. (45 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 977 mb.

Tropical Storm Krosa Passes East of Japan

Tropical Storm Krosa passed east of Japan on Friday.  At 11:00 p.m. EDT on Friday the center of Tropical Storm Krosa was located at latitude 36.8°N and longitude 143.4°E which put the center about 130 miles (210 km) east-northeast of Tokyo, Japan.  Krosa was moving toward the north-northeast at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 972 mb.

Tropical Storm Krosa passed east of Japan on Friday.  Even though Krosa was a tropical storm, there was a clear area at the center of its circulation.  The clear area was surrounded by a broken ring of thunderstorms.  The strongest winds were occurring in that broken ring of storms.  Thunderstorms were occurring in bands in the eastern side of Tropical Storm Krosa. Bands in the western side of Krosa’s circulation consisted primarily of showers and lower clouds.

The distribution of wind speeds in Tropical Storm Krosa was more symmetrical on Friday.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Krosa’s circulation.

Tropical Storm Krosa will move through an environment unfavorable for the intensification of a tropical cyclone during the next 24 hours.  Krosa will move over water where the Sea Surface Temperatures are near 26°C.  It will move under the eastern side of an upper level trough that is north of Japan.  The upper level trough will produce southwesterly winds that will cause moderate vertical wind shear.  Cooler Sea Surface Temperatures and moderate vertical wind shear will cause Tropical Storm Krosa to start a transition to an extratropical cyclone during the next 24 hours.

The upper level trough north of Japan will steer Tropical Storm Krosa toward the east-northeast during the next 24 hours.  On its anticipated track, Tropical Storm Krosa will move away from Japan.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 13W formed south of Japan.  At 11:00 p.m. EDT on Friday the center of Tropical Depression 13W was located at latitude 28.1°N and longitude 137.5°E which put the center about 325 miles (520 km) west-northwest of Iwo To.  Tropical Depression 13W 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 998 mb.

Tropical Storm Krosa Spins Southeast of Japan

Tropical Storm Krosa was still spinning over the Western North Pacific Ocean southeast of Japan on Thursday afternoon.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Krosa was located at latitude 32.0°N and longitude 141.9°E which put the center about 290 miles (465 km) south-southeast of Tokyo, Japan.  Krosa was moving toward the north-northwest at 9 m.p.h. (15 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 980 mb.

The structure of Tropical Storm Krosa started to change on Thursday as it continued to spin over the Western North Pacific Ocean southeast of Japan.  The inner end of a rainband wrapped around the eastern and northern sides of the center of Krosa’s circulation.  A large circular eye appeared to be forming at the center of Krosa, even through Krosa was just a tropical storm.  Bands of showers and thunderstorms were revolving around the center of Tropical Storm Krosa.

The circulation around Tropical Storm Krosa was relatively small for a tropical storm southeast of Japan.  Winds to tropical storm force extended out 110 miles (175 km) from the center of Krosa’s circulation.

Tropical Storm Krosa will move through an environment somewhat favorable for intensification during the next 24 hours.  Krosa will move over water where the Sea Surface Temperatures are near 27°C.  It will move under the middle of an upper level low that is southeast of Japan.  The upper level winds are weak near the center of the upper level low and there will be little vertical wind shear.  However, the upper level low will inhibit upper level divergence.  In addition, Krosa’s circulation is surrounded by drier air.  Tropical Storm Krosa could intensify during the next 24 hours in spite of the effects of the upper level low and the drier air.

Tropical Storm Krosa will move around the western end of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Krosa toward the north during the next 24 hours.  On its anticipated track, the center of Tropical Storm Krosa could pass to the east of Tokyo on Friday.