Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Typhoon Guchol Moves North

Typhoon Guchol moved toward the north over the Western North Pacific Ocean on Friday morning. At 11:00 a.m. EDT on Friday the center of Typhoon Guchol was located at latitude 18.6°N and longitude 130.0°E which put it about 465 miles (750 km) south of Minamidiatojima, Japan. Guchol was moving toward the north at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h). The minimum surface pressure was 970 mb.

Typhoon Guchol was showing evidence of weakening on Friday morning. A circular eye with a diameter of 50 miles (80 km) was at the center of Guchol’s circulation. The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms. There was a break in the northwestern part of the ring of storms. Other thunderstorms were occurring in bands in the southern and eastern sides of Typhoon Guchol. Bands in the northern and western parts of Guchol’s circulation consisted primarily of showers and lower clouds. Storms near the center of circulation 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 Guchol. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation.

Typhoon Guchol will move through an environment that will become less favorable for intensification during the next 24 hours. Guchol will move over water where the Sea Surface Temperatures are near 28˚C. Typhoon Guchol will move closer to an upper level trough west of Japan. The upper level trough will produce westerly winds that will blow toward the northern part of Guchol’s circulation. Those winds will cause the vertical wind shear to increase. The increase in wind shear will make the environment less favorable for intensification. Typhoon Guchol could weaken during the next 24 hours.

Typhoon Guchol will move around the western part of high pressure system over the Western North Pacific Ocean. The high pressure system will steer Guchol toward the north during the next 24 hours. The upper level trough west of Japan will steer Guchol toward the northeast during the weekend. On its anticipated track Typhoon Guchol could pass between Minamidaitojima and Iwo To during fthe weekend.

Guchol Strengthens to a Typhoon

Former Tropical Storm Guchol strengthened to a typhoon on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Typhoon Guchol was located at latitude 16.1°N and longitude 131.6°E which put it about 670 miles (1080 km) south of Minamidiatojima, Japan. Guchol was moving toward the west-northwest at 7 m.p.h. (11 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 982 mb.

Former Tropical Storm Guchol strengthened to a typhoon over the Western North Pacific Ocean west of the Marianas on Wednesday night. The inner end of a rainband wrapped around the center of Typhoon Guchol. A circular eye was visible on satellite images at the center of Guchol’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 core or Typhoon Guchol. Storms near the core generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 35 miles (55 km) from the center of Guchol. Winds to tropical storm force extended out 160 miles (260 km) from the center of circulation.

Typhoon Guchol will move through an environment favorable for intensification during the next 24 hours. Guchol 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 Guchol is likely to intensify during the next 24 hours.

Typhoon Guchol will move around the western part of high pressure system over the Western North Pacific Ocean. The high pressure system will steer Guchol toward the northwest during the next 24 hours. Guchol will move toward the northeast later this week after it passes the western end of the high pressure system. On its anticipated track Typhoon Guchol could be between Minamidaitojima and Iwo To in four days.

Tropical Storm Guchol Intensifies

Tropical Storm Guchol intensified over the Western North Pacific Ocean on Wednesday morning. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Guchol was located at latitude 15.4°N and longitude 132.8°E which put it about 715 miles (1155 km) south of Minamidiatojima, Japan. Guchol was moving toward the northwest at 9 m.p.h. (15 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 988 mb.

Tropical Storm Guchol intensified over the warm water in the Western North Pacific Ocean west of the Marianas on Wednesday morning. The inner end of a rainband wrapped around the center of Guchol’s circulation and an eye appeared to be forming at the center. Bands of showers and thunderstorms were revolving around the center of Tropical Storm Guchol. Storms near the center of circulation began to generate upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 90 miles (145 km) from the center of Guchol.

Tropical Storm Guchol will move through an environment favorable for intensification during the next 36 hours. Guchol 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. Tropical Storm Guchol will intensify during the next 36 hours. Guchol could strengthen to a typhoon within 18 hours.

Tropical Storm Guchol will move around the western part of high pressure system over the Western North Pacific Ocean. The high pressure system will steer Guchol toward the northwest during the next 36 hours. On its anticipated track Tropical Storm Guchol will move farther away from the Marianas. Guchol could be south of Minamidaitojima in four days.

Tropical Storm Guchol Forms West of Marianas

Tropical Storm Guchol formed over the Western North Pacific Ocean west of the Marianas on Tuesday. At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Guchol was located at latitude 114.6°N and longitude 134.6°E which put it about 785 miles (1265 km) south-southeast of Minamidiatojima, Japan. Guchol was moving toward the north at 7 m.p.h. (11 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.

A low pressure system over the Western North Pacific Ocean west of the Marianas strengthened on Tuesday and the Japan Meteorological Agency designated the system as Tropical Storm Guchol. The distribution of thunderstorms in Tropical Storm Guchol was asymmetrical. Many of the thunderstorms were occurring bands in the southern half of Guchol’s circulation. Bands in the northern half of the circulation consisted primarily of showers and lower clouds. Storms near the center of circulation began to generate upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 45 miles (75 km) from the center of Guchol.

Tropical Storm Guchol will move through an environment favorable for intensification during the next 36 hours. Guchol 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. Tropical Storm Guchol will intensify during the next 36 hours. Guchol could strengthen to a typhoon within 36 hours.

Tropical Storm Guchol will move around the western part of high pressure system over the Western North Pacific Ocean. The high pressure system will steer Guchol toward the northwest during the next 36 hours. On its anticipated track Tropical Storm Guchol will move farther away from the Marianas. Guchol could be south of Minamidaitojima in five days.

Tropical Storm Mawar Brings Wind and Rain to Okinawa

Tropical Storm Mawar brought wind and rain to Okinawa on Thursday. At 11:00 a.m. EDT on Thursday the center of Tropical Storm Mawar was located at latitude 26.1°N and longitude 127.5°E which put it about 65 miles (105 km) southwest of Okinawa. Mawar was moving toward the northeast at 13 m.p.h. (20 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 972 mb.

Former Typhoon Mawar weakened to a tropical storm as it moved closer to Okinawa on Thursday. Even though Mawar was a tropical storm, it still produced gusty winds and rain in Okinawa. A weather station in Naha measured a sustained wind speed of 41 m.p.h. (66 km/h). The distribution of thunderstorms was asymmetrical in Tropical Storm Mawar. Most of the thunderstorms were occurring in bands east and south of the center of Mawar. Bands in the northern and western parts of Tropical Storm Mawar consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 250 miles (400 km) from the center of Mawar’s circulation.

Tropical Storm Mawar will move through an environment that will be unfavorable for intensification during the next 48 hours. Mawar will move over water where the Sea Surface Temperatures are near 25˚C. It will move under the eastern part of an upper level trough that is west of Japan. The upper level trough will produce southwesterly winds that will blow toward the top of Mawar’s circulation. Those winds will cause more vertical wind shear. Tropical Storm Mawar will also pull drier air from Asia into the western part of its circulation. More vertical wind shear and drier air will cause Tropical Storm Mawar to gradually weaken.

The upper level trough west of Japan will steer Tropical Storm Mawar toward the northeast during the next 48 hours. On its anticipated track the center of Mawar will pass near Okinawa during the next few hours. Weather conditions in Okinawa will start to improve when Tropical Storm Mawar moves away later today. Mawar will pass south of Honshu after it moves away from Okinawa. Tropical Storm Mawar could pass south of Tokyo in less than 48 hours.

Typhoon Mawar Moves South-southeast of Miyakojima

Typhoon Mawar move south-southeast of Miyakojima on Wednesday morning. At 11:00 a.m. EDT on Wednesday the center of Typhoon Mawar was located at latitude 23.0°N and longitude 125.6°E which put it about 120 miles (195 km) south-southeast of Miyakojima, Japan. Mawar was moving toward the north-northeast at 5 m.p.h. (8 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.

Typhoon Mawar continued to weaken slowly as it moved closer to the southern Ryukyu Islands on Wednesday. The circulation around Mawar was pulling drier air from Asia into the western part of the typhoon. Bands in the western half of Typhoon Mawar consisted primarily of showers and lower clouds. Many of the thunderstorms in Mawar were occurring in bands in the eastern half of the typhoon. Storms in the eastern half of Mawar’s circulation generated upper level divergence that pumped mass away to the east of the typhoon. Winds to typhoon force extended out 60 miles (95 km) from the center of Mawar. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation.

Typhoon Mawar will move through an environment that will be less favorable for intensification during the next 24 hours. Mawar will move over water where the Sea Surface Temperatures are near 27˚C. It will move under the the axis of an upper level ridge over the Western North Pacific Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. The drier air in the western half of Mawar’s circulation air will inhibit the formation of thunderstorms in that part of the typhoon. In addition, since Typhoon Mawar is moving slowly, winds in the lower levels are likely to mix cooler water to the surface of the Pacific Ocean. The effects of the drier air and mixing of cooler water to the surface of the ocean are likely to cause Typhoon Mawar to weaken gradually during the next 24 hours.

Typhoon Mawar will move around the western part of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Mawar toward the north-northeast during the next 24 hours. On its anticipated track, the center of Typhoon Mawar will pass a little to the east of Miyakojima in 12 hours. Mawar could approach Okinawa in 24 hours. Mawar is likely to be tropical storm when it reaches Okinawa.

Typhoon Mawar Slows South of the Ryukyu Islands

Typhoon Mawar slowed over the Western North Pacific Ocean south of the Ryukyu Islands on Tuesday. At 11:00 a.m. EDT on Tuesday the center of Typhoon Mawar was located at latitude 20.9°N and longitude 125.0°E which put it about 260 miles (420 km) south of Miyakojima, Japan. Mawar was moving toward the north at 3 m.p.h. (5 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 Mawar weakened as it moved slowly toward the Ryukyu Islands on Tuesday. The circulation around Mawar appeared to pull drier air from Asia into the northwestern part of the typhoon. Thunderstorms in bands in the northwestern quadrant of Typhoon Mawar weakened on Tuesday. The northwestern part of the eyewall also weakened. Most of the remaining thunderstorms were occurring in the southern half of Typhoon Mawar. Storms near the center of Mawar’s circulation generated upper level divergence that pumped mass away from the typhoon. The divergence of mass in the upper levels was less than the convergence of mass in the lower levels of Typhoon Mawar and the surface pressure continued to increase.

Even though Typhoon Mawar was weaker, it continued to have a large circulation after several eyewall replacement cycles. Winds to typhoon force extended out 70 miles (110 km) from the center of Mawar. Winds to tropical storm force extended out 225 miles (360 km) from the center of circulation.

Typhoon Mawar will move through an environment that will become less favorable for intensification during the next 24 hours. Mawar will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the the axis of an upper level ridge over the Western North Pacific Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Drier air will persist northwest of Typhoon Mawar. The drier air will inhibit the formation of thunderstorms in the northern half of Mawar’s circulation. In addition, since Typhoon Mawar is moving slowly, winds in the lower levels are likely to mix cooler water to the surface of the Pacific Ocean. The effects of the drier air and mixing of cooler water to the surface of the ocean are likely to cause Typhoon Mawar to weaken gradually during the next 24 hours.

Typhoon Mawar will move around the western part of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Mawar slowly toward the north during the next 36 hours. On its anticipated track, the center of Typhoon Mawar will be near Miyakojima in 36 hours. Mawar could be near Okinawa in less than 72 hours.

Typhoon Mawar Moves Toward Southern Ryukyu Islands

Typhoon Mawar moved toward the southern Ryukyu Islands on Monday morning. At 11:00 a.m. EDT on Monday the center of Typhoon Mawar was located at latitude 19.8°N and longitude 125.5°E which put it about 330 miles (535 km) south of Miyakojima, Japan. Mawar was moving toward the north-northwest at 5 m.p.h. (8 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. (235 km/h). The minimum surface pressure was 956 mb.

Typhoon Mawar was in an equilibrium with its environment during much of the past 24 hours. The inner end of a rainband recently wrapped around the existing eye and eyewall and another pair of concentric eyewalls developed. The inner eye had a diameter of 30 miles (50 km). The inner eyewall was surrounded by a clear area, called a moat, and a much larger outer eyewall. Bands of showers and thunderstorms were revolving around the concentric eyewalls. The strongest rainbands were in the southern half of Mawar’s circulation. Storms near the concentric eyewalls generated upper level divergence that pumped mass away from the typhoon. The upper level divergence pumped away an amount of mass that was nearly equal to the mass converging in the lower levels of Mawar’s circulation. Since the upper level divergence was nearly equal to the lower level convergence, Typhoon Mawar maintained a nearly steady intensity during the past 24 hours.

The circulation around Typhoon Mawar continued to be large. Winds to typhoon force extended out 70 miles (110 km) from the center of Mawar’s circulation. Winds to tropical storm force extended out 250 miles (400 km) from the center of Mawar. The Hurricane Intensity Index (HII) for Typhoon Mawar was 20.6. The Hurricane Size Index (HSI) was 21.1 and the Hurricane Wind Intensity Size Index (HWISI) was 41.7. Typhoon Mawar was similar in intensity to Hurricane Rita when Rita hit Southwest Louisiana in 2005. Mawar was a little smaller than Rita was.

Typhoon Mawar will move through an environment favorable for a strong typhoon during the next 24 hours. Mawar will move over water where the Sea Surface Temperatures are near 29˚C. It will move under the the axis of an upper level ridge over the Western North Pacific Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Although the environment is favorable, the formation of concentric eyewalls is likely to start an eyewall replacement cycle that will cause Typhoon Mawar to weaken gradually during the next 24 hours.

Typhoon Mawar will move around the western part of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Mawar toward the north during the next 36 hours. The steering winds will weaken as Mawar moves around the western end of the high pressure system. On its anticipated track, Typhoon Mawar will move slowly toward the southern Ryukyu Islands during the next 36 hours.

Typhoon Mawar Moves South of Ryukyu Islands

Typhoon Mawar moved south of the Ryukyu Islands on Sunday morning. At 5:00 a.m. EDT on Sunday the center of Typhoon Mawar was located at latitude 17.7°N and longitude 125.7°E which put it about 505 miles (815 km) southeast of Ishigakijima, Japan. Mawar was moving toward the west-northwest at 11 m.p.h. (17 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.

Typhoon Mawar continued to weaken gradually on Sunday morning as it moved over the Western North Pacific Ocean south of the Ryukyu Islands. A circular eye with a diameter of 20 miles (32 km) was present at the center of Mawar’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Numerous bands of showers and thunderstorms were revolving around the center of Typhoon Mawar. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical storm in all directions. The upper level divergence was still not removing as much mass as was converging in the lower levels of Mawar’s circulation which caused the surface pressure to continue to increase slowly.

Typhoon Mawar continued to be a large typhoon even though it was gradually weakening. Winds to typhoon force extended out 80 miles (130 km) from the center of Mawar’s circulation. Winds to tropical storm force extended out 250 miles (400 km) from the center of Mawar. The Hurricane Intensity Index (HII) for Typhoon Mawar was 22.1. The Hurricane Size Index (HSI) was 26.6 and the Hurricane Wind Intensity Size Index (HWISI) was 48.7. Typhoon Mawar was similar in size and intensity to Hurricane Jeanne when Jeanne hit South Florida in 2004.

Typhoon Mawar will move through an environment favorable for a strong typhoon during the next 24 hours. Mawar will move over water where the Sea Surface Temperatures are near 29˚C. It will move under the the axis of an upper level ridge over the Western North Pacific Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Although the environment is favorable, Typhoon Mawar will continue to weaken gradually as long as the upper level divergence is removing less mass than is converging in the lower levels. Typhoon Mawar is forecast to continue to weaken during the next 24 hours.

Typhoon Mawar will move around the southwestern part of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Mawar toward the west-northwest during the next 24 hours. Typhoon Mawar will move toward the north when it reaches the western end of the high pressure system early next week. On its anticipated track, Typhoon Mawar will move toward the southern Ryukyu Islands next week.

Typhoon Mawar Weakens a Little

Typhoon Mawar weakened a little on Saturday as it moved over the Western North Pacific Ocean south of the Ryukyu Islands. At 11:00 a.m. EDT on Saturday the center of Typhoon Mawar was located at latitude 16.9°N and longitude 130.4°E which put it about 650 miles (1050 km) southeast of Ishigakijima, Japan. Mawar was moving toward the west-northwest at 15 m.p.h. (24 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.

Typhoon Mawar weakened a little after it went through another eyewall replacement cycle. The previous inner eye and eyewall dissipated. However, a circular eye with a diameter of 30 miles (50 km) was present at the center of Mawar’s circulation. The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms. Numerous bands of showers and thunderstorms were revolving around the center of Typhoon Mawar. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical storm in all directions. The upper level divergence was not able to remove as much mass as was converging in the lower levels of Mawar’s circulation which caused the surface pressure to increase slowly.

The recent eyewall replacement cycle caused the size of the circulation around Typhoon Mawar to remain large. Winds to typhoon force extended out 80 miles (130 km) from the center of Mawar’s circulation. Winds to tropical storm force extended out 275 miles (445 km) from the center of Mawar. The Hurricane Intensity Index (HII) for Typhoon Mawar was 31.6. The Hurricane Size Index (HSI) was 30.0 and the Hurricane Wind Intensity Size Index (HWISI) was 61.6. Typhoon Mawar was similar in size and intensity to Hurricane Wilma when Wilma was over the Northwest Caribbean Sea in 2005.

Typhoon Mawar will move through an environment favorable for a powerful typhoon during the next 24 hours. Mawar will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the the axis of an upper level ridge over the Western North Pacific Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Although the environment is favorable, the recent eyewall replacement cycle partially disrupted the inner core of Typhoon Mawar. Since the upper level divergence is removing less mass than is converging in the lower levels, the surface pressure is likely to increase slowly. If the surface pressure continues to increase, Typhoon Mawar will weaken gradually during the next 24 hours.

Typhoon Mawar will move around the southern part of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Mawar toward the west-northwest during the next 24 hours. On its anticipated track, Typhoon Mawar could move south of Ishigakijima, Japan in 48 hours.