Namtheun Strengthens to a Typhoon North of Wake Island

Former Tropical Storm Namtheun strengthened to a typhoon over the Western North Pacific Ocean north of Wake Island on Saturday morning. At 5:00 a.m. EDT on Saturday the center of Typhoon Namtheun was located at latitude 31.4°N and longitude 165.6°E which put it about 800 miles (1290 km) north of Wake Island. Namtheun was moving toward the north-northeast at 18 m.p.h. (29 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. (150 km/h). The minimum surface pressure was 979 mb.

Former Tropical Storm Namtheun passed over water where the Sea Surface Temperatures are near 27˚C during the past 24 hours and it was able to extract enough energy to strengthen to a typhoon. A small eye formed at the center of Typhoon Namtheun. The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms. Storms near the center of Namtheun generated upper level divergence that pumped mass away from the typhoon. The circulation around Typhoon Namtheun was relatively small. Winds to typhoon force extended out 20 miles (30 km) from the center of Namtheun. Winds to tropical storm force extended out 115 miles (185 km) from the center of circulation.

An upper level trough east of Japan will steer Typhoon Namtheun toward the north-northeast during the weekend. On its anticipated track Namtheun will move toward the Aleutian Islands. Typhoon Namtheun will move into an environment unfavorable for intensification during the weekend. Namtheun will move over much cooler water. The upper level trough east of Japan will produce strong southwesterly winds that will blow toward the top of Namtheun’s circulation. Those winds will cause moderate vertical wind shear. The combination of cooler water and more vertical wind shear will cause Typhoon Namtheun to make a transition to an extratropical cyclone as it moves toward the Aleutian Islands.

Tropical Storm Namtheun Spins Southeast of Japan

Tropical Storm Namtheun was spinning southeast of Japan on Friday morning. At 5:00 a.m. EDT on Friday the center of Tropical Storm Namtheun was located at latitude 26.6°N and longitude 161.9°E which put it about 495 miles (800 km) east-northeast of Minami Tori Shima. Namtheun was moving toward the east-northeast at 18 m.p.h. (29 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.

Tropical Storm Namtheun was the only current tropical cyclone on Friday morning as it churned over the Western North Pacific Ocean between Japan and Hawaii. Namtheun intensified during the past 24 hours as it moved well to the east of the main islands of Japan. The inner end of a rainband wrapped around the center of Tropical Storm Namtheun. A broken ring of thunderstorms was around the center of circulation. The strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Namtheun. Storms near the core generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 85 miles (135 km) from the center of circulation.

Tropical Storm Namtheun will move through an environment somewhat favorable for intensification during the next 24 hours. Namtheun will move over water where the Sea Surface Temperatures are near 27˚C. An upper level trough southeast of Japan will produce southwesterly winds that will blow toward the top of Namtheun’s circulation. Those winds will cause some vertical wind shear and the wind shear will inhibit intensification. Tropical Storm Namtheun could strengthen during the next 24 hours. Namtheun will move over colder water during the weekend. It will also move in a region where the upper level winds will be stronger. Tropical Storm Namtheun will weaken during the weekend.

The upper level trough southeast of Japan will steer Tropical Storm Namtheun toward the northeast during the next several days. On its anticipated track Namtheun will move farther away from Japan.

Hurricane Pamela Makes Landfall on West Coast of Mexico

Hurricane Pamela made landfall on the west coast of Mexico northwest of Mazatlan near La Cruz on Wednesday morning. At 8:00 a.m. EDT on Wednesday the center of Hurricane Pamela was located at latitude 23.7°N and longitude 106.8°W which put it about 40 miles (65 km) northwest of Mazatlan, Mexico. Pamela was moving toward the northeast 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 987 mb.

A Hurricane Warning was in effect for the portion of the coast from Bahia Tempehuaya to Escuinapa, Mexico. The Hurricane Warning included Mazatlan. Tropical Storm Warnings were in effect for the portions of the coast from Altata to Bahia Tempehuaya, Mexico and from Escuinapa to Cabo Corrientes, Mexico.

Hurricane Pamela was being affected by moderate vertical wind shear as it approached the west coast of Mexico. A large upper level trough over the western U.S. was producing southwesterly winds that were blowing toward the top of Pamela’s circulation. Northerly winds in the lower levels of the western side of Hurricane Pamela pulled drier air into its circulation. The combination of moderate vertical wind shear and drier air caused an asymmetrical distribution of thunderstorms. The strongest thunderstorms and the strongest winds were occurring in bands in the northeastern part of Hurricane Pamela. Bands in other parts of the circulation consisted primarily of showers and lower clouds. Winds to hurricane force extended out 30 miles (50 km) in the northeastern quadrant of Pamela’s circulation. Winds to tropical storm force extended out 130 miles (210 km) on the eastern side of the circulation. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation.

The upper level trough over the western U.S. will steer Hurricane Pamela quickly toward the northeast during the next 24 hours. The circulation in the lower levels of Pamela will weaken quickly when it moves over the mountains in western Mexico. Pamela will drop locally heavy rain over parts of Sinaloa and Durango. Flash floods could occur in some locations. The remnants of of the middle and upper parts Pamela’s circulation could contribute to rainfall over Texas on Thursday.

Tropical Storm Kompasu Brings Wind and Rain to Hainan

Tropical Storm Kompasu brought wind and rain to Hainan on Wednesday. At 5:00 a.m. EDT on Wednesday the center of Tropical Storm Kompasu was located at latitude 19.2°N and longitude 110.0°E which put it about 50 miles (80 km) southwest of Haikou, China. Kompasu was moving toward the west at 22 m.p.h. (35 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 981 mb.

Tropical Storm Kompasu brought wind and rain as it moved over Hainan on Wednesday. The strongest thunderstorms were in bands on the western side of Kompasu’s circulation. Bands on the eastern side of the circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 200 miles (320 km) from the center of Tropical Storm Kompasu.

Tropical Storm Kompasu was moving under the southern part of an upper level ridge over China. The ridge was producing strong easterly winds that were blowing toward the top of Kompasu’s circulation. Those winds were causing moderate vertical wind shear. The flow around the northern side of Tropical Storm Kompasu was pulling drier air from Asia into the circulation. The combination of moderate vertical wind shear and drier air was causing the stronger thunderstorms to be on the western side of Kompasu.

Tropical Storm Kompasu will move around the southern side of a high pressure system over China. The high pressure system will steer Kompasu quickly toward the west during the next 24 hours. On its anticipated track the center of Kompasu will move quickly across the Gulf of Tonkin. Tropical Storm Kompasu will reach the coast of northern Vietnam in 18 hours. Gusty winds and rain will reach the coast before the center arrives because the stronger thunderstorms are on the western side of Kompasu. Vertical wind shear and drier air will prevent intensification of Tropical Storm Kompasu. Kompasu will bring gusty winds and locally heavy rain to northern Vietnam and Laos. Locally heavy rain could cause flash floods in some locations.

Pamela Strengthens to a Hurricane Southwest of Mazatlan

Former Tropical Storm Pamela strengthened to a hurricane southwest of Mazatlan, Mexico on Tuesday morning. At 8:00 a.m. EDT on Tuesday the center of Hurricane Pamela was located at latitude 19.9°N and longitude 109.0°W which put it about 280 miles (455 km) southwest of Mazatlan, Mexico. Pamela was moving toward the north at 13 m.p.h. (20 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 985 mb.

A Hurricane Warning was in effect for the portion of the coast from Bahia Tempehuaya to Escuinapa, Mexico. The Hurricane Warning included Mazatlan. Tropical Storm Warnings were in effect for the portions of the coast from Altata to Bahia Tempehuaya, Mexico and from Escuinapa to Cabo Corrientes, Mexico. A Tropical Storm Watch was in effect for the portion of the coast of Baja California from Cabo San Lucas to Los Barilles.

Former Tropical Storm Pamela strengthened to a hurricane over the Eastern North Pacific Ocean southwest of Mazatlan on Tuesday morning. More thunderstorms developed near the center of Hurricane Pamela. Those thunderstorms generated more upper level divergence that pumped mass away from the hurricane. The removal of mass caused the surface pressure to decrease. Bands of showers and thunderstorms were revolving around the core of Hurricane Pamela. Winds to hurricane force extended out 25 miles (40 km) on the east side of Pamela. Winds to tropical storm force extended out 90 miles (145 km) from the center of circulation.

Hurricane Pamela will move through a region where the environment is somewhat favorable for intensification during the next 18 hours. Pamela will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the the southern part of an upper level trough over the western U.S. The trough will produce southwesterly winds that will blow toward the top of Hurricane Pamela’s circulation. Those winds will cause some vertical wind shear. The wind shear will inhibit intensification, but the shear will not be strong enough to prevent Pamela from getting stronger.

Hurricane Pamela will move around the western part of a high pressure system over Mexico during the next few hours. The high pressure system will steer Pamela toward the north during that time period. The upper level trough over the western U.S. will turn Pamela toward the northeast in a few hours. On its anticipated track Hurricane Pamela will approach the west coast of Mexico early on Wednesday morning. Pamela will bring strong winds and locally heavy rain to the section of the coast near Mazatlan. Heavy rain could cause flash floods in parts of Sinaloa and Durango. The remnants of Pamela’s circulation could contribute to rainfall over Texas later this week,

Tropical Storm Kompasu Brings Wind and Rain to Northern Luzon

Tropical Storm Kompasu brought wind and rain to northern Luzon on Monday. At 11:00 a.m. EDT on Monday the center of Tropical Storm Kompasu was located at latitude 18.9°N and longitude 120.9°E which put it about 35 miles (55 km) north of Claveria, Philippines. Kompasu was moving toward the west 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 981 mb.

Rainbands in the southern side of Tropical Storm Kompasu brought wind and rain to northern Luzon on Monday. The center of Kompasu passed just north of Luzon. Thunderstorms in bands in southern half of Tropical Storm Kompasu passed over the northern end of Luzon. Kompasu strengthened as it approached northern Luzon. More thunderstorms developed in bands revolving around the center of Tropical Storm Kompasu. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 145 miles (235 km) from the center of Kompasu.

Tropical Storm Kompasu will move through an environment somewhat favorable for intensification during the next 36 hours. Kompasu will move over water where the Sea Surface Temperatures are near 29˚C. It will move south of an upper level ridge over China. The ridge will produce northeasterly winds that will blow toward the top of Kompasu’s circulation. Those winds will cause moderate vertical wind shear and the wind shear will inhibit intensification. Tropical Storm Kompasu is likely to strengthen gradually during the next 24 hours. Kompasu could intensify to a typhoon over the South China Sea.

Tropical Storm Kompasu will move south of a high pressure system over China. The high pressure system will steer Kompasu toward the west during the next several days. On its anticipated track the center of Tropical Storm Kompasu will pass south of Hong Kong in 24 hours. Kompasu could approach Hainan in 36 hours.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Namtheun intensified east of the northern Marianas. At 11:00 a.m. EDT on Monday the center of Tropical Storm Namtheun was located at latitude 19.4°N and longitude 154.0°E which put it about 555 miles (895 km) east of Agrihan. Namtheun was moving toward the west-northwest at 16 m.p.h. (26 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 988 mb.

Tropical Storm Pamela Intensifies, Hurricane Watch for Mexico

Tropical Storm Pamela intensified over the Eastern North Pacific Ocean on Monday morning and the government of Mexico issued a Hurricane Watch for a portion of the west coast. At 11:00 p.m. EDT on Monday the center of Tropical Storm Pamela was located at latitude 16.8°N and longitude 108.1°W which put it about 455 miles (735 km) south-southwest of Mazatlan, Mexico. Pamela was moving toward the northwest at 8 m.p.h. (13 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 995 mb.

A Hurricane Watch was in effect for the portion of the coast from Bahia Tempehuaya to Escuinapa, Mexico. Tropical Storm Watches were in effect for the portions of the coast from Altata to Bahia Tempehuaya and from Escuinapa to San Blas. A Tropical Storm Watch was also in effect for the portion of the coast of Baja California from Los Barilles to Cabo San Lucas, Mexico.

Tropical Storm Pamela intensified more rapidly on Monday morning. The inner end of a rainband wrapped tightly around the southern and eastern sides of the center of Pamela. Storms near the center of circulation generated strong upper level divergence that pumped mass away from the tropical storm. The removal of mass allowed the surface pressure to decrease more quickly. Bands of showers and thunderstorms were revolving around the core of Tropical Storm Pamela. The circulation around Pamela was relatively small. Winds to tropical storm force extended out 70 miles (110 km) from the center of circulation.

Tropical Storm Pamela will move through a region where the environment is favorable for intensification during the next 36 hours. Pamela will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the axis of an upper level ridge over the Eastern North Pacific Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Storm Pamela could strengthen to a hurricane during the next 12 hours. Pamela could intensify rapidly once an inner core with an eye and eyewall forms. Pamela could rapidly intensify to a major hurricane by Tuesday night.

Tropical Storm Pamela will move around the southwestern part of a high pressure system over Mexico during the next 24 hours. The high pressure system will steer Pamela toward the north-northwest during that time period. An upper level trough over the western U.S. will turn Pamela toward the northeast on Tuesday. On its anticipated track Pamela could be south of Baja California on Tuesday evening. Pamela could be a major hurricane when it approaches the west coast of Mexico on Wednesday morning.

Tropical Storm Pamela Forms South of Mexico

Tropical Storm Pamela formed south of Mexico on Sunday afternoon. At 5:00 p.m. EDT on Sunday the center of Tropical Storm Pamela was located at latitude 15.5°N and longitude 105.9°W which put it about 265 miles (425 km) south-southwest of Manzanillo, Mexico. Pamela was moving toward the west-northwest at 15 m.p.h. (24 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 1005 mb.

A low pressure system south of Mexico strengthened on Sunday afternoon and the National Hurricane Center designated the system as Tropical Storm Pamela. The circulation around Tropical Storm Pamela was gradually becoming more organized. A band of showers and thunderstorms was wrapping around the western and southern sides of the center of Pamela. Storms near the center of circulation generated upper level divergence that pumped mass away to the west of the tropical storm. Other bands of showers and thunderstorms were revolving around the center of Tropical Storm Pamela. Winds to tropical storm force extended out 60 miles (95 km) in the northeastern quadrant of Pamela’s circulation. The winds in the other parts of the circulation were blowing at less than tropical storm force.

Tropical Storm Pamela will move through a region where the environment is favorable for intensification during the next 36 hours. Pamela will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the axis of an upper level ridge over the Eastern North Pacific Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Storm Pamela will intensify during the next 36 hours. It could strengthen to a hurricane by Monday night.

Tropical Storm Pamela will move around the southwestern part of a high pressure system over Mexico during the next 36 hours. The high pressure system will steer Pamela toward the northwest during that time period. An upper level trough over the western U.S. will turn Pamela toward the northeast later on Tuesday. On its anticipated track Pamela could be south of Baja California on Tuesday night. Pamela is likely to be a hurricane when it approaches the west coast of Mexico on Wednesday afternoon.

Tropical Storm Lionrock Drops Heavy Rain on Northern Vietnam

Tropical Storm Lionrock dropped heavy rain on parts of northern Vietnam on Saturday night. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Lionrock was located at latitude 20.4°N and longitude 107.1°E which put it about 25 miles (40 km) southeast of Haiphong, Vietnam. Lionrock was moving toward the west-northwest at 15 m.p.h. (24 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 995 mb.

Tropical Storm Lionrock dropped heavy rain over the part of northern Vietnam between Hanoi and Haiphong on Saturday night. The heaviest rain was falling in bands in the western half of Tropical Storm Lionrock. Bands in the eastern side of Lionrock consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 120 miles (195 km) from the center of Lionrock’s circulation.

Tropical Storm Lionrock will move south of a high pressure system over China during the next 24 hours. The high pressure system will steer Lionrock toward the west during the next day or so. On its anticipated track Tropical Storm Lionrock will move across northern Vietnam and northern Laos. Lionrock will bring gusty winds and locally heavy rain to parts of northern Vietnam and northern Laos. Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Kompasu was spinning east of Luzon and Tropical Storm Namtheun formed east of the northern Marianas. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Kompasu was located at latitude 15.9°N and longitude 129.8°E which put it about 470 miles (760 km) east of Luzon. Kompasu was moving toward the 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 990 mb. Kompasu is forecast to move toward the west-northwest and to strengthen.

At 11:00 p.m. EDT on Saturday the center of Tropical Storm Namtheun was located at latitude 17.0°N and longitude 160.3°E which put it about 980 miles (1580 km) east of Alamagan. Namtheun was moving toward the west at 8 m.p.h. (13 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. Namtheun was forecast to move toward the northwest and to strengthen.

Tropical Storm Lionrock Drops Heavy Rain on Hainan

Tropical Storm Lionrock dropped heavy rain on Hainan on Friday. At 11:00 a.m. EDT on Friday the center of Tropical Storm Lionrock was located at latitude 19.1°N and longitude 110.2°E which put it about 50 miles (80 km) south of Haikou, China. Lionrock was moving toward the north at 7 m.p.h. (11 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 991 mb.

Tropical Storm Lionrock brought gusty winds and heavy rain to Hainan on Friday. The center of Lionrock was over Hainan. Bands of showers and thunderstorms on the northern and western sides of Tropical Storm Lionrock were dropping heavy rain over much of Hainan. Bands on the southern and eastern sides of Lionrock consisted primarily of showers and lower clouds. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical storm. The circulation around Tropical Storm Lionrock was large. Winds to tropical storm force extended out 220 miles (350 km) from the center of circulation.

Tropical Storm Lionrock is likely to weaken during the next 12 hours while the center of circulation moves over Hainan. Lionrock will move into an environment favorable for intensification when the center moves over the Gulf of Tonkin. Lionrock will move over water where the Sea Surface Temperatures are near 29˚C. It will move under the western side of a small upper level ridge. The ridge will produce southerly winds that will blow toward the top of Lionrock’s circulation. Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification. Tropical Storm Lionrock is likely to intensify slowly after the center of circulation moves over the Gulf of Tonkin.

Tropical Storm Lionrock will move around the southwestern part of a subtropical high pressure system over the Western North Pacific Ocean during the next 12 hours. The subtropical high will steer Lionrock toward the northwest. On its anticipated track the center of Tropical Storm Lionrock will move across Hainan and it will emerge over the Gulf of Tonkin on Saturday. Lionrock will continue to bring gusty winds and locally heavy rain to Hainan during the next 12 hours. Heavy rain could cause flash floods in some locations. Tropical Storm Lionrock will move south of a second high pressure system that is centered over China during the weekend. The second high pressure system will steer Lionrock toward the west. Tropical Storm Lionrock could approach the coast of northern Vietnam in 36 hours.

Elsewhere over the Western North Pacific Ocean, a former tropical depression east of the Philippines strengthened to Tropical Storm Kompasu. At 11:00 a.m. EDT on Friday the center of Tropical Storm Kompasu was located at latitude 13.8°N and longitude 131.5°E which put it about 570 miles (920 km) east of Daet, Philippines. Kompasu was stationary. 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.