Tropical Storm Madeline Forms Southwest of Mexico

Tropical Storm Madeline formed over the Eastern North Pacific Ocean southwest of Mexico on Saturday afternoon. At 5:00 p.m. EDT on Saturday the center of Tropical Storm Madeline was located at latitude 15.9°N and longitude 106.9°W which put it about 520 miles (840 km) south-southeast of the southern tip of Baja California. Madeline was moving toward the north at 1 m.p.h. (2 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.

The circulation around a low pressure system over the Eastern North Pacific Ocean southwest of Mexico strengthened on Saturday afternoon and the National Hurricane Center designated the system as Tropical Storm Madeline. The circulation around Tropical Storm Madeline was still organizing on Saturday afternoon. A distinct low level center of circulation was evident on visible satellite images. However, the bands close to the center consisted primarily of showers and lower clouds. Thunderstorms were occurring in bands in the eastern and western edges of Madeline’s circulation. Winds to tropical storm force extended out 125 miles (200 km) in the southern side of Tropical Storm Madeline. The winds in the northern side of Madeline were blowing at less than tropical storm force.

Tropical Storm Madeline will move through an environment somewhat favorable for intensification during the next 36 hours. Madeline will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western part of an upper level ridge over Mexico. The ridge will produce southerly winds that will blow toward the top of Madeline’s circulation. Those winds will cause some vertical wind shear. The wind shear will inhibit intensification, but the shear may not be strong enough to prevent it. Tropical Storm Madeline could intensify gradually during the next 36 hours.

Tropical Storm Madeline will move around the western end of a high pressure system over Mexico. The high pressure system will steer Madeline toward the north-northwest during the next 36 hours. On its anticipated track Tropical Storm Madeline could be south of Baja California on Monday morning.

Tropical Depression Lester Brings Rain to Southern Mexico

Tropical Depression Lester brought rain to southern Mexico on Saturday afternoon. At 2:00 p.m. EDT on Saturday the center of Tropical Depression Lester was located at latitude 16.5°N and longitude 98.5°W which put it about 85 miles (135 km) east-southeast of Acapulco, Mexico. Lester was moving toward the north at 10 m.p.h. (16 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 1009 mb.

Former Tropical Storm Lester quickly weakened to a tropical depression after the center made landfall on the coast of Mexico east of Acapulco. The government of Mexico discontinued the tropical storm warnings and watches for the coast. Tropical Depression Lester is forecast to dissipate quickly as it moves farther inland over Mexico. Even though Lester will weaken quickly, bands in the eastern side of Lester’s circulation will drop locally heavy rain over parts of Guerrero and Oaxaca. Heavy rain could cause flash floods in some locations.

Tropical Storm Fiona Brings Wind and Rain to the Leeward Islands

Tropical Storm Fiona brought wind and rain to the Leeward Islands on Friday night. At 11:00 p.m. EDT on Friday the center of Tropical Storm Fiona was located at latitude 16.6°N and longitude 62.2°W which put it about 55 miles (90 km) west-northwest of Guadeloupe. Fiona was moving toward the west at 14 m.p.h. (22 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 1002 mb.

Tropical Storm Warnings were in effect for Saba, St. Eustatius, St. Maarten, Antigua, Barbuda, St. Kitts, Nevis, Montserrat, Anguilla, Guadeloupe, St. Martin and St. Barthelemy, Puerto Rico, Culebra, Vieques, the U.S. Virgin Islands, the British Virgin Islands and the portion of the coast from Cabo Caucedo to Puerto Plata, Dominican Republic. Tropical Storm Watches were in effect for Dominica and for the portion of the coast from Cabo Caucedo to Barahona, Dominican Republic.

More thunderstorms developed near the center of Tropical Storm Fiona on Friday night which caused Fiona to strengthen. Although there were more thunderstorms near the center of circulation, most of the thunderstorms were still occurring in bands on the eastern side of Tropical Storm Fiona. Bands in the western half of the circulation consisted primarily of showers and lower clouds. The new thunderstorms near the center of Fiona generated upper level divergence that pumped mass away to the north and east of the tropical storm. Winds to tropical storm force extended out 140 miles (220 km) from the center of Tropical Storm Fiona.

Tropical Storm Fiona will move through an environment somewhat favorable for intensification during the next 24 hours. Fiona will move over water where the Sea Surface Temperatures are near 29˚C. An upper level ridge over the tropical Atlantic Ocean will produce southwesterly winds that will blow toward the top of Tropical Storm Fiona. Those winds will cause vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Fiona could continue to strengthen gradually, but the wind shear will limit intensification during the next 24 hours.

Tropical Storm Fiona will move around the southern side of the subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Fiona toward the west-northwest during the next 36 hours. Tropical Storm Fiona will continue to cause gusty winds and locally heavy rain to the northern Leeward Islands during the next 12 hours. Heavy rain could cause flash floods in some locations. On its anticipated track Tropical Storm Fiona could be southeast of Puerto Rico by Saturday evening. Fiona could be near the eastern end of the Dominican Republic by Sunday evening. There is a chance that Fiona could be a hurricane by that time.

Powerful Typhoon Nanmadol Is East of Okinawa

Powerful Typhoon Nanamadol was east of Okinawa on Friday night. At 11:00 p.m. EDT on Friday the center of Typhoon Nanmadol was located at latitude 26.4°N and longitude 132.7°E which put it about 330 miles (530 km) east of Okinawa. Nanmadol was moving toward the northwest at 9 m.p.h. (15 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.

Powerful Typhoon Nanmadol was churning over the Western North Pacific Ocean east of Okinawa on Friday night. A circular eye with a diameter of 23 miles (37 km) was present at the center of Nanmadol. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Nanmadol. Storms near the core generated upper level divergence that pumped mass away from the typhoon in all directions.

The size of the circulation around Typhoon Nanmadol increased on Friday when Nanmadol intensified. Winds to typhoon force extended out 100 miles (160 km) from the center of Nanmadol. Winds to tropical storm force extended out 260 miles (420 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Nanmadol was 31.6. The Hurricane Size Index (HSI) was 28.0 and the Hurricane Wind Intensity Size Index (HWISI) was 59.6. Typhoon Nanmadol was capable of causing widespread severe damage.

Typhoon Nanmadol will move through an environment capable of supporting a powerful typhoon during the next 24 hours. Nanmadol 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 Nanmadol could maintain much of its intensity during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then concentric eyewalls could form. That would be the start of an eyewall replacement cycle that would cause Nanmadol to weaken.

Typhoon Nanmadol will move around the southwestern part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Nanmadol toward the northwest during the next 24 hours. On its anticipated track the center of Typhoon Nanmadol will be east of Minami Daito Jima within 12 hours. Nanmadol could be east of Amami Oshima in 24 hours. Typhoon Nanmadol will bring strong, gusty winds and heavy rain to parts of the northern Ryukyu Islands during the weekend. Nanmadol could be near western Kyushu in 36 hours.

Tropical Storm Fiona Approaches the Leeward Islands

Tropical Storm Fiona approached the Leeward Islands on Friday afternoon. At 2:00 p.m. EDT on Friday the center of Tropical Storm Fiona was located at latitude 16.2°N and longitude 60.3°W which put it about 75 miles (120 km) east of Guadeloupe. Fiona was moving toward the west at 14 m.p.h. (22 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 1005 mb.

Tropical Storm Warnings were in effect for Saba, St. Eustatius, St. Maarten, Antigua, Barbuda, St. Kitts, Nevis, Montserrat, Anguilla, Guadeloupe, St. Martin and St. Barthelemy, Puerto Rico, Culebra, Vieques, the U.S. Virgin Islands, and the British Virgin Islands. Tropical Storm Watches were in effect for Dominica and the portion of the coast from Cabo Engano to Cabo Frances Viejo, Dominican Republic.

Tropical Storm Fiona was nearing the Leeward Islands on Friday afternoon. The distribution of thunderstorms in Tropical Storm Fiona continued to be asymmetrical. Most of the thunderstorms were occurring in bands in the eastern side of Fiona’s circulation. Bands in the western half of the circulation consisted primarily of showers and lower clouds. Tropical Storm Fiona was moving under the northern side of an upper level ridge over the tropical Atlantic Ocean. The ridge was producing southwesterly winds that were blowing toward the top of Fiona’s circulation. Those winds were causing moderate vertical wind shear and the wind shear was causing the asymmetrical distribution of thunderstorms. Winds to tropical storm force extended out 140 miles (220 km) from the center of Fiona.

Tropical Storm Fiona will move through an environment somewhat favorable for intensification during the next 24 hours. Fiona will move over water where the Sea Surface Temperatures are near 28˚C. However, the upper level ridge over the tropical Atlantic Ocean will continue to cause vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Fiona could strengthen a little, but the wind shear will limit intensification during the next 24 hours.

Tropical Storm Fiona will move around the southern side of the subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Fiona toward the west during the next 36 hours. On its anticipated track Tropical Storm Fiona will move over the Leeward Islands on Friday evening. Fiona will bring gusty winds and locally heavy rain to the northern Leeward Islands. Heavy rain could cause flash floods in some locations. Tropical Storm Fiona could be southeast of Puerto Rico by Saturday evening.

Tropical Depression 13E Strengthens to Tropical Storm Lester, Mexico Issues Warning

Former Tropical Depression Thirteen-E strengthened to Tropical Storm Lester south of Mexico on Friday morning and the government of Mexico issued a Tropical Storm Warning for a portion of the coast. At 8:00 a.m. EDT on Friday the center of Tropical Storm Lester was located at latitude 13.4°N and longitude 96.1°W which put it about 160 miles (255 km) south of Puerto Angel, Mexico. Lester was moving toward the northwest at 5 m.p.h. (8 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 1005 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Punta Maldonado to Zihuatanejo, Mexico. The Tropical Storm Warning included Acapulco. A Tropical Storm Watch was in effect for the portion of the coast from Punta Maldonado to Laguna de Chacahua, Mexico. A Tropical Storm Watch was in effect from Zihuatanejo to Lazaro Cardenas, Mexico.

The circulation around former Tropical Depression Thirteen-E strengthened on Friday morning and the National Hurricane Center upgraded it to Tropical Storm Lester. Even though former Tropical Depression Thirteen-E strengthened to Tropical Storm Lester, the distribution of thunderstorms continued to be asymmetrical. Most of the thunderstorms were occurring in bands in the western half of Lester’s circulation. Bands in the eastern half of the circulation consisted primarily of showers and lower clouds. Storms near the center of circulation generated upper level divergence that pumped mass away to the west of the tropical storm. Winds to tropical storm force extended out 45 miles (75 km) in the southern half of Lester’s circulation. The winds in the northern half of the circulation were blowing at less than tropical storm force.

Tropical Storm Lester will move through an environment somewhat favorable for intensification during the next 36 hours. Lester will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the southern side of an upper level ridge over Mexico. The upper level ridge will produce easterly winds that will blow toward the top of the tropical depression. Those winds will cause vertical wind shear and the wind shear will inhibit intensification. Tropical Storm Lester likely to strengthen gradually during the next 36 hours.

Tropical Storm Lester will move around the southwestern part of a high pressure system that extends over Mexico. The high pressure system will steer Lester toward the northwest during the next 36 hours. On its anticipated track Tropical Storm Lester will approach the southwest coast of Mexico on Saturday morning. Lester will bring gusty winds and locally heavy rain to Guerrero. Heavy rain could cause flash floods in some locations.

Typhoon Nanmadol Rapidly Intensifies to Equivalent of a Major Hurricane

Typhoon Nanmadol rapidly intensified to the equivalent of a major hurricane south of Japan during Thursday night. At 11:00 p.m. EDT on Thursday the center of Typhoon Nanmadol was located at latitude 24.1°N and longitude 135.4°E which put it about 535 miles (860 km) east-southeast of Okinawa. Nanmadol was moving toward the northwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 947 mb.

Typhoon Nanmadol rapidly intensified to the equivalent of a major hurricane over the Western North Pacific Ocean south of Japan during Thursday night. A well formed circular eye was present at the center of Nanmadol’s circulation. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Nanmadol. Storms near the core generated strong upper level divergence that pumped mass away from the typhoon in all directions.

The circulation around Typhoon Nanmadol was symmetrical. Winds to typhoon force extended out 60 miles (95 km) from the center of Nanmadol. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Nanmadol was 23.6. The Hurricane Size Index (HSI) was 20.6 and the Hurricane Wind Intensity Size Index (HWISI) was 44.2. Typhoon Nanmadol was capable of causing widespread major damage.

Typhoon Nanmadol will move through an environment favorable for intensification during the next 24 hours. Nanmadol 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 Nanmadol will intensify during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then concentric eyewalls could form. That would be the start of an eyewall replacement cycle that would cause Nanmadol to weaken.

Typhoon Nanmadol will move around the southwestern part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Nanmadol toward then northwest during the next 36 hours. On its anticipated track the center of Typhoon Nanmadol will be east of Minami Daito Jima within 24 hours. Nanmadol could be east of Amami Oshima in 36 hours. Typhoon Nanmadol will bring strong, gusty winds and heavy rain to parts of the northern Ryukyu Islands during the weekend.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Muifa weakened over the northern Yellow Sea. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Muifa was located at latitude 38.5°N and longitude 121.8°E which put it about 50 miles (80 km) northeast of Yantai, China. Muifa was moving toward the north-northeast at 16 m.p.h. (26 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.

Tropical Depression Forms South of Mexico, Watch Issued

Tropical Depression Thirteen-E formed over the Eastern North Pacific Ocean south of Mexico on Thursday and the government of Mexico issued a Tropical Storm Watch for a portion of the coast. At 8:00 p.m. EDT on Thursday the center of Tropical Depression Thirteen-E was located at latitude 12.8°N and longitude 95.6°W which put it about 215 miles (345 km) south-southeast of Puerto Angel, Mexico. The tropical depression was moving toward the northwest at 3 m.p.h. (5 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 1007 mb.

A Tropical Storm Watch was in effect for the portion of the coast from Laguna de Chacahua to Zihuatanejo, Mexico. The Tropical Storm Watch includes Acapulco.

The circulation around a low pressure system over the Eastern North Pacific Ocean strengthened on Thursday and the National Hurricane Center designated the system as Tropical Depression Thirteen-E. Tropical Depression Thirteen-E had a well defined low level center of circulation but the distribution of thunderstorms was asymmetrical. Most of the thunderstorms were occurring in bands in the western half of the tropical depression. Bands in the eastern half of the circulation consisted primarily of showers and lower clouds. Storms near the center of circulation generated upper level divergence that pumped mass away to the west of the tropical depression.

Tropical Depression Thirteen-E will move through an environment somewhat favorable for intensification during the next 36 hours. The tropical depression will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the southern side of an upper level ridge over Mexico. The upper level ridge will produce easterly winds that will blow toward the top of the tropical depression. Those winds will cause vertical wind shear and the wind shear will inhibit intensification. Tropical Depression Thirteen-E is likely to strengthen gradually during the next 36 hours.

Tropical Depression Thirteen-E will move around the southwestern part of a high pressure system that extends over Mexico. The high pressure system will steer the tropical depression toward the northwest during the next 36 hours. On its anticipated track Tropical Depression Thirteen-E will approach the southwest coast of Mexico on Saturday morning. It is likely to be a tropical storm when it approaches the coast.

Tropical Storm Fiona Prompts Watch for Puerto Rico

The potential effects of Tropical Storm Fiona prompted the issuance of Tropical Storm Watches for Puerto Rico and the Virgin Islands on Thursday afternoon. Tropical Storm Warnings were in effect for the northern Leeward Islands. At 5:00 p.m. EDT on Thursday the center of Tropical Storm Fiona was located at latitude 16.3°N and longitude 55.4°W which put it about 425 miles (685 km) east of the Leeward Islands. Fiona was moving toward the west at 14 m.p.h. (22 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 1006 mb.

Tropical Storm Warnings were in effect for Saba, St. Eustatius, St. Maarten, Antigua, Barbuda, St. Kitts, Nevis, Montserrat, Anguilla, Guadeloupe, St. Martin and St. Barthelemy. Tropical Storm Watches were in effect for Puerto Rico, Culebra, Vieques, the U.S. Virgin Islands, and the British Virgin Islands.

Tropical Storm Fiona continued to be affected by strong vertical wind shear on Thursday afternoon. The center of Fiona was surrounded by a swirl of showers and lower clouds. Thunderstorms were occurring in bands in the eastern edge of Fiona’s circulation. Tropical Storm Fiona was under the northern part of an upper level ridge over the tropical Atlantic Ocean. The upper level ridge was producing westerly winds that were blowing across the top of Fiona’s circulation. Those winds were causing strong vertical wind shear and the wind shear was blowing the tops off of many of the thunderstorms that start to develop. The vertical wind shear was causing the low level circulation around Tropical Storm Fiona to look a little less organized. Winds to tropical storm force extended out 140 miles (220 km) from the center of Fiona’s circulation.

Tropical Storm Fiona will move through an environment marginally favorable for intensification during the next 36 hours. Fiona will move over water where the Sea Surface Temperatures are near 28˚C. However, the upper level ridge over the tropical Atlantic Ocean will continue to cause vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Fiona could weaken if the upper level winds get stronger. The upper level winds could be weaker when Fiona moves over the northeastern Caribbean Sea during the weekend.

Tropical Storm Fiona will move around the southern side of the subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Fiona toward the west during the next 36 hours. On its anticipated track Tropical Storm Fiona could approach the Leeward Islands on Friday afternoon. Fiona could bring gusty winds and locally heavy rain to the northern Leeward Islands. Tropical Storm Fiona could be southeast of Puerto Rico by Saturday evening.

Tropical Storm Fiona Prompts Warnings for Leeward Islands

A potential threat posed by Tropical Storm Fiona prompted the issuance of Tropical Storm Warnings for some of the Leeward Islands. At 11:00 a.m. EDT on Thursday the center of Tropical Storm Fiona was located at latitude 16.6°N and longitude 54.3°W which put it about 495 miles (800 km) east of the Leeward Islands. Fiona was moving toward the west at 14 m.p.h. (22 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 1002 mb.

Tropical Storm Warnings were in effect for Saba, St. Eustatius, St. Maarten, Antigua, Barbuda, St. Kitts, Nevis, Montserrat and Anguilla. Tropical Storm Watches were in effect for Guadeloupe, St. Martin and St. Barthelemy.

Tropical Storm Fiona was being affected by strong vertical wind shear on Thursday morning. The center of Fiona was surrounded by a swirl of showers and lower clouds. Thunderstorms were occurring in bands in the eastern edge of Fiona’s circulation. Tropical Storm Fiona was under the northern part of an upper level ridge over the tropical Atlantic Ocean. The upper level ridge was producing westerly winds that were blowing across the top of Fiona’s circulation. Those winds were causing strong vertical wind shear and the wind shear was blowing the tops off of many of the thunderstorms that start to develop. In spite of the vertical wind shear, the low level circulation around Tropical Storm Fiona was still well organized. Winds to tropical storm force extended out 140 miles (220 km) from the center of Fiona’s circulation.