Category Archives: Tropical Cyclones

Information about tropical cyclones

Tropical Storm Sepat Moves Toward Honshu

Tropical Storm Sepat moved toward Honshu on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Sepat was located at latitude 29.7°N and longitude 140.7°E which put the center about 420 miles (680 km) south of Tokyo, Japan.  Sepat was moving toward the northwest at 14 m.p.h. (22 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.

Tropical Storm Sepat strengthened a little on Monday morning, but Sepat was showing signs of weakening on Monday evening.  Thunderstorms were still occurring near the center of Tropical Storm Sepat.  Thunderstorms were also occurring bands revolving around the center of Sepat’s circulation.  Storms near the center of Sepat generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass in the upper levels was balanced by the inflow of mass in the lower levels of Tropical Storm Sepat.  The balance of upper level divergence and inflow in the lower levels caused the surface pressure to remain steady.

The distribution of wind speeds in Tropical Storm Sepat was asymmetrical.  Winds to tropical storm force extended out 110 miles (175 km) in the eastern side of Sepat’s circulation.  The winds in the western side of Tropical Storm Sepat were blowing at less than tropical storm force.

Tropical Storm Sepat will move through an environment that will become unfavorable for intensification during the next 24 hours.  Sepat will move over water where where the Sea Surface Temperatures are near 26°C.  It will move under the northern part of an upper level low south of Japan.  The upper level low will produce northeasterly winds that will blow toward the top of Sepat’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear  and marginal Sea Surface Temperatures will cause Tropical Storm Sepat to weaken during the next 24 hours.  Sepat is likely to weaken to a tropical depression on Tuesday.

Tropical Storm Sepat will move around the western end of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Sepat toward the north-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Sepat will continue to move toward Honshu.

Tropical Storm Sepat Forms Southeast of Japan

Tropical Storm Sepat formed over the Western North Pacific Ocean southeast of Japan on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Sepat was located at latitude 25.1°N and longitude 144.3°E which put the center about 215 miles (345 km) east of Iwo To.  Sepat was moving toward the northwest at 12 m.p.h. (19 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 1004 mb.

A low pressure system over the Western North Pacific Ocean southeast of Japan strengthened on Sunday night and the Japan Meteorological Agency designated the system as Tropical Storm Sepat.  The distribution of thunderstorms in Tropical Storm Sepat was asymmetrical.  Thunderstorms were occurring in bands in the northern side of Sepat’s circulation.  The bands in the southern side of Tropical Storm Sepat consisted primarily of showers and lower clouds.

Tropical Storm Sepat was under the eastern side of an upper level low that was south of Japan.  The upper level low was producing southerly winds that were blowing toward the top of Sepat’s circulation.  Those winds were causing moderate vertical wind shear.  The wind shear was causing the asymmetrical distribution of thunderstorms.

The distribution of wind speeds in Tropical Storm Sepat was also asymmetrical.  Winds to tropical storm force extended out 110 miles (175 km) in the eastern side of Sepat’s circulation.  The winds in the western side of Tropical Storm Sepat were blowing at less than tropical storm force.

Tropical Storm Sepat will move through an environment somewhat favorable for intensification during the next 24 hours.  Sepat will move over water where where the Sea Surface Temperatures are near 28°C.  The upper level low south of Japan will continue to cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Storm Sepat is likely to intensify during the next 24 hours.

Tropical Storm Sepat will move around the western end of a high pressure system over the Western North Pacific Ocean.  The high pressure system and the upper low south of Japan will steer Sepat toward the north-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Sepat will move toward Honshu.

Hurricane Erick Hits Southern Mexico

Hurricane Erick hit the coast of southern Mexico on Thursday morning.  Erick started to weaken after it moved inland near the border between Oaxaca and Guerrero.  At 2:00 p.m. EDT on Thursday the center of Hurricane Erick was located at latitude 17.1°N and longitude 99.0°W which put the center about 60 miles (95 km) east-northeast of Acapulco, Mexico.  Erick was moving toward the northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 988 mb.

A Hurricane Warning is in effect for the portion of the coast from Puerto Escondido to Acapulco, Mexico.

A Tropical Storm Warning was in effect for the portion of the coast from Acapulco to Tecpan de Galeana, Mexico.

Hurricane Erick rapidly intensified to a Category 4 hurricane on the Saffir-Simpson Scale before it made landfall on the coast of Mexico.  The maximum sustained wind speed at the time of landfall was 140 m.p.h. (225 km/h).

Hurricane force winds extended out 15 miles (25 km) from the center of Erick’s circulation at the time of landfall.  Winds to tropical storm force extended out 90 miles (145 km) from the center of Hurricane Erick.

The Hurricane Intensity Index (HII) for Hurricane Erick at the time of landfall was 28.2.  The Hurricane Size Index (HSI) was 8.1 and the Hurricane Wind Intensity Size Index (HWISI) was 36.3.  Hurricane Erick was similar in size and intensity to Hurricane Charley when Charley hit southwest Florida in 2004.

The center of Hurricane Erick made landfall near Punta Maldonado.  Erick will continue to move northwest over Guerrero.  Hurricane Erick will weaken quickly when it moves over the Sierra Madres del Sur.  Erick will continue to drop heavy rain over parts of Oaxaca and Guerrero as it weakens.  Heavy rain could cause flash floods in some locations.

Hurricane Erick Rapidly Intensifies to Cat. 2

Hurricane Erick rapidly intensified to a Category 2 hurricane on the Saffir-Simpson Scale as it moved over the Eastern North Pacific Ocean south of Mexico on Wednesday.  At 2:00 p.m. EDT on Wednesday the center of Hurricane Erick was located at latitude 14.2°N and longitude 96.3°W which put the center about 215 miles (345 km) southeast of Punta Maldonado, Mexico.    Erick was moving toward the northwest at 9 m.p.h. (15 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 971 mb.

A Hurricane Warning was in effect for the portion of the coast from Puerto Angel to Acapulco, Mexico.

A Hurricane Watch was in effect for the portion of the coast from Acapulco to Tecpan de Galeana, Mexico. 

A Tropical Storm Warning was in effect for the portion of the coast from Puerto Angel to Salina Cruz, Mexico.  A Tropical Storm Warning was in effect for the portion of the coast from Acapulco to Tecpan de Galeana, Mexico.

A U.S. Air Force Reserve Hurricane Hunter reconnaissance plane investigating Hurricane Erick on Wednesday afternoon found that Erick had rapidly intensified to Category 2 on the Saffir-Simpson Scale.  A circular eye with a diameter of 15 miles (24 km) was present at the center of Erick’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 of Hurricane Erick.  Storms near the core generated strong upper level divergence that pumped mass away in all directions from the hurricane.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The distribution of winds speeds around Hurricane Erick was fairly symmetrical.  Winds to hurricane force extended out 15 miles (25 km) from the center of Erick’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Hurricane Erick.

Hurricane Erick will move through an environment very favorable for intensification during the next 18 hours.  Erick will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge over southern Mexico and the adjacent part of the Eastern North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Hurricane Erick will intensify during the next 18 hours. Erick is likely to intensify rapidly.  Hurricane Erick is likely to strengthen to a major hurricane by Thursday.

Hurricane Erick will move around the southwestern part of a high pressure system over Central America and southern Mexico.  The high pressure system will steer Erick toward the northwest during the next 24 hours.  On its anticipated track, Hurricane Erick will move toward the coast of southern Mexico.  Erick is likely to make landfall in southern Mexico between Acapulco and Punta Maldonado early on Thursday.

Hurricane Erick is likely to be a major hurricane when it makes landfall on the coast of Mexico.  Erick will bring strong winds and heavy rain to parts of Oaxaca, Guerrero and Michoacan.  The strongest winds and heaviest rains will occur in Guerrero.  Heavy rain will cause flash floods in some locations.  Hurricane Erick could also cause a storm surge of up to 10 feet (3 meters) along the coast.

Erick Intensifies to a Hurricane

Former Tropical Storm Erick intensified to a hurricane over the Eastern North Pacific Ocean south of Mexico on Wednesday morning.  At 8:00 a.m. EDT on Wednesday the center of Hurricane Erick was located at latitude 13.5°N and longitude 95.7°W which put the center about 275 miles (440 km) southeast of Punta Maldonado, Mexico.   Erick was moving toward the 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 991 mb.

A Hurricane Warning was in effect for the portion of the coast from Puerto Angel to Acapulco, Mexico.

A Hurricane Watch was in effect for the portion of the coast from Acapulco to Tecpan de Galeana, Mexico.  A Hurricane Watch was in effect for the portion of the coast from Puerto Angel to Bahias de Huatulco, Mexico.

A Tropical Storm Warning was in effect for the portion of the coast from Puerto Angel to Salina Cruz, Mexico.

Former Tropical Storm Erick intensified to a hurricane over the Eastern North Pacific Ocean south of Mexico on Wednesday morning.  The inner end of a rainband wrapped most of the way around the center of Erick’s circulation.  A small circular eye appeared to be forming at the center of Hurricane Erick.  Bands of showers and thunderstorms were revolving around the center of Erick’s circulation.  Storms near the center of Erick generated strong upper level divergence that pumped mass away from the hurricane in all directions.  The removal of large amounts of mass caused the surface pressure to decrease more quickly.

The distribution of wind speeds around Hurricane Erick became more symmetrical when it intensified.  Winds to hurricane force extended out 15 miles (25 km) from the center of Erick’s circulation.  Winds to tropical storm force extended out 70 miles (110 km) from the center of Hurricane Erick.

Hurricane Erick will move through an environment very favorable for intensification during the next 24 hours.  Erick will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge over southern Mexico and the adjacent part of the Eastern North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Hurricane Erick will intensify during the next 24 hours.  Erick could rapidly intensify at times.  Hurricane Erick could strengthen to a major hurricane by Thursday.

Hurricane Erick will move around the southwestern part of a high pressure system over Central America and southern Mexico.  The high pressure system will steer Erick toward the northwest during the next 24 hours.  On its anticipated track, Hurricane Erick will move toward the coast of southern Mexico.  Erick is likely to make landfall in southern Mexico between Acapulco and Punta Maldonado on Thursday.

Hurricane Erick could be a major hurricane when it makes landfall on the coast of Mexico.  Erick will bring strong winds and heavy rain to parts of Oaxaca, Guerrero and Michoacan.  The strongest winds and heaviest rains will occur in Guerrero.  Heavy rain will cause flash floods in some locations.  Hurricane Storm Erick could also cause a storm surge of up to 10 feet (3 meters) along the coast.

Tropical Storm Erick Strengthens

Tropical Storm Erick strengthened on Tuesday as it moved over the Eastern North Pacific Ocean south of Mexico.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Erick was located at latitude 13.1°N and longitude 94.9°W which put the center about 330 miles (535 km) southeast of Punta Maldonado, Mexico.  Erick was moving toward the northwest at 7 m.p.h. (11 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.

A Hurricane Warning was in effect for the portion of the coast from Puerto Angel to Acapulco, Mexico.

A Hurricane Watch was in effect for the portion of the coast from Acapulco to Tecpan de Galeana, Mexico.  A Hurricane Watch was in effect for the portion of the coast from Puerto Angel to Bahias de Huatulco, Mexico.

A Tropical Storm Warning was in effect for the portion of the coast from Puerto Angel to Salina Cruz, Mexico.

Tropical Storm Erick strengthened on Tuesday.  The inner end of a rainband wrapped around the western and southern sides of the center of Erick’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Tropical Storm Erick.  Storms near the center of Erick 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 Erick was somewhat asymmetrical.  Winds to tropical storm force extended out 90 miles (145 km) in the western half of Erick’s circulation.  Winds to tropical storm force only extended out 45 miles (75 km) in the eastern side of Tropical Storm Erick.

Tropical Storm Erick will move through an environment very favorable for intensification during the next 36 hours.  Erick will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge over Central America and the adjacent part of the Eastern North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Storm Erick will intensify during the next 36 hours.  Erick could rapidly intensify at times.  Tropical Storm Erick will intensify to a hurricane on Wednesday.

Tropical Storm Erick will move around the southwestern part of a high pressure system over Central America and southern Mexico.  The high pressure system will steer Erick toward the northwest during the next 36 hours.  On its anticipated track, Tropical Storm Erick will move toward the coast of southern Mexico.  Erick could make landfall in southern Mexico between Acapulco and Punta Maldonado on Thursday.

Tropical Storm Erick will be a hurricane when it makes landfall on the coast of Mexico.  Erick will bring strong winds and heavy rain to parts of Oaxaca, Guerrero and Michoacan.  Heavy rain will cause flash floods in some locations.  Tropical Storm Erick could also cause a storm surge of up to 10 feet (3 meters) along the coast.

Tropical Storm Erick Forms, Hurricane Watch for Mexico

Tropical Storm Erick formed over the Eastern North Pacific Ocean south of Mexico early on Tuesday.  The government of Mexico issued a Hurricane Watch for the portion of the coast.  At 8:00 a.m. EDT on Tuesday the center of Tropical Storm Erick was located at latitude 12.1°N and longitude 93.8°W which put the center about 515 miles (830 km) southeast of Acapulco, Mexico.  Erick was moving toward the west-northwest at 12 m.p.h. (19 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 Hurricane Watch was in effect for the portion of the coast from Bahias de Huatulco to Punta Maldonado, Mexico.

A Tropical Storm Watch was in effect for the portion of the coast from Bahias de Huatulco to Salina Cruz, Mexico.

A low pressure system over the Eastern North Pacific Ocean strengthened during Monday night and the U.S. National Hurricane Center designated the system as Tropical Storm Erick.  The circulation around Tropical Storm Erick exhibited more organization on Tuesday morning.  Bands of thunderstorms were revolving around the center of Erick’s circulation.  Storms near the center of Erick generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

Tropical Storm Erick will move through an environment very favorable for intensification during the next 36 hours.  Erick will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge over Central America and the adjacent part of the Eastern North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Storm Erick will intensify during the next 36 hours.  Erick could rapidly intensify to a hurricane by Wednesday.

Tropical Storm Erick will move around the southwestern part of a high pressure system over Central America and southern Mexico.  The high pressure system will steer Erick toward the northwest during the next 36 hours.  On its anticipated track, Tropical Storm Erick will move toward the coast of southern Mexico.  Erick could make landfall in southern Mexico between Acapulco and Punta Maldonado on Thursday.

Tropical Storm Erick will be a hurricane when it makes landfall on the coast of Mexico.  Erick will bring strong winds and heavy rain to parts of Oaxaca, Guerrero and Michoacan.  Heavy rain will cause flash floods in some locations.  Tropical Storm Erick could also cause a storm surge of up to 10 feet (3 meters) along the coast.

NHC Initiates Advisories on Potential Tropical Cyclone Five-E

The U.S. National Hurricane Center (NHC) initiated advisories on Potential Tropical Cyclone Five-E on Monday afternoon.  At 5:00 p.m. EDT on Monday the center of Potential Tropical Cyclone Five-E was located at latitude 10.6°N and longitude 91.7°W which put the center about 610 miles (980 km) southeast of Punta Maldonado, Mexico.  Potential Tropical Cyclone Five-E was moving toward the west-northwest at 8 m.p.h. (13 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.

More thunderstorms developed in a low pressure system over the Eastern North Pacific Ocean south of Guatemala on Monday afternoon and the U.S. National Hurricane Center (NHC) began issuing advisories on the system.  NHC designated the system as Potential Tropical Cyclone Five-E.

Thunderstorms formed near the center of Potential Tropical Cyclone Five-E.  Numerous thunderstorms also developed in bands revolving around the center of the low pressure system.  Thunderstorms near the center of the low pressure system began to generate upper level divergence that pumped mass away from Potential Tropical Cyclone Five-E.

Potential Tropical Cyclone Five-E will move through an environment very favorable for intensification during the next 48 hours.  The low pressure system will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge over Central America and the adjacent part of the Eastern North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Potential Tropical Cyclone Five-E will intensify during the next 48 hours.  It will strengthen to a tropical storm on Tuesday.  Potential Tropical Cyclone Five-E could rapidly intensify to a hurricane by Wednesday.

Potential Tropical Cyclone Five-E will move around the southwestern part of a high pressure system over Central America.  The high pressure system will steer the low pressure system toward the northwest during the next 48 hours.  On its anticipated track, Potential Tropical Cyclone Five-E will move toward the coast of southern Mexico.  It could make landfall in southern Mexico on Thursday.

Potential Tropical Cyclone Five-E is likely to be a hurricane when it makes landfall.  Watches and Warnings for portions of the coast of southern Mexico are likely to be issued on Tuesday.

Tropical Storm Dalila Weakens

Tropical Storm Dalila weakened as it moved away from Mexico on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Dalila was located at latitude 18.2°N and longitude 107.9°W which put the center about 235 miles (380 km) west-southwest of Manzanillo, Mexico.  Dalila was moving toward the west-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 999 mb.

Tropical Storm Dalila weakened on Sunday when it moved over cooler water south of Baja California.  Many of the thunderstorms in Dalila’s circulation weakened when the tropical storm move over cooler water.  Thunderstorms were still occurring in bands in the western part of Tropical Storm Dalila.  Bands in the other parts of Dalila’s circulation consisted primarily of showers and lower clouds.  The thunderstorms remaining in Tropical Storm Dalila generated less upper level divergence.  More mass was converging in the lower levels of the atmosphere  which caused the surface pressure to increase.

The size of the circulation around Tropical Storm Dalila decreased as Dalila weakened.  Winds to tropical storm force extended out 90 miles (145 km) from the center of Dalila’s circulation.

Tropical Storm Dalila will move through an environment unfavorable for intensification during the next 24 hours.  Dalila will move over water where where the Sea Surface Temperatures are near 24°C.  It will move under the southern part of an upper level ridge over southern Mexico and the adjacent part of the Eastern North Pacific Ocean.  The upper level ridge will produce east-northeasterly winds that will blow toward the top of Dalila’s circulation.  Those winds will cause the vertical wind shear to increase.  Cooler Sea Surface Temperatures and more vertical wind shear will cause Tropical Storm Dalila to continue to weaken during the next 24 hours.

Tropical Storm Dalila will move around the southwestern part of a high pressure system over Mexico.  The high pressure system will steer Dalila toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Dalila will continue to move farther away from the coast of southwestern Mexico.

Tropical Storm Dalila Intensifies Southwest of Mexico

Tropical Storm Dalila intensified over the Eastern North Pacific Ocean southwest of Mexico on Saturday morning.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Dalila was located at latitude 16.5°N and longitude 104.1°W which put the center about 175 miles (285 km) south of Manzanillo, Mexico.  Dalila was moving toward the northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 996 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Tecpan de Galeana to Cabo Corrientes, Mexico.

Tropical Storm Dalila intensified over the Eastern North Pacific Ocean southwest of Mexico on Saturday morning.  More thunderstorms formed near the center of Dalila’s circulation.   More thunderstorms also developed in bands revolving around the center of Tropical Storm Dalila.  Storms near the center of Dalila generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Storm Dalila was large.  Winds to tropical storm force extended out 230 miles (370 km) from the center of Dalila’s circulation.

Tropical Storm Dalila will move through an environment favorable for intensification during the next 24 hours.  Dalila will move over water where where the Sea Surface Temperatures are near 27°C.  It will move under the middle part of an upper level ridge over southern Mexico and the adjacent part of the Eastern North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Storm is likely to intensify during the next 24 hours.

Tropical Storm Dalila will move around the southwestern part of a high pressure system over Mexico.  The high pressure system will steer the tropical disturbance toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Dalila will start to move a little farther away from the coast of southwestern Mexico.

Thunderstorms in bands in the northern periphery of Tropical Storm Dalila will bring gusty winds and locally heavy rain to coastal portions of southwestern Mexico.  The heaviest rain is likely fall in parts of Guerrero, Michoacan, and Colima.  Heavy rain could cause flash floods in some location.