Category Archives: Eastern and Central Pacific

TCs between Mexico and Hawaii

Possible Development East-Northeast of Hawaii

The National Hurricane Center (NHC) indicated that a low pressure system over the Eastern North Pacific Ocean east-northeast of Hawaii could develop into a subtropical or a tropical cyclone during the next 48 hours. The low pressure system is currently designated as Invest 90E. At 1:00 p.m. EST on Thursday the center of Invest 90E was located at latitude 21.8°N and longitude 136.1°W which put it about 1280 miles (2065 km) east-northeast of Hilo, Hawaii. It was moving toward the west-northwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 1006 mb.

The National Hurricane Center issued a Special Tropical Weather Outlook on Thursday afternoon which indicated that a low pressure system over the Eastern North Pacific Ocean had a 40% probability of development into a subtropical or a tropical cyclone during the next 48 hours. The low pressure system has been moving slowly toward the west between Baja California and Hawaii. The low pressure system currently has a hybrid structure. A well organized low level center of circulation was evident on visible satellite images. The low level center was located just to the east of a low pressure system in the middle and upper troposphere. The upper low was producing southerly winds that were blowing toward the top of the low level circulation. Those winds were causing moderate vertical wind shear and the wind shear was affecting the structure of the system. The strongest thunderstorms were occurring in bands north and east of the low level center of circulation. Bands south and west of the low level center consisted primarily of showers and lower clouds.

Invest 90E will move through an environment somewhat favorable for the formation of a subtropical or a tropical cyclone during the next 24 hours. The surface center of circulation will move over water where the Sea Surface Temperatures are near 24˚C. Since the upper low contains colder air, that water temperature is warm enough to support the development of a subtropical or a tropical cyclone. The low in the middle and upper troposphere will continue to cause moderate vertical wind shear. The wind shear will inhibit the development of a tropical cyclone. The current hybrid structure of Invest 90E and the marginally warm Sea Surface Temperatures would favor the development of a subtropical cyclone. However, if the strength of the upper level winds decreases, then a tropical cyclone could form.

Invest 90E will move south of a surface high pressure system over the Eastern North Pacific Ocean. The high pressure system will steer the low level center of circulation toward the west-northwest during the next 24 hours. On its anticipated track Invest 90E will move slowly toward the Central Pacific Ocean.

Tropical Depression Terry Churns West

Tropical Depression Terry churned westward over the Eastern North Pacific Ocean on Wednesday. At 10:00 a.m. EST on Wednesday the center of Tropical Depression Terry was located at latitude 11.7°N and longitude 116.9°W which put it about 900 miles (1450 km) south-southwest of the southern tip of Baja California. Terry was moving toward the west at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h). The minimum surface pressure was 1008 mb.

The distribution of thunderstorms around Tropical Depression Terry was asymmetrical. The strongest thunderstorms were occurring in bands in the southern half of Terry’s circulation. Bands in the northern half of the tropical depression consisted of showers and lower clouds. Sinking drier air was being pulled into the northern side of Tropical Depression Terry. The drier air was inhibiting the formation of thunderstorms in that part of the circulation. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical depression.

Tropical Depression Terry will move through an environment marginally favorable for intensification during the next 24 hours. Terry will move over water where the Sea Surface Temperatures are near 27˚C. It will move under the axis of an upper level ridge. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Drier air near the northern side of Terry’s circulation could continue to inhibit the develop of thunderstorms in that part of the tropical depression. Tropical Depression Terry is likely to maintain its intensity during the next 24 hours. Terry could strengthen if more thunderstorms develop near the center of circulation.

Tropical Depression Terry will move south of a surface high pressure system over the Eastern North Pacific Ocean during the next few days. The high pressure system will steer Terry toward the west. On its anticipated track Tropical Depression Terry will continue to move farther away from Mexico.

Tropical Storms Sandra and Terry Develop over East Pacific

Tropical Storms Sandra and Terry developed over the Eastern North Pacific Ocean on Sunday afternoon. At 4:00 p.m. EST on Sunday the center of Tropical Storm Sandra was located at latitude 14.0°N and longitude 115.2°W which put it about 705 miles (1135 km) south-southwest of the southern tip of Baja California. Sandra was moving toward the west-northwest at 10 m.p.h. (16 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 1006 mb.

At 4:00 p.m. EST on Sunday the center of Tropical Storm Terry was located at latitude 8.5°N and longitude 102.6°W which put it about 735 miles (1180 km) south of Manzanillo, Mexico. Terry was moving toward the west 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 1007 mb.

Based on data from a scatterometer on a satellite, the National Hurricane Center upgraded former Tropical Depression Nineteen-E to Tropical Storm Sandra on Sunday afternoon. It appeared from later satellite images that Tropical Storm Sandra might already be weakening. A large upper level trough approaching the west coast of the U.S. was producing strong southerly winds that were blowing across the top of Sandra’s circulation. Those winds were causing moderate vertical wind shear. The strong upper level winds blew the tops off thunderstorms near the center of Sandra. The strongest remaining thunderstorms were occurring in bands east of the center. Bands in other parts of Tropical Storm Sandra consisted primarily of showers and lower clouds. The strongest winds were in the eastern half of Sandra. Winds to tropical storm force extended out 90 miles in the eastern half of Sandra. The winds in the western half of the circulation were blowing at less than tropical storm force.

Tropical Storm Sandra will move through an environment mostly unfavorable for intensification during the next several days. Sandra will move over water where the Sea Surface Temperatures are near 27˚C. However, the large upper level trough will continue to produce strong vertical wind shear. The wind shear is likely to prevent Tropical Storm Sandra from strengthening. The strong shear could blow the top off of Sandra’s circulation and Tropical Storm Sandra is more likely to weaken during the next several days. Sandra will move south of a surface high pressure system over the Eastern North Pacific Ocean. The high pressure system will steer Sandra toward the west. On its anticipated track Tropical Storm Sandra will move farther away from Mexico.

More thunderstorms developed near the center of former Tropical Depression Eighteen-E on Sunday afternoon and the National Hurricane Center upgraded the system to Tropical Storm Terry. The circulation around Tropical Storm Terry exhibited more organization on satellite images. More thunderstorms also formed in bands revolving around the center of Terry. Storms near the center generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 60 miles (95 km) on the eastern side of Terry’s circulation. The winds in the western half of Terry were blowing at less than tropical storm force.

Tropical Storm Terry will move through an environment somewhat favorable for intensification during the next 24 hours. Terry will move over water where the Sea Surface Temperatures are near 28˚C. It will move through a region where the upper level wind are weak and there will be little vertical wind shear. Tropical Storm Terry could slowly intensify during the next 24 hours.

Tropical Storm Terry will move around the southern side of a surface high pressure system over the Eastern North Pacific Ocean. The high will steer Terry toward the west during the next few days. On its anticipated track Tropical Storm Terry will move farther away from Mexico.

Tropical Depression Forms South of El Salvador

Tropical Depression Eighteen-E formed over the Eastern North Pacific Ocean south of El Salvador in Thursday morning. At 11:00 a.m. EDT on Thursday the center of Tropical Depression Eighteen-E was located at latitude 9.4°N and longitude 90.0°W which put it about 300 miles (485 km) south of San Salvador, El Salvador. The tropical depression was moving toward the west 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 1007 mb.

Thunderstorms formed closer to the center of a small low pressure system south of El Salvador on Thursday morning and the National Hurricane Center designated the system as Tropical Depression Eighteen-E. The strongest thunderstorms were occurring in a band a little to the east of the center of circulation. Storms in that band began to generate upper level divergence that pumped mass away from the tropical depression. Bands in the western half of the depression consisted of showers and lower clouds.

Tropical Depression Eighteen-E will move through an environment somewhat favorable for intensification during the next 48 hours. The depression will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the northern part of an upper level ridge west of Central America. The northern part of the upper level ridge will produce weak westerly winds that will blow toward the top of the depression’s circulation. Those winds will cause some vertical wind shear. The wind shear will inhibit intensification, but it will not be strong enough to prevent the tropical depression from getting stronger. Tropical Depression Eighteen-E is likely to slowly intensify to a tropical storm during the next several days.

Tropical Depression Eighteen-E will move around the southern side of a surface high pressure system over the Eastern North Pacific Ocean. The high will steer the tropical depression toward the west during the next few days. On its anticipated track Tropical Depression Eighteen-E will move farther away from Central America.

Hurricane Rick Makes Landfall on West Coast of Mexico

Hurricane Rick made landfall on the west coast of Mexico on Monday morning. At 8:00 a.m. EDT on Monday the center of Hurricane Rick was located at latitude 18.2°N and longitude 102.1°W which put it about 15 miles (25 km) north-northeast of Lazaro Cardenas, Mexico. Rick was moving toward the north at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h). The minimum surface pressure was 977 mb.

A Hurricane Warning was in effect for the portion of the coast from Tecpan De Galeana to Punta San Telmo, Mexico. Tropical Storm Warnings were in effect for the portions of the coast from Punta San Telmo to Manzanillo and from Tecpan de Galeana to Acapulco, Mexico.

Hurricane Rick made landfall on the west coast of Mexico between Zihuatenajo and Lazaro Cardenas on Monday morning. Rick intensified before it made landfall. The maximum sustained wind speed increased to 105 m.p.h. (165 km/h) which made Rick a Category 2 hurricane on the Saffir-Simpson Scale. Even though Hurricane Rick intensified, the circulation remained relative small. Winds to hurricane force extended out 25 miles (40 km) from the center of Rick. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation.

The Hurricane Intensity Index (HII) for Hurricane Rick was 17.8. The Hurricane Size Index (HSI) was 8.2 and the Hurricane Wind Intensity Size Index (HWISI) was 26.0. Hurricane Rick was capable of causing regionalized serious damage.

Hurricane Rick was bringing strong winds and locally heavy rain to the portion of the coast between Lazaro Cardenas and Zihuatenajo. There were reports of damage in Ixtapa. Winds blowing water toward the coast were causing a storm surge. Heavy rain was falling over parts of Guerrero and Michoacan. The heavy rain could cause flash floods in some locations. Hurricane Rick will weaken steadily now that the center is inland. However, heavy rain will spread over inland sections of Guerrero and Michoacan and flash floods could occur in those areas.

Hurricane Rick Moves Toward Mexico

Hurricane Rick moved slowly toward the west coast of Mexico on Sunday afternoon. At 2:00 p.m. EDT on Sunday the center of Hurricane Rick was located at latitude 16.4°N and longitude 101.7°W which put it about 85 miles (135 km) south of Zihuatenajo, Mexico. Rick was moving toward the north at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h). The minimum surface pressure was 980 mb.

A Hurricane Warning was in effect for the portion of the coast from Tecpan De Galeana to Punta San Telmo, Mexico. Tropical Storm Warnings were in effect for the portions of the coast from Punta San Telmo to Manzanillo and from Tecpan de Galeana to Acapulco, Mexico.

The intensity of Hurricane Rick was steady during the past few hours. The inner core of Rick’s circulation was not as well organized as it was on Saturday afternoon. There were breaks in the ring of thunderstorms surrounding the center of Hurricane Rick. Storms near the center of circulation continued to generate upper level divergence that pumped mass away from the hurricane. Bands of showers and thunderstorms revolved around the center of Rick. The circulation around Hurricane Rick was small. Winds to hurricane force extended out 15 miles (25 km) from the center of Rick. Winds to tropical storm force extended out 60 miles (95 km) from the center of circulation.

Hurricane Rick will move through an environment favorable for intensification during the next 12 hours. Rick will move over water where the Sea Surface Temperatures are near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Hurricane Rick could intensify during the next 12 hours. However, the less organized core of Rick will limit intensification. An upper level trough near the west coast of the U.S. will produce strong southwesterly winds that will blow toward the top of Rick’s circulation on Monday. Those winds will cause vertical wind shear and the shear could cause Hurricane Rick to weaken as it nears the coast of Mexico.

Hurricane Rick will move around the western part of a high pressure system over Mexico during the next 24 hours. A large upper level trough near the west coast of the U.S. will cause the high pressure system to weaken. As the high pressure system weakens, the southern part of the upper level trough will steer Rick toward the north. On its anticipated track Hurricane Rick could make landfall on the west coast of Mexico on Sunday night. Hurricane Rick will bring strong winds and locally heavy rain to the portion of the coast near Zihuatanejo. Heavy rain could cause flash floods in parts of Guerrero and Michoacan on Sunday night and Monday.

Rick Rapidly Intensifies to a Hurricane South of Mexico

Former Tropical Storm Rick rapidly intensified to a hurricane south of Mexico early on Saturday. At 8:00 a.m. EDT on Saturday the center of Hurricane Rick was located at latitude 14.3°N and longitude 101.5°W which put it about 235 miles (380 km) south of Zihuatenajo, Mexico. Rick was moving toward the north-northwest at 6 m.p.h. (10 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 990 mb.

A Hurricane Watch was in effect for the portion of the coast from Tecpan De Galeana to Punta San Telmo, Mexico. Tropical Storm Watches were in effect for the portions of the coast from Punta San Telmo to Manzanillo and from Tecpan de Galeana to Acapulco, Mexico.

Former Tropical Storm Rick intensified rapidly during Friday night and it strengthened to a hurricane early on Saturday. A small eye formed at the center of Hurricane Rick. 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 Rick’s circulation. Storms near the core generated upper level divergence that pumped mass away from the hurricane. The removal of mass allowed the surface pressure to decrease quickly. The circulation around Hurricane Rick was small. Winds to hurricane force extended out 15 miles (25 km) from the center of Rick. Winds to tropical storm force extended out 60 miles (95 km) from the center of circulation.

Hurricane Rick will move through an environment very favorable for intensification during the next 24 hours. Rick will move over water where the Sea Surface Temperatures are near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Hurricane Rick will likely continue to intensify rapidly during the next 24 hours. Rick could strengthen to a major hurricane on Sunday.

Hurricane Rick will move around the western part of a high pressure system over Mexico during the next 24 hours. A large upper level trough approaching the west coast of the U.S. will cause the high pressure system to weaken during the weekend. As the high pressure system weakens, the southern part of the upper level trough will steer Rick toward the north. On its anticipated track Hurricane Rick could approach the west coast of Mexico by later on Sunday. Rick could be a major hurricane when it approaches the coast of Mexico. The Hurricane and Tropical Storm Watches are likely to be changed to warnings later today. Hurricane Rick could bring strong winds and heavy rain to Guerrero and Michoacan on Sunday night and Monday.

TD 17E Strengthens to Tropical Storm Rick, Mexico Issues Watches

Former Tropical Depression Seventeen-E strengthened to Tropical Storm Rick on Friday afternoon and the government of Mexico issued a Hurricane Watch and Tropical Storm Watches for portions of the coast. At 5:00 p.m. EDT on Friday the center of Tropical Storm Rick was located at latitude 13.1°N and longitude 101.0°W which put it about 460 miles (745 km) south-southeast of Manzanillo, Mexico. Rick was moving toward the west-northwest 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 1005 mb.

A Hurricane Watch was issued for the portion of the coast from Zihuatenajo to Punta San Telmo, Mexico. Tropical Storm Watches were issued for the portions of the coast from Punta San Telmo to Manzanillo and from Zihuatenajo to Tecpan de Galeana, Mexico.

The circulation around former Tropical Depression Seventeen-E strengthened on Friday afternoon and the National Hurricane Center upgraded the system to Tropical Storm Rick. The inner end of a rainband wrapped around the western and southern sides of the center of Tropical Storm Rick. Other bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center generated upped level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 45 miles (75 km) in the northern half of Tropical Storm Rick. The winds in the southern half of the circulation were blowing at less than tropical storm force.

Tropical Storm Rick will move through an environment favorable for intensification during the next 36 hours. Rick will move over water where the Sea Surface Temperatures are near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Storm Rick will continue to intensify steadily during the next 36 hours. Rick could strengthen to a hurricane on Saturday.

Tropical Storm Rick will move around the southern part of a high pressure system over Mexico during the next few hours. A large upper level trough approaching the west coast of the U.S. will cause the high pressure system to weaken during the weekend. When the high pressure system weakens, the southern part of the upper level trough will turn Rick toward the north-northwest. On its anticipated track Tropical Storm Rick could approach the west coast of Mexico by later on Sunday. Rick could be a hurricane when it approaches the coast of Mexico. The Hurricane and Tropical Storm Watches are likely to be changed to warnings on Saturday.

Tropical Depression Seventeen-E Forms South of Mexico

Tropical Depression Seventeen-E formed south of Mexico on Friday morning. At 11:00 a.m. EDT on Friday the center of Tropical Depression Seventeen-E was located at latitude 12.7°N and longitude 100.5°W which put it about 505 miles (810 km) south-southeast of Manzanillo, Mexico. The depression was moving toward the west 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 1007 mb.

The circulation around a low pressure system over the Eastern North Pacific Ocean south of Mexico exhibited more organization on Friday morning and the National Hurricane Center designated the system as Tropical Depression Seventeen-E. The circulation around Tropical Depression Seventeen-E was still organizing. More thunderstorms developed near the center of the depression. More thunderstorms also formed in bands revolving around the center of circulation. Storms near the center began to generate upper level divergence that pumped mass away from the tropical depression.

Tropical Depression Seventeen-E will move through an environment 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 through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Depression Seventeen-E is likely to intensify steadily during the next 36 hours. The depression is likely to intensify to a tropical storm later today and it could strengthen to a hurricane on Saturday.

Tropical Depression Seventeen-E will move around the southern part of a high pressure system over Mexico during the next few hours. A large upper level trough approaching the west coast of the U.S. will cause the high pressure system to weaken during the weekend. When the high pressure system weakens, the southern part of the upper level trough will turn the tropical depression toward the north-northwest. On its anticipated track Tropical Depression Seventeen-E could approach the west coast of Mexico by later on Sunday. The tropical depression could be a hurricane when it approaches the coast of Mexico. Watches could be issued for a portion of the coast later on Friday or on Saturday morning.

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.