Tag Archives: Alvin

Alvin Weakens to a Depression

Former Tropical Storm Alvin weakened to a tropical depression over the Eastern North Pacific Ocean south of Baja California on Saturday morning.  At 11:00 a.m. EDT on Saturday the center of Tropical Depression Alvin was located at latitude 20.7°N and longitude 109.5°W which put the center about 155 miles (250 km) south of the southern tip of Baja California.  Alvin was moving toward the north at 9 m.p.h. (15 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 1006 mb.

Former Tropical Storm Alvin weakened to a tropical depression over the Eastern North Pacific Ocean south of Baja California on Sunday morning.  An upper level low over Baja California caused strong southwesterly winds that blew across the top of Alvin’s circulation.  Those winds caused strong vertical wind shear.  In addition, Alvin moved over water where the Sea Surface Temperatures are near 24°C.  Strong vertical wind shear and cool Sea Surface Temperatures caused former Tropical Storm Alvin to weaken.

Most of the thunderstorms in former Tropical Storm Alvin dissipated due to the strong vertical wind shear and cooler Sea Surface Temperatures.  The circulation around Tropical Depression Alvin existed primarily in the lower levels of the atmosphere.  Bands of showers and lower clouds were revolving around the center of Alvin’s circulation.  Since there were no thunderstorms to generate upper level divergence and to pump mass away, the surface pressure was increasing gradually.

Tropical Depression Alvin will move through an environment very unfavorable for intensification during the next 24 hours.  Alvin will move over water where where the Sea Surface Temperatures are near 24°C.  The upper level low over Baja California will continue to produce southwesterly winds that will blow across the top of Alvin’s circulation.  Those winds will continue to cause strong vertical wind shear.  The combination of cool Sea Surface Temperatures and strong vertical wind shear will cause Tropical Depression Alvin to continue to weaken during the next 24 hours.

Tropical Depression Alvin will move around the western part of a high pressure system over Mexico.  The high pressure system over Mexico and the upper level low over Baja California will steer Alvin toward the north during the next 24 hours.  On its anticipated track, Tropical Depression Alvin will closer to the southern end of Baja California.

Tropical Storm Alvin Weakens South of Baja California

Tropical Storm Alvin weakened on Friday as it moved over the Eastern North Pacific Ocean south of Baja California.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Alvin was located at latitude 18.1°N and longitude 109.0°W which put the center about 335 miles (540 km) south of the southern tip of Baja California.  Alvin was moving toward the north-northwest at 10 m.p.h. (16 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 1001 mb.

An upper level low over Baja California produced southwesterly winds that blew toward the top of Tropical Storm Alvin on Friday.  Those winds caused the vertical wind shear to increase.  The increase in vertical wind shear caused Alvin to weaken.  The increase in wind shear also caused the distribution of thunderstorm around Tropical Storm Alvin to become asymmetrical.  Thunderstorms were still occurring in bands in the northern side of Alvin’s circulation.  Bands in the southern side of Tropical Storm Alvin consisted primarily of showers and lower clouds.

Even though Tropical Storm Alvin weakened on Friday,  the size of the circulation did not change much.  Winds to tropical storm force extended out 140 miles (225 km) from the center of Alvin’s circulation.

Tropical Storm Alvin will move through an environment that will become even more unfavorable for intensification during the next 24 hours.  Alvin will move over water where where the Sea Surface Temperatures are near 25°C.  It will move under the southeastern part of the upper level low over Baja California.  The upper level low will continue to produce southwesterly winds that will blow toward the top of Alvin’s circulation.  Those winds will cause strong vertical wind shear on Saturday.  The combination of cool Sea Surface Temperatures and strong vertical wind shear will cause Tropical Storm Alvin to continue to weaken during the next 24 hours.

Tropical Storm Alvin will move around the western part of a high pressure system over Mexico. The high pressure system over Mexico and the upper level low over Baja California will steer Alvin toward the north during the next 24 hours.  On its anticipated track, Tropical Storm Alvin will closer to the southern end of Baja California.

Tropical Storm Alvin Intensifies Southwest of Mexico

Tropical Storm Alvin intensified over the Eastern North Pacific Ocean southwest of Mexico on Thursday.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Alvin was located at latitude 16.0°N and longitude 107.9°W which put the center about 305 miles (495 km) west-southwest of Manzanillo, Mexico.  Alvin 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 999 mb.

Tropical Storm Alvin intensified over the Eastern North Pacific Ocean southwest of Mexico on Thursday.  The inner end of a rainband wrapped around the western side of the center of Alvin’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Tropical Storm Alvin.  Storms near the center of Alvin generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The area of tropical storm force winds increased in size when Tropical Storm Alvin intensified on Thursday.  Winds to tropical storm force extended out 140 miles (225 km) from the center of Alvin’s circulation.

Tropical Storm Alvin will move into an environment that will become unfavorable for intensification during the next 24 hours.  Alvin will move over water where where the Sea Surface Temperatures are near 26°C.  It will move under the southeastern part of an upper level low over Baja California.  The upper level low will produce southwesterly winds that will blow toward the top of Alvin’s circulation.  Those winds will cause the vertical wind shear to increase on Friday.  The combination of cooler Sea Surface Temperatures and more vertical wind shear will cause Tropical Storm Alvin to start to weaken during the next 24 hours.

Tropical Storm Alvin will move around the southwestern part of a high pressure system over Mexico.  The high pressure system over Mexico and the upper level low over Baja California will steer Alvin toward the north-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Alvin will move parallel to the west coast of Mexico.

Depression Strengthens to Tropical Storm Alvin

Former Tropical Depression One-E strengthened to Tropical Storm Alvin over the Eastern North Pacific Ocean south of Mexico on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Alvin was located at latitude 13.8°N and longitude 106.3°W which put the center about 345 miles (555 km) south-southwest of Manzanillo, Mexico.  Alvin was moving toward the 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 1005 mb.

Former Tropical Depression One-E strengthened on Thursday morning and the U.S. National Hurricane Center designated the system as Tropical Storm Alvin.  Numerous thunderstorms formed near the center of Alvin’s circulation.  More thunderstorms also developed in bands revolving around the center of Tropical Storm Alvin.  Storms near the center of Alvin generated more upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

Winds to tropical storm force extended out 45 miles (75 km) from the center of Tropical Storm Alvin.

Tropical Storm Alvin will move through an environment favorable for intensification during the next 24 hours.  Alvin will move over water where where the Sea Surface Temperatures are near 28°C.  It will move under the western part of an upper level ridge that is south of Mexico.  The upper level ridge will produce southerly winds that will blow toward the top of Alvin’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Alvin will intensify during the next 24 hours.

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

Alvin Strengthens Into a Hurricane Southwest of Baja California

Former Tropical Storm Alvin strengthened into a hurricane southwest of Baja California on Thursday evening.  At 11:00 p.m. EDT on Thursday the center of Hurricane Alvin was located at latitude 17.4°N and longitude 115.4°W which put it about 520 miles (840 km) southwest of the southern tip of Baja California.  Alvin was moving toward the northwest at 16 m.p.h. (26 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 992 mb.

The circulation around Hurricane Alvin exhibited much greater organization on Wednesday.  A small circular eye with a diameter of 10 miles (15 km) appeared at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  The circulation around Hurricane Alvin was very small.  Winds to hurricane force extended out only 10 miles (15 km) from the center of circulation.  Winds to tropical storm force extended out about 50 miles (80 km) from the center.

Hurricane Alvin may be near its maximum intensity.  Alvin was moving over water where the Sea Surface Temperature was near 27°C.  However, it will move over cooler water on Friday.  The small size of the circulation around Hurricane Alvin could allow it to weaken quickly once it moves over the cooler water.

Hurricane Alvin will move near the western end of a subtropical ridge over Eastern North Pacific Ocean.  The ridge will steer Alvin toward the west-northwest during the next several days.  On its anticipated track Hurricane Alvin is forecast to weaken when it moves over colder water between Baja California and Hawaii.

Tropical Storm Alvin Develops South of Baja California

Tropical Storm Alvin developed south of Baja California on Wednesday morning, when former Tropical Depression One-E strengthened to a tropical storm.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Alvin was located at latitude 14.7°N and longitude 109.4°W which put it about 565 miles (915 km) south of the southern tip of Baja California.  Alvin 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 1005 mb.

The circulation around Tropical Storm Alvin exhibited greater organization on Wednesday morning.  A band of thunderstorms wrapped around the eastern side of the center of circulation.  Other bands of showers and thunderstorms were organizing in the eastern half of the circulation.  Winds to tropical storm force extended out about 35 miles (55 km) from the center on the eastern side of the circulation.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Alvin will move through an environment favorable for intensification during the next 24 to 36 hours.  Alvin will move over water where the Sea Surface Temperature is near 28°C.  Tropical Storm Alvin will move south of an upper level ridge.  The ridge will produce northeasterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Storm Alvin will intensify during the next day or two and it could strengthen into a hurricane.

The upper level ridge will steer Tropical Storm Alvin toward the west during the next several days.  Alvin could move a little to the south of due west during the next 24 hours.  On its anticipated track Tropical Storm Alvin will move steadily farther away from Mexico.