Tag Archives: Baja California

Tropical Storm Gil Forms South of Baja California

Tropical Storm Gil formed over the Eastern North Pacific Ocean south of Baja California on Wednesday night.  At 5:00 a.m. EDT on Thursday the center of Tropical Storm Gil was located at latitude 12.7°N and longitude 115.1°W which put the center about 785 miles (1260 km) south-southwest of the southern tip of Baja California.  Gil was moving toward the west 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 1004 mb.

A low pressure system over the Eastern North Pacific Ocean south of Baja California strengthened on Wednesday night and the U.S. National Hurricane Center designated the system as Tropical Storm Gil.

The circulation around Tropical Storm Gil was organizing quickly on Thursday morning.  Numerous thunderstorms formed near the center of Gil’s circulation.  Thunderstorms also developed in bands revolving around the center of Tropical Storm Gil.  Storms near the center of Gil 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 speed in Tropical Storm Gil was asymmetrical.  Winds to tropical storm force extended out 160 miles (260 km) in the eastern side of Gil’s circulation.  Winds to tropical storm force extended out 60 miles (95 km) in the western side of Tropical Storm Gil.

Tropical Storm Gil will move through an environment very favorable for intensification during the next 24 hours.  Gil will move over water where the Sea Surface Temperatures are near 28°C.   It will move under the southern side of an upper level ridge over the Eastern North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Gil’s circulation.  However, the winds in the lower atmosphere will also blow from the east.  So, there will be little vertical wind shear.  Tropical Storm Gil will intensify during the next 24 hours.  Gil could intensify rapidly,  Tropical Storm Gil could strengthen to a hurricane by Friday.

Tropical Storm Gil will move around the southern side of a high pressure system over the Eastern North Pacific Ocean.  The high pressure system will steer Gil toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Gil will move away from Baja California.

Elsewhere, Tropical Storm Iona moved quickly away from Hawaii.  At 5:00 a.m. EDT on Thursday the center of Tropical Storm Iona was located at latitude 12.3°N and longitude 166.9°W which put the center about 860 miles (1385 km) southwest of Honolulu, Hawaii.  Iona was moving toward the west at 23 m.p.h. (37 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.

Hurricane Flossie Weakens Rapidly

Hurricane Flossie weakened rapidly on Wednesday evening as it moved over the Eastern North Pacific Ocean south of Baja California.  At 11:00 p.m. EDT on Wednesday the center of Hurricane Flossie was located at latitude 19.8°N and longitude 110.2°W which put the center about 215 miles (345 km) south of Cabo San Lucas, Mexico.  Flossie was moving toward the northwest at 8 m.p.h. (13 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 986 mb.

Hurricane Flossie was weakening rapidly on Wednesday evening as it moved over cooler water south of Baja California.  Many of the thunderstorms in Flossie’s circulation were dissipating,  The bands revolving around the center of Hurricane Flossie consisted primarily of showers and lower clouds.  The dissipation of the thunderstorms in Flossie greatly reduced the upper level divergence.  Much less mass was being pumped away from Hurricane Flossie.  The continued convergence of mass in the lower levels of Flossie’s circulation caused the surface pressure to increase quickly.

The circulation around Hurricane Flossie was small.  Winds to hurricane force extended out 25 miles (40 km) from the center of Flossie’s circulation.  Winds to tropical storm force extended out 70 miles (110 km) from the center of Hurricane Flossie.

Hurricane Flossie will move through an environment that will be unfavorable for intensification during the next 24 hours.  Flossie will move over water where where the Sea Surface Temperatures are near 23°C.  It will move under the middle of an upper level ridge over 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.  Even though there will be little vertical wind shear, the cooler water south of Baja California will cause Hurricane Flossie to continue to weaken on Thursday.

Hurricane Flossie will move around the southwestern part of a high pressure system over Mexico.  The high pressure system will steer the Flossie toward the northwest during the next 24 hours.  On its anticipated track, Hurricane Flossie will remain south of Baja California.

Flossie Intensifies to a Major Hurricane

Hurricane Flossie intensified to a major hurricane over the Eastern North Pacific Ocean southwest of Mexico on Tuesday evening.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Flossie was located at latitude 18.2°N and longitude 107.4°W which put the center about 365 miles (585 km) south-southeast of Cabo San Lucas, Mexico.   Flossie was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 140 m.p.h. (220 km/h).   The minimum surface pressure was 962 mb.

A Tropical Storm Warning is in effect for the portion of the coast from Punta San Telmo to Playa Perula, Mexico.

Hurricane Flossie continued to intensify on Tuesday evening.  A circular eye was at the center of Flossie’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 Flossie.  Storms near the center of Flossie generated upper level divergence that pumped mass away from the hurricane in all directions.  The removal of mass caused the surface pressure to decrease.

The circulation around Hurricane Flossie was relatively small.  Winds to hurricane force extended out 25 miles (40 km) from the center of Flossie’s circulation.  Winds to tropical storm force extended out 90 miles (145 km) from the center of Hurricane Flossie.

The Hurricane Intensity Index (HII) for Hurricane Flossie is 20.6.  The Hurricane Size Index (HSI) is 8.3 and the Hurricane Wind Intensity Size Index (HWISI) is 28.9.  Hurricane Flossie is similar in size and intensity to Hurricane Zeta when Zeta hit Louisiana in 2020.

Hurricane Flossie will move through an environment that will be somewhat favorable for intensification during the next 12 hours.  Flossie will move over water where where the Sea Surface Temperatures are near 27°C.  It will move under the middle of an upper level ridge over 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 Flossie could continue to intensify during the next 12 hours.  Flossie will move over cooler water later in Wednesday.  Hurricane Flossie will start to weaken when it moves over cooler water.

Hurricane Flossie will move around the southwestern part of a high pressure system over Mexico.  The high pressure system will steer the Flossie toward the northwest during the next 24 hours.  On its anticipated track, Hurricane Flossie will start to move farther away from the coast of southwestern Mexico.  Flossie will move south of Baja California on Wednesday night.

Bands in the northeastern side of Hurricane Flossie will bring gusty winds and locally heavy rain to parts of the coast of southwestern Mexico.  The heaviest rain will fall in parts of Michoacan, Colima, and Jalisco.  Heavy rain could cause flash floods in some locations.

Hurricane Flossie Strengthens to Cat. 2

Hurricane Flossie strengthened to Category 2 on the Saffir-Simpson Scale as it moved over the Eastern North Pacific Ocean southwest of Mexico on Tuesday morning.  At 11:00 a.m. EDT on Tuesday the center of Hurricane Flossie was located at latitude 17.4°N and longitude 105.9°W which put the center about 150 miles (240 km) southwest of Manzanillo, Mexico.  Flossie was moving toward the northwest at 10 m.p.h. (16 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 974 mb.

A Tropical Storm Warning is in effect for the portion of the coast from Punta San Telmo to Playa Perula, Mexico.

A Tropical Storm Watch is in effect for the portion of the coast from Playa Perula to Cabo Corrientes, Mexico.  A Tropical Storm Watch is in effect for the portion of the coast from Punta San Telmo to Zihuatanejo, Mexico.

The inner end of a rainband wrapped around the center of Hurricane Flossie on Tuesday morning.  A circular eye was visible at the center of Flossie’s circulation on satellite images.  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 Flossie.  Storms near the center of Flossie generated upper level divergence that pumped mass away from the hurricane in all directions.  The removal of mass caused the surface pressure to decrease.

The area of hurricane force winds speeds in Hurricane Flossie increased on Tuesday.  Winds to hurricane force extended out 25 miles (40 km) from the center of Flossie’s circulation.  Winds to tropical storm force extended out 90 miles (145 km) from the center of Hurricane Flossie.

Hurricane Flossie will move through an environment very favorable for intensification during the next 24 hours.  Flossie will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge over 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 Flossie will intensify during the next 24 hours.  Flossie could intensify rapidly at times.  Hurricane Flossie is likely to strengthen to a major hurricane by Wednesday.

Hurricane Flossie will move around the southwestern part of a high pressure system over Mexico.  The high pressure system will steer the Flossie toward the northwest during the next 24 hours.  On its anticipated track, Hurricane Flossie will move parallel to the coast of southwestern Mexico.  Flossie is likely to move south of Baja California on Wednesday night.

Bands in the northeastern side of Hurricane Flossie will bring gusty winds and locally heavy rain to parts of the coast of southwestern Mexico.  The heaviest rain will fall in parts of Guerrero, Michoacan, Colima, and Jalisco.  Heavy rain could cause flash floods in some locations.

Tropical Storms Barbara and Cosme Spin West of Mexico

Tropical Storms Barbara and Cosme were spinning over the Eastern North Pacific Ocean west of Mexico on Tuesday morning.  At 5:00 a.m. EDT on Tuesday the center of Tropical Storm Barbara was located at latitude 19.1°N and longitude 108.1°W which put the center about 180 miles (290 km) west-southwest of Cabo Corrientes, Mexico.  Barbara was moving toward the northwest at 8 m.p.h. (13 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.

Former Hurricane Barbara weakened back to a tropical storm as it moved over cooler water south of Baja California during Monday night.  Thunderstorms were still occurring near the center of Barbara’s circulation.  Those thunderstorms generated upper level divergence that pumped mass away from the tropical storm.  However, the upper level divergence pumped away less mass than was converging in the lower level’s of Barbara’s circulation.  The accumulation of mass in the lower levels caused the surface pressure to increase.

The circulation around Tropical Storm Barbara was small.  Winds to tropical storm force extended out 70 miles (110 km) from the center of Barbara’s circulation.

Tropical Storm Barbara will move through an environment unfavorable for intensification during the next 24 hours.  Barbara will move over water where where the Sea Surface Temperatures are near 24°C. It will move under the middle part of an upper level ridge over Mexico and 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 Barbara will continue to weaken during the next 24 hours as it moves over colder water.

Tropical Storm Barbara will move around the southwestern part of a high pressure system over Mexico.  The high pressure system will steer Barbara toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Barbara will move slowly toward the southern end of Baja California.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Cosme was spinning south of Baja California.  At 5:00 a.m. EDT on Tuesday the center of Tropical Storm Cosme was located at latitude 15.3°N and longitude 114.5°W which put the center about 605 miles (975 km) south-southwest of the southern tip of Baja California.  Cosme was moving toward the west-northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 993 mb.

Tropical Storm Cosme maintained its intensity during Monday night.  Thunderstorms were occurring near the center of Cosme’s circulation.  Thunderstorms were also occurring in bands in the western side of Tropical Storm Cosme.  Bands in the eastern side of Cosme’s circulation consisted primarily of showers and lower clouds.  Storms near the center of Cosme generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass in the upper levels was almost the same as the inflow of mass in the lower level of Tropical Storm Cosme.  As a result of the balance of inflow and outflow, the surface pressure remained nearly constant.

The circulation around Tropical Storm Cosme was small.  Winds to tropical storm force extended out 85 miles (135 km) from the center of Cosme’s circulation.

Tropical Storm Cosme will move through an environment slightly unfavorable for intensification during the next 24 hours.  Cosme will move over water where where the Sea Surface Temperatures are near 25°C.  It will move under the southern side of an upper level ridge over Mexico and the Eastern North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Cosme’s circulation.  Those winds will cause some vertical wind shear. The combination of cooler Sea Surface Temperatures and some vertical wind shear will likely cause Tropical Storm Cosme to start to weaken during the next 24 hours.

Tropical Storm Cosme will move around the western part of a high pressure system over Mexico.  The high pressure system will steer Cosme toward the north during the next 24 hours.  On its anticipated track, Tropical Storm Cosme will remain far to the south of Baja California.

Barbara Intensifies to Hurricane Southwest of Mexico

Former Tropical Storm Barbara intensified to a hurricane over the Eastern North Pacific Ocean southwest of Mexico on Monday morning.  At 11:00 a.m. EDT on Monday the center of Hurricane Barbara was located at latitude 17.6°N and longitude 106.1°W which put the center about 155 miles (245 km) southwest of Manzanillo, Mexico.  Barbara was moving toward the northwest at 10 m.p.h. (16 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.

Former Tropical Storm Barbara intensified to a hurricane over the Eastern North Pacific Ocean southwest of Mexico on Monday morning.  The inner end of a rainband wrapped around the southern and eastern side of the center of Barbara’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Hurricane Barbara.  Storms near the center of Barbara generated upper level divergence that pumped mass away from the hurricane.  The removal of mass caused the surface pressure to decrease.

The circulation around Hurricane Barbara was small.  Winds to hurricane force extended out 15 miles (25 km) from the center of Barbara’s circulation.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Hurricane Barbara.

Hurricane Barbara will move through an environment favorable for intensification during the next 12 hours.  Barbara 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 Mexico and 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 Barbara could continue to intensify during the next 12 hours.  Barbara will move over cooler water by Tuesday which will cause it to start to weaken.

Hurricane Barbara will move around the southwestern part of a high pressure system over Mexico.  The high pressure system will steer Barbara toward the northwest during the next 24 hours.  On its anticipated track, Hurricane Barbara will move closer to the southern end of Baja California.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Cosme was also intensifying.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Cosme was located at latitude 14.5°N and longitude 113.3°W which put the center about 620 miles (1000 km) south-southwest of the southern tip of Baja California.  Cosme was moving toward the west-northwest at 6 m.p.h. (10 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 994 mb.

Tropical Storm Cosme Forms South of Baja California

Tropical Storm Cosme formed over the Eastern North Pacific Ocean south of Baja California on Sunday afternoon.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Cosme was located at latitude 13.3°N and longitude 111.0°W which put the center about 665 miles (1075 km) south of the southern tip of Baja California.  Cosme was moving toward the northwest at 8 m.p.h. (13 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 999 mb.

A low pressure system over the Eastern North Pacific Ocean south of Baja California strengthened on Sunday afternoon and the U.S. National Hurricane Center designated the system as Tropical Storm Cosme.  More thunderstorms formed near the center of Tropical Storm Cosme.  Thunderstorms also developed in bands in the southern and western parts of Cosme’s circulation.  Bands in the eastern and northern parts of Tropical Storm Cosme consisted primarily of showers and lower clouds.  Storms near the center of Cosme generated upper level divergence that pumped mass away to the west of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Storm Cosme was relatively small. Winds to tropical storm force extended out 45 miles (75 km) from the center of Cosme’s circulation.

Tropical Storm Cosme will move through an environment favorable for intensification during the next 24 hours.  Cosme will move over water where where the Sea Surface Temperatures are near 28°C.  It will move under the southern side of an upper level ridge over Mexico and the Eastern North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Cosme’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be strong enough to prevent Cosme from intensifying.  Tropical Storm Cosme will intensify during the next 24 hours.

Tropical Storm Cosme will move around the western part of a high pressure system over Mexico.  The high pressure system will steer Cosme toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Cosme will remain far to the south of Baja California.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Barbara strengthened southwest of Mexico.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Barbara was located at latitude 16.0°N and longitude 104.1°W which put the center about 205 miles (325 km) southwest of Zihuatanejo, Mexico.  Barbara was moving toward the west-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.

Tropical Storm Cosme and Tropical Storm Barbara will move close enough to each other during the next few days that their two circulations are likely to interact.

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.