Tag Archives: Eastern North Pacific Ocean

Tropical Storm Bud Brings Wind & Rain to Baja California, New Depression Forms South of Acapulco

Tropical Storm Bud brought wind and rain to the southern part of Baja Calfornia on Tuesday while a new tropical depression formed south of Acapulco, Mexico.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Bud was located at latitude 22.2°N and longitude 109.8°W which put it about 50 miles (80 km) south of Cabo San Lucas, Mexico.  Bud was moving toward the north-northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1000 mb.

A Tropical Storm Warning remained in effect for the portion of the coast from Santa Fe to La Paz, Mexico including Cabo San Lucas.  The government of Mexico issued new Tropical Storm Watches for the portions of the coast from La Paz to San Evaristo and from Altata to Huatabampito, Mexico.

Rainbands on the northern side of the circulation of Tropical Storm Bud were producing winds to tropical storm force over the southern end of Baja California.  New thunderstorms began to form when a band north and east of the center of circulation moved over the southern part of the Gulf of California.  The Sea Surface Temperature of the water in the Gulf is near 27°C which is warmer than the water of the Eastern North Pacific Ocean south of Baja California.  The additional energy from the ocean may have contributed to the formation of the new storms.

A trough in the upper levels is forecast to steer Tropical Storm Bud toward the north-northeast during the next several days,  Bud could maintain its intensity for another 24 hours if the center of circulation passes southeast of Baja California.  If the center passes over Baja, the mountains would disrupt the circulation in the lower levels and Tropical Storm Bud would weaken.  In either case Tropical Storm Bud will bring gusty winds and heavy rain to the southern end of Baja California for another day or so.  Bud will bring gusty winds and heavy rain to the west coast of Mexico later on Friday.  Heavy rain could cause flash flooding in some locations.

Tropical Depression Four-E formed south of Acapulco on Thursday afternoon.  At 5:00 p.m. EDT on Thursday the center of Tropical Depression Four-E was located at latitude 15.5°N and longitude 100.1°W which put it about 100 miles (155 km) south of Acapulco, Mexico.  It was moving toward the northwest at 6 m.p.h. (10 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 1008 mb.  Because of the proximity to the coast the government of Mexico issued a Tropical Storm Watch for the portion of the coast from Tecpan de Galeana to Punta Maldonado.

A center of circulation developed in a cluster of thunderstorms south of Mexico and the National Hurricane Center designated the system as Tropical Depression Four-E.  The circulation was still organizing.  Several fragmented bands of showers and thunderstorms formed in the outer portions of the circulation.  The center of circulation was broad and there were several smaller cyclonic rotations swirling around inside the broader center.

Tropical Depression Four-E will move through an environment that will be favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  The upper level winds will be weak and there will be little vertical wind shear.  The proximity to the coast will be the primary factor inhibiting intensification.  The circulation could pull in drier air from Mexico.  Tropical Depression Four-E is expected to strengthen into a tropical storm on Friday.

Tropical Depression Four-E will move around the western end of a subtropical ridge, but the steering currents are likely to be weak.  The depression is expected to move slowly toward the north-northwest during the next day or two.  On its anticipated track the center of the depression could move near the coast during the weekend.  It could bring gusty winds and locally heavy rain.  The rain could cause flash floods.

Bud Quickly Strengthens to a Hurricane

Former Tropical Storm Bud quickly strengthened into a hurricane on Sunday.  At 5:00 p.m. EDT on Sunday the center of Hurricane Bud was located at latitude 15.3°N and longitude 104.2°W which put it about 365 miles (590 km) south-southeast of Cabo Corrientes, Mexico.  Bud was moving toward the northwest at 9 m.p.h. (15 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.  The government of Mexico issued a Tropical Storm Watch for the portion of the coast from Manzanillo to Cabo Corrientes.

Hurricane Bud strengthened quickly and the circulation exhibited the structure of a hurricane.  An eye formed at the center of circulation, although the eye was obscured intermittently by clouds.  A nearly complete ring of thunderstorms surrounded the eye and the strongest winds were occurring in the ring of storms.  Bands of showers and thunderstorms revolved around the core of Hurricane Bud.  Most of the stronger rainbands were occurring in the eastern half of the circulation.  Winds near the core of Bud were generating upper level divergence which was pumping mass away from the hurricane.  The removal of mass allowed the pressure to decrease rapidly, which generated a stronger pressure gradient force and higher wind speeds.

Most of the stronger winds were occurring on the eastern side of Hurricane Bud.  Winds to hurricane force extended out about 25 miles (40 km) to the east of the center of circulation.  Winds to tropical storm force extended out about 150 miles (240 km) to the east of the center.  The large area of tropical storm force winds on the eastern side of Hurricane Bud is the reason the government of Mexico issued a Tropical Storm Watch for a portion of the west coast of Mexico.

Hurricane Bud will continue to move through a very favorable environment for several more days.  Bud will move over water where the Sea Surface Temperature is near 30°C.  Bud will move through a region where the upper level winds will be weak and there will be little vertical wind shear.  Hurricane Bud will strengthen more and it could intensify rapidly during the next day or two.  Bud could strengthen into a major hurricane on Monday or Tuesday.

Hurricane Bud is moving near the western end of a ridge over Mexico.  The ridge is steering Bud toward the northwest  and that motion is forecast to continue for another day or two.  Hurricane Bud is likely to move more toward the north when it reaches the western end of the ridge.  On its anticipated track the center of Hurricane Bud will remain west of the west coast of Mexico.  Bud could approach the southern end of Baja California in four days.

Even though the center of Hurricane Bud is likely to remain west of the west coast of Mexico, some of the outer rainbands could move over parts of western Mexico.  Bud could bring gusty winds to places near the coast.  In addition Hurricane Bud could drop locally heavy rain in those areas and flash flooding will be possible.  Bud is likely to weaken before it reaches Baja California, but it could also bring gusty winds and heavy rains to that region later this week.

Elsewhere, Tropical Storm Aletta continued to weaken over cooler water.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Aletta was located at latitude 16.6°N and longitude 115.7°W which put it about 575 miles (925 km) southwest of the southern tip of Baja California.  Aletta was moving toward the west at 7 m.p.h. (11 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 1002 mb.

Tropical Storm Bud Forms South of Mexico, Aletta Weakens

Tropical Storm Bud formed south of Mexico on Saturday while former Hurricane Aletta weakened rapidly to a tropical storm.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Bud was located at latitude 12.9°N and longitude 102.0°W which put it about 575 miles (920 km) south-southeast of Cabo Corrientes, Mexico.  Bud 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 1003 mb.

The circulation of Tropical Storm Bud organized quickly on Saturday.  A distinct low level center of circulation formed.  Several bands of showers and thunderstorms formed in all parts of the circulation.  Storms near the center of circulation generated upper level divergence which pumped mass away from the tropical storm.  Winds to tropical storms force extended out about 60 miles (95 km) from the center of circulation.

Tropical Storm Bud will move through an environment favorable for intensification during the next several days.  Bud will move over water where the Sea Surface Temperature is near 30°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Bud is likely to intensify steadily during the next day or two and it could intensify rapidly once an eye forms.

Tropical Storm Bud is being steered to the northwest by a ridge over Mexico.  That general motion is expected to continue for several more days.  On its anticipated track Tropical Storm Bud will move roughly parallel to the west coast of Mexico.  Bud could be near the southern tip of Baja California in about five days.

Former Hurricane Aletta moved over cooler water and it weakened rapidly on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Aletta was located at latitude 15.9°N and longitude 114.3°W which put it about 560 miles (905 km) south-southwest of the southern tip of Baja California.  Aletta was moving toward the west 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 999 mb.

Aletta Strengthens Into a Hurricane

Former Tropical Storm Aletta strengthened into a hurricane on Thursday.  At 5:00 p.m. EDT on Thursday the center of Hurricane Aletta was located at latitude 15.3°N and longitude 110.0°W which put it about 455 miles (730 km) west-southwest of Manzanillo, Mexico.  Aletta was moving toward the west-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 987 mb.

A circular eye developed at the center of Hurricane Aletta on Thursday afternoon.  The inner ends of several rainbands wrapped part of the way around the eye and a broken ring of thunderstorms surrounded the eye.  The strongest winds were occurring in the broken ring of storms.  Several other bands of showers and thunderstorms were revolving around the core of Hurricane Aletta.  Storm near the core were generating strong upper level divergence which was pumping mass away from the hurricane.  Winds to hurricane force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 90 miles (150 km) from the center.

Hurricane Aletta will move through an environment favorable for intensification during the next 24 to 36 hours.  Aletta will move over water where the Sea Surface Temperature is near 29°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Aletta is likely to strengthen during the next day or two and it could intensify rapidly if the ring of storms completely encircles the eye.

Hurricane Aletta is moving southwest of a ridge over Mexico which is steering the hurricane toward the west-northwest.  Aletta could move a little more toward the northwest when it reaches the western end of the ridge.  On its anticipated track Hurricane Aletta will move farther away from the west coast of Mexico.