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Fabio Strengthens to a Hurricane South of Baja California

Former Tropical Storm Fabio strengthened into a hurricane Monday morning as it moved south of Baja California.  At 11:00 a.m. EDT on Monday the center of Hurricane Fabio was located at latitude 12.8°N and longitude 110.9°W which put it about 700 miles (1125 km) south of the southern tip of Baja California.  Fabio was moving toward the west-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 989 mb.

The inner core of Hurricane Fabio exhibited signs of greater organization on Monday morning.  Microwave satellite imagery provided evidence of a rainband wrapping around the southern and eastern sides of the center of circulation.  There were intermittent signs that an eye could be forming at the center of circulation.  Several bands of showers and thunderstorms were revolving around the core of the circulation.  The strongest thunderstorms were occurring in bands south and east of the center of Hurricane Fabio.  The bands north and west of the center were weaker, which may indicate that there was some drier air in those parts of the circulation.  Thunderstorms near the core of Fabio were generating upper level divergence which was pumping mass away from the hurricane in all directions.

Hurricane Fabio will be moving through an environment that is very favorable for intensification.  Fabio will move over water where the Sea Surface Temperature is near 28.5°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  It will continue to strengthen and it could intensify rapidly once an eye forms and persists.  Fabio is forecast to strengthen to a major hurricane on Tuesday.

Hurricane Fabio is moving south of a subtropical ridge which is steering the hurricane toward the west-northwest.  The west-northwesterly motion is forecast to continue during the next several days.  On its anticipated track Hurricane Fabio will move away from Baja California.

Tropical Storm Fabio Develops West of Mexico

Tropical Storm Fabio developed west of Mexico on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Fabio was located at latitude 12.0°N and longitude 107.4°W which put it about 770 miles (1240 km) south-southeast of the southern tip of Baja California.  Fabio was moving toward the west-northwest at 13 m.p.h. (20 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 1000 mb.

The circulation of Tropical Storm Fabio was still organizing.  There was a broad low level center of circulation, but it did not have a well developed inner core.  Multiple bands of showers and thunderstorms were revolving around the broad low level center.  The storms in the rainbands were generating some upper level divergence which was starting to pump mass away from the tropical storm.

Tropical Storm Fabio will move through an environment that is very favorable for intensification.  Fabio will move over water where the Sea Surface Temperature is near 28.5°C.  An upper level ridge northeast of Tropical Storm Fabio will produce easterly winds which will blow toward the top of the circulation.  However, the wind speed will be similar at all levels and there will not be much vertical wind shear.  Tropical Storm Fabio will continue to intensify in the favorable environment.  Once a primary rainband wraps around the center of circulation, an inner core will develop.  Tropical Storm Fabio could intensify rapidly when an eye starts to form.  Fabio could strengthen into a major hurricane in two or three days.

Tropical Storm Fabio was moving south of a subtropical ridge which was steering the tropical storm toward the west-northwest.  A general west-northwesterly motion is expected to continue during the next few days.  On its anticipated track the center of Tropical Storm Fabio will pass well to the south of Baja California.

Elsewhere over the Eastern North Pacific Ocean Tropical Depression Emilia continued to weaken over cooler water.  At 11:00 a.m. EDT on Sunday the center of Tropical Depression Emilia was located at latitude 19.3°N and longitude 123.0°W which put it about 880 miles (1415 km) west-southwest of the southern tip of Baja California.  Emilia was moving toward the west-northwest at 12 m.p.h. (19 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 1006 mb.

Tropical Storm Emilia Develops South of Baja California

Tropical Storm Emilia developed south of Baja California on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Emilia was located at latitude 14.4°N and longitude 112.4°W which put it about 610 miles (980 km) south-southwest of the southern tip of Baja California.  Emilia was moving toward the west-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 1005 mb.

The distribution of thunderstorms around Tropical Storm Emilia was asymmetrical.  Most of the showers and thunderstorms were occurring in bands west and north of the center of circulation.  The center was located near the eastern edge of a cluster of thunderstorms.  Bands east of the center consisted of showers and low clouds.  The cluster of storms west of the center of circulation was generating upper level divergence which was pumping mass away to the west and north of the tropical storm.

Tropical Storm Emilia will move through an environment somewhat favorable for intensification during the next day or two.  Emilia will move over water where the Sea Surface Temperature is near 28°C.  An upper level ridge centered near the southern tip of Baja California was producing northeasterly winds which were blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and they were probably the reason why most of the thunderstorms were located west and north of the center of circulation.  The vertical shear is likely to limit intensification during the next 24 hours.  The shear is forecast to decrease on Friday and Tropical Storm Emilia could strengthen faster if that occurs.

The portion of the ridge in the middle troposphere was steering Tropical Storm Emilia toward the west-northwest and that general motion is expected to continue for several more days.  On its anticipated track Emilia will move farther away from the west coast of Mexico.

Tropical Storm Daniel Develops Southwest of Baja California

Tropical Storm Daniel developed southwest of Baja California on Sunday after a relatively quiet week in the tropics.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Daniel was located at latitude 16.0°N and longitude 115.9°W which put it about 615 miles (990 km) southwest of the southern tip of Baja California.  Daniel was moving toward the north 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.

Microwave satellite data indicated that a better organized center of circulation was present inside former Tropical Depression Five-E and the National Hurricane Center designated the system as Tropical Storm Daniel on Sunday morning.  A band of showers and thunderstorms wrapped around the south and east sides of a small tight center of circulation.  Several bands of showers and thunderstorms were revolving around the center.  Bands northwest of the center of circulation consisted primarily of showers and lower clouds.  Storms near the center began to generate upper level divergence which pumped mass away from the tropical storm.

Tropical Storm Daniel will move through an environment favorable for intensification for about another 24 hours.  Daniel is moving over water where the Sea Surface Temperature is near 27°C.  Tropical Storm Daniel will move over cooler water in about a day or so.  There is an upper level low northwest of Daniel.  The low is generating southerly winds which are blowing toward the top of the tropical storm.  Those winds are causing moderate vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Storm Daniel could intensify a little more during the next 24 hours, but Daniel is likely to weaken when it moves over cooler water.

The upper low northwest of Tropical Storm Daniel was steering the tropical storm toward the north.  The upper low is moving toward the west.  Tropical Storm Daniel if forecast to turn more toward the northwest on Monday as it moves around the western side of the upper low.  When Daniel moves over cooler water the clouds will not grow as tall and the tropical storm will be steered by the winds lower in the atmosphere.  The subtropical high over the Pacific Ocean is forecast to steer Daniel more toward the west later next week after the tropical storm weakens.

Bud Rapidly Intensifies Into a Major Hurricane

Hurricane Bud rapidly intensified Monday into a major hurricane southwest of Mexico.  At 11:00 a.m. EDT on Monday the center of Hurricane Bud was located at latitude 16.7°N and longitude 106.8°W which put it about 265 miles (425 km) south-southwest of Cabo Corrientes, Mexico.  Bud was moving toward the northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 140 m.p.h. (225 km/h).  The minimum surface pressure was 955 mb.  A Tropical Storm Watch remained in effect for the portion of the coast from Manzanillo to Cabo Corrientes, Mexico.

The circulation around Hurricane Bud is very well organized.  A circular eye exists at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds are occurring in the ring of storms.  A number of bands of showers and thunderstorms are revolving around the core of the circulation.  The overall circulation is quite symmetrical and there are rainbands in all quadrants of Hurricane Bud.  Storms near the core are generating strong upper level divergence which is pumping mass away from the hurricane in all directions.

Hurricane Bud exhibits all of the characteristics of a well organized hurricane.  Winds to hurricane force extend out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extend out about 140 miles (225 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Bud is 22.1.  The Hurricane Size Index (HSI) is 12.4 and the Hurricane Wind Intensity Size Index (HWISI) is 34.5.

Hurricane Bud will move through an environment favorable for a major hurricane for another 12 to 24 hours.  Bud is currently over water where the Sea Surface Temperature is near 29°C, but the Sea Surface Temperature of the water ahead of the hurricane is cooler.  Hurricane Bud will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Bud could intensify during the next 12 to 24 hours, because of little shear.  However, Bud is likely to weaken after that, when it moves over cooler water.

Hurricane Bud is moving near the western end of a subtropical ridge which is steering the hurricane toward the northwest.  That general motion is expected to continue for another day or so.  Bud is forecast to turn more toward the north when it reaches the western end of the ridge.  On its anticipated track the core of Hurricane Bud is expected to remain west of the west coast of Mexico.  Bud could approach the southern part of Baja California in about four days.

Elsewhere, former Tropical Storm Aletta weakened to a tropical depression.  At 11:00 a.m. EDT on Monday the center of Tropical Depression Aletta was located at latitude 16.8°N and longitude 117.8°W which put it about 665 miles (1070 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 35 m.p.h. (55km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1005 mb.

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.

Hurricane Aletta Rapidly Intensifies to Category 4

Hurricane Aletta rapidly intensified Friday morning to Category 4 on the Saffir-Simpson Scale.  At 11:00 a.m. EDT on Friday the center of Hurricane Aletta was located at latitude 15.8°N and longitude 111.2°W which put it about 505 miles (815 km) west-southwest of Manzanillo, Mexico.  Aletta was moving toward the west at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 140 m.p.h. (220 km/h) and there were wind gusts to 165 m.p.h. (265 km/h).  The minimum surface pressure was 943 mb.

An environment with warm Sea Surface Temperatures and little vertical wind shear allowed Hurricane Aletta to intensify rapidly during Thursday night and Friday morning.  A small circular eye was evident at the center of circulation.  A tight ring of strong thunderstorms completely surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of strong storms were revolving around the eastern and northern sides of the core of Hurricane Aletta.  Storms around the core were generating very strong upper level divergence which was pumping away large quantities of mass from the hurricane.  The removal of mass allowed the pressure to decrease rapidly and a stronger pressure gradient force generated much stronger winds.

Hurricane Aletta has a relatively small circulation.  Winds to hurricane force extended out about 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out about 100 miles (160 km) from the center.  The Hurricane Intensity Index (HII) was 28.3.  The Hurricane Size Index (HSI) was 10.8 and the Hurricane Wind Intensity Size Index (HWISI) was 39.1.  Hurricane Aletta is very similar in intensity and size to Hurricane Charley in 2004 when Charley hit southwest Florida.

Hurricane Aletta will remain in a favorable environment of warm water and little vertical wind shear for another 12 to 24 hours.  So, it could strengthen more in the short term.  Aletta will start to move over cooler water during the next day or so.  There will be less energy in the upper ocean to support the intense hurricane.  In addition, a upper level trough to the northwest of Aletta will produce southwesterly winds which will blow toward the top of the circulation.  Increased vertical wind shear will speed up the rate of weakening.  Since the circulation of Hurricane Aletta is relatively small, it could weaken fairly quickly.

Hurricane Aletta is moving around the southwestern part of a ridge over Mexico.  The ridge has been steering Aletta toward the west.  A turn more toward the northwest is expected when Hurricane Aletta nears the western end of the ridge.  On its anticipated track Hurricane Aletta is forecast to move farther away from the west coast of Mexico.

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.

Tropical Storm Aletta Forms West of Mexico

Tropical Storm Aletta formed west of Mexico on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Aletta was located at latitude 14.3°N and longitude 108.4°W which put it about 425 miles (680 km) southwest of Manzanillo, Mexico.  Aletta was moving toward the west at 7 m.p.h. (11 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.

A distinct low level center of circulation developed within a large area of showers and thunderstorms over the eastern North Pacific Ocean west of Mexico on Wednesday and the National Hurricane Center designated the system as Tropical Storm Aletta.  The circulation of Aletta was still organizing.  Several bands of showers and thunderstorms developed east of the center of circulation.  The bands in the western half of the circulation consisted primarily of showers and low clouds.  Storms near the center of circulation were generating upper level divergence which was pumping mass away from Tropical Storm Aletta.

Tropical Storm Aletta will move through an environment favorable for intensification during the next 48 hours.  Aletta will move over water where the Sea Surface Temperature is near 29°C.  An upper level trough located northwest of Tropical Storm Aletta will produce southwesterly 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.  Aletta will likely strengthen into a hurricane during the next several days.

Tropical Storm Aletta is moving south of a ridge over Mexico.  The ridge is steering Aletta toward the west.  A general motion toward the west-northwest is forecast for the next several days.  On its anticipated track Tropical Storm Aletta will move farther away from the west coast of Mexico.