Tag Archives: EP02

Tropical Storm Cosme Forms Southwest of Baja California

Tropical Storm Cosme formed southwest of Baja California on Saturday.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Cosme was located at latitude 15.6°N and longitude 115.7°W which put it about 630 miles (1015 km) southwest of the southern tip of Baja California.  Cosme was moving toward the west-northwest at 14 m.p.h. (22 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.

The National Hurricane Center (NHC) determined on Saturday that a distinct center of circulation had developed in a broader area of lower pressure and NHC designated the system as Tropical Storm Cosme.  The distribution of thunderstorms around Tropical Storm Cosme was asymmetrical.  The stronger thunderstorms were occurring in bands in the eastern half of the circulation.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  An upper level trough near Baja California was producing strong southwesterly winds which were blowing across the top of the circulation.  Those winds were causing strong vertical wind shear and they were probably the reason for the asymmetrical distribution of thunderstorms.  Winds to tropical storm force extended out about 150 miles (240 km) from the center of circulation.

Tropical Storm Cosme will move through an environment that is not favorable for significant intensification.  Cosme will move over water where the Sea Surface Temperature is near 26°C.  The upper level trough will continue to produce southwesterly winds that will blow toward the top of Tropical Storm Cosme.  The upper level winds are likely to weaken somewhat, but they will continue to cause vertical wind shear.  Tropical Storm Cosme could intensify a little during the next 24 hours, but it is not likely to strengthen significantly.

Tropical Storm Cosme will move south of a subtropical high pressure system over Eastern North Pacific Ocean.  The high will steer Cosme toward the west-northwest.  On its anticipated track Tropical Storm Cosme is forecast to remain well to the west of Baja California.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Barbara continued to weaken as it moved toward Hawaii.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Barbara was located at latitude 18.7°N and longitude 139.2°W which put it about 1040 miles (1670 km) east of Hilo, Hawaii.  Barbara was moving toward the west at 17 m.p.h. (28 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 1000 mb.

Barbara Weakens to a Tropical Storm

Former Hurricane Barbara weakened to a tropical storm on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Barbara was located at latitude 18.6°N and longitude 134.7°W which put it about 1330 miles (2145 km) east of Hilo, Hawaii.  Barbara was moving toward the west-northwest at 13 m.p.h. (20 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 997 mb.

The effects of vertical wind shear and cooler Sea Surface Temperatures caused former Hurricane Barbara to weaken quickly to a tropical storm on Friday.  An upper level trough northeast of Hawaii produced strong southwesterly winds which blew the upper portion of the circulation north of the remainder of the tropical storm.  In addition, Tropical Storm Barbara moved over water where the Sea Surface Temperature was near 25°C which meant there was less energy to support the development of taller thunderstorms.  Tropical Storm Barbara still had a well formed circulation in the lower levels of the atmosphere.  However, as a result of the strong shear and cooler water, bands consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out about 140 miles (220 km) from the center of circulation.

Tropical Storm Barbara will continue to move over cooler water and through a region of strong vertical wind shear during the next several days.  Barbara will continue to weaken and it could be a tropical depression on Saturday.

Since Tropical Storm Barbara contains few tall thunderstorms, it is being steered by winds closer to the surface.  A subtropical high pressure system north of Barbara will steer the tropical storm toward the west.  On its anticipated track Tropical Storm Barbara will move toward Hawaii.

Hurricane Barbara Starts to Weaken

Hurricane Barbara started to weaken on Wednesday when it moved over cooler water well to the east of Hawaii.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Barbara was located at latitude 14.3°N and longitude 127.5°W which put it about 1860 miles (2990 km) east of Hilo, Hawaii.  Barbara was moving toward the west-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 140 m.p.h. (220 km/h) and there were wind gusts to 170 m.p.h. (275 km/h).  The minimum surface pressure was 941 mb.

The circulation around Hurricane Barbara remained very well organized.  There was a circular eye 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.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Barbara.  Storms near the core of the circulation were generating strong upper level divergence which was pumping mass away from the hurricane.  Winds to hurricane force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 185 miles (295 km) from the center.

Hurricane Barbara still rated at Category 4 on the Saffir-Simpson Scale.  The Hurricane Intensity Index (HII) for Barbara was 28.3.  The Hurricane Size Index (HSI) was 16.5 and the Hurricane Wind Intensity Size Index (HWISI) was 44.8.

Hurricane Barbara will gradually move into an environment less capable of supporting a strong hurricane during the next few days.  Barbara will move over water where the Sea Surface Temperature is near 26°C.  As a result, Hurricane Barbara will extract less energy from the upper ocean and it will gradually weaken.  Barbara will move closer to an upper level trough located northeast of Hawaii.  When Hurricane Barbara gets closer to the trough later this week, stronger upper level southwesterly winds will create more vertical wind shear and the hurricane will weaken more quickly.

Hurricane Barbara will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Barbara toward the west-northwest during the next 24 to 36 hours.  The ridge is forecast to strengthen on Friday and it will steer Hurricane Barbara more toward the west when that happens.  On its anticipated track Barbara could approach Hawaii in about five days.  It will be much weaker by that time.

Barbara Rapidly Intensifies Into a Major Hurricane

Hurricane Barbara rapidly intensified into a major hurricane on Tuesday as it moved over the Eastern North Pacific Ocean between Baja California and Hawaii.  At 11:00 a.m. EDT on Tuesday the center of Hurricane Barbara was located at latitude 12.5°N and longitude 122.2°W which put it about 1080 miles (1740 km) southwest of the southern tip of Baja California.  Barbara was moving toward the west-northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 948 mb.

Hurricane Barbara continued to intensify rapidly on Tuesday.  A circular eye became more evident on satellite imagery.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Storms near the core of Barbara were generating strong upper level divergence which was pumping mass away from the hurricane in all directions.  Multiple bands of showers and thunderstorms were revolving around the core of Hurricane Barbara.  Winds to hurricane force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 200 miles (320 km) in the southeastern quadrant of the circulation.  Tropical storm force winds extended out about 120 miles (195 km) from the center in the other three quadrants.

Hurricane Barbara was at Category 4 on the Saffir-Simpson Scale.  The Hurricane Intensity Index (HII) for Barbara was 25.1.  The Hurricane Size Index (HSI) was 11.0 and the Hurricane Wind Intensity Size Index (HWISI) was 36.1.

Hurricane Barbara will move through an environment very favorable for strong hurricanes for another 12 to 24 hours.  Barbara will move over water where the Sea Surface Temperature is near 28°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Barbara is likely to intensify further during the next 12 hours.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Barbara to weaken.  Hurricane Barbara will approach cooler water on Wednesday and it is likely to start to weaken by that time.  Barbara will move into an area where the upper level winds are stronger later this week and it could weaken more quickly when the wind shear increases.

Hurricane Barbara will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Barbara in a west-northwesterly direction during the next several days.  On its anticipated track Hurricane Barbara will move in the general direction of Hawaii.

Barbara Rapidly Intensifies Into a Hurricane

Former Tropical Storm Barbara rapidly intensified into a hurricane over the Eastern North Pacific Ocean on Monday.  At 5:00 p.m. EDT on Monday the center of Hurricane Barbara was located at latitude 11.5°N and longitude 118.5°W which put it about 970 miles (1560 km) southwest of the southern tip of Baja California.  Barbara was moving toward the west at 16 m.p.h. (26 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 983 mb.

Hurricane Barbara intensified rapidly on Monday.  An eye formed at the center of circulation and a ring of strong thunderstorms surrounded the eye.  The strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of the circulation.  Storm near the core of Barbara 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 160 miles (260 km) from the center.

Hurricane Barbara will move through an environment very favorable for intensification during the next 36 to 48 hours.  Barbara will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Barbara will continue to intensify rapidly and it is expected to strengthen into a major hurricane on Tuesday.

Hurricane Barbara will move south of a subtropical ridge over the Eastern North Pacific Ocean during the next few days.  The ridge will steer Barbara toward the west-northwest.  On its anticipated track Hurricane Barbara will move farther away from Baja California and the rest of Mexico.

Tropical Storm Barbara Forms South of Baja California

Tropical Storm Barbara formed south of Baja California on Sunday as the remnants of former Hurricane Alvin were dissipating over the Eastern North Pacific Ocean.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Barbara was located at latitude 10.6°N and longitude 110.4°W which put it about 850 miles (1370 km) south of the southern tip of Baja California.  Barbara was moving toward the west-northwest at 16 m.p.h. (26 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.

More thunderstorms developed near the center of a low pressure system south of Baja California on Sunday and the National Hurricane Center designated the system as Tropical Storm Barbara.  Bands of showers and thunderstorms were revolving around the center of circulation.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm.  Tropical Storm Barbara was larger than former Hurricane Alvin.  Winds to tropical storms force extended out about 80 miles (130 km) from the center of circulation.

Tropical Storm Barbara will move through an environment favorable for intensification during the next several days.  Barbara 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.  Tropical Storm Barbara will continue to intensify and it is likely to strengthen into a hurricane by the middle of the week.  Barbara could intensify rapidly when the inner core is more developed.

Tropical Storm Barbara will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Barbara toward the west-northwest.  On its anticipated track Tropical Storm Barbara will move away from Baja California and the rest of Mexico.

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.