Tag Archives: Baja California

Hurricane Sandra Turns Toward Mexico

Hurricane Sandra moved around the western end of a subtropical ridge and turned toward Mexico on Thursday.  At 10:00 p.m. EST on Thursday the center of Hurricane Sandra was located at latitude 18.0°N and longitude 109.7°W which put it about 340 miles (545 km) south of the southern tip of Baja California and about 490 miles (790 km) south-southwest of Culiacan, Mexico.  Sandra was moving toward the north at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 956 mb.  The government of Mexico issued a Tropical Storm Watch for the coast of Baja California from Todos Santos to Los Barriles.

Hurricane Sandra appeared to develop concentric eyewalls on Thursday.  A primary rainband wrapped around the tiny pinhole eye at the center of the hurricane.  Satellite imagery suggests that the tiny inner eye still exists inside the larger outer eye.  Sandra reached Category 4 on the Saffir-Simpson Scale on Thursday morning, but the formation of concentric eyewalls weakened the hurricane back to Category 3 later in the day.  Sandra remains a well organized hurricane.  It has a well defined core surrounded by a ring of strong thunderstorms.  Spiral bands of storms are in the northeastern quadrant of the circulation.

Hurricane Sandra will move into a less favorable environment on Friday.  It will be over water where the Sea Surface Temperature is near 29°C.  However, a large upper level trough along the west coast of North America will generate strong southwesterly winds.  Those winds will cause strong vertical wind shear, which will tilt the circulation toward the northeast.  The upper level winds will also inhibit upper level divergence from the western part of Sandra.  The strong wind shear will weaken Hurricane Sandra on Friday.  Some models are predicting that the shear could be strong enough to blow the middle and upper parts of the circulation northeast of the low level circulation.  If that happens, then Hurricane Sandy could weaken very quickly,

The upper level trough will steer Hurricane Sandra toward the northeast on Friday.  Sandra will likely move faster toward the northeast by Friday night.  On its anticipated track Sandra could be near the southern tip of Baja California by Friday night and it could approach the west coast of Mexico on Saturday.  Sandra could still be a hurricane when it nears Baja California, but it is more likely to be a tropical storm.  It could be a tropical storm or depression by the time it reaches the west coast of Mexico.

Sandra Quickly Intensifies into a Major Hurricane

Hurricane Sandra intensified quickly into a major hurricane on Wednesday.  At 4:00 p.m. EST on Wednesday the center of Hurricane Sandra was located at latitude 13.0°N and longitude 109.9°W which put it about 685 miles (1100 km) south of the southern tip of Baja California.  Sandra was moving toward the northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) which made Sandra a Category 3 hurricane on the Saffir-Simpson Scale and qualified it as a major hurricane.  There were wind gusts to 140 m.p.h. (225 km/h) and the minimum surface pressure was 967 mb.  Sandra is the ninth major hurricane to form over the Eastern North Pacific during 2015, which is a new record for that basin.

Sandra is a small well organized hurricane.  It has a well defined eye surrounded by a ring of thunderstorms, but hurricane force winds only extend out about 25 miles (40 km) from the center.  Thunderstorms in the core of Sandra are producing upper level divergence which is pumping out mass and allowing the surface pressure to decrease.  Sandra is an environment that favors further intensification.  It is over water where the Sea Surface Temperature is near 30°C.  The upper level winds are light and there is not much vertical wind shear.  Sandra could become a Category 4 hurricane on Thursday.

Hurricane Sandra is moving around the western end of a subtropical ridge to the east of it.  Sandra turned toward the northwest on Wednesday and it will gradually start moving more toward the north on Thursday.  A large deepening upper level trough off the west coast of North American will create southwesterly winds that will start to steer Sandra toward the northeast on Friday.  On its anticipated track Hurricane Sandra will approach the southern tip of Baja California on Friday night.

TD 22E Intensifies to Tropical Storm Sandra

A core circulation organized quickly on Tuesday inside Tropical Depression 22E and it intensified into Tropical Storm Sandra.  At 4:00 p.m. EST on Tuesday the center of Tropical Storm Sandra was located at latitude 11.9°N and longitude 107.2°W which put it about 780 miles south-southeast of the southern tip of Baja California.  Sandra was moving toward the west-northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 997 mb.

Eastern upper level winds which were blowing over the top of Tropical Depression 22E diminished on Tuesday and the depression intensified into Tropical Storm Sandra.  A primary rainband wrapped around the center of circulation  and an inner core developed near the interior end of the band.  As the band wrapped around the center of circulation a ring of thunderstorms began to take on the structure of an eyewall.  Those thunderstorms also started to generate some upper level divergence.  The circulation of Sandra is still organizing and other spiral bands are starting to form.

Tropical Storm Sandra is in an environment that is favorable for intensification.  It is over water where the Sea Surface Temperature is near 30°C.  Although there is still some vertical wind shear, it is much less than it was on Monday.  A combination of very warm water and little vertical wind shear could allow Sandra to intensify very quickly.  It is likely to become a hurricane with 12 to 18 hours and it could become a major hurricane within 24 to 36 hours.  In a couple of days Sandra will start to encounter strong upper level winds from the southwest.  The increased vertical wind shear at that time will cause it to weaken.

Tropical Storm Sandra is starting to move around the western end of a subtropical ridge that has been steering toward the north.  Sandra should gradually turn toward the north during the next 24 hours.  It is likely to move mainly toward the north until Thursday when southwesterly winds will turn it toward the northeast.  Sandra could be approaching the southern tip of Baja California by Friday night.

Tropical Depression 22E Forms Southwest of Mexico

A small center of circulation formed within a larger area of thunderstorms southwest of Mexico on Monday and the National Hurricane Center designated the system as Tropical Depression 22E.  At 4:00 p.m. EST on Monday the center of Tropical Depression 22E (TD22E) was located at latitude 10.8°N and longitude 102.9°W which put it about 465 miles (750 km) south-southwest of Acapulco, Mexico.  TD22E was moving toward the west at 18 m.p.h. (30 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were gusts to 45 m.p.h. (70 km/h).  The minimum surface pressure was 1005 mb.

TD22E is still in the early stages of an organizational process.  The small center of circulation is located near the western end of a long band of thunderstorms.  There are not many thunderstorms south and west of the center and there is not much evidence of spiral bands.  A subtropical ridge northeast of TD22E is pushing the depression quickly toward the west and its rapid movement is retarding the organizational process.

TD22E is currently in an environment that is marginal for intensification.  It is over water where the Sea Surface Temperature (SST) is near 30°C, which is very favorable for intensification.  However, the ridge northeast of TD22E is causing strong easterly winds to blow over the top of the depression.  The strong vertical wind shear and the rapid motion of the depression are negative factors for intensification.

As TD22E moves farther west, the vertical wind shear is expected to decrease and the depression is expected to move more slowly.  When that happens, TD22E will be able to more efficiently use the energy it is getting from the warm water and it will intensify.  A period of rapid intensification may occur once the core of the circulation is better organized.  TD22E could become a tropical storm on Tuesday and it could become a hurricane later this week.

The subtropical ridge is steering TD22E quickly toward the west.  In another 24 to 36 hours TD22E is likely to reach the western end of the ridge.  At that time it will slow down and turn toward the north.  TD22E will encounter southwesterly winds when it moves farther north.  Those winds will push TD22E toward the northeast later this week.  On its anticipated track TD22E could be near the southern tip of Baja California by the end of the week.

Tropical Depression 16E Could Bring Heavy Rain to Southwest U.S.

A center of circulation organized within a cluster of thunderstorms west of Baja California on Sunday and the system was designated Tropical Depression Sixteen-E.  At 5:00 p.m. EDT on Sunday the center of Tropical Depression Sixteen-E (TD16E) was located at latitude 25.0°N and longitude 113.7°W which put it about 90 miles (145 km) west of Cabo San Lazaro, Mexico.  TD16E was moving toward the north-northwest at 14 m.p.h. (22 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. (70 km/h).  The minimum surface pressure was 1003 mb.

Tropical Depression 16E has only a few hours before it will move over the central part of Baja California.  Although it is over water where the Sea Surface Temperature is near 27°C little, if any, intensification is expected.  When TD16E crosses Baja California, the terrain and increased vertical wind shear are likely to blow the upper portion of the circulation northward faster than the lower portion of the circulation.  The high clouds could reach parts of the southwestern U.S. within 24 hours.  Moving over mountains will disrupt the lower part of the circulation, but the rotation in the middle levels could persist for several days as it moves northward.

An upper level ridge centered over Texas and an upper level low west of Baja California are combining to steer TD16E northward and that general motion should continue for the next several days.  On its anticipated track TD16E could reach the coast of Baja California near Punta Abreojos in about 12 hours.  It could then move across Baja and the Gulf of California and make a second landfall on the coast west of Hermosillo on Monday morning.  TD16E or its remnants could be approaching southern Arizona later on Monday.  Convection and a flow of moisture associated with TD16E could produce locally heavy rainfall when it is forced to rise of mountains.  It could cause flooding in parts of Baja California, northwestern Mexico and the southwestern U.S.

Tropical Storm Linda Forms South of Baja California

A spiral band continued to wrap more tightly around the center of circulation inside a large low pressure system west of Mexico on Sunday and the National Hurricane Center designated the system as Tropical Storm Linda.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Linda was located at latitude 14.1°N and longitude 109.0°W which put it about 610 miles (980 km) south of the southern tip of Baja California.  Linda was moving toward the northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 45 m.p.h. (70 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1000 mb.

The circulation in Tropical Storm Linda is well organized.  There is one main spiral rainband and multiple outer rainbands.  Outside of the core of the circulation there are fewer thunderstorms east of the center, which could mean that some drier air is being pulled into that part of the storm.  Thunderstorms in the core are generating upper level divergence.  Linda is over water where the Sea Surface Temperatures (SSTs) are above 29°C.  An upper level trough near the west coast of the U.S. and an upper level ridge over northern Mexico are combining to create an outflow channel to the northeast, which is enhancing the flow of mass away from the tropical storm.  There is little vertical wind shear over the top of Linda and the environment is favorable for further intensification.  A period of rapid intensification is possible and Linda is likely to become a hurricane.  Eventually, when it moves farther north, Linda will move into an area of cooler SSTs and more vertical wind shear, which will cause it to weaken.

Linda appears to be moving a little more toward the west-northwest this afternoon.  The upper level ridge over northern Mexico is expected to steer it in a generally northwesterly direction during the next few days.  On its anticipated track, Linda would move west of Baja California during the middle of next week.

Tropical Storm Kevin Forms Southwest of Baja California

Vertical wind shear decreased enough on Thursday to allow more thunderstorms to develop near the center of Tropical Depression 14E and the National Hurricane Center upgraded it to Tropical Storm Kevin.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Kevin was located at latitude 17.9°N and longitude 115.6°W which put it about 505 miles (815 km) southwest of the southern tip of Baja California.  Kevin was moving toward the north at 6 m.p.h. (9 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1000 mb.

Tropical Storm Kevin is a small tropical cyclone.  Winds to tropical storm force only extend out about 70 miles (115 km) from the center of circulation.  There is one short spiral band wrapping around the northwest side of the center and another short band wrapping around the southwest side of the center.  There are not many thunderstorms in the eastern half of the circulation.  Kevin is over water where the Sea Surface Temperature (SST) is near 29°C.  However, a large, high amplitude upper level trough along the west coast of the U.S. is generating moderate southwesterly winds over the top of Kevin.  The vertical wind shear inhibited the development of Kevin, but the shear seems to have lessened today and the circulation in the tropical storm has consolidated around the center.  Thunderstorms near the center of Kevin are generating upper level divergence over a small area.

As Kevin moves farther north it will move over cooler SSTs.   When it gets north of latitude 22°N, Kevin will move over SSTs cooler than 26°C.  If the vertical wind shear remains moderate, Kevin could intensify further during the next 24 to 48 hours.  After about two days, the tropical storm will move over cooler SSTs and into an area with more vertical wind shear.  At that point Kevin is likely to start to spin down.

A ridge over Mexico is steering Kevin toward the north and that general motion is expected to continue for another day or two.  When Kevin moves over cooler SSTs, the thunderstorms will not be as tall and it will be steered by the winds lower in the atmosphere.  Those winds could push Kevin more toward the west during the weekend.

Hurricane Carlos Weakening Quickly

It appears from satellite imagery that vertical wind shear quickly weakened Hurricane Carlos on Tuesday night.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Carlos was located at latitude 18.2°N and longitude 104.5°W which put it about 55 miles (90 km) south-southwest of Manzanillo, Mexico.  Carlos was moving toward the northwest at 5 m.p.h. (7 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 988 mb.  A Hurricane Watch was in effect for the portion of the coast from Playa Perula to Punta San Telmo, Mexico and a Tropical Storm Warning was in effect for the portion of the coast from Cabo Corrientes to Punta San Telmo, Mexico.

After intensifying on Tuesday afternoon and exhibiting well developed upper level divergence, the structure of Hurricane Carlos degenerated quickly on Tuesday night.  Most of the strong thunderstorms dissipated.  Satellite imagery showed an exposed low level center near the Mexican coast, while the upper level canopy was moving westward away from the low level center.  The decoupling of the upper and low parts of the circulation, usually leads to quick weakening of a hurricane.  The small size of Carlos could allow it to weaken even more quickly than an average hurricane.  The most recent satellite images showed a few thunderstorms forming south of the center of circulation.  However, wind shear caused by an upper level ridge north of Carlos may be too strong to allow for the system to regain its vertical integrity.  Tropical cyclones that are sheared apart sometimes have one chance to redevelop.  The low level center is moving closer to the coast of Mexico and interaction with land may prevent any chance for redevelopment.

If the low level center remains separated from the rest of the system and it does not extend higher into the atmosphere, it will be steered by the winds in the lower levels.  Those winds appear to be taking it north-northwest toward the coast.  Carlos could dissipate quickly if it makes landfall, or the circulation could linger for a day or two if it stays farther offshore.

Very Small Hurricane Carlos Moving Just West of Mexico

Hurricane Carlos has a very small circulation and the tropical storm force winds extend out less than 50 miles (80 km) from the center.  At 8:00 p.m. EDT on Monday the center of Hurricane Carlos was located at latitude 17.2°N and longitude 103.3°W which put it about 90 miles (145 km) southwest of Lazaro Cardenas, Mexico and about 140 miles (225 km) south-southeast of Manzanillo.  Carlos was moving toward the west-northwest at 6 m.p.h. (9 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 989 mb.  A Hurricane Watch and a Tropical Storm Warning is in effect for the portion of the coast from Playa Perula to Punta San Telmo.

The small circulation of Hurricane Carlos continues to move over the Pacific Ocean west of Mexico.  It is moving over water where the Sea Surface Temperature is about 29°C.  An upper level ridge north of the hurricane is generating northeasterly winds that are impinging on the northern side of Carlos.  Those winds are inhibiting upper level divergence from the northern side of Carlos.  The small circulation means than any thunderstorms form near the center and the strongest storms are south of the center.  The small circulation also means that wind shear can have a very big effect on Carlos.  Even moderate winds in the upper levels would be strong enough to disrupt the vertical coherence of the hurricane and blow away the upper part of Carlos.  The vertical wind shear is expected to be modest in the short term, and Carlos is forecast to maintain its intensity for a day or two.  However, it would not take much increase in the wind shear to blow the top off Carlos.

The upper level ridge is expected to continue to steer Carlos toward the west-northwest for 24 to 36 hours.  After that time two scenarios are possible.  In one scenario the upper level ridge weakens and Carlos turns northward and moves very close the coast of Mexico near Cabo Corientes.  In an alternative scenario the ridge maintains its intensity and it steers Carlos toward the west-northwest for the next few days.  A third scenario, which could occur at any time, would happen if wind shear blows the top off of Carlos.  In that case the surface circulation would be steered westward by the lower level flow until it dissipated.  These three possible scenarios make the future track of Carlos very uncertain.

Small Tropical Storm Carlos Moving West of Acapulco

Carlos weakened to a tropical storm as it moved west of Acapulco, Mexico on Sunday.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Carlos was located at latitude 16.7°N and longitude 101.3°W which put it about 95 miles (150 km) west of Acapulco and about 110 miles (175 km) southeast of Lazaro Cardenas.  Carlos was moving toward the northwest at 6 m.p.h. (9 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 998 mb.  Carlos is a small tropical cyclone.  The tropical storm force winds only extend out about 50 miles (80 km) from the center and it has a Hurricane Size Index (HSI) of 1.7.  The government of Mexico has issued a Hurricane Warning for the portion of the coast that extends from Punta San Telmo to Tecpan de Galeana.  A Hurricane Watch has been issued for the portion of the coast from Playa Perula to Punta San Telmo.

Carlos was nearly stationary for several days and its winds mixed cooler water to the surface.  In addition the circulation pulled in drier air from Mexico as it got closer to the coast.  The combined effects of cooler water and drier resulted in less energy to drive the circulation and Carlos weakened to a tropical storm on Sunday.  Late in the day it started to move toward the northwest and get away from the cooler water.  Carlos is moving over an area where the Sea Surface Temperature (SST) is near 30°C.  Recent satellite images indicate that stronger thunderstorms are forming near the center of circulation.  The flow around Carlos is still pulling in drier air from Mexico and there are fewer thunderstorms in the northern half of the tropical storm.  The small size of Carlos means that it can strengthen or weaken more quickly than a larger storm because there is less mass to accelerate.  The upper level winds over Carlos have lessened and there is not as much vertical wind shear.  If Carlos remains over water, it is likely to intensify back to a hurricane on Monday.

An upper level ridge over Mexico is moving slowly toward the east and it is starting to steer Carlos toward the northwest.  The ridge is expected to continue to steer the tropical storm toward the northwest or west-northwest on Monday.  As Carlos approaches the western end of the ridge is expected to turn more toward the west-northwest.  There is some uncertainty about where the turn will occur.  Guidance from some models have Carlos turning farther east and making a landfall between Manzanillo and Cabo Corientes, while some other models have the tropical storm moving farther west before turning.  Either scenario is plausible and hence, the high degree of uncertainty about the future track of Carlos.