Tag Archives: 01E

One-E Becomes Earliest East Pacific Tropical Depression

Tropical Depression One-E became Saturday the earliest tropical depression for form over the Eastern North Pacific Ocean during the satellite era which began in 1966.  The previous date of the earliest formation over that region was May 9, 2017 when a depression formed that would ultimately strengthen into Tropical Storm Adrian.  At 11:00 a.m. EDT on Saturday the center of Tropical Depression One-E was located at latitude 14.1°N and longitude 116.1°E which put it about 730 miles (1175 km) southwest of the southern tip of Baja California.  The depression was moving toward the northwest at 7 m.p.h. (11 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.

More thunderstorms developed near the center of a low pressure system previously designated as Invest 90E southwest of Baja California on Saturday morning and National Hurricane Center designated the system as Tropical Depression One-E.  Tropical Depression One-E is the first tropical depression to form over the Eastern North Pacific Ocean during the month of April in the satellite era .  The distribution of thunderstorms around the depression was asymmetrical.  Many of the stronger thunderstorms were occurring in bands in the southern half of the circulation.  Bands in the northern half of the circulation consisted primarily of showers and lower clouds.  The southern half of the circulation was over warmer Sea Surface Temperatures, which may have contributed to the development of thunderstorms in that part of the tropical depression.

Tropical Depression One-E will move through an environment somewhat favorable for intensification during the next 24 hours.  The depression will move over water where the Sea Surface Temperature is near 26.5°C.  It will move under the western end of an upper level ridge over the Eastern North Pacific Ocean.  The ridge will produce southerly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear and they will inhibit intensification.  Conditions could be favorable enough to allow Tropical Depression One-E to strengthen into a tropical storm during the next 24 hours.  The depression will move over cooler Sea Surface Temperatures later on Sunday, which will cause it to weaken.

Tropical Depression One-E will move around the western end of a high pressure system over the Eastern North Pacific Ocean during the next 24 hours.  The high will steer the depression toward the northwest on Saturday.  A second high pressure system over the North Pacific Ocean will block the northward movement of the depression later on Sunday.  The second high will steer the depression more toward the west later in the weekend.

Alvin Strengthens Into a Hurricane Southwest of Baja California

Former Tropical Storm Alvin strengthened into a hurricane southwest of Baja California on Thursday evening.  At 11:00 p.m. EDT on Thursday the center of Hurricane Alvin was located at latitude 17.4°N and longitude 115.4°W which put it about 520 miles (840 km) southwest of the southern tip of Baja California.  Alvin was moving toward the northwest at 16 m.p.h. (26 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 992 mb.

The circulation around Hurricane Alvin exhibited much greater organization on Wednesday.  A small circular eye with a diameter of 10 miles (15 km) appeared 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.  The circulation around Hurricane Alvin was very small.  Winds to hurricane force extended out only 10 miles (15 km) from the center of circulation.  Winds to tropical storm force extended out about 50 miles (80 km) from the center.

Hurricane Alvin may be near its maximum intensity.  Alvin was moving over water where the Sea Surface Temperature was near 27°C.  However, it will move over cooler water on Friday.  The small size of the circulation around Hurricane Alvin could allow it to weaken quickly once it moves over the cooler water.

Hurricane Alvin will move near the western end of a subtropical ridge over Eastern North Pacific Ocean.  The ridge will steer Alvin toward the west-northwest during the next several days.  On its anticipated track Hurricane Alvin is forecast to weaken when it moves over colder water between Baja California and Hawaii.

Tropical Storm Alvin Develops South of Baja California

Tropical Storm Alvin developed south of Baja California on Wednesday morning, when former Tropical Depression One-E strengthened to a tropical storm.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Alvin was located at latitude 14.7°N and longitude 109.4°W which put it about 565 miles (915 km) south of the southern tip of Baja California.  Alvin was moving toward the west 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 circulation around Tropical Storm Alvin exhibited greater organization on Wednesday morning.  A band of thunderstorms wrapped around the eastern side of the center of circulation.  Other bands of showers and thunderstorms were organizing in the eastern half of the circulation.  Winds to tropical storm force extended out about 35 miles (55 km) from the center on the eastern side of the circulation.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Alvin will move through an environment favorable for intensification during the next 24 to 36 hours.  Alvin will move over water where the Sea Surface Temperature is near 28°C.  Tropical Storm Alvin will move south of an upper level ridge.  The ridge will produce northeasterly 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.  Tropical Storm Alvin will intensify during the next day or two and it could strengthen into a hurricane.

The upper level ridge will steer Tropical Storm Alvin toward the west during the next several days.  Alvin could move a little to the south of due west during the next 24 hours.  On its anticipated track Tropical Storm Alvin will move steadily farther away from Mexico.

Tropical Depression One-E Forms West of Mexico

Tropical Depression One-E formed west of Mexico on Tuesday afternoon.  More thunderstorms developed close to the center of a low pressure system over the Eastern North Pacific Ocean and the National Hurricane Center designated the system as Tropical Depression One-E.  At 5:00 p.m. EDT on Tuesday the center of Tropical Depression One-E was located at latitude 15.2°N and longitude 105.7°W which put it about 280 miles (450 km) south-southwest of Manzanillo, Mexico.  The depression was moving toward the west-northwest at 15 m.p.h. (24 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 1007 mb.

The circulation around Tropical Depression One-E exhibited greater organization on Tuesday afternoon.  Several short bands of showers and thunderstorms were developing near the center of circulation.  One band was north of the center, another was west of the center and a third band was south of the center of circulation.  Bands east of the center consisted primarily of showers and lower clouds.  Thunderstorms near the center of circulation were beginning to generate upper level divergence which was pumping mass away from the tropical depression.

Tropical Depression One-E will move through an environment favorable for intensification during the next day or two.  The depression will move over water where the Sea Surface Temperature is near 28°C.  It will move south of an upper level ridge over Mexico and the Eastern North Pacific Ocean.  The ridge will produce northeasterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear which will slow the rate of intensification, but the shear will not be strong enough to prevent intensification.  Tropical Depression One-E is likely to intensify into a tropical storm during the next 24 to 36 hours.

A subtropical ridge north of Tropical Depression One-E will steer the depression toward the west-northwest.  On its anticipated track Tropical Depression One-E will move away from Mexico.  It is forecast to pass south of Baja California.

Tropical Depression 01E Forms Southwest of Baja California

Tropical Depression 01E formed southwest of Baja California on Thursday afternoon.  A distinct low level center of circulation formed inside a larger area of low pressure that was previously designated as Invest 90E.  The National Hurricane Center (NHC) determined that the system possessed sufficient organization and NHC designated it as Tropical Depression 01E.  At 5:00 p.m. EDT on Thursday the center of Tropical Depression 01E was located at latitude 12.4°N and longitude 126.5°W which put it about 1310 miles (2105 km) west-southwest of the southern tip of Baja California.  Tropical Depression 01E was moving toward the west-northwest at 5 m.p.h. (8 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 1007 mb.

Tropical Depression 01E formed in a larger area of low pressure that was moving slowly westward over the Eastern North Pacific Ocean.  More thunderstorms formed near the center of the low pressure system and a distinct low level center became apparent on visible satellite images.  An upper level trough located west of the depression was producing southwesterly winds which are blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and the shear was limiting the development of thunderstorms in the western half of the depression.  Most of the stronger thunderstorms were occurring east of the center of circulation.  The bands in the western half of the depression consisted mostly of lower clouds and showers.  Storms east of the center were producing some upper level divergence which was pumping mass away to the east of the depression.

Tropical Depression 01E will move through an environment only marginally favorable for intensification.  It will move over water where the Sea Surface Temperature is near 27°C.  So, there is enough energy in the upper ocean to support intensification.  However, the upper level trough will continue to produce moderate vertical wind shear.  The upper level winds could be strong enough to prevent further intensification.  If the upper level winds slow, then there is a chance the depression could strengthen into a tropical storm during the next day or two.

Tropical Depression 01E is moving south of a subtropical ridge which is steering the depression toward the west-northwest.  The subtropical ridge is forecast to steer the depression in a general westerly direction during the next several days.  On its anticipated track Tropical Depression 01E poses no immediate threat to any land areas.

Strong Shear Weakens Adrian to a Tropical Depression

Strong vertical wind shear weakened Tropical Storm Adrian to a tropical depression on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Depression Adrian was located at latitude 10.5°N and longitude 93.1°W which put it about 420 miles (675 km) south-southeast of Salina Cruz, Mexico.  Adrian was moving toward the northwest at 5 m.p.h. (7 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 1007 mb.

An upper level ridge east of Adrian generated strong southeasterly winds which produced strong vertical wind shear and literally blew the top off of the tropical storm.  The upper half of the circulation was carried well to the northwest of low level circulation.  The low level circulation consists low clouds and weak showers.  No new thunderstorms have formed in the low level circulation since it decoupled from the upper half of the circulation.

Strong upper level winds are likely to continue to create strong vertical wind shear on Thursday.  Tropical Depression Adrian is likely to remain weak on Thursday.  If the low level circulation persists for several more days, then the upper level winds could weaken.  The Sea Surface Temperature is near 30°C.  So, if there is still a low level circulation, some strengthening could occur when the upper level winds diminish.

Tropical Storm Adrian Develops South of Guatemala

Tropical Storm Adrian developed south of Guatemala on Tuesday.  Adrian became the earliest tropical storm to form over the Eastern North Pacific Ocean during the satellite era.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Adrian was located at latitude 9.5°N and longitude 92.3°W which put it about 360 miles (575 km) southwest of San Salvador, El Salvador.  Adrian was moving toward the west-northwest at 7 m.p.h. (11 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.

A well defined low level center of circulation developed within a large area of thunderstorms over the Eastern North Pacific Ocean on Tuesday and the National Hurricane Center classified the system as Tropical Storm Adrian.  A primary rainband wrapped about half way around the western side of the center of circulation.  Additional bands of showers and thunderstorms formed farther away from the center.  There were more thunderstorms west of the center, but bands were forming in all quadrants of Tropical Storm Adrian.  The strongest winds were occurring close to the center of circulation, which is the typical structure of a tropical cyclone.  Thunderstorms near the core of Adrian were beginning to generate upper level divergence which was pumping away mass.

Tropical Storm Adrian will be moving through an environment that will be favorable for intensification.  Adrian will move over water where the Sea Surface Temperature will be about 30.5°C.  An upper level ridge east of Adrian is producing southeasterly winds which are blowing toward the top of the circulation.  Those winds are causing some vertical wind shear, but the shear should not be great enough to prevent intensification.  Tropical Storm Adrian is likely to intensify during the next several days and it could become a hurricane later this week.

Adrian is moving around the southwestern part of a subtropical ridge, which is steering the tropical storm toward the west-northwest.  A general west-northwesterly motion is expected to continue for several more days.  When Adrian reaches the western end of the ridge later this week, the tropical storm will turn toward the north and it will move closer toward the coast.

Tropical Depression One-E Forms South of Mexico

A low level center of circulation developed near the southern edge of thunderstorms near the coast of Mexico on Monday and the National Hurricane Center designated the system as Tropical Depression One-E.  At 5:00 p.m. EDT on Monday the center of Tropical Depression One-E (TD1E) was located at latitude 14.2°N and longitude 97.0°W which put it about 185 miles (295 km) southwest of Salina Cruz, Mexico.  TD1E was moving toward the northeast at 7 m.p.h. (11 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 1006 mb.  The government of Mexico issued a Tropical Storm Watch for the portion of the coast that extends from Puerto Escondido to Boca de Pijijiapan, Mexico.

Tropical Depression One-E is not a particularly well organized circulation.  A large upper level trough that extends from west of Mexico over the Gulf of Mexico is producing strong southwesterly winds that are blowing over the top of the depression.  The is the same upper level trough that is also causing the vertical wind shear over Tropical Storm Colin in the Gulf of Mexico.  As a result of the significant vertical wind shear, most of the strong thunderstorms are occurring north and east of the center of circulation.  The wind shear may be causing the tropical depression to be tilted toward the northeast with height.  The low level center of circulation is near the southern edge of the stronger thunderstorms.  The thunderstorms generating some upper level divergence to the east of the depression.

The environment around TD1E is only marginal for further intensification.  The depression is over water where the Sea Surface Temperature is near 31°C.  However, the vertical wind shear is forecast to continue and TD1E does not have much time to intensify before the center moves over land.  Little change in intensity is expected and only slight strengthening may occur before landfall.  TD1E is likely to weaken rapidly after landfall.  However, it will be interesting to see if the middle and upper part of the circulation make it to the Gulf of Mexico.

The upper level trough is expected to continue to steer TD1E toward the northeast.  On its anticipated track, the low level center is forecast to reach the coast of Mexico in 12 to 24 hours.  In cases like this when there is strong vertical wind shear near the coast of Mexico, the upper portion of the circulation sometimes gets separated from the lower level circulation.  In that case, the upper half of the circulation would continue northeast while the lower circulation either lingers near the coast or moves slowly inland and dissipates.

The primary risks from Tropical Depression One-E are locally heavy rain and flash flooding.