Category Archives: Eastern and Central Pacific

TCs between Mexico and Hawaii

Tropical Storm Douglas Strengthens Quickly

Tropical Storm Douglas strengthened quickly over the Eastern North Pacific Ocean on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Douglas was located at latitude 12.4°N and longitude 124.2°W which put it about 2110 miles (3390 km) east of Hilo, Hawaii.  Douglas was moving toward the west-southwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 998 mb.

The circulation around Tropical Storm Douglas exhibited much better organization on Tuesday morning.  The inner end of a rainband wrapped around the southern and eastern sides of the center of circulation.  Bands of showers and thunderstorms were revolving around around the center of Douglas.  The strongest bands were in the southern half of Tropical Storm Douglas.  Storms near the center of circulation were generating upper level divergence which was pumping mass away from the tropical storm.  Winds to tropical storm force extended out about 40 miles (65 km) from the center of Douglas.

Tropical Storm Douglas will move through an environment favorable for intensification during the next several days.  Douglas 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.  Tropical Storm Douglas is likely to intensify into a hurricane during the next 24 hours and it could strengthen into a major hurricane later this week.

Tropical Storm Douglas will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high is likely to steer Douglas toward the west-northwest during the next few days.  On its anticipated track Tropical Storm Douglas could approach Hawaii by late in the weekend.

Elsewhere over the Eastern North Pacific Ocean, Tropical Depression Seven-E weakened over cooler water east of Hawaii.  At 11:00 a.m. EDT on Tuesday the center of Tropical Depression Seven-E was located at latitude 19.3°N and longitude 134.1°W which put it about 1575 miles (2535 km) west of the southern tip of Baja California.  The depression was moving toward west at 13 m.p.h. (20 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 1009 mb.

Two Tropical Depressions Form Over Eastern Pacific

Two tropical depressions formed over the Eastern North Pacific Ocean on Monday.  At 11:00 a.m. EDT on Monday the center of Tropical Depression Seven-E was located at latitude 18.7°N and longitude 130.3°E which put it about 1345 miles (2170 km) west of the southern tip of Baja California.  The depression was moving toward the northwest at 13 m.p.h. (20 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.

At 11:00 a.m. EDT on Monday the center of Tropical Depression Eight-E was located at latitude 13.7°N and longitude 119.8°W which put it about 905 miles (1460 km) southwest of the southern tip of Baja California.  The depression was moving toward the west-southwest 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 1008 mb.

The distribution of thunderstorms around Tropical Depression Seven-E was asymmetrical.  The strongest storms were occurring in bands southwest of the center of circulation.  Bands in other parts of the depression consisted primarily of showers and lower clouds.  The depression was already to moving over water where the Sea Surface Temperature was near 25°C.  It was moving under the southwestern part of an upper level ridge which was producing northeasterly winds.  Those winds were blowing toward the top of the depression and they were causing moderate vertical wind shear.  Cooler water and wind shear were contributing to the asymmetrical distribution of thunderstorms.

Tropical Depression Seven-E is likely to weaken since it will continue to move over cooler water.  The depression will move south of a subtropical high pressure system.  The high will steer the depression toward the west while it weakens.  On its anticipated track the depression will weaken long before it could pose a threat to Hawaii.

The distribution of thunderstorms around Tropical Depression Eight-E is also asymmetrical.  Many of the strongest storms were occurring in bands in the western half of the circulation.  Some thunderstorms began to develop in bands in the eastern half of the depression on Monday morning.  Storms on the western side of the circulation began to generate upper level divergence which pumped mass away from the depression.

Tropical Depression Eight-E will move through an environment favorable for intensification during the next several days.  The depression will move over water where the Sea Surface Temperature is near 29°C.  The upper level ridge over the Eastern North Pacific Ocean will produce northeasterly winds which will blow toward the top of the depression.  Those winds will cause some vertical wind shear, but the shear will have less effect because the depression will be over warmer water.  Tropical Depression Eight-E will strengthen during the next 48 hours and it could intensify into a hurricane.

Tropical Depression Eight-E will move around the southern side of the subtropical high pressure system over the Eastern North Pacific Ocean.  The high will steer the depression toward the west during the next few days.  On its anticipated track the depression will move in the general direction of Hawaii.

Tropical Storm Cristina Starts to Weaken

Tropical Storm Cristina started to weaken on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Cristina was located at latitude 20.6°N and longitude 121.0°W which put it about 730 miles (1175 km) west of the southern tip of Baja California.  Cristina was moving toward the west at 14 m.p.h. (22 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.

Tropical Storm Cristina began to weaken on Saturday when it moved over cooler water.  Cristina moved over water where the Sea Surface Temperature was near 24°C.  The circulation around Tropical Storm Cristina was well organized, but the thunderstorms were not as tall,  A thin broken ring of thunderstorms surrounded the center of circulation and the strongest winds were occurring in that ring of storms.  Other bands of showers and thunderstorms were revolving around the center of circulation.  Storms near the center were still generating upper level divergence.  However, the circulation was unable to extract enough energy from the cooler water to maintain the stronger wind speeds.  Winds to tropical storm force extended out about 80 miles (130 km) from the center of circulation.

Tropical Storm Cristina will continue to weaken during the next few days when it moves over water where the Sea Surface Temperature is near 23°C.  Cristina could weaken to a tropical depression by Monday.

Tropical Storm Cristina will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high will steer Cristina toward the west during the next few days.  On its anticipated track Tropical Storm Cristina will move in the general direction of Hawaii while it weakens.

Tropical Storm Cristina Forms South of Acapulco

Tropical Storm Cristina formed south of Acapulco on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Cristina was located at latitude 11.2°N and longitude 101.3°W which put it about 405 miles (650 km) south-southwest of Acapulco, Mexico.  Cristina was moving toward the west-northwest at 15 m.p.h. (24 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 distinct low pressure center organized quickly in a tropical wave south of Mexico on Monday.  Satellite images showed a well developed counterclockwise rotation around the center of circulation.  Bands of showers and thunderstorms were revolving around the center of Tropical Storm Cristina.  The inner end of a rainband wrapped around the southern and eastern sides of the center of circulation.  Storms near the center of circulation were generating upper level divergence which was pumping mass away in all directions from the tropical storm,  Winds to tropical storm force extended out about 35 miles (55 km) from the center of Cristina.

Tropical Storms Cristina will move through an environment favorable for intensification during the next several days.  Cristina will move over water where the Sea Surface Temperature is near 29.5°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Cristina will continue to strengthen and it could intensify rapidly.  Cristina will intensify into a hurricane within 36 hours and it could strengthen into a major hurricane later this week.

Tropical Storm Cristina will move around the southwestern part of a ridge of high pressure over Mexico and the southwestern U.S.  The ridge will steer Cristina toward the west-northwest during the next few days.  On its anticipated track Tropical Storm Cristina will move away from the west coast of Mexico.

Tropical Depression Four-E Forms Southwest of Baja California

Tropical Depression Four-E formed just southwest of Baja California on Monday night.  At 11:00 p.m. EDT on Monday the center of Tropical Depression Four-E was located at latitude 20.5°N and longitude 112.6°W which put it about 240 miles (385 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 1004 mb.

The circulation around a low pressure system southwest of Baja California exhibited more organization on Monday night and the National Hurricane Center designated the system as Tropical Depression Four-E.  The distribution of thunderstorms around the depression was asymmetrical.  A band of stronger thunderstorms wrapped around the northern side of the center of circulation.  The strongest winds were occurring in that band of storms.  Bands in other parts of the depression consisted of primarily of showers and lower clouds.

Tropical Depression Four-E will move into an environment mostly unfavorable for intensification.  The depression will move over water where the Sea Surface Temperature is near 24.5°C.  An upper level trough over the western U.S. and an upper level ridge over Mexico will produce southwesterly winds which will blow toward the top of the depression.  Those winds will cause moderate vertical wind shear.  The colder water and moderate shear will prevent the potential for significant intensification.  The depression could maintain its intensity during the next six to twelve hours but it is likely to weaken later on Tuesday.

Tropical Depression Four-E will move around the western end of a ridge of high pressure over Mexico.  The ridge will steer the depression slowly toward the northwest.   On its anticipated track Tropical Depression Four-E will pass west of Baja California.

Tropical Storm Boris Develops East-Southeast of Hawaii

Tropical Storm Boris developed east-southeast of Hawaii on Thursday afternoon.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Boris was located at latitude 11.2°N and longitude 137.1°W which put it about 1330 miles (2145 km) east-southeast of Hilo, Hawaii.  Boris was moving toward the west-northwest at 9 m.p.h. (15 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.

More thunderstorms developed Thursday afternoon near a low pressure system southeast of Hawaii that was previously designated as Tropical Depression Three-E.  A scatterometer on board a satellite detected winds to 40 m.p.h. (65 km) near the center of the low pressure system and the National Hurricane Center designated the system as Tropical Storm Boris.  A band of showers and thunderstorms wrapped around the southern and eastern sides of the center of circulation and the strongest winds were occurring in that band of storms.  A few other short bands of showers and thunderstorms developed in the eastern half of Boris.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out about 50 miles from the center of circulation.

Tropical Storm Boris will move through an environment marginally favorable for intensification during the next 12 to 24 hours.  Boris will move over water where the Sea Surface Temperature is near 26.5°C.  A large upper level trough between Hawaii and the West Coast of the U.S. will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear and the shear will limit intensification.  In addition, there is drier air north and west of Tropical Storm Boris.  Boris could intensify during the next 12 hours in spite of the moderate vertical wind shear and drier air.  However, Tropical Storm Boris will move into a region where the upper level winds are stronger during the weekend.  When the vertical wind shear increases, Boris will weaken.

Tropical Storm Boris will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The will steer Boris toward the west-northwest during the next 24 hours.  When Tropical Storm Boris weakens during the weekend, it will be steered by winds closer to the surface.  Those winds will steer Boris toward the west.  On its anticipated track the weakening Tropical Storm Boris will pass southeast of Hawaii.

Tropical Storm Amanda Drops Heavy Rain on Guatemala and El Salvador

Tropical Storm Amanda dropped heavy rain on parts of Guatemala and El Salvador on Sunday.  At 8:00 a.m. EDT on Sunday the center of Tropical Storm Amanda was located at latitude 14.2°N and longitude 90.4°W which put it about 30 miles (50 km) south-southeast of Guatemala City, Guatemala.  Amanda was moving toward the north-northeast at 9 m.p.h. (15 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.

Tropical Storm Warnings remained in effect for the entire coasts of Guatemala and El Salvador.

The circulation around former Tropical Depression Two-E strengthened on Sunday morning as it approached the coast of Guatemala and the National Hurricane Center designated the system as Tropical Storm Amanda.  Winds to tropical storm force extended out 50 miles (80 km) on the eastern side of Amanda.  Winds on the western side of the circulation were mostly less than tropical storm force.

The heaviest rain in Tropical Storm Amanda was falling near the center of circulation and in bands on the eastern side of the circulation.  Tropical Storm Amanda was located on the eastern side of a much larger counterclockwise circulation that is sometimes called a Central American Gyre (CAG).  The CAG will steer Amanda toward the north during the next 24 to 36 hours.  On its anticipated track Tropical Storm Amanda will move across Guatemala toward the southern Yucatan peninsula.  Amanda will drop locally heavy rain over parts of El Salvador, Guatemala, Belize and eastern Mexico.  The heavy rain could cause flash floods in some locations.

The lower level part of the circulation of Tropical Storm Amanda will weaken while the tropical storm moves over land.  The circulation of Amanda that is above the surface could move over the Bay of Campeche early next week.  A new tropical cyclone could form over the Bay of Campeche if that happens.  The National Hurricane Center is indicating that there is a 50% probability of the formation of a tropical cyclone over the Bay of Campeche during the next five days.

Tropical Depression Two-E Forms Near Guatemala

Tropical Depression Two-E formed near the coast of Guatemala on Saturday.  At 8:00 p.m. EDT on Saturday the center of Tropical Depression Two-E was located at latitude 12.6°N and longitude 91.0°W which put it about 90 miles (145 km) south of Puerto San Jose, Guatemala.  The depression was moving toward the north-northeast at 4 m.p.h. (6 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 1005 mb.

Tropical Storm Warnings were in effect for the entire coasts of El Salvador and Guatemala.

A distinct center of circulation developed south of the coast of Guatemala on Saturday.  More thunderstorms formed near the center and the National Hurricane Center designated the system as Tropical Depression Two-E.  Thunderstorms continued to form near the center.  Bands of showers and thunderstorms were revolving around the center of the depression.  The depression was near the center of a much larger counterclockwise circulation that is sometimes called a Central American Gyre (CAG).

Tropical Depression Two-E will move through an environment favorable for intensification during the next few hours.  The depression will move over water where the Sea Surface Temperature is near 30°C.  It will move under an upper level ridge over Central America.  The upper level winds are weak and there will be little vertical wind shear.  Tropical Depression Two-E could strengthen during the next few hours and there is a chance it could intensify into a tropical storm.

Tropical Depression Two-E will move around the western end of a high pressure system.  The high will steer the depression toward the north-northeast.  On its anticipated track the center of Tropical Depression Two-E will make landfall on the coast of Guatemala on Sunday.  The depression could drop heavy rain over  Guatemala, El Salvador and western Honduras.  The heavy rain could cause flash floods.

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.

Possible Tropical Development

A tropical cyclone could possibly form south of Baja California during the next few days.  The system has been designated as Invest 90E.  At 2:00 p.m. EDT on Thursday the center of Invest 90E was located at latitude 10.2°N and longitude 111.7°W which put it about 870 miles (1405 km) south of the southern tip of Baja California.  It was moving toward the west at 9 mp.h. (15 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 1008 mb.

An area of thunderstorms has persisted south of Baja California for the past several days.  More thunderstorms developed on Thursday.  Visible satellite images indicated that the thunderstorms were organizing into bands and there was some counterclockwise rotation of the bands around a center of circulation.  There appeared to be a low level center of circulation.  However, there were not enough thunderstorms around the center of circulation for the system to be classified as a tropical cyclone.

Invest 90E will move through an environment somewhat favorable for the formation of a tropical cyclone during the next 48 hours.  it will move over water where the Sea Surface Temperature is near 29°C.  Invest 90E 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 across the top of the system.  Those winds will cause moderate vertical wind shear and they will inhibit the formation of a tropical cyclone.   If the strength of the upper level wind diminishes slightly, then the environment will become more favorable for the formation of a tropical cyclone.  The National Hurricane Center indicated that the probability of formation of a tropical cyclone during the next two days was 40%.

Invest 90E will move around the western end of a high pressure system over the far Eastern North Pacific Ocean during the next several days.  The high will steer the system toward the northwest.  On its anticipated track Invest 90E will remain well to the southwest of Baja California during the weekend.