Category Archives: Eastern and Central Pacific

TCs between Mexico and Hawaii

Tropical Depression One-E Forms Southwest of Baja California

Tropical Depression One-E formed over the Eastern North Pacific Ocean far to the southwest of Baja California on Tuesday afternoon.  At 5:00 p.m. EDT on Tuesday the center of Tropical Depression One-E was located at latitude 9.4°N and longitude 126.7°W which put the center about 1450 miles (2335 km) southwest of the southern tip of Baja California.  The tropical depression was moving toward the west at 3 m.p.h. (5 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.

A low pressure system over the Eastern North Pacific Ocean southwest of Baja California strengthened on Tuesday afternoon and the U.S. National Hurricane Center designated the system as Tropical Depression One-E.

The distribution of thunderstorms in Tropical Depression One-E was asymmetrical.  Thunderstorms were occurring in bands in the northern half of the tropical depression.  Bands in the southern half of Tropical Depression One-E consisted primarily of showers and lower clouds.  Storms near the center of Tropical Depression One-E began to generate upper level divergence that pumped mass away from the tropical depression.  The removal of mass caused the surface pressure to start to decrease slowly.

Tropical Depression One-E will move through an environment favorable for intensification during the next 24 hours.  The tropical depression will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the western part of an upper level ridge that is west of Mexico.  The upper level ridge will produce southerly winds that will blow toward the top of the tropical depression.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Depression One-E is likely to intensify to a tropical storm during the next 24 hours.

Tropical Depression One-E will move around the southwestern part of a high pressure system that is over the Eastern North Pacific Ocean.  The high pressure system will steer the tropical depression slowly toward the northwest during the next 24 hours.  On its anticipated track, Tropical Depression One-E will remain far to the southwest of Baja California during the next few days.

Eastern North Pacific Hurricane Season Begins

The Eastern North Pacific Hurricane season officially began on Friday May 15, 2026.  The season began quietly.  No tropical depressions, tropical storms or hurricanes were present over the Eastern North Pacific Ocean.  No tropical cyclones are expected to form over the Eastern North Pacific Ocean during the next few days.   Whenever a tropical storm does form over the Eastern North Pacific Ocean, the first name on the list will be Amanda.

A strong El Niño pattern is expected to develop over the Equatorial Pacific Ocean during the next few months.  Much warmer than normal Sea Surface Temperatures (SSTs) are expected to be present over the eastern Equatorial Pacific Ocean during the hurricane season.   During a strong El Niño the Sea Surface Temperatures over much of the Eastern North Pacific Ocean are also usually warmer than normal.

While the effect of an El Niño on the Atlantic hurricane season is typically to reduce the number of tropical storms and hurricanes because of more vertical wind shear, the effect of an El Niño on the activity over the Eastern North Pacific can be more complicated.  The effect of an El Niño on the Eastern North Pacific hurricane activity depends partly on where the warmest Equatorial Sea Surface Temperatures are located.

The warmer Sea Surface Temperatures associated with an El Niño produce more rising motion and convection.  The stronger rising motion begins to move toward the east when it reaches the upper troposphere where it produces stronger westerly winds which in turn cause more vertical wind shear.

Warmer Sea Surface Temperatures are favorable for more and stronger hurricanes.  If the stronger rising motion occurs over the eastern part of the Equatorial Pacific, then the increased vertical wind shear will occur over the Caribbean Sea.  In that case the El Niño contributes to a more active Eastern North Pacific hurricane season, because the stronger wind shear is not over the Eastern North Pacific.

However, if the stronger rising motion occurs a little farther to the west in the Equatorial Pacific southeast of Hawaii, then there will be more vertical wind shear over parts of the Eastern North Pacific Ocean.  The stronger vertical wind shear will partially offset the effect of the Warmer Sea Surface Temperatures.  The warmer SSTs may result in more tropical storms, but more vertical wind shear may somewhat limit the number and strength of hurricanes that form over the Eastern North Pacific.

So, the effect of a strong El Niño on the Eastern North Pacific hurricane season in 2026 will depend on where the strongest convection occurs during the next few months.

 

Tropical Storm Sonia Spins Southwest of Baja California

Tropical Storm Sonia continued to spin over the Eastern North Pacific Ocean southwest of Baja California on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Sonia was located at latitude 13.7°N and longitude 119.9°W which put the center about 910 miles (1470 km) southwest of the southern tip of Baja California.  Sonia was moving toward the west at 3 m.p.h. (5 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 1002 mb.

An upper level trough over the Eastern North Pacific Ocean was producing southerly winds that were blowing toward the top of Tropical Storm Sonia.  Those winds were causing moderate vertical wind shear.  The moderate vertical wind shear was causing the distribution of thunderstorms in Tropical Storm Sonia to be asymmetrical.  Thunderstorms were occurring in bands in the northern half of Sonia’s circulation.  Bands in the southern half of Tropical Storm Sonia consisted primarily of showers and lower clouds.

The circulation around Tropical Storm Sonia was small.  Winds to tropical storm force extended out 60 miles (95 km) from the center of Sonia’s circulation.

Tropical Storm Sonia will move through an environment that will be marginally favorable for intensification during the next 24 hours.  Sonia will move over water where the Sea Surface Temperatures are near 27°C.  However, the upper level trough over the Eastern North Pacific Ocean will continue to cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  Tropical Storm Sonia could intensify a little during the next 24 hours.

Tropical Storm Sonia will move around the southern side of a high pressure system over the Eastern North Pacific Ocean.  The high pressure system will steer Sonia toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Sonia will remain far to the southwest of Baja California.

Tropical Storm Sonia Forms Southwest of Baja California

Tropical Storm Sonia formed over the Eastern North Pacific Ocean southwest of Baja California early on Saturday.  At 5:00 a.m. EDT on Saturday the center of Tropical Storm Sonia was located at latitude 13.3°N and longitude 117.6°W which put the center about 835 miles (1340 km) southwest of the southern tip of Baja California.  Sonia was moving toward the west 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 1006 mb.

A low pressure system over the Eastern North Pacific Ocean southwest of Baja California strengthened early on Saturday and the U.S. National Hurricane Center designated the system as Tropical Storm Sonia.

More thunderstorms developed near the center of Tropical Storm Sonia early on Saturday.  Thunderstorms also were forming in bands revolving around the center of Sonia’s circulation.  Storms near the center of Sonia started to generate upper level divergence that pumped mass away from the tropical storm.

The circulation around Tropical Storm Sonia was small.  Winds to tropical storm force extended out 60 miles (95 km) in the northern half of Sonia’s circulation.  Winds to tropical storm force extended out 25 miles (40 km) in the southern side of Tropical Storm Sonia.

Tropical Cyclone Sonia will move through an environment that is favorable for intensification during the next 24 hours.  Sonia will move over water where the Sea Surface Temperatures are near 27°C.  It will move under the eastern side of an upper level trough that is over the Eastern North Pacific Ocean.  The upper level trough will produce southwesterly winds that will blow toward the top of Sonia’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Storm Sonia will intensify during the next 24 hours.

Tropical Storm Sonia will move around the southern side of a high pressure system over the Eastern North Pacific Ocean.  The high pressure system will steer Sonia toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Sonia will move farther away from Baja California.

Raymond Weakens to a Tropical Depression

Former Tropical Storm Raymond weakened to a tropical depression south of Baja California on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Depression Raymond was located at latitude 22.5°N and longitude 109.9°W which put the center about 30 miles (50 km) south of the southern tip of Baja California.  Raymond 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. (75 km/h).  The minimum surface pressure was 1005 mb.

Former Tropical Storm Raymond weakened to a tropical depression south of Baja California on Saturday.  Most of the thunderstorms in Raymond’s circulation dissipated.  The bands revolving around the center of Tropical Depression Raymond consisted primarily of showers and lower clouds.  There were no thunderstorms near the center of Raymond’s circulation to generate upper level divergence.  Converging winds in the lower levels of the atmosphere caused the surface pressure to increase.

Tropical Depression Raymond will move through an environment that will be unfavorable for intensification during the next 24 hours.  Raymond will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the southwestern part of an upper level ridge that is over Mexico.  The upper level ridge will produce easterly winds that will blow toward the top of Raymond’s circulation.  Those winds will cause strong vertical wind shear.  The strong wind shear will cause Tropical Depression Raymond to continue to weaken.

Tropical Depression Raymond will move around the western side of a high pressure system that is over Mexico.  The high pressure system will steer Raymond toward the north during the next 24 hours.  On its anticipated track, Tropical Depression Raymond will move across the southern part of Baja California on Saturday night.

Tropical Depression Raymond will bring gusty winds and isolated heavy rain to parts of southern Baja California.

Tropical Storm Raymond Moves West of Mexico

Tropical Storm Raymond moved west of Mexico on Friday afternoon.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Raymond was located at latitude 19.1°N and longitude 106.5°W which put the center about 145 miles (230 km) west of Manzanillo, Mexico.  Raymond was moving toward the northwest at 17 m.p.h. (28 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.

A Tropical Storm Warning was in effect for the portion of the coast from Manzanillo to Cabo Corrientes, Mexico.  A Tropical Storm Warning was in effect for Las Islas Marias.  A Tropical Storm Warning was in effect for the portion of the coast from Los Barriles to Santa Fe, Mexico.

The distribution of thunderstorms in Tropical Storm Raymond was still asymmetrical on Friday afternoon. Thunderstorms were occurring in bands in the southern and western parts of Raymond’s circulation.  Bands in the northern and eastern parts of Tropical Storm Raymond consisted primarily of shower and lower clouds.  Storms near the center of Raymond generated some upper level divergence that pumped mass away to the west of the tropical storm.

The circulation around Tropical Storm Raymond was small.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Raymond’s circulation.

Tropical Storm Raymond will move through an environment that will be only marginally favorable for intensification during the next 24 hours.  Raymond will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the southwestern part of an upper level ridge that is over Mexico.  The upper level ridge will produce easterly winds that will blow toward the top of Raymond’s circulation.  Those winds will cause strong vertical wind shear.  The strong wind shear will inhibit intensification. Tropical Storm Raymond is likely to weaken on Saturday because of the strong vertical wind shear.

Tropical Storm Raymond will move around the western side of a high pressure system that is over Mexico.  The high pressure system will steer Raymond toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Raymond will reach the southern end of Baja California on Saturday.

Tropical Storm Raymond will bring gust winds and locally heavy rain to the southern part of Baja California.  Heavy rain could cause flash floods in some locations.

Elsewhere over the Eastern North Pacific Ocean, former Tropical Storm Priscilla weakened west of Baja California.  At 5:00 p.m. EDT on Friday the center of Tropical Depression Priscilla was located at latitude 26.3°N and longitude 115.4°W which put the center about 220 miles (355 km) west-northwest of Cabo San Lazaro, Mexico.  Priscilla was moving toward the north at 6 m.p.h. (10 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.

Tropical Storm Raymond Forms South of Mexico

Tropical Storm Raymond formed over the Eastern North Pacific Ocean south of Mexico on Thursday.  At 2:00 p.m. EDT on Thursday the center of Tropical Storm Raymond was located at latitude 16.1°N and longitude 101.0°W which put the center about 115 miles (185 km) south-southeast of Zihuatanejo, Mexico.  Raymond was moving toward the 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 1002 mb.

A Tropical Storm Watch is in effect for the portion of the coast from Zihuatanejo to Cabo Corrientes, Mexico.

A low pressure system over the Eastern North Pacific Ocean south of Mexico strengthened on Thursday and the U.S. National Hurricane Center designated the system as Tropical Storm Raymond.

The distribution of thunderstorms in Tropical Storm Raymond was asymmetrical.  Thunderstorms were occurring in bands in the southern and western parts of Raymond’s circulation.  Bands in the northern and eastern parts of Tropical Storm Raymond consisted primarily of shower and lower clouds.  Storms near the center of Raymond started to generate upper level divergence that pumped mass away to the west of the tropical storm.

Tropical Storm Raymond will move through an environment that will be somewhat favorable for intensification during the next 24 hours.  Raymond will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level ridge that is over Mexico.  The upper level ridge will produce easterly winds that will blow toward the top of Raymond’s circulation.  Those winds will cause strong vertical wind shear.  The strong wind shear will inhibit intensification.  Tropical Storm Raymond could intensify a little on Friday if the upper level winds do not get any stronger.

Tropical Storm Raymond will move around the western side of a high pressure system that is over Mexico.  The high pressure system will steer Raymond toward the northwest during the next 24 hours.  On its anticipated track, the center of Tropical Storm Raymond will move near the coast of Mexico between Zihuatanejo and Cabo Corrientes on Friday.

Tropical Storm Raymond will bring gusty winds and locally heavy rain to coastal sections of Colima, Michoacan, and western Guerrero.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Priscilla continued to weaken west of Baja California.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Priscilla was located at latitude 23.8°N and longitude 114.7°W which put the center about 165 miles (265 km) west-southwest of Cabo San Lazaro, Mexico.  Priscilla was moving toward the north-northwest at 8 m.p.h. (13 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 996 mb.

Priscilla Weakens to a Tropical Storm

Former Hurricane Priscilla weakened to a tropical storm over the Eastern North Pacific Ocean south of Baja California on Wednesday afternoon.  At 2:00 p.m. EDT on Wednesday the center of Tropical Storm Priscilla was located at latitude 21.7°N and longitude 112.7°W which put the center about 195 miles (310 km) west-southwest of the southern tip of Baja California.  Priscilla was moving toward the northwest at 7 m.p.h. (11 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 985 mb.

A Tropical Storm Watch was in effect for the portion of the coast from Cabo San Lucas to Cabo San Lazaro, Mexico.

Former Hurricane Priscilla rapidly weakened to a tropical storm south of Baja California on Wednesday.  Thunderstorms around the center of Priscilla’s circulation and in the northern half of the circulation weakened.  Bands in those parts of Tropical Storm Priscilla consisted primarily of showers and lower clouds.  Thunderstorms were still occurring in bands in the southern and western periphery of Priscilla’s circulation.  Weakening of the thunderstorms near the core of Tropical Storm Priscilla greatly reduced the upper level divergence.  With much less upper level divergence the inflow of mass in the lower levels of the atmosphere caused the surface pressure to increase.

The circulation around Tropical Storm Priscilla was still large.  Winds to tropical storm force extended out 160 miles (260 km) from the center of Priscilla’s circulation.

Tropical Storm Priscilla will move through an environment that will become even more unfavorable for intensification during the next 24 hours.  Priscilla will move over water where the Sea Surface Temperatures are near 26°C.  An upper level trough near the west coast of the U.S. will produce southwesterly winds that will blow toward the top of Priscilla’s circulation.  Those winds will cause the vertical wind shear to increase.  The effects of cooler water and increasing vertical wind shear will cause Tropical Storm Priscilla to continue to weaken during the next 24 hours.

Tropical Storm Priscilla will move around the western end of a high pressure system over Mexico.  The high pressure system will steer Priscilla toward the north-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Priscilla will move west of Cabo San Lazaro on Thursday.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Octave continued to gradually weaken far to the southwest of Baja California.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Octave was located at latitude 15.4°N and longitude 116.2.°W which put the center about 660 miles (1065 km) southwest of the southern tip of Baja California.  Octave was moving toward the east at 12 m.p.h. (19 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.

Hurricane Priscilla Starts to Weaken

Hurricane Priscilla started to weaken on Tuesday evening.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Priscilla was located at latitude 20.6°N and longitude 111.5°W which put the center about 190 miles (305 km) south-southwest of the southern tip of Baja California.  Priscilla was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 962 mb.

A Tropical Storm Watch was in effect for the portion of the coast from Cabo San Lucas to Cabo San Lazaro, Mexico.

Hurricane Priscilla started to weaken on Tuesday evening after Priscilla had strengthened to Category 2 on the Saffir-Simpson Scale earlier in the day.  Hurricane Priscilla appeared to have mixed cooler water to the surface of the Eastern North Pacific Ocean.  A large eye with a diameter of 50 miles (80 km) was still present at the center of Priscilla’s circulation.  However, the ring of thunderstorms surrounding the eye was broken in several places.  Also, many of the thunderstorms in bands in the eastern side of Hurricane Priscilla had weakened.  The bands in the eastern part of Priscilla’s circulation consisted primarily of showers and lower clouds.  Thunderstorms were still occurring in bands in the western half of Hurricane Priscilla.

The circulation around Hurricane Priscilla was still large.  Winds to hurricane force extended out 45 miles (75 km) from the center of Priscilla’s circulation.  Winds to tropical storm force extended out 195 miles (315 km) from the center of Hurricane Priscilla.

The Hurricane Intensity Index (HII) for Hurricane Priscilla was 17.8.  The Hurricane Size Index (HSI) was 17.1 and the Hurricane Wind Intensity Size Index (HWISI) was 34.9.

Hurricane Priscilla will move through an environment that will become more unfavorable for intensification during the next 24 hours.  An upper level trough near the west coast of the U.S. will start to produce southwesterly winds that will blow toward the top of Priscilla’s circulation.  Those winds will cause the vertical wind shear to begin to increase.  In addition, the cooler water mixed to the surface of the ocean by Priscilla’s winds will limit the energy transfer from the ocean to the atmosphere.  The effects of cooler water and increasing vertical wind shear will cause Hurricane Priscilla to weaken during the next 24 hours.

Hurricane Priscilla will move around the western end of a high pressure system over Mexico.  The high pressure system will steer Priscilla toward the north-northwest during the next 24 hours.  On its anticipated track, Hurricane Priscilla will move parallel to the coast of southwestern Baja California on Wednesday.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Octave weakened far to the southwest of Baja California.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Octave was located at latitude 15.2°N and longitude 118.0.°W which put the center about 750 miles (1205 km) southwest of the southern tip of Baja California.  Octave was moving toward the east 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 1000 mb.

Hurricane Priscilla Moves South of Baja California

Hurricane Priscilla moved south of Baja California on Monday night.  At 11:00 p.m. EDT on Monday the center of Hurricane Priscilla was located at latitude 19.1°N and longitude 108.5°W which put the center about 275 miles (445 km) south-southeast of the southern tip of Baja California.  Priscilla was moving toward the northwest at 9 m.p.h. (15 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 972 mb.

A Tropical Storm Watch was in effect for the portion of the coast from Cabo San Lucas to Cabo San Lazaro, Mexico.

Hurricane Priscilla was showing evidence of intensification on Monday evening.  New tall thunderstorms were forming just to the south of the center of Priscilla’s circulation.  Microwave satellite imagery was indicating that an eye might be forming at the center of Hurricane Priscilla.  Bands of showers and thunderstorms were revolving around the center.  Storms near the center of Priscilla generated upper level divergence that pumped mass away from the hurricane.  The removal of mass caused the surface pressure to decrease.

The circulation around Hurricane Priscilla was very large.  Winds to hurricane force extended out 50 miles (80 km) in the eastern side of Priscilla’s circulation.  Winds to hurricane force extended out 25 miles (40 km) in the western side of Priscilla.  Winds to tropical storm force extended out 185 miles (295 km) from the center of Hurricane Priscilla.

Hurricane Priscilla will move through an environment favorable for intensification during the next 24 hours.  Priscilla will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the middle of an upper level ridge over Mexico and the Eastern North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Hurricane Priscilla will intensify during the next 24 hours.  Priscilla could strengthen to a major hurricane on Tuesday.

Hurricane Priscilla will move around the western end of a high pressure system over Mexico.  The high pressure system will steer Priscilla slowly toward the northwest during the next 24 hours.  On its anticipated track, Hurricane Priscilla will move closer to the southern part of Baja California on Tuesday.

Elsewhere over the Eastern North Pacific Ocean, former Hurricane Octave weakened back to a tropical storm on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Octave was located at latitude 15.8°N and longitude 120.4°W which put the center about 840 miles (1355 km) southwest of the southern tip of Baja California.  Octave was moving toward the east-southeast 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 998 mb.