Category Archives: Eastern and Central Pacific

TCs between Mexico and Hawaii

Tropical Storm Norbert Develops Southwest of Mexico

Tropical Storm Norbert developed southwest of Mexico on Tuesday morning.  At 5: 00 a.m. EDT on Tuesday the center of Tropical Storm Norbert was located at latitude 13.7°N and longitude 106.2°W which put it about 385 miles (625 km) south-southwest of Manzanillo, Mexico.  Norbert was moving toward the northwest 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.

The wind speed increased around a low pressure system southwest of Mexico on Tuesday morning and the National Hurricane Center designated the system as Tropical Storm Norbert.  More thunderstorms formed near the center of Norbert.  Storms near the center of circulation started to generate upper level divergence which pumped mass away to the northeast of the tropical storm.  Bands of showers and thunderstorms were developing outside the center of Norbert.  The circulation around Tropical Storm Norbert was small.  Winds to tropical storm force extended out 25 miles from the center of circulation.

Tropical Storm Norbert will be in an environment that is somewhat favorable for intensification.  Norbert will move over water where the Sea Surface Temperature is near 29°C.  A large upper level trough extends from northern Mexico over the Eastern North Pacific Ocean.  The trough will produce southwesterly winds which will blow toward the top of Tropical Storm Norbert.  Those winds will cause vertical wind shear and the shear will inhibit intensification.  Tropical Storm Norbert could strengthen if the shear is not too strong.

Tropical Storm Norbert will be in a region where the steering currents are weak..  Norbert is not likely to move very much during the next several days.  If Tropical Storm Norbert remains in the same location for more than a day, its winds will mix cooler water to the surface.  That would limit the energy Norbert could extract from the ocean, and the tropical storm could weaken.

Elsewhere over the Eastern North Pacific, Tropical Storm Marie continued to churn west away from Baja California.  At 5:00 a.m. EDT on Tuesday the center of Tropical Storm Marie was located at latitude 21.7°W and longitude 134.3°W which put it about 1560 miles (2510 km) west of the southern tip of Baja California.  Marie was moving toward the west-northwest at 9 m.p.h. (15 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 1003 mb.

Hurricane Marie Weakens West of Baja California

Hurricane Marie weakened west of Baja California on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Hurricane Marie was located at latitude 19.5°N and longitude 127.9°W which put it about 1180 miles (1900 km) west of the southern tip of Baja California.  Marie 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) and there were wind gusts to 135 m.p.h. (220 km/h).  The minimum surface pressure was 960 mb.

Hurricane Marie began to move over water where the Sea Surface Temperature was cooler than 26°C on Saturday evening.  Marie was unable to extract enough energy from the ocean to maintain its intensity.  The circulation around Hurricane Marie pulled cooler, more stable air around its southern side.  The rainbands in the southern half of Marie started to weaken.  The southern side of the eyewall weakened too.  Strong thunderstorms were still occurring in rainbands in the northern half of Hurricane Marie.  Winds to hurricane force extended out 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center.

Hurricane Marie will move around the western side of a ridge of high pressure over the southwestern U.S.  The high will steer Marie toward the north-northwest during the next few days.  Hurricane Marie will move over even cooler water during the next several days, which will cause it to weaken more quickly.  Marie could weaken to a tropical depression by the middle of next week.  Eventually, some of the moisture in Hurricane Marie could be transported over California by the end of next week.

Marie Strengthens into a Major Hurricane

Hurricane Marie strengthened into a major hurricane on Thursday.  At 11:00 p.m. EDT on Thursday the center of Hurricane Marie was located at latitude 15.6°N and longitude 122.1°W which put it about 940 miles (1515 km) west-southwest of the southern tip of Baja California.  Marie was moving toward the west-northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 957 mb.

The circulation around Hurricane Marie was very well organized on Thursday night.  There was a small circular eye with a diameter of 12 miles (19 km) at the center of Marie.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Hurricane Marie.  Storms near the core were generating strong upper level divergence which was pumping mass away from the hurricane in all directions.  Winds to hurricane force extended out 20 miles (30 km) from the center of Marie.  Winds to tropical storm force extended out 125 miles (200 km) from the center.

Hurricane Marie will move through an environment favorable for intensification during the next 24 hours.  Marie 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 Marie is likely to strengthen on Friday.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could begin which would cause Marie to weaken.  Hurricane Marie will move over cooler water during the weekend.  Marie will extract less energy from the ocean which will cause the wind speed to decrease.

Hurricane Marie will move south of a ridge of high pressure over the southwestern U.S. and Eastern North Pacific Ocean.  The high will steer Marie toward the west-northwest during the next several days.  On its anticipated track Hurricane Marie will move farther away from Baja California.

Marie Rapidly Strengthens Into a Hurricane

Former Tropical Storm Marie rapidly strengthened into a hurricane on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Marie was located at latitude 14.3°N and longitude 115.1°W which put it about 685 miles (1100 km) south-southwest of the southern tip of Baja California.  Marie was moving toward the west 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 988 mb.

The circulation around Hurricane Marie exhibited much greater organization on Wednesday afternoon.  The inner end of a rainband wrapped entirely around the center of Marie.  Other bands of showers and thunderstorms were revolving around the core of Hurricane Marie.  Storms near the core generated upper level divergence which pumped mass away to the west of the hurricane.  The circulation around Marie was small.  Winds to hurricane force only extended out 15 miles (25 km) from the center of circulation.  Winds to tropical storm force only extended out 60 miles from the center.

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

Hurricane Marie will move south of a ridge of high pressure over the southwestern U.S.  The high will steer Marie toward the west-northwest during the next few days.  On its anticipated track Hurricane Marie will move farther away Baja California.

Tropical Storm Marie Forms South of Baja California

Tropical Storm Marie formed south of Baja California on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Marie was located at latitude 13.6°N and longitude 109.5°W which put it about 645 miles (1035 km) south of the southern tip of Baja California.  Marie was moving toward the west 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 1005 mb.

More thunderstorms developed near the center of a small low pressure system south of Baja California on Tuesday afternoon and the National Hurricane Center designated the system as Tropical Storm Marie.  The circulation around Marie was still organizing.  More thunderstorms were forming around the center of Tropical Storm Marie.  Bands of showers and thunderstorms were also developing and the bands were revolving around the center of the tropical storm.  Storms near the center of Marie started to generate upper level divergence which began to pump mass away to the west of the tropical storm.  The circulation around the Tropical Storm Marie was small.  Winds to tropical storm force extended out 25 miles (40 km) from the center of circulation.

Tropical Storm Marie will move through an environment favorable for intensification during the next two to three days.  Marie 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 Marie could intensify into a hurricane within 36 hours.  Marie could strengthen more rapidly once an inner core with an eye and an eyewall forms.  Tropical Storm Marie could intensify into a major hurricane later this week.

Tropical Storm Marie will move south of a ridge of high pressure over the southwestern U.S.  The high will steer Marie toward the west-northwest during the next several days.  On its anticipated track Tropical Storm Marie will move farther away from Baja California.

Tropical Storm Lowell Forms South of Baja California

Tropical Storm Lowell formed south of Baja California on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Lowell was located at latitude 17.4°N and longitude 113.6°W which put it about 450 miles (725 km) south-southwest of the southern tip of Baja California.  Lowell was moving toward the west-northwest at 16 m.p.h. (26 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 1001 mb.

A scatterometer onboard a satellite detected winds to 45 m.p.h. (75 km/h) on the southeast side of former Tropical Depression Seventeen-E on Monday afternoon and the National Hurricane Center upgraded the system to Tropical Storm Lowell.  The circulation around Lowell was not well organized.  The strongest thunderstorms were occurring in bands in the southwestern quadrant of the tropical storm.  Bands in the other parts of Tropical Storm Lowell consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 85 miles (135 km) on the southern side of Lowell.  Winds on the northern side of the circulation were blowing at less than tropical storm force.

An upper level ridge over the Eastern North Pacific Ocean was producing northeasterly winds which were blowing toward the top of Tropical Storm Lowell.  Those winds were causing moderate vertical wind shear and they were responsible for the stronger thunderstorms being in the southwestern quadrant of Lowell.  The moderate upper level winds also appeared to be tilting the top part of Tropical Storm Lowell toward the southwest of the circulation at the surface.

Tropical Storm Lowell will move over water where the Sea Surface Temperature is near 28°C.  So, there will be sufficient energy in the upper ocean to support intensification.  If the upper level winds weaken, then Lowell could intensify during the next several days.  However, if the upper level winds remain at their current speed, then it will be difficult for the tropical storm to become more organized.  The wind shear is forecast to decrease slowly, which would allow Tropical Storm Lowell to strengthen gradually.

Tropical Storm Lowell will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high is forecast to steer Lowell toward the west during the next few days.  On its anticipated track Tropical Storm Lowell will move farther away from Baja California.

Tropical Storm Karina Forms Southwest of Baja California

Tropical Storm Karina formed southwest of Baja California on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Karina was located at latitude 17.6°N and longitude 114.7°W which put it about 480 miles (775 km) southwest of the southern tip of Baja California.  Karina was moving toward the west-northwest at 10 m.p.h. (16 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 1001 mb.

More thunderstorms formed near the center of a low pressure system southwest of Baja California on Sunday and the National Hurricane Center designated the system as Tropical Storm Karina.  The distribution of thunderstorms around Tropical Storm Karina was asymmetrical.  Many of the stronger thunderstorms were occurring in bands in the southwestern part of Karina’s circulation.  Bands in other parts of the tropical storm consisted primarily of showers and lower clouds.  Storms near the center of circulation began to generate upper level divergence which pumped mass away to the west of the tropical storm.  Winds to tropical storm force extended out 90 miles in the southwestern quadrant of Tropical Storm Karina.  Winds in other parts of the circulation were blowing at less than tropical storm force.

Tropical Storm Karina will move through an environment somewhat favorable for intensification during the next 24 hours.  Karina will move over water where the Sea Surface Temperature is near 28°C.  It will move south of an upper level ridge that extends from the southwestern U.S. over the Eastern North Pacific Ocean.  The ridge will produce northeasterly winds which will blow toward the top of Tropical Storm Karina.  Those winds will cause moderate vertical wind shear.  The shear will inhibit intensification, but it will not be strong enough to prevent Karina from intensifying.

Tropical Storm Karina will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high will steer Karina toward the west-northwest during the next several days.  On its anticipated track Tropical Storm Karina will move farther away from Baja California.

Tropical Storm Julio Develops South of Mexico

Tropical Storm Julio developed south of Mexico on Saturday afternoon.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Julio was located at latitude 16.1°N and longitude 102.7°W which put it about 180 miles (290 km) south-southwest of Zihuatanejo, Mexico.  Julio was moving toward the west-northwest at 20 m.p.h. (32 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 middle and upper portion of the circulation around former Hurricane Nana moved westward from Guatemala over the Gulf of Tehuantepec south of Mexico.  A surface circulation redeveloped over the Eastern North Pacific Ocean.  More thunderstorms formed near the center of the surface circulation and the National Hurricane Center designated the system as Tropical Storm Julio on Saturday afternoon.

The circulation around Tropical Storm Julio was small.  Winds to tropical storm force only extended out 35 miles from the center of Julio.  The stronger winds were occurring north of the center of circulation.  Thunderstorms continued to form near the center.  Short, narrow bands of showers and thunderstorms were revolving around the center of circulation.

Tropical Storm Julio will move through an environment only marginally favorable for intensification.  Julio will move over water where the Sea Surface Temperature is near 30°C.  So, there is sufficient energy in the upper ocean to support intensification.  However, an upper level ridge over Mexico will produce easterly winds which will blow toward the top of Julio.  Those winds will cause moderate vertical wind shear which will inhibit intensification.  In addition, visible satellite images suggest that there is another small low pressure system about 250 miles (400 km) west of Tropical Storm Julio.  Interaction with the small low pressure system could also disrupt the circulation around Julio.

The ridge over Mexico will steer Tropical Storm Julio toward the west-northwest.  However, interaction with the small low pressure system west of Julio could also affect the track.  On its anticipated track Tropical Storm Julio will move toward a position south of Baja California on Sunday night.

Tropical Storms Hernan and Iselle Form West of Mexico

Tropical Storms Hernan and Iselle formed west of Mexico.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Hernan was located at latitude 19.1°N and longitude 106.2°W which put it about 95 miles (155 km) south-southwest of Cabo Corrientes, Mexico.  Hernan was moving toward the north-northwest at 5 m.p.h. (8 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 1001 mb.

The circulation around Tropical Storm Hernan was not well organized.  An upper level ridge over the southwestern U.S. and northern Mexico was producing northeasterly winds which were blowing toward the top of Hernan.  Those winds were causing strong vertical wind shear.  As a result of the shear, the stronger thunderstorms were occurring in bands in the southern part of the circulation.  Bands in the other parts of Tropical Storm Hernan consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 100 miles in the southern half of Hernan.  Winds in the northern half of the circulation were blowing at less than tropical storm force.

Tropical Storm Hernan will move through an environment unfavorable for intensification during the next several days.  Hernan will move over water where the Sea Surface Temperature is near 29°C.  So, there will be plenty of energy in the upper ocean to support intensification.  However, the upper level ridge will continue to cause strong vertical wind shear, which will inhibit potential intensification.  Tropical Storm Hernan is likely to weaken on Friday when it moves over colder water.  Hernan could approach the southern end of Baja California on Friday.

At 11:00 a.m. EDT on Thursday the center of Tropical Storm Iselle was located at latitude 17.0°N and longitude 115.8°W which put it about 560 miles (900 km) southwest of the southern tip of Baja California.  Iselles was moving toward the northeast at 5 m.p.h. (8 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 1001 mb.

The circulation around Tropical Storm Iselle was also not well organized.  It was being sheared by the same upper level ridge that was causing strong vertical wind shear over Tropical Storm Hernan.  Most of the thunderstorms in Iselle were also occurring in the southern half of the circulation.  Tropical storm force winds extended out 100 miles from the center in the southern half of Tropical Storm Iselle.  Iselle will also move through an environment unfavorable for intensification.

Hurricane Genevieve Brings Wind and Rain to Baja California

Hurricane Genevieve brought wind and rain to southern Baja California on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Hurricane Genevieve was located at latitude 23.3°N and longitude 111.4°W which put it about 120 miles (195 km) south-southeast of Cabo San Lazaro, Mexico.  Genevieve was moving toward the northwest at 12 m.p.h. (19 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 984 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Los Barriles to Cabo San Lazaro, Mexico.  A Tropical Storm Watch was in effect for the portion of the coast from Los Barriles to La Paz, Mexico.

The center of Hurricane Genevieve passed just southwest of the southern tip of Baja California on Thursday morning.  A weather station at the Cabo San Lucas Marina reported a wind gust of 90 m.p.h. (145 km/h).  Bands of thunderstorms were dropping heavy rain on parts of southern Baja California.  There were reports of flash floods in some locations.

Hurricane Genevieve will weaken during the next several days as it moves over cooler water.  Genevieve will move over water where the Sea Surface Temperatures are cooler than 26°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Genevieve will weaken gradually as it moves over cooler water.

Hurricane Genevieve will move around the southwestern part of a ridge of high pressure over the southwestern U.S. and northern Mexico.  The ridge will steer Genevieve toward the northwest.  On its anticipated track Hurricane Genevieve will move parallel to the west coast of Baja California.  Genevieve will continue to bring gusty winds to the southern part of Baja California.  It will also drop move heavy rain and additional flash floods are likely.