Category Archives: Eastern and Central Pacific

TCs between Mexico and Hawaii

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.

Hurricane Genevieve Rapidly Intensifies to Cat. 4

Hurricane Genevieve rapidly intensified to Category 4 on the Saffir-Simpson Scale over the Eastern North Pacific Ocean.  At 8:00 a.m. EDT on Tuesday the center of Hurricane Genevieve was located at latitude 17.7°N and longitude 107.6°W which put it about 390 miles (630 km) south-southeast of the southern tip of Baja California.  Genevieve was moving toward the northwest a 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 950 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Los Barriles to Todos Santos, Mexico.  Tropical Storm Watches were in effect for the portion of the coast from Los Barriles to La Paz and from Todos Santos to Sante Fe, Mexico.

Hurricane Genevieve continued to intensify rapidly during the past 24 hours and it reached Category 4 on the Saffir-Simpson Scale.  A circular eye with a diameter of 20 miles (32 km) formed at the center of Genevieve.  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 Genevieve.  Storms near the core were generating strong upper level divergence which was pumping mass away from the hurricane in all directions.

The circulation around Hurricane Genevieve increased in size during the past 24 hours.  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.  The Hurricane Intensity Index (HII) for Hurricane Genevieve was 25.1.  The Hurricane Size Index (HSI) was 10.9 and the Hurricane Wind Intensity Size Index (HWISI) was 36.0.

Hurricane Genevieve will move through an environment very favorable for strong hurricanes during the next 24 hours.  Genevieve 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 Genevieve could strengthen further during the next 24 hours.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could occur.  The eyewall replacement cycle would cause Hurricane Genevieve to weaken.

Hurricane Genevieve will move south of a ridge of high pressure over the southwestern U.S. and northern Mexico.  The high will steer Genevieve toward the northwest during the next several days.  On its anticipated track the center of Hurricane Genevieve will pass west of Baja California.  However, Genevieve could come close enough to the coast to bring tropical storm force winds and locally heavy rain to the southern portion of Baja California.  Locally heavy rain could cause flash floods in some locations.

Genevieve Rapidly Intensifies into a Hurricane

Former Tropical Storm Genevieve rapidly intensified into a hurricane southwest of Mexico on Monday morning.  At 11:00 a.m. EDT on Monday the center of Hurricane Genevieve was located at latitude 14.3°N and longitude 103.0°W which put it about 250 miles (400 km) south-southwest of Zihuantanejo, Mexico.  Genevieve was moving toward the west-northwest at 18 m.p.h. (30 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. (120 km/h).  The minimum surface pressure was 992 mb.

Former Tropical Storm Genevieve rapidly intensified into a hurricane during the past 24 hours.  The inner end of a rainband was wrapping around the center of circulation and an eye was forming at the center of Genevieve.  Bands of showers and thunderstorms were revolving around the core of Hurricane Genevieve.  Storms near the core were generating upper level divergence which was pumping mass away from the hurricane in all directions.  Winds to hurricane force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 125 miles (200 km) from the center.

Hurricane Genevieve will move through an environment very favorable for intensification during the next 24 hours.  Genevieve will move over water where the Sea Surface Temperature is near 30°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 continue to intensify rapidly and it could strengthen into a major hurricane during the next 24 hours.

Hurricane Genevieve will move south of a ridge over high pressure over the southwestern U.S. and northern Mexico.  The ridge will steer Genevieve toward the west-northwest during the next few days.  On its anticipated track Hurricane Genevieve could be south of Baja California on Wednesday.

Tropical Storm Genevieve Spins Up Quickly South of Mexico

Tropical Storm Genevieve spun up quickly south of Mexico on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Genevieve was located at latitude 12.2°N and longitude 99.2°W which put it about 410 miles (665 km) south-southeast of Zihuatanejo, Mexico.  Genevieve was moving toward the west-northwest at 20 m.p.h. (32 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 1004 mb.

The circulation around former Tropical Depression Twelve-E organized quickly on Sunday afternoon and the National Hurricane Center upgraded the system to Tropical Storm Genevieve.  More thunderstorms developed near the center of circulation.  Bands of showers and thunderstorms were revolving around the center of Genevieve.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm.  Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

Tropical Storm Genevieve will move through an environment very favorable for intensification during the next several days.  Genevieve will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds will be weak and there will be little vertical wind shear.  Tropical Storm Genevieve will intensify rapidly.  Genevieve will strengthen into a hurricane within 24 hours and it could intensify into a major hurricane during the next 48 hours.

Tropical Storm Genevieve will move around the southern side of a ridge of high pressure over the southwestern U.S. and northern Mexico.  The ridge will steer Genevieve toward the west-northwest.  On its anticipated track Tropical Storm Genevieve could pass south of the Baja California during the middle of the week.

Tropical Storm Fausto Develops Southwest of Baja California

Tropical Storm Fausto developed southwest of Baja California on Sunday morning.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Fausto was located at latitude 20.7°N and longitude 119.6°W which put it about 640 miles (1020 km) west-southwest of the southern tip of Baja California.  Fausto was moving toward the 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 1004 mb.

More thunderstorms formed near the center of former Tropical Depression Eleven-E on Sunday morning and the National Hurricane Center upgraded the system to Tropical Storm Fausto.  The distribution of thunderstorms around Fausto was asymmetrical.  Many of the thunderstorms were occurring in bands in the northern half of the circulation.  The strongest winds were occurring in those bands of thunderstorms.  Bands in the southern half of the tropical storm consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 50 miles (80 km) in the northern half of the circulation.  The wind in the southern half of the circulation was blowing at less than tropical storm force.

Tropical Storm Fausto will move through an environment unfavorable for intensification.  Fausto will move over water where the Sea Surface Temperature is near 25°C.  An upper level trough west of Tropical Storm Fausto will produce southerly winds which will blow toward the top of the circulation.  Those winds will cause vertical wind shear which will also inhibit potential intensification.  Tropical Storm Faust is likely to weaken slowly when it moves over cooler water.

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

Elsewhere over the Eastern North Pacific Ocean, Tropical Depression Twelve-E spun up quickly south of Mexico and Tropical Depression Ten-E stalled between Mexico and Hawaii.  At 11:00 a.m. EDT on Sunday the center of Tropical Depression Twelve-E was located at latitude 11.3°N and longitude 97.3°W which put it about 525 miles (850 km) southeast of Zihuatanejo, Mexico.  The depression was moving toward the north-northwest at 18 m.p.h. (30 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.  Tropical Depression Twelve-E is forecast to intensify quickly and it could strengthen into a major hurricane during the next several days.

At 11:00 a.m. EDT on Sunday the center of Tropical Depression Ten-E was located at latitude 13.7°N and longitude 134.0°W which put it about 1700 miles (2735 km) west-southwest of the southern tip of Baja California.  The depression was moving toward the north-northwest at 3 m.p.h. (5 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.

Elida Strengthens to a Hurricane South of Baja California

Former Tropical Storm Elida strengthened to a hurricane south of Baja California on Monday afternoon.  At 5:00 p.m. EDT on Monday the center of Hurricane Elida was located at latitude 19.6°N and longitude 110.9°W which put it about 235 miles (380 km) south-southwest of the southern tip of Baja California.  Elida was moving toward the west-northwest at 14 m.p.h. (22 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 990 mb.

The circulation around Hurricane Elida exhibited better organization on Monday afternoon.  The inner end of a rainband was wrapping around the center of circulation.  Bands of showers and thunderstorms were revolving around the core of Elida.  The strongest thunderstorms were in bands in the southern and eastern parts of the hurricane.  Bands in the northwestern part of the circulation consisted primarily of showers and lower clouds.  Storms near the core of Elida were generating upper level divergence which was pumping mass away from the hurricane.  Winds to hurricane force extended out 20 miles (30 km) on the eastern side of the circulation.  Winds to tropical storm force extended out 70 miles (110 km) from the center.

Hurricane Elida will move through an environment favorable for intensification during the next 24 hours.  Elida will move over water where the Sea Surface Temperature is near 28°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Elida will strengthen on Tuesday.  Elida will move over cooler water during the middle of the week, which will cause it to weaken.

Hurricane Elida will move around the southern part of an ridge of high pressure that extended from northern Mexico over the Eastern North Pacific Ocean.  The ridge will steer Elida toward the west-northwest during the next several days.  On its anticipated track Hurricane Elida will gradually move farther away from Baja California.