Category Archives: Eastern and Central Pacific

TCs between Mexico and Hawaii

Tropical Storm Kenneth Forms Southwest of Baja California

Tropical Storm Kenneth formed over the Eastern North Pacific Ocean southwest of Baja California on Tuesday afternoon. At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Kenneth was located at latitude 15.1°N and longitude 121.0°W which put it about 900 miles (1450 km) southwest of the southern tip of Baja California. Kenneth was moving toward the west 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 1004 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 Storm Kenneth. The distribution of thunderstorms around Tropical Storm Kenneth was very asymmetrical. Most of the thunderstorms were occurring in a couple of bands in the northwestern part of Kenneth’s circulation. Bands in the other parts of the tropical storm consisted primarily of showers and lower clouds. Winds to tropical storm force were also occurring in the northwestern quadrant of Tropical Storm Kenneth. The winds in the other parts of Kenneth’s circulation were blowing at less than tropical storm force.

Tropical Storm Kenneth will move through an environment somewhat favorable for intensification during the next 24 hours. Kenneth will move over water where the Sea Surface Temperatures are near 27°C. It will move under the southern part of an upper level ridge over the Eastern North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Kenneth’s circulation. Those winds will cause moderate vertical wind shear. The wind shear will inhibit intensification. Tropical Storm Kenneth could intensify on Wednesday, if the vertical wind shear is not too strong. An upper level trough east of Hawaii will produce southwesterly winds that will affect Kenneth later this week. The southwesterly winds will cause more vertical wind shear and the wind shear will cause Tropical Storm Kenneth to weaken.

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

Jova Weakens to a Tropical Storm

Former Hurricane Jova weakened to a tropical storm over the Eastern North Pacific Ocean west of Baja California during Friday night. At 5:00 a.m. EDT on Saturday the center of Tropical Storm Jova was located at latitude 21.5°N and longitude 124.6°W which put it about 945 miles (1520 km) west of the southern tip of Baja California. Jova was moving toward the west-northwest at 13 m.p.h. (21 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 986 mb.

Former Category 5 Hurricane Jova weakened to a tropical storm over cooler water during Friday night. Even though Jova weakened to a tropical storm, its circulation was well organized. Tropical Storm Jova completed an eyewall replacement cycle as it moved over cooler water. The original inner eye and eyewall dissipated. The outer eyewall surrounded a clear area at the center of Jova’s circulation. Bands of showers and thunderstorms revolved around the center of Tropical Storm Jova. The thunderstorms did not rise as high in the atmosphere because of the cooler water at the surface of ocean. Winds to tropical storm force extended out 115 miles (185 km) from the center of Jova’s circulation.

Tropical Storm Jova will move through an environment unfavorable for intensification during the next 48 hours. Jova will move over water where the Sea Surface Temperatures are near 24°C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Storm Jova will continue to weaken gradually over cooler water, even though there will be little vertical wind shear. Jova could weaken to a tropical depression by the end of the weekend.

Tropical Storm Jova will move around the southern part of a high pressure system over the Eastern North Pacific Ocean. The high pressure system will steer Jova toward the west-northwest during the next 48 hours. On its anticipated track, Tropical Storm Jova will move farther away from Baja California.

Hurricane Jova Weakens Southwest of Baja California

Hurricane Jova weakened over the Eastern North Pacific Ocean southwest of Baja California on Thursday. At 11:00 p.m. EDT on Thursday the center of Hurricane Jova was located at latitude 18.3°N and longitude 118.6°W which put it about 645 miles (1040 km) west-southwest of the southern tip of Baja California. Jova was moving toward the west-northwest at 17 m.p.h. (28 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 951 mb.

Hurricane Jova started an eyewall replacement cycle on Thursday. The inner end of a rainband wrapped around the original eye and eyewall. A larger outer eyewall surrounded the original eye and eyewall. The inner eyewall, which was where the strongest winds were, began to weaken after the outer eyewall developed. The inner eyewall was still evident on microwave satellite images on Thursday night. A larger clear area, sometimes called a moat, was between the inner eyewall and the outer eyewall. Bands of showers and thunderstorms were revolving around the two concentric eyewalls.

Hurricane Jova started to weaken as the eyewall replacement cycle progressed. Winds to hurricane force extended out 25 miles (40 km) from the center of Jova’s circulation. Winds to tropical storm force extended out 140 miles (220 km) from the center of circulation. The Hurricane Intensity Index (HII) was 23.6. The Hurricane Size Index (HSI) was 10.4 and the Hurricane Wind Intensity Size Index (HWISI) was 34.0.

Hurricane Jova will move through an environment that will become unfavorable for intensification during the next 24 hours. Jova 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 Jova will weaken during the next 24 hours as the inner eyewall dissipates. Jova will weaken more quickly when it moves over cooler water.

Hurricane Jova will move around the southern part of a high pressure system over northern Mexico and the Eastern North Pacific Ocean. The high pressure system will steer Jova toward the west-northwest during the next 24 hours. On its anticipated track, Hurricane Jova will move farther away from Baja California.

Hurricane Jova Rapidly Intensifies to Cat. 5

Hurricane Jova rapidly intensified to Category 5 on the Saffir-Simpson Scale over the Eastern North Pacific Ocean south of Baja California on Wednesday. At 11:00 p.m. EDT on Wednesday the center of Hurricane Jova was located at latitude 15.4°N and longitude 113.0°W which put it about 535 miles (865 km) south-southwest of the southern tip of Baja California. Jova was moving toward the west-northwest at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 190 m.p.h. (305 km/h). The minimum surface pressure was 929 mb.

Hurricane Jova intensified from a tropical depression to a Category 5 hurricane in 48 hours. A circular eye with a diameter of 12 miles (19 km) formed at the center of Jova’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Hurricane Jova. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the hurricane. The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The size of the circulation around Hurricane Jova increased as Jova rapidly intensified. Winds to hurricane force extended out 30 miles (50 km) from the center of Jova’s circulation. Winds to tropical storm force extended out 115 miles (185 km) from the center of circulation. The Hurricane Intensity Index (HII) was 35.0. The Hurricane Size Index (HSI) was 9.0 and the Hurricane Wind Intensity Size Index (HWISI) was 44.0.

Hurricane Jova will move through an environment favorable for intensification during the next 12 hours. Jova will move over water where the Sea Surface Temperatures are 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 Jova could continue to intensify during the next 12 hours. The inner end of a rainband appeared to be wrapping around the existing eye and eyewall in the core of Jova’s circulation. If concentric eyewalls form, then an eyewall replacement cycle will cause Hurricane Jova to weaken on Thursday. Jova will move over cooler water on Friday, which will also cause it to weaken.

Hurricane Jova will move around the southern part of a high pressure system over northern Mexico and the Eastern North Pacific Ocean. The high pressure system will steer Jova toward the west-northwest during the next 24 hours. On its anticipated track, Hurricane Jova will stay far to the southwest of Baja California.

Jova Rapidly Intensifies to a Major Hurricane

Hurricane Jova rapidly intensified to a major hurricane over the Eastern North Pacific Ocean south of Baja California on Wednesday. At 5:00 p.m. EDT on Wednesday the center of Hurricane Jova was located at latitude 14.9°N and longitude 111.7°W which put it about 565 miles (910 km) south-southwest of the southern tip of Baja California. Jova was moving toward the west-northwest at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 953 mb.

Hurricane Jova intensified very rapidly to a major hurricane on Wednesday. A circular eye with a diameter of 12 miles (19 km) formed at the center of Jova’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Hurricane Jova. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the hurricane. The removal of large amounts of mass caused the surface pressure to decrease rapidly.

Hurricane Jova rapidly intensified to Category 4 on the Saffir-Simpson Scale. Winds to hurricane force extended out 25 miles (40 km) from the center of Jova’s circulation. Winds to tropical storm force extended out 130 miles (210 km) from the center of circulation. The Hurricane Intensity Index (HII) was 25.1. The Hurricane Size Index (HSI) was 7.4 and the Hurricane Wind Intensity Size Index (HWISI) was 32.5.

Hurricane Jova will move through an environment favorable for intensification during the next 24 hours. Jova will move over water where the Sea Surface Temperatures are 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 Jova will intensify during the next 24 hours. Jova could strengthen to Category 5 on the Saffir-Simpson Scale.

Hurricane Jova will move around the southern part of a high pressure system over northern Mexico and the Eastern North Pacific Ocean. The high pressure system will steer Jova toward the west-northwest during the next 24 hours. On its anticipated track, Hurricane Jova will stay far to the southwest of Baja California.

Jova Rapidly Intensifies to a Hurricane

Former Tropical Storm Jova rapidly intensified to a hurricane over the Eastern North Pacific Ocean south of Baja California during Tuesday night. At 5:00 a.m. EDT on Wednesday the center of Hurricane Jova was located at latitude 13.6°N and longitude 109.6°W which put it about 640 miles (1035 km) southeast of the southern tip of Baja California. Jova was moving toward the west-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 979 mb.

The maximum sustained wind speed in former Tropical Storm Jova increased 45 m.p.h. (75 km/h) during the past 24 hours. The inner end of a rainband wrapped most of the way around the center of Hurricane Jova. The strongest winds were occurring in the inner end of the rainband. A small circular eye was starting to appear on microwave satellite images. Other bands of showers and thunderstorms were revolving around the core of Hurricane Jova. Storms near the core generated upper level divergence that pumped mass away from the hurricane. Winds to hurricane force extended out 15 miles (20 km) from the center of Jova’s circulation. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation.

Hurricane Jova will move through an environment favorable for intensification during the next 36 hours. Jova 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 over Mexico and the Eastern North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Jova’s circulation. The winds in the lower levels of the atmosphere will also blow from the east and there will be little vertical wind shear. Hurricane Jova will intensify during the next 36 hours. Jova is likely to strengthen to a major hurricane by Wednesday.

Hurricane Jova will move around the southern part of a high pressure system over northern Mexico and the Eastern North Pacific Ocean. The high pressure system will steer Jova toward the west-northwest during the next 36 hours. On its anticipated track, Hurricane Jova will stay far to the southwest of Baja California.

Tropical Storm Jova Forms South of Mexico

Tropical Storm Jova formed south of Mexico on Monday night. At 5:00 a.m. EDT on Tuesday the center of Tropical Storm Jova was located at latitude 12.8°N and longitude 106.9°W which put it about 725 miles (1165 km) south-southeast of the southern tip of Baja California. Jova 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 1004 mb.

A low pressure system over the Eastern North Pacific Ocean south of Mexico strengthened during Monday night and the U.S. National Hurricane Center designated the system as Tropical Storm Jova. The circulation around Jova was still organizing on Tuesday morning. It was difficult to see the surface center of Tropical Storm Jova on infrared satellite images. More thunderstorms were developing in bands revolving around the center of circulation. Winds to tropical storm force extended out 60 miles (95 km) in the northeastern quadrant of Jova’s circulation. The winds in the other parts of Tropical Storm Jova were blowing at less than tropical storm force.

Tropical Storm Jova will move through an environment favorable for intensification during the next 36 hours. Jova 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 over Mexico and the Eastern North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Jova’s circulation. The winds in the lower levels of the atmosphere will also blow from the east and there will be little vertical wind shear. Tropical Storm Jova will intensify during the next 36 hours. Jova could strengthen to a hurricane on Wednesday.

Tropical Storm Jova will move around the southern part of a high pressure system over northern Mexico and the Eastern North Pacific Ocean. The high pressure system will steer Jova toward the west-northwest during the next 36 hours. On its anticipated track, Tropical Storm Jova will move farther away from the west coast of Mexico.

Tropical Storm Irwin Forms over the Eastern North Pacific

Tropical Storm Irwin formed over the Eastern North Pacific Ocean on Sunday. At 5:00 p.m. EDT on Sunday the center of Tropical Storm Irwin was located at latitude 17.2°N and longitude 121.3°W which put it about 835 miles (1315 km) west-southwest of the southern tip of Baja California. Irwin was moving toward the west-northwest at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 40 m.p.h. (60 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 998 mb.

A low pressure system over the Eastern North Pacific Ocean west-southwest of Baja California strengthened on Sunday and the U.S. National Hurricane Center designated the system as Tropical Storm Irwin. The distribution of thunderstorms in Irwin’s circulation was asymmetrical. Most of the thunderstorms were occurring in bands in the southern half of Tropical Storm Irwin. Bands in the northern side of Irwin’s circulation consisted primarily of showers and lower clouds. The distribution of winds in Tropical Storm Irwin was also asymmetrical. Winds to tropical storm force extended out 60 miles (95 km) in the eastern side of Irwin. The winds in the western side of the circulation were blowing at less than tropical storm force.

Tropical Storm Irwin will move through an environment that is only marginally favorable for intensification during the next 24 hours. Irwin will move over water where the Sea Surface Temperatures are near 26°C. It will move under the southwestern part of an upper level ridge over the Eastern North Pacific Ocean. The ridge will produce northeasterly winds that will blow toward the top of Irwin’s circulation. Those winds will cause moderate vertical wind shear and the wind shear will inhibit intensification. There is also a region of drier air northwest of Tropical Storm Irwin. Tropical Storm Irwin could get a little stronger on Monday, but the vertical wind shear and the drier air will limit any intensification.

Tropical Storm Irwin will move south of a subtropical high pressure system over the Eastern North Pacific Ocean. The high pressure system will steer Irwin toward the west during the next few days. On its anticipated track, Tropical Storm Irwin will move toward the Central Pacific Ocean.

Tropical Storm Hilary Drops Heavy Rain on Southern California

Tropical Storm Hilary dropped heavy rain over parts of southern California on Sunday. At 5:00 p.m. EDT on Sunday the center of Tropical Storm Hilary was located at latitude 31.3°N and longitude 116.1°W which put it about 115 miles (185 km) south-southeast of San Diego, California. Hilary was moving toward the north at 23 m.p.h. (37 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 990 mb.

A Tropical Storm Warning was in effect for the portion of the coast from the U.S. border with Mexico to the Point Mugu, California. The Tropical Storm Warning included San Diego. The Tropical Storm Warning also included Catalina Island. A Tropical Storm Warning was in effect for the portion of the coast from Punta Eugenia, Mexico to the border with the U.S. A Tropical Storm Warning was in effect for the portion of the coast from Bahia San Bautista to Guaymas, Mexico.

Former Hurricane Hilary weakened to a tropical storm as the center of Hilary moved over the northern part of Baja California. Bands in the northern part of Hilary’s circulation brought gusty winds to parts of southern California and Arizona. Winds to tropical storm force extended out 230 miles (370 km) from the center of Hilary’s circulation. A weather station at the Imperial, California airport reported a sustained wind speed of 40 m.p.h. (65 km/h) and a wind gust of 61 m.p.h. (98 km/h). A weather station in Yuma, Arizona reported at sustained wind speed of 45 m.p.h. (75 km/h) and a wind gust of 59 m.p.h. (95 km/h).

The circulation around the northern side of Tropical Storm Hilary interacted with an upper level low west of California to drop heavy rain over parts of southern California. Weather stations in Carlsbad, Ramona, Los Angeles, Riverside, Big Bear, Borrego, Palmdale, Edwards Air Force Base, and Gray Butte, California were all reporting heavy rain at 7:00 p.m. EDT.

The upper low west of California will pull Tropical Storm Hilary quickly to the north during the next 24 hours. The center of Hilary’s circulation will pass east of San Diego on Sunday evening. Tropical Storm Hilary continue to weaken as it moves inland over the Southwest U.S. The circulation of Hilary will move over Nevada on Monday. The upper and lower parts of Hilary’s circulation could decouple because of strong vertical wind shear. Tropical Storm Hilary will continue to produce gusty winds and locally heavy rain during the next 24 hours. The heaviest rain is likely to fall where the wind forces the air to rise over mountains. Heavy rain is likely to cause flash floods in some locations. Flood Watches have been issued for parts of southern California, southern Nevada, southern Utah and western Arizona. Hilary could also bring strong winds to mountains in southern Nevada, southern Utah and western Arizona.

Hurricane Hilary Brings Wind and Rain to Baja California

Hurricane Hilary brought wind and rain to Baja California on Saturday night. At 11:00 p.m. EDT on Saturday the center of Hurricane Hilary was located at latitude 25.3°N and longitude 114.6°W which put it about 175 miles (280 km) south of Punta Eugenia, Mexico. Hilary was moving toward the north-northwest at 18 m.p.h. (30 km/h). The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 105 m.p.h. (165 km/h). The minimum surface pressure was 968 mb.

Even though center of Hurricane Hilary was south of Punta Eugenia, Hilary brought strong winds and locally heavy rain to Baja California on Saturday night. A weather station in Loreto, Mexico reported a sustained wind speed of 58 m.p.h. (93 km/h) and a wind gust of 69 m.p.h. (111 km/h). There were reports of flash floods in Santa Rosalia, Mexico.

A Hurricane Warning was in effect for the portion of the coast from Punta Abreojos to Cabo San Quintin, Mexico. A Hurricane Watch was in effect for the portion of the coast from Cabo San Quintin to Ensenada, Mexico. A Tropical Storm Warning was in effect for the portion of the coast from Punta Abreojos to Todos Santos, Mexico. A Tropical Storm Warning was in effect for the portion of the coast from Los Barriles to Guaymas, Mexico. A Tropical Storm Warning was in effect for the portion of the coast from the U.S. border with Mexico to the Point Mugu, California. The Tropical Storm Warning included San Diego. The Tropical Storm Warning also included Catalina Island. A Tropical Storm Warning was in effect for the portion of the coast from Cabo San Quintin, Mexico to the border with the U.S. A Tropical Storm Watch was in effect for the portion of the coast from Guaymas to Huatabampito, Mexico.

Hurricane Hilary was weakening on Saturday night. There was no longer an eye visible on satellite images of Hurricane Hilary. The distribution of thunderstorms in Hilary was asymmetrical. Many of the thunderstorms were occurring in bands in the northern half of Hilary’s circulation. Bands in the southern half of the circulation consisted primarily of showers and lower clouds.

The circulation around Hurricane Hilary was still large even though Hilary was weakening. Winds to hurricane force extended out 45 miles (75 km) from the center of Hilary’s circulation. Winds to tropical storm force extended out 265 miles (425 km) from the center of circulation. The Hurricane Intensity Index (HII) was 13.9. The Hurricane Size Index (HSI) was 18.7 and the Hurricane Wind Intensity Size Index (HWISI) was 32.6. Hurricane Hilary was similar in size and intensity to Hurricane Matthew when Matthew hit South Carolina in 2016.

Hurricane Hilary will be moving into an environment that will be unfavorable for a hurricane during the next 24 hours. Hilary will move over water where the Sea Surface Temperatures are colder than 26°C. It will move between an upper level ridge over Mexico and the south central U.S. and an upper level low west of California. The upper level ridge and upper level low will interact to produce northerly winds that will blow toward the top of Hilary’s circulation. Those winds will cause the vertical wind shear to increase. The combination of cooler water and more vertical wind shear will cause Hurricane Hilary to weaken during the next 24 hours. In addition, much of the circulation in the eastern side of Hurricane Hilary will pass over Baja California. The mountains in Baja California will partially disrupt the flow of air around Hurricane Hilary.

The upper level ridge over the south central U.S. and the upper level low west of California will steer Hurricane Hilary toward the north-northwest during the next 24 hours. On its anticipated track, the center of Hurricane Hilary will be near Punta Eugenia early Sunday morning. Hilary will continue to produce strong, gusty winds and locally heavy rain in Baja California on Sunday. Heavy rain is likely to cause flash floods in some locations.

Hurricane Hilary could take a track similar to the one taken by Hurricane Nora in 1997. The center of Hilary will reach southern California by Sunday evening. Hilary will weaken to a tropical storm before it reaches southern California. Hilary will bring strong winds and locally heavy rain to parts of southern California. The heaviest rain is likely to fall where the wind force the air to rise over mountains. Heavy rain is likely to cause flash floods in some locations. Flood Watches have been issued for parts of southern California, southern Nevada, southern Utah and western Arizona. Hilary could also bring strong winds to mountains in southern Nevada, southern Utah and western Arizona.