Tag Archives: Eastern North Pacific

Tropical Storm Tara Develops South of Manzanillo

Tropical Storm Tara developed south of Manzanillo, Mexico on Monday.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Tara was located at latitude 17.6°N and longitude 104.4°W which put it about 95 miles (155 km) south of Manzanillo, Mexico.  Tara was moving toward the west-northwest at 2 m.p.h. (3 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 Tropical Storm Watch was in effect for the portion of the coast from Punta San Telmo to Cabo Corrientes, Mexico.

The circulation around Tropical Storm Tara is still organizing.  More thunderstorms are developing near the center of circulation.  Several bands of showers and thunderstorms are beginning to form around the center.  Storms near the center are starting to generate upper level divergence which is pumping mass away to the east of the tropical storm.  The circulation around  Tropical Storm Tara is small.  Winds to tropical storm force only extend out about 35 miles (55 km) from the center of circulation.

Tropical Storm Tara will be in an environment somewhat favorable for intensification.  Tara will move over water where the Sea Surface Temperature is near 29°C.  An upper level trough near Baja California will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear which will inhibit intensification.  The wind shear will not stop intensification, but they will slow it.  Tropical Storm Tara will remain close to Mexico and there is a chance that drier air from land could enter the northern part of the circulation.  Tropical Storm Tara is forecast to strengthen gradually.  However, because the circulation around Tropical Storm Tara is small, it could intensify or weaken very quickly if the environmental conditions change.

Tropical Storm Tara will be in an area where the steering currents are weak for another day or two.  Tara is forecast to move slowly toward the west-northwest during the next 24 to 48 hours.  On its anticipated track Tropical Storm Tara will remain west of Mexico.  However, several forecast models predict that Tara will move more northward and make landfall west of Manzanillo.  The government of Mexico issued a Tropical Storm Watch for that portion of the coast in case Tara brings tropical storm force winds to the coast.

Tropical Storm Sergio Cause Warnings for Baja California

Tropical Storm Sergio prompted the issuance of warnings and watches for parts of Baja California on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Sergio was located at latitude 20.0°N and longitude 121.5°W which put it about 770 miles (1240 km) west-southwest of the southern tip of Baja California.  Sergio was moving toward the northeast at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 992 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Punta Eugenia to Cabo San Lazaro, Mexico.  A Tropical Storm Watch was in effect for the portion of the coast from Bahia San Juan Bautista to San Evaristo, Mexico.

Tropical Storm Sergio weakened slightly on Wednesday, but the structure of the circulation remained well organized.  A large clear area at the center of circulation was the remnant of the eye that existed when Sergio was a hurricane.  The remnant of the eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Several thin bands of showers and thunderstorms were revolving around the core of Tropical Storm Sergio.  Winds to tropical storm force extended out about 140 miles (225 km) from the center of Sergio.

Tropical Storm Sergio will move over cooler water on Thursday.  An upper level trough west of California will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear.  The combination of cooler water and more wind shear will cause Tropical Storm Sergio to weaken slowly.

The upper level trough will steer Tropical Storm Sergio toward the northeast during the next several days.  On its anticipated track Tropical Storm Sergio will reach Baja California on Thursday night.  Sergio will bring gusty winds, but locally heavy rain is a greater risk because heavy rain could cause flash floods.

Hurricane Sergio Turns Back Toward Baja California

Hurricane Sergio turned back toward Baja California on Tuesday morning.  At 11:00 a.m. EDT on Tuesday the center of Hurricane Sergio was located at latitude 16.6°N and longitude 127.4°W which put it about 1215 miles (1960 km) west-southwest of the southern tip of Baja California.  Sergio was moving toward the northeast at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 95 m.p.h. (155 km/h).  The minimum surface pressure was 982 mb.

Hurricane Sergio was slowly weakening.  It appeared that cooler, drier air was entering the western half of the circulation.  Sergio has been moving slowly and its winds may have mixed some cooler water to the surface of the ocean.  Rainbands on the western side of Sergio consisted primarily of showers and lower clouds and thunderstorms in western side of the eyewall were weakening.  Stronger thunderstorms were still occurring in the eastern side of the eyewall and that was where the strongest winds were occurring.  Some strong storms were also occurring in a band southeast of the center of circulation.

Hurricane Sergio will move through an environment that will cause it to continue to weaken slowly.  Sergio is currently over water where the Sea Surface Temperature is near 27°C, but it will move over cooler water in a day or so.  An upper level trough centered west of California will produce southwesterly winds which will cause more vertical wind shear.  The combination of cooler water and more wind shear will cause Hurricane Sergio to weaken to a tropical storm within the next 24 to 36 hours.

The upper level trough will steer Hurricane Sergio toward the northeast during the next several days.  On its anticipated track Sergio could approach central Baja California on Thursday night.  It will likely be a tropical storm at that time.  Tropical Storm Watches could be issued for parts of the coast later today or on Wednesday.  Sergio will bring gusty winds and it will drop locally heavy rain.  The rain could cause flash flooding.  Sergio could also bring some rain to New Mexico and west Texas during the weekend.

Major Hurricane Sergio Churns Southwest of Baja California

Major Hurricane Sergio churned southwest of Baja California.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Sergio was located at latitude 13.3°N and longitude 117.9°W which put it about 845 miles (1360 km) southwest of the southern tip of Baja California.  Sergio was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 955 mb.

Hurricane Sergio is a well organized hurricane.  There is a circular eye at the center of circulation.  A ring of strong thunderstorms surrounds the eye and the strongest winds are occurring in that ring of storms.  Several bands of showers and thunderstorms are revolving around the core of Hurricane Sergio.  Storms near the core are generating strong upper level divergence which is pumping mass away in all directions from the hurricane.

Winds to hurricane force extend out about 45 miles (75 km) from the center of Hurricane Sergio.  Winds to tropical storm force extend out about 150 miles (240 km) from the center of circulation.  The Hurricane intensity Index (HII) for Hurricane Sergio is 23.6.  The Hurrricane Size Index (HSI) is 15.1 and the Hurricane Wind Intensity Size Index (HWISI) is 38.7.

Hurricane Sergio will remain in an environment capable of supporting a major hurricane for several more days.  Sergio will move over water where the Sea Surface Temperature is near 28°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Sergio could strengthen to Category 4 on the Saffir-Simpson Scale.  Hurricane Sergio will move over cooler water in a couple of days and it is likely to weaken when that occurs.

Hurricane Sergio will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Sergio toward the northwest during the next day or so.  The ridge is forecast to strengthen on Friday and it will steer Sergio more toward the west when that happens.  On its expected track Hurricane Sergio will move gradually farther away from Baja California.

Hurricane Rosa Moves Toward Baja California

Hurricane Rosa moved toward Baja California on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Hurricane Rosa was located at latitude 22.4°N and longitude 118.9°W which put it about 440 miles (710 km) south-southwest of Punta Eugenia, Mexico.  Rosa was moving toward the north at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 969 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Punta Abreojos to Cabo San Quintin, Mexico.  A Tropical Storm Watch was in effect for the portion of the coast from Bahia de los Angeles to San Felipe, Mexico.

Hurricane Rosa will move into an environment unfavorable for hurricanes on Sunday.  Rosa will move over water where the Sea Surface Temperature is cooler than 26°C.  In addition an upper level low near the west coast of the U.S. will produce southwesterly winds which will cause vertical wind shear.  The combination of cooler water and more vertical wind shear will cause Hurricane Rosa to weaken.  Rosa could weaken to a tropical storm by Sunday night.

The upper low will steer Hurricane Rosa toward the northeast during the next several days.  On its anticipated track Rosa could reach Baja California on Monday.  It will likely be a tropical storm at that time.  Even though it will weaken, Rosa will drop heavy rain over parts northern Baja California and the southwestern U.S.  The heavy rain could cause flash floods.

Elsewhere over the Eastern North Pacific Ocean Tropical Storm Sergio formed southwest of Acapulco, Mexico.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Sergio was located at latitude 12.3°N and longitude 103.3°W which put it about 390 miles (630 km) southwest of Acapulco, Mexico.  Sergio was moving toward the west 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 1003 mb.

Hurricane Olivia Churns Toward Hawaii

Hurricane Olivia churned toward Hawaii on Saturday.  At 11:00 a.m. EDT on Saturday the center of Hurricane Olivia was located at latitude 21.4°N and longitude 138.0°W which put it about 1110 miles (1790 km) east of Hilo, Hawaii.  Olivia was moving toward the west at 15 m.p.h. (24 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 983 mb.

Hurricane Olivia weakened slowly on Saturday, but it still had a well organized circulation.  There was a circular eye at the center of circulation.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Olivia.  The rainbands in the eastern half of the circulation were stronger than the bands in the western half of the circulation.  Storms near the core of Olivia were generating upper level divergence.

Hurricane Olivia will move through an environment that could allow it to remain a hurricane for several more days.  Olivia is currently over water where the Sea Surface Temperature is near 25°C, but it will move over slightly warmer water during the next several days.  An upper level trough north of Hawaii will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear and they could cause Hurricane Olivia to weaken to a tropical storm early next week.

Hurricane Olivia will move south of a subtropical high over the Eastern North Pacific Ocean.  The high will steer Olivia toward the west during the next day or two.  The ridge is forecast to strengthen early next week and it will steer Olivia more toward the west-southwest.  On its anticipated track Hurricane Olivia could approach Hawaii on Tuesday night.

Elsewhere, Tropical Storm Norman moved north of Hawaii and weakened, while Tropical Depression Eighteen-E developed southwest of Baja California.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Norman was located at latitude 26.0°N and longitude 154.4°W which put it about 395 miles (630 km) northeast of Honolulu, Hawaii. Norman was moving toward the northwest at 9 m.p.h. (15 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 998 mb.

At 11:00 a.m. EDT on Saturday the center of Tropical Depression Eighteen-E was located at latitude 16.1°N and longitude 115.9°W which put it about 610 miles (980 km) southwest of the southern tip of Baja California.  It was moving toward the west-northwest at 12 m.p.h. (19 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.

Hurricanes Norma and Olivia Continue Westward

Hurricanes Norman and Olivia continued to move westward across the Pacific Ocean on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Norman was located at latitude 19.9°N and 148.4°W which put it about 435 miles (700 km) east of Hilo, Hawaii. Norman was moving toward the west at 8 m.p.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 962 mb.

At 5:00 p.m. EDT on Wednesday the center of Hurricane Olivia was located at latitude 17.3°N and longitude 123.5°W which put it about 960 miles (1550 km) west-southwest of the southern tip of Baja California.  Olivia was moving toward the west-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 974 mb.

Although Hurricane Norman was in seemingly a less favorable environment, it intensified on Wednesday while Hurricane Olivia weakened.  The eye of Hurricane Norman became more distinct and it strengthened back to major hurricane status.  Hurricane Olivia weakened to Category 2 on the Saffir-Simpson Scale.  Both hurricanes were similar in size.  Winds to hurricane force extended out about 30 miles (50 km) from the center of Hurricane Norman and about 25 miles (40 km) from the center of Hurricane Olivia.  Winds to tropical storm force extended out about 115 miles (185 km) from the centers of both Hurricane Norman and Hurricane Olivia.

Both hurricanes are forecast to weaken gradually during the next several days.  Hurricane Norman will move over water cooler than 26.5°C.  An upper level trough will produce westerly winds which will blow toward the top of the circulation and cause more vertical wind shear.  The combination of cooler water and more shear will cause Hurricane Norman to weaken. Hurricane Olivia is currently over water where the Sea Surface Temperature is near 28°C, but it too will move over cooler water.  An upper level ridge north of Olivia will produce northwesterly winds which will cause more vertical wind shear.  Hurricane Olivia is also forecast to weaken during the next several days.

The upper level trough is forecast to turn Hurricane Norman toward the northwest on Thursday.  On its anticipated track Hurricane Norman will pass north of the Hawaiian Islands.  The ridge north of Hurricane Olivia is forecast to steer Olivia in a general westerly direction for another four or five days.  On its anticipated track Hurricane Olivia could be east of Hawaii by the end of the weekend.

Tropical Storm Olivia Forms South of Baja California

Tropical Storm Olivia formed south of Baja California on Sunday morning.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Olivia was located at latitude 17.0°N and longitude 112.4°W which put it about 440 miles (705 km) south-southwest of the southern tip of Baja California.  Olivia 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 circulation of Tropical Storm Olivia was not well organized.  Most of the stronger thunderstorms were occurring in bands southwest of the center of circulation.  The bands in the other parts of the tropical storm consisted primarily of showers and lower clouds.  Olivia was located southeast of an upper level ridge.  The ridge was producing northeasterly winds which were blowing across the top of the circulation.  Those winds were causing vertical wind shear and they were probably the reason why the stronger thunderstorms were confined to the southwestern part of Tropical Storm Olivia.

Tropical Storm Olivia will move into an environment that is more favorable for intensification.  Olivia will move over water where the Sea Surface Temperature is near 29°C.  It will move away from the northeasterly winds in the upper levels and the vertical wind shear is likely to decrease.  Intensification will occur slowly until the circulation becomes more well organized.  Once more thunderstorms form in other parts of the circulation, Tropical Storm Olivia could strengthen more quickly.

Tropical Storm Olivia will move south of a ridge of high pressure over the Eastern North Pacific Ocean.  The ridge will steer Olivia in a westerly direction during the next several days.  On its anticipated track Tropical Storm Olivia will move away from Baja California.

Elsewhere over the Eastern North Pacific Ocean, Hurricane Norman strengthened back to Category 4 on the Saffir-Simpson Scale.  At 11:00 a.m. EDT on Sunday the center of Hurricane Norman was located at latitude 17.6°N and longitude 129.1°W which put it about 1295 miles (2085 km) west-southwest of the southern tip of Baja California.  Norman was moving toward the west-northwest at 18 m.p.h. (30 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 949 mb.  Norman could be northeast of Hawaii in four or five days.

Hurricane Norman Rapidly Intensifies to Cat. 4

Hurricane Norman rapidly intensified to Category 4 on the Saffir-Simpson Scale on Thursday.  At 5:00 p.m. EDT on Thursday the center of Hurricane Norman was located at latitude 17.5°N and longitude 118.8°W which put it about 685 miles (1105 km) west-southwest of the southern tip of Baja California.  Norman was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 175 m.p.h. (285 km/h).  The minimum surface pressure was 937 mb.

The circulation Hurricane Norman is very symmetrical.  There is a small eye at the center of circulation and the eye is surrounded by a ring of strong thunderstorms.  The strongest winds are occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Storm.  Storms near the core were generating strong upper level divergence which was pumping mass away from the hurricane in all directions.

Hurricane Norman has a small circulation.  Winds to hurricane force extend out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force only extend out about 80 miles (130 km) from the center.  The Hurricane Intensity Index (HII) for Norman is 31.6.  The Hurricane Size Index (HSI) is 8.6 and the Hurricane Wind Intensity Size Index (HWISI) is 40.2.  Hurricane Norman is a small, but powerful hurricane.

Hurricane Norman will remain in a very favorable environment for another day or so.  Norman 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 Norman could strengthen a little more during the next 24 hours unless an eyewall replacement cycle begins.  Norman is likely to move over slightly cooler water during the weekend and there may not be enough energy to maintain such a powerful hurricane.

Hurricane Norman will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Norman a little to the south of a due westerly course.  On its anticipated track Hurricane Norman will move toward the Central Pacific.

Elsewhere over the Central Pacific Ocean, Hurricane Miriam turned toward the north-northwest.  At 5:00 p.m. EDT on Thursday the center of Hurricane Miriam was located at latitude 15.7°N and longitude 141.6°W which put it about 930 miles (1495 km) east-southeast of Hilo, Hawaii.  Miriam was moving toward the north-northwest at 8 m.p.h. (13 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 982 mb.

Miriam and Norman Become Hurricanes

Both former Tropical Storm Miriam and Tropical Storm Norman strengthened into hurricanes over the Eastern North Pacific on Wednesday afternoon.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Miriam was located at latitude 14.0°N and longitude 139.7°W which put it about 1090 miles east of Hilo, Hawaii.  Miriam was moving toward the west at 9 m.p.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 992 mb.

At 5:00 p.m. EDT on Wednesday the center of Hurricane Norman was located at latitude 17.6°N and longitude 116.9°W which put it about 545 miles (875 km) southwest of the southern tip of Baja California.  Norman was moving toward the west at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts t0 90 m.p.h. (145 km/h).  The minimum surface pressure was 987 mb.

An inner rainband wrapped much of the way around the center of circulation and an eye developed at the center  of Hurricane Miriam on Wednesday.  Storms near the core of Miriam generated strong upper level divergence which pumped mass away from the hurricane.  Several bands of showers and thunderstorms were revolving around the core of the circulation.  The strongest rainbands were south and east of the center of Hurricane Miriam.  Rainbands on the northwest side of the circulation contained more showers and low clouds.

An inner rainband also wrapped most of the way around the center of Hurricane Norman on Wednesday and an eye appeared to be forming at the center of circulation.  Several bands of showers and thunderstorms were revolving around the core of Norman.  The distribution of thunderstorms in Norman was more symmetrical.  Storms around the core of Hurricane Norman were generating well developed upper level divergence.

Both Hurricane Miriam and Hurricane Norman were moving south of a subtropical ridge over the Eastern North Pacific Ocean.  Miriam could reach the end of the ridge in the next day or two and turn toward the north.  The ridge is forecast to steer Hurricane Norman westward during the next two or three days.

Hurricane Miriam will approach an upper level trough east of Hawaii.  The trough will produce southwesterly winds which will increase vertical wind shear.  The shear is forecast to cause Miriam to weaken.  Hurricane Norman will move over water where the Sea Surface Temperature is near 28°C.  Norman will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Norman is forecast to intensify into a major hurricane.