Tag Archives: Hilo

Tropical Storm Akoni Develops Southeast of Hawaii

Tropical Storm Akoni developed southeast of Hawaii on Thursday.  At 7:00 p.m. EDT on Thursday the center of Tropical Storm Akoni was located at latitude 12.2°N and longitude 144.8°W which put it about 855 miles (1380 km) southeast of Hilo, Hawaii.  Akoni was moving toward the west 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 1003 mb.

More thunderstorms developed near an area of low pressure southeast of Hawaii on Thursday and the Central Pacific Hurricane Center designated it as Tropical Storm Akoni when satellites indicated there were winds to tropical storm force.  The circulation around Tropical Storm Akoni was still organizing.  Bands of showers and thunderstorms were forming.  The strongest rainbands were in the southern half of the circulation.  Bands in the northern half of the circulation were not as strong.  Winds to tropical storm force extended out about 70 miles (110 km) from the center of circulation.

Tropical Storm Akoni will move through an environment favorable for intensification during the next several days.  Akoni will move over water where the Sea Surface Temperature is near 28°C.  It will move southeast of an upper level trough northeast of Hawaii.  The trough will produce southwesterly winds which will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Storm Akoni is forecast to strengthen gradually during the next several days.

Tropical Storm Akoni will move south of a subtropical high pressure system over the eastern and central Pacific Ocean.  The high will steer Akoni toward the west-northwest.  On its anticipated track Tropical Storm Akoni will be south of Hawaii on Sunday.

Elsewhere, Hurricane Juliette was weakening slowly southwest of Baja California.  At 5:00 p.m. EDT on Thursday the center of Hurricane Juliette was located at latitude 21.3°N and 120.8°W which put it about 870 miles (1380 km) west-southwest of the southern tip of Baja California.  Juliette was moving toward the northwest at 12 m.p.h. (19 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 980 mb.

Tropical Storm Gil Forms Over Eastern North Pacific

Tropical Storm Gil formed over the Eastern North Pacific Ocean on Saturday.  A scatterometer onboard a satellite found winds to tropical storm force northeast of the center of former Tropical Depression Eight-E and the National Hurricane Center designated the system as Tropical Storm Gil.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Gil was located at latitude 15.0°N and longitude 122.4°W which put it about 980 miles (1580 km) west-southwest of the southern tip of Baja California.  Gil was moving toward the west-northwest 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 about 50 m.p.h. (80 km/h).  The minimum surface pressure was 1006 mb.

The circulation around Tropical Storm Gil was asymmetrical.  There was a distinct low level center of circulation which was visible on satellite imagery.  However, the stronger thunderstorms were occurring east of the center of circulation.  Bands in the western half of Gil consisted primarily of showers and lower clouds.  An upper level trough south of California was producing strong westerly winds which were blowing across the top of the circulation.  The winds were causing strong vertical wind shear and they were contributing to the asymmetrical distribution of thunderstorms.  Tropical storm force winds were occurring within 80 miles (130 km) of the center of Tropical Storm Gil only in the northeastern quadrant of of the circulation.

Tropical Storm Gil will move through an environment only marginally favorable for intensification.  Gil will move over water where the Sea Surface Temperature is near 27°C.  However, the upper level trough will continue to cause significant vertical wind shear.  The strong vertical wind shear will inhibit intensification of Tropical Storm Gil.  Gil could weaken to a tropical depression if the shear increases.

Tropical Storm Gil will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Gil in a westward direction during the next several days.  On its anticipated track, Tropical Storm Gil will move farther away from Mexico.

Elsewhere over the Central Pacific Ocean, strong vertical wind shear was weakening Tropical Storm Erick and Tropical Storm Flossie.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Erick was located at latitude 17.3°N and longitude 163.9°W which put it about 480 miles (770 km) southwest of Honolulu, Hawaii.  Erick was moving toward the west at 13 m.p.h. (20 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.

At 5:00 p.m. EDT on Saturday the center of Tropical Storm Flossie was located at latitude 18.8°N and longitude 144.5°W which put it about 695 miles (1115 km) east of Hilo, Hawaii.  Flossie was moving toward the west-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 1003 mb.

Weakening Tropical Storm Erick Passes South of Hawaii

A weakening Tropical Storm Erick was passing south of Hawaii on Friday.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Erick was located at latitude 16.8°N and longitude 157.4°W which put it about 310 miles (505 km) south of Honolulu, Hawaii.  Erick was moving toward the west-northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 1000 mb.

An upper level trough northwest of the Hawaii Islands was producing strong southwesterly winds which were blowing across the top of Tropical Storm Erick.  Those winds were causing strong vertical wind shear, which was causing Erick to weaken quickly.  Most of the thunderstorms were occurring in bands northeast of the center of circulation.  Bands near the center and in other parts of Tropical Storm Erick consisted primarily of showers and lower clouds.  The stronger winds were occurring in the northern half of the circulation.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

A Flash Flood Watch was in effect for the Big Island of Hawaii through Saturday morning.  Counterclockwise flow around Tropical Storm Erick was producing southeasterly which were blowing up the slopes on the Big Island.  The enhanced rising will also increase rainfall on those slopes and flash floods could occur in some locations.

Elsewhere, Tropical Storm Flossie was showing signs of strengthening back into a hurricane.  An eye appeared to be forming at the center of Flossie.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Flossie was located at latitude 17.1°N and longitude 137.8°W which put it about 1145 miles (1845 km) east of HIlo, Hawaii.  Flossie was moving toward the west-northwest at 17 m.p.h. (28 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 993 mb.

Erick Rapidly Intensifies Into Major Hurricane

Erick rapidly intensified into a major hurricane over the the Central Pacific Ocean during Monday night.  At 11:00 a.m. EDT on Tuesday the center of Hurricane Erick was located at latitude 13.4°N and longitude 142.8°W which put it about 920 miles (1485 km) east-southeast of Hilo, Hawaii.  Erick was moving toward the west at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 140 m.p.h. (225 km/h).  The minimum surface pressure was 966 mb.

The core of Hurricane Erick intensified rapidly during the overnight hours.  The eye became more circular and distinct on infrared satellite images.  The diameter of the eye was about 12 miles (19 km) on Tuesday morning.  Thunderstorms in the ring around the eye grew taller and the wind speed around the eye increased quickly.  Storms around the core of Erick generated strong upper level divergence which pumped mass away from the hurricane.  Multiple bands of showers and thunderstorms were revolving around the core of the circulation.

The circulation around Hurricane Erick was relatively small.  Winds to hurricane force were occurring within 25 miles (40 km) of the center of circulation.  Winds to tropical storm force extended out about 100 miles (160 km) of the center.  The Hurricane Intensity Index (HII) for Hurricane Erick was 20.6.  The Hurricane Size Index (HSI) was 8.2 and the Hurricane Wind Intensity Size Index (HWISI) was 28.8.

Hurricane Erick will remain in an environment favorable for intensification for about another 24 hours.  Erick 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 during the next day or so.  Hurricane Erick will approach an upper level trough east of Hawaii on Wednesday.  The trough will produce stronger southwesterly winds which will cause the vertical wind shear to increase.  Hurricane Erick will start to weaken when the wind shear increases.

Hurricane Erick will move south of a subtropical high pressure system over the Eastern and Central North Pacific Ocean.  The high will steer Erick toward the west during the next several days.  On its anticipated track Hurricane Erick could be south of Hawaii on Thursday night.

Elsewhere, Tropical Storm Flossie was nearing hurricane strength over the Eastern North Pacific Ocean.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Flossie was located at latitude 12.2°N and longitude 120.5°W which put it about 1015 mile (1635 km) southwest of the southern tip of Baja California.  Flossie was moving toward the west at 15 m.p.h. (24 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 999 mb.

Hurricane Erik and Tropical Storm Flossie Strengthen

Hurricane Erick and Tropical Storm Flossie both moved westward and strengthened over the Eastern North Pacific Ocean on Monday.  At 11:00 p.m. EDT on Monday the center of Hurricane Erick was located at latitude 12.7°N and longitude 140.0°W which put it about 1110 miles (1790 km) east-southeast of Hilo, Hawaii.  Erick was moving west 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. (145 km/h).  The minimum surface pressure was 990 mb.

The circulation around Hurricane Erick exhibited greater organization on Monday.  A small eye developed at the center of circulation.  The eye was surround by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms,  Winds to hurricane force extended out about 20 miles (30 km) from the center of circulation.  Bands of showers and thunderstorms were revolving around the core of Hurricane Erick.  Storms near the core were generating upper level divergence which was pumping mass away from the hurricane.  Winds to tropical storm force extended out about 70 miles (110 km) from the center.

Hurricane Erick will move through an environment favorable for intensification during the next 48 hours.  Erick 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 Erick will intensify during the next two days and it could strengthen into a major hurricane.  Eventually, Erick will approach an upper level trough east of Hawaii and the vertical wind shear will increase.

Hurricane Erick will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high will steer Erick toward the west. On its anticipated track Hurricane Erick could be southeast of Hawaii on Thursday.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Flossie was also intensifying.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Flossie was located at latitude 12.3°N and longitude 117.8°W which put it about 895 miles (1445 km) southwest of the southern tip of Baja California.  Flossie was moving toward the west at 17 m.p.h. (28 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 1001 mb.  Tropical Storm Flossie is also forecast to move westward and strengthen.

Tropical Storm Erick Forms Over Eastern North Pacific

Tropical Storm Erick formed over the Eastern North Pacific Ocean on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Erick was located at latitude 11.9°N and longitude 126.8°W which put it about 1955 miles (3145 km) east-southeast of Hilo, Hawaii.  Erick was moving toward the west at 17 m.p.h. (28 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 low pressure system over the Eastern North Pacific Ocean and the National Hurricane Center designated the system as Tropical Storm Erick.  The circulation around Erick was still organizing.  A small cluster of thunderstorms formed near the center of circulation and the strongest winds were occurring in that cluster.  Winds to tropical storm force extended out about 25 miles (40 km) from the center of circulation.  Bands of showers and thunderstorms were developing and the bands were beginning to revolve around the center of Tropical Storm Erick.  Storms near the center of circulation were starting to generate upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Erick will move through an environment favorable for intensification during the next 48 to 72 hours.  Erick will move over water where the Sea Surface Temperature is near 27.5°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Erick will strengthen and it could become a hurricane within 48 hours.  Erick could intensify more rapidly if an eye and eyewall form.

Tropical Storm Erick will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The subtropical high will steer Erick toward the west-northwest during the next few days.  On its anticipated track Tropical Storm Erick could be southeast of Hawaii in four or five days.

Tropical Storm Cosme Forms Southwest of Baja California

Tropical Storm Cosme formed southwest of Baja California on Saturday.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Cosme was located at latitude 15.6°N and longitude 115.7°W which put it about 630 miles (1015 km) southwest of the southern tip of Baja California.  Cosme was moving toward the west-northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 1001 mb.

The National Hurricane Center (NHC) determined on Saturday that a distinct center of circulation had developed in a broader area of lower pressure and NHC designated the system as Tropical Storm Cosme.  The distribution of thunderstorms around Tropical Storm Cosme was asymmetrical.  The stronger thunderstorms were occurring in bands in the eastern half of the circulation.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  An upper level trough near Baja California was producing strong southwesterly winds which were blowing across the top of the circulation.  Those winds were causing strong vertical wind shear and they were probably the reason for the asymmetrical distribution of thunderstorms.  Winds to tropical storm force extended out about 150 miles (240 km) from the center of circulation.

Tropical Storm Cosme will move through an environment that is not favorable for significant intensification.  Cosme will move over water where the Sea Surface Temperature is near 26°C.  The upper level trough will continue to produce southwesterly winds that will blow toward the top of Tropical Storm Cosme.  The upper level winds are likely to weaken somewhat, but they will continue to cause vertical wind shear.  Tropical Storm Cosme could intensify a little during the next 24 hours, but it is not likely to strengthen significantly.

Tropical Storm Cosme will move south of a subtropical high pressure system over Eastern North Pacific Ocean.  The high will steer Cosme toward the west-northwest.  On its anticipated track Tropical Storm Cosme is forecast to remain well to the west of Baja California.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Barbara continued to weaken as it moved toward Hawaii.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Barbara was located at latitude 18.7°N and longitude 139.2°W which put it about 1040 miles (1670 km) east of Hilo, Hawaii.  Barbara was moving toward the west at 17 m.p.h. (28 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 1000 mb.

Barbara Weakens to a Tropical Storm

Former Hurricane Barbara weakened to a tropical storm on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Barbara was located at latitude 18.6°N and longitude 134.7°W which put it about 1330 miles (2145 km) east of Hilo, Hawaii.  Barbara was moving toward the west-northwest at 13 m.p.h. (20 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 997 mb.

The effects of vertical wind shear and cooler Sea Surface Temperatures caused former Hurricane Barbara to weaken quickly to a tropical storm on Friday.  An upper level trough northeast of Hawaii produced strong southwesterly winds which blew the upper portion of the circulation north of the remainder of the tropical storm.  In addition, Tropical Storm Barbara moved over water where the Sea Surface Temperature was near 25°C which meant there was less energy to support the development of taller thunderstorms.  Tropical Storm Barbara still had a well formed circulation in the lower levels of the atmosphere.  However, as a result of the strong shear and cooler water, bands consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out about 140 miles (220 km) from the center of circulation.

Tropical Storm Barbara will continue to move over cooler water and through a region of strong vertical wind shear during the next several days.  Barbara will continue to weaken and it could be a tropical depression on Saturday.

Since Tropical Storm Barbara contains few tall thunderstorms, it is being steered by winds closer to the surface.  A subtropical high pressure system north of Barbara will steer the tropical storm toward the west.  On its anticipated track Tropical Storm Barbara will move toward Hawaii.

Hurricane Barbara Starts to Weaken

Hurricane Barbara started to weaken on Wednesday when it moved over cooler water well to the east of Hawaii.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Barbara was located at latitude 14.3°N and longitude 127.5°W which put it about 1860 miles (2990 km) east of Hilo, Hawaii.  Barbara was moving toward the west-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 140 m.p.h. (220 km/h) and there were wind gusts to 170 m.p.h. (275 km/h).  The minimum surface pressure was 941 mb.

The circulation around Hurricane Barbara remained very well organized.  There was a circular eye at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Barbara.  Storms near the core of the circulation were generating strong upper level divergence which was pumping mass away from the hurricane.  Winds to hurricane force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 185 miles (295 km) from the center.

Hurricane Barbara still rated at Category 4 on the Saffir-Simpson Scale.  The Hurricane Intensity Index (HII) for Barbara was 28.3.  The Hurricane Size Index (HSI) was 16.5 and the Hurricane Wind Intensity Size Index (HWISI) was 44.8.

Hurricane Barbara will gradually move into an environment less capable of supporting a strong hurricane during the next few days.  Barbara will move over water where the Sea Surface Temperature is near 26°C.  As a result, Hurricane Barbara will extract less energy from the upper ocean and it will gradually weaken.  Barbara will move closer to an upper level trough located northeast of Hawaii.  When Hurricane Barbara gets closer to the trough later this week, stronger upper level southwesterly winds will create more vertical wind shear and the hurricane will weaken more quickly.

Hurricane Barbara will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Barbara toward the west-northwest during the next 24 to 36 hours.  The ridge is forecast to strengthen on Friday and it will steer Hurricane Barbara more toward the west when that happens.  On its anticipated track Barbara could approach Hawaii in about five days.  It will be much weaker by that time.

Hurricane Olivia Causes Tropical Storm Watches for Hawaii

The potential impacts of Hurricane Olivia caused the issuance of Tropical Storm Watches for Hawaii on Sunday night.  Tropical Storm Watches were issued for Oahu, Maui County including Maui, Molokai, Lanai, and Kahoolawe, and Hawaii County.  At 11:00 p.m. EDT on Sunday the center of Hurricane Olivia was located at latitude 21.4°N and longitude 146.1°W which put it about 595 miles (960 km) east-northeast of Hilo, Hawaii.  Olivia was moving toward the west 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 988 mb.

Hurricane Olivia maintained its intensity and structure on Sunday.  A circular eye persisted at the center of circulation and a ring of thunderstorms surrounded the eye.  The strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Olivia.  Winds to hurricane force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 125 miles (200 km) from the center.

Hurricane Olivia will move through a less favorable environment during the next several days.  Olivia will move over water where the Sea Surface Temperature is near 26°C.  So, there will be enough energy in the upper ocean to support a hurricane.  However, an upper level trough north of Hawaii will produce southwesterly winds which will blow toward the top of Hurricane Olivia.  Those winds will cause more vertical wind shear and Hurricane Olivia could weaken to a tropical storm as it approaches Hawaii.

Hurricane Olivia will move south of a subtropical high pressure system over the Central Pacific Ocean.  The high is forecast to strengthen and it will steer Olivia on a west-southwesterly track.  On its anticipated track Olivia could approach Hawaii late on Tuesday.  Olivia will bring gusty winds and it could cause power outages.  Locally heavy rain and the potential for flash floods are greater risks.