Tag Archives: Hilo

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.

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.

Tropical Storm Norman Forms Southwest of Baja California

Tropical Storm Norman formed southwest of Baja California on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Norman was located at latitude 17.5°N and longitude 113.9°W which put it about 455 miles (730 km) southwest of the southern tip of Baja California.  Norman was moving toward west-northwest at 10 m.p.h. (16 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.

The circulation of Tropical Storm Norman organized quickly on Wednesday.  A distinct low level center of circulation developed in an area of thunderstorms southwest of Baja California and the National Hurricane Center designated the system as Tropical Storm Norman.  A primary rainband wrapped part of the way around the center of circulation.  Several other bands of showers and thunderstorms formed and began to revolve around the core of Norman.  Storms near the core started to generate strong upper level divergence which was pumping mass away from the tropical storm in all directions.

Tropical Storm Norman will be moving through an environment favorable for intensification during the next several days.  Norman will move over water where the Sea Surface Temperature is near 29°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Norman could intensify to a hurricane in the next 24 hours.  Once an eye forms and the inner core is full organized, Norman could intensify rapidly.  It could strengthen into a major hurricane later this week.

Tropical Storm Norman will move south of a subtropical ridge over the Eastern North Pacific during the next few days.  The ridge will steer Norman in a general westerly direction.  On its anticipated track Tropical Storm Norman will move toward the Central Pacific.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Miriam continued to move westward.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Miriam was located at latitude 14.1°N and longitude 137.4°W which put it about 1230 miles (1980 km) east of HIlo, Hawaii.  Miriam was moving toward the west 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 1000 mb.

Hurricane Lane Drops Heavy Rain on Hawaii

Hurricane Lane dropped heavy rain on Hawaii on Thursday.  The airport in Hilo, Hawaii reported 14.02 inches (356 mm) of rain during the past 24 hours.  At 11:00 p.m. EDT Thursday the center of Hurricane Lane was located at latitude 17.8°N and longitude 157.9°W which put it about 240 miles (390 km) south of Honolulu, Hawaii.  Lane was moving toward the north-northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 140 m.p.h. (225 km/h).  The minimum surface pressure was 959 mb.

Hurricane Warnings were in effect for Oahu and Maui County including the islands of Maui, Lanai, Molokai and Kahoolawe.  A Hurricane Watch was in effect for Kauai County including the islands of Kauai and Niihau.  A Tropical Storm Warning was in effect for Hawaii County.

Hurricane Lane began to weaken on Thursday.  An upper level trough west of Hawaii was producing southwesterly winds which were blowing toward the top of the hurricane.  Those winds were causing moderate vertical wind shear and they were obstructing upper level divergence to the west of Hurricane Lane.  The wind shear prevented the circulation from pumping as much mass away from the hurricane and the surface pressure began to increase.

Hurricane Lane retained a strong circulation in spite of increased vertical wind shear.  Winds to hurricane force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out 125 miles (205 km) from the center.  The core of Hurricane Lane passed over NOAA buoy 51002.  The strongest winds occurred in the northern eyewall.  The buoy measured a sustained wind speed of 83 m.p.h. (133 km/h).  It also reported a wind gust to 105 m.p.h. (170 km/h).  The winds were significantly weaker in the southern half of the circulation.

The upper level trough gradually turned Hurricane Lane more toward the north on Thursday.  A general motion toward the north is forecast for Friday.  On its anticipated track Hurricane Lane could approach Maui and Oahu on Friday night.  Lane is forecast to weaken further during the next 24 hours.  Guidance from numerical models suggests that the weaker circulation will be steered by winds in the lower levels when it nears Maui and Oahu.  The models are forecasting a turn toward the west.  Hurricane Lane could cause gusty winds and power outages.  The greater risk will be caused by the locally heavy rain, which will create the potential for flash floods.  Flash floods may develop very quickly in areas of steep terrain.

Powerful Hurricane Lane Prompts Hurricane Watches for Hawaii

A potential threat from powerful Hurricane Lane prompted the Central Pacific Pacific Hurricane Center to issued Hurricane Watches for parts of Hawaii on Tuesday morning.  Hurricane Watches were issued for Hawaii County and Maui County including the islands of Maui, Lanai, Molokai and Kahoolawe.  At 11:00 a.m. EDT on Tuesday the center of Hurricane Lane was located at latitude 14.1°N and longitude 152.3°W which put it about 620 miles (995 km) southeast of Honolulu, Hawaii.  Lane was moving toward the west at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 180 m.p.h. (290 km/h).  The minimum surface pressure was 950 mb.

The circulation of Hurricane Lane is very well organized.  There is a circular eye at the center of circulation and the eye is surrounded by a ring of strong thunderstorms.  The strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Lane.  A NOAA P-3 aircraft encountered strong turbulence during a mission into Lane last night and the aircraft will be examined before it flies again.  Storms around the core of the circulation were generating strong upper level divergence which was pumping mass away from the hurricane.

Hurricane Lane has a large symmetrical circulation.  Winds to hurricane force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 240 miles (390 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane was 31.6.  The Hurricane Size Index (HSI) was 13.7 and the Hurricane Wind Intensity Size Index (HWISI) was 45.3.  Those indices indicate that Hurricane Lane was stronger and larger than Hurricane Dennis was when Dennis hit the northern Gulf Coast in 2005.

Hurricane Lane will move through an environment capable of supporting a major hurricane for another 24 to 48 hours.  Lane will move over water where the Sea Surface Temperature is between 27°C and 28°C.  It will move through an environment where the upper level winds are weak during the next 24 hours and there will be little vertical wind shear during that time period.  An upper level trough west of Hawaii will move closer to Hurricane Lane on Wednesday.  Southwesterly winds on the eastern side of the trough will increase the vertical wind shear.  Hurricane Lane is likely to weaken on Wednesday, but it could weaken slowly.

Hurricane Lane is moving around the western end of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge has been steering Lane toward the west.  Hurricane Lane will turn more toward the northwest when it reaches the end of the ridge.  The upper level trough could steer Lane more toward the north on Thursday and Friday.  Guidance from forecast models has been trending toward a track closer to Hawaii and that prompted the issuance of Hurricane Watches for some of the Hawaiian Islands.

Major Hurricane Lane Churns Southeast of Hawaii

Major Hurricane Lane churned southeast of Hawaii on Monday.  At 5:00 p.m. EDT on Monday the center of Hurricane Lane was located at latitude 13.6°N and longitude 149.1°W which put it about 580 miles (930 km) southeast of Hilo, Hawaii.  Lane was moving toward the west at 12 m.p.h. (19 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).  Th minimum surface pressure was 964 mb.

There was a circular eye with a diameter of 16 miles (26 km) at the center of Hurricane Lane.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Hurricane Lane.  Storms near the core were generating upper level divergence which was pumping mass away from the hurricane in all directions.

The circulation of Hurricane Lane was relatively compact.  Winds to hurricane force extended out about 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out about 125 miles (205 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Lane was 25.1.  The Hurricane Size Index (HSI) was 10.3 and the Hurricane Wind Intensity Size Index (HWISI) was 35.4.

Hurricane Lane will move through an environment during the next day or two that will allow it to maintain much of its intensity.  Lane 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 relatively weak and there will not be a lot of vertical wind shear.  Hurricane Lane could remain a major hurricane for several more days.  An upper level trough will approach the hurricane from the west in 36 to 48 hours.  Stronger southwesterly winds ahead of the trough will increase vertical wind shear and Hurricane Lane will likely weaken later this week.

Hurricane Lane will move south of a subtropical ridge during the next 24 to 36 hours.  The ridge will steer Lane in a general westerly direction.  The upper level trough approaching from the west will turn Hurricane Lane more toward the northwest.  The timing and sharpness of the turn toward the northwest is still uncertain, but Hurricane Lane could move closer to the Hawaiian Islands during the middle of the week.