Tag Archives: Hilo

Possible Development East-Northeast of Hawaii

The National Hurricane Center (NHC) indicated that a low pressure system over the Eastern North Pacific Ocean east-northeast of Hawaii could develop into a subtropical or a tropical cyclone during the next 48 hours. The low pressure system is currently designated as Invest 90E. At 1:00 p.m. EST on Thursday the center of Invest 90E was located at latitude 21.8°N and longitude 136.1°W which put it about 1280 miles (2065 km) east-northeast of Hilo, Hawaii. It was moving toward the west-northwest at 12 m.p.h. (19 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 1006 mb.

The National Hurricane Center issued a Special Tropical Weather Outlook on Thursday afternoon which indicated that a low pressure system over the Eastern North Pacific Ocean had a 40% probability of development into a subtropical or a tropical cyclone during the next 48 hours. The low pressure system has been moving slowly toward the west between Baja California and Hawaii. The low pressure system currently has a hybrid structure. A well organized low level center of circulation was evident on visible satellite images. The low level center was located just to the east of a low pressure system in the middle and upper troposphere. The upper low was producing southerly winds that were blowing toward the top of the low level circulation. Those winds were causing moderate vertical wind shear and the wind shear was affecting the structure of the system. The strongest thunderstorms were occurring in bands north and east of the low level center of circulation. Bands south and west of the low level center consisted primarily of showers and lower clouds.

Invest 90E will move through an environment somewhat favorable for the formation of a subtropical or a tropical cyclone during the next 24 hours. The surface center of circulation will move over water where the Sea Surface Temperatures are near 24˚C. Since the upper low contains colder air, that water temperature is warm enough to support the development of a subtropical or a tropical cyclone. The low in the middle and upper troposphere will continue to cause moderate vertical wind shear. The wind shear will inhibit the development of a tropical cyclone. The current hybrid structure of Invest 90E and the marginally warm Sea Surface Temperatures would favor the development of a subtropical cyclone. However, if the strength of the upper level winds decreases, then a tropical cyclone could form.

Invest 90E will move south of a surface high pressure system over the Eastern North Pacific Ocean. The high pressure system will steer the low level center of circulation toward the west-northwest during the next 24 hours. On its anticipated track Invest 90E will move slowly toward the Central Pacific Ocean.

Tropical Storm Jimena Develops East-southeast of Hawaii

Tropical Storm Jimena developed east-southeast of Hawaii on Thursday morning. At 5:00 a.m. EDT on Thursday the center of Tropical Storm Jimena was located at latitude 15.5°N and longitude 136.6°W which put it about 1265 miles (2040 km) east-southeast of Hilo, Hawaii. Jimena was moving toward the northwest at 7 m.p.h. (11 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 former Tropical Depression Nine-E on Thursday morning and the National Hurricane Center upgraded the system to Tropical Storm Jimena. The circulation around Jimena was asymmetrical. Many of the stronger thunderstorms were developing in the eastern half of Tropical Storm Jimena. Bands in the western half of Jimena consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 40 miles (65 km) in the northeastern quadrant of the circulation. The winds in the other parts of Jimena were blowing at less that tropical storm force.

Tropical Storm Jimena will move through an environment only marginally favorable for intensification during the next 24 hours. Jimena will move over water where the Sea Surface Temperatures are near 26°C. It will move through an area where the upper level winds are weak and there will be little vertical wind shear. Tropical Storm Jimena will move over cooler water on Friday. Jimena could strengthen a little during the next 24 hours, but it is likely to weaken when it moves over cooler water.

Tropical Storm Jimena will move around the southern side of a subtropical high pressure system over the Eastern North Pacific Ocean. The high will steer Jimena toward the west-northwest during the next several days. On its anticipated track Tropical Storm Jimena could be east-northeast of Hawaii in a few days.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Hilda was weakening to the northeast of Tropical Storm Jimena. At 5:00 a.m. EDT on Thursday the center of Tropical Storm Hilda was located at latitude 20.1°N and longitude 129.2°W which put it about 1255 miles (2020 km) west of the southern tip of Baja California. Hilda was moving toward the west-northwest at 9 m.p.h. (15 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.

Hurricane Felicia and Tropical Storm Guillermo Weaken

Both Hurricane Felicia and Tropical Storm Guillermo weakened on Monday morning. At 11:00 a.m. EDT on Monday the center of Hurricane Felicia was located at latitude 16.3°N and longitude 132.3°W which put it about 1515 miles (2435 km) east of Hilo, Hawaii. Felicia was moving toward the west at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h). The minimum surface pressure was 990 mb.

Hurricane Felicia weakened rapidly on Monday morning. Felicia moved over water where the Sea Surface Temperatures was near 26°C. The air over the cooler water was also drier. When the drier air entered the small circulation around Hurricane Felicia, thunderstorms in the eyewall and in the rainbands weakened. The eye at the center of Felicia filled with lower clouds. Many of the bands consisted primarily of showers and lower clouds. The strongest thunderstorms were occurring in a small area east of the center of circulation. Winds to hurricane force extended out 15 miles (25 km) from the center. Winds to tropical storm force extended out 45 miles (75 km) from the center of circulation.

Hurricane Felicia will continue to weaken during the next several days. Felicia will move over water where the Sea Surface Temperatures are near 26°C. It will continue to be an environment where the air is relatively dry, which will inhibit the formation of thunderstorms. An upper level trough near Hawaii will produce southwesterly winds that will blow across the top of Felicia. Those winds will cause moderate vertical wind shear and the wind shear will cause Felicia to weaken faster. Hurricane Felicia could weaken to a tropical depression by Tuesday night.

Hurricane Felicia will move south of a subtropical high pressure system over the Eastern North Pacific Ocean. The high will steer Felicia toward the west during the next several days. On its anticipated track the remnants of Hurricane Felicia could pass south of Hawaii at the end of the week.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Guillermo also weakened on Monday morning. At 11:00 a.m. EDT on Monday the center of Tropical Storm Guillermo was located at latitude 19.1°N and longitude 117.8°W which put it about 575 miles (925 km) west-southwest of the southern tip of Baja California. Guillermo was moving toward the west at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1005 mb.

Hurricane Douglas Prompts Hurricane Warning for Oahu

The approach of Hurricane Douglas prompted the issuance of a Hurricane Warning for Oahu on Saturday afternoon.  At 5:00 p.m. EDT on Saturday the center of Hurricane Douglas was located at latitude 19.5°N and 150.1°W which put it about 325 miles (525 km) east of Hilo, Hawaii.  Douglas was moving toward the west-northwest at 18 m.p.h. (30 km/h).  The maximum sustained wind speed was 90 m.p.h. (150 km/h) and there were wind gusts to 110 m.p.h. (175 km/h).  The minimum surface pressure was 984 mb.

A Hurricane Warning was in effect for Oahu.  Hurricane Watches were in effect for Hawaii, Maui, Lanai, Molokai and Kahoolawe.  Tropical Storm Warnings were in effect for Hawaii, Maui, Lanai, Molokai and Kahoolawe.  Tropical Storm Watches were in effect for Kauai and Niihau.

Hurricane Douglas weakened gradually on Saturday as it moved over cooler water.  Douglas was moving over water where the Sea Surface Temperature was near 25°C.  As a result of the cooler water, thunderstorms did not grow as high in the atmosphere.  There was still an eye at the center of circulation, but breaks began to appear in the ring of storms around the eye.  Most of the stronger thunderstorms were in the northern half of the circulation.  Bands in the southern half of the circulation consisted mainly of showers and lower clouds.   Winds to hurricane force extended out about 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out about 110 miles (175 km) from the center.

Hurricane Douglas will move around the southern side of a subtropical high pressure system over the North Pacific Ocean.  The high will steer Douglas toward the west-northwest during the next several days.  On its anticipated track Hurricane Douglas will pass north of the Big Island of Hawaii on Sunday morning.  The core of Douglas could pass near Oahu on Sunday night.

Hurricane Douglas will bring gusty winds to the Hawaiian Islands.  The strongest winds could occur on Oahu.  Winds speeds will be greater at higher elevations.  Douglas could drop heavy rain on the sides of the islands where the wind blows up the slopes.  Flash flooding will be possible.

Hurricane Douglas Prompts Watches for Hawaii

Hurricane Douglas prompted the issuance of Hurricane Watches for some of the Hawaiian Islands on Friday afternoon.  At 5:00 p.m. EDT on Friday the center of Hurricane Douglas was located at latitude 17.0°N and longitude 143.5°W which put it about 785 miles (1260 km) east of Hilo, Hawaii.  Douglas was moving toward the west-northwest at 18 m.p.h. (30 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 967 mb.

Hurricane Watches were issued for Hawaii, Maui, Lanai, Molokai and Kahoolawe.

Hurricane Douglas continued on a track toward the Hawaiian Islands on Friday, which prompted the issuance of Hurricane Watches.  Douglas was weakening slowly as it moved over slightly cooler water.  In addition, Hurricane Douglas appeared to go through an eyewall replacement cycle which may have contributed to the weakening.  Even though it had weakened, Douglas remained a powerful, well organized hurricane.  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.  Bands of showers and thunderstorms were revolving around the core of Hurricane Douglas.  Storms near the core were generating upper level divergence which was pumping mass away from the hurricane.

Winds to hurricane force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 120 miles (195 km) from the center of Douglas.  The Hurricane Intensity Index (HII) for Hurricane Douglas was 20.6.  The Hurricane Size Index (HSI) was 9.9 and the Hurricane Wind Intensity Size Index (HWISI) was 30.5.  Hurricane Douglas was capable of causing localized major damage.

Hurricane Douglas will move through an environment less favorable for major hurricanes during the next several days.  Douglas will move over water where the Sea Surface Temperature is near 25°C.  So, Hurricane Douglas will not be able to extract as much energy from the upper ocean.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  The lack of wind shear will allow Hurricane Douglas to weaken gradually.

Hurricane Douglas will move south of a subtropical high pressure system over the Eastern and Central North Pacific Ocean.  The high will steer Douglas toward the west-northwest.  On its anticipated track Hurricane Douglas will approach Hawaii on Sunday.

Hurricane Douglas Strengthens to a Major Hurricane

Hurricane Douglas strengthened to a major hurricane on Thursday morning.  At 5:00 a.m. EDT on Thursday the center of Hurricane Douglas was located at latitude 13.1°N and longitude 134.7°W which put it about 1470 miles (2365 km) east-southeast of Hilo, Hawaii.  Douglas was moving toward the west-northwest at 17 m.p.h. (28 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 967 mb.

Hurricane Douglas strengthened rapidly into a major hurricane during the past 24 hours.  A circular eye formed at the center of Douglas.  A ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Hurricane Douglas.  Storms near the core were generating strong upper level divergence which was pumping mass away from the hurricane.  Winds to hurricane force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center.

Hurricane Douglas will move through an environment favorable for intensification during the next 12 to 24 hours.  Douglas 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 Douglas could strengthen on Thursday.  Douglas will start to move over slightly cooler water on Friday.  It is likely to weaken slowly once the core of the circulation moves over the cooler water.

Hurricane Douglas will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high will steer Douglas toward the west-northwest during the next few days.  On its anticipated track Hurricane Douglas could approach Hawaii on Sunday.  Watches could be issued for Hawaii later this week.

Tropical Storm Douglas Strengthens Into a Hurricane

Former Tropical Storm Douglas strengthened into a hurricane east of Hawaii on Wednesday morning.  At 11:00 a.m. EDT on Monday the center of Hurricane Douglas was located at latitude 11.8°N and longitude 129.5°W which put it about 1785 miles (2870 km) east-southeast of Hilo, Hawaii.  Douglas was moving toward the west at 15 m.p.h. (24 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 993 mb.

Former Tropical Storm Douglas exhibited more organization on satellite images.  The inner end of a rainband wrapped around the center of circulation and an eye was visible intermittently on satellite images.  Bands of showers and thunderstorms were revolving around the center of Hurricane Douglas.  Storms near the center were generating upper level divergence which was pumping mass away from the hurricane.  Winds to hurricane force extended out 20 miles (30 km) from the center of circulation.  Winds to tropical storm force extended out 80 miles (130 km) from the center.

Hurricane Douglas will move through an environment favorable for intensification during the next several days.  Douglas will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Douglas will continue to intensify and it could strengthen into a major hurricane.

Hurricane Douglas will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high will steer Douglas toward the west-northwest.  On its anticipated track Hurricane Douglas could approach Hawaii on Sunday.  Watches could be issued for Hawaii later this week when Douglas moves closer.

Tropical Storm Douglas Strengthens Quickly

Tropical Storm Douglas strengthened quickly over the Eastern North Pacific Ocean on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Douglas was located at latitude 12.4°N and longitude 124.2°W which put it about 2110 miles (3390 km) east of Hilo, Hawaii.  Douglas was moving toward the west-southwest at 15 m.p.h. (24 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 998 mb.

The circulation around Tropical Storm Douglas exhibited much better organization on Tuesday morning.  The inner end of a rainband wrapped around the southern and eastern sides of the center of circulation.  Bands of showers and thunderstorms were revolving around around the center of Douglas.  The strongest bands were in the southern half of Tropical Storm Douglas.  Storms near the center of circulation were generating upper level divergence which was pumping mass away from the tropical storm.  Winds to tropical storm force extended out about 40 miles (65 km) from the center of Douglas.

Tropical Storm Douglas will move through an environment favorable for intensification during the next several days.  Douglas will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Douglas is likely to intensify into a hurricane during the next 24 hours and it could strengthen into a major hurricane later this week.

Tropical Storm Douglas will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high is likely to steer Douglas toward the west-northwest during the next few days.  On its anticipated track Tropical Storm Douglas could approach Hawaii by late in the weekend.

Elsewhere over the Eastern North Pacific Ocean, Tropical Depression Seven-E weakened over cooler water east of Hawaii.  At 11:00 a.m. EDT on Tuesday the center of Tropical Depression Seven-E was located at latitude 19.3°N and longitude 134.1°W which put it about 1575 miles (2535 km) west of the southern tip of Baja California.  The depression was moving toward west at 13 m.p.h. (20 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 1009 mb.

Tropical Storm Boris Develops East-Southeast of Hawaii

Tropical Storm Boris developed east-southeast of Hawaii on Thursday afternoon.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Boris was located at latitude 11.2°N and longitude 137.1°W which put it about 1330 miles (2145 km) east-southeast of Hilo, Hawaii.  Boris was moving toward the west-northwest at 9 m.p.h. (15 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 Thursday afternoon near a low pressure system southeast of Hawaii that was previously designated as Tropical Depression Three-E.  A scatterometer on board a satellite detected winds to 40 m.p.h. (65 km) near the center of the low pressure system and the National Hurricane Center designated the system as Tropical Storm Boris.  A band of showers and thunderstorms wrapped around the southern and eastern sides of the center of circulation and the strongest winds were occurring in that band of storms.  A few other short bands of showers and thunderstorms developed in the eastern half of Boris.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out about 50 miles from the center of circulation.

Tropical Storm Boris will move through an environment marginally favorable for intensification during the next 12 to 24 hours.  Boris will move over water where the Sea Surface Temperature is near 26.5°C.  A large upper level trough between Hawaii and the West Coast of the U.S. will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear and the shear will limit intensification.  In addition, there is drier air north and west of Tropical Storm Boris.  Boris could intensify during the next 12 hours in spite of the moderate vertical wind shear and drier air.  However, Tropical Storm Boris will move into a region where the upper level winds are stronger during the weekend.  When the vertical wind shear increases, Boris will weaken.

Tropical Storm Boris will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The will steer Boris toward the west-northwest during the next 24 hours.  When Tropical Storm Boris weakens during the weekend, it will be steered by winds closer to the surface.  Those winds will steer Boris toward the west.  On its anticipated track the weakening Tropical Storm Boris will pass southeast of Hawaii.

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.