Tag Archives: Hawaii

Fernanda Rapidly Intensifies Into a Hurricane

Former Tropical Storm Fernanda rapidly intensified into a hurricane on Thursday.  At 5:00 p.m. EDT on Thursday the center of Hurricane Fernanda was located at latitude 11.2°N and longitude 116.0°W which put it about 900 miles (1450 km) south-southwest of the southern tip of Baja California.  Fernanda 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 95 m.p.h. (155 km/h).  The minimum surface pressure was 990 mb.

A primary rainband wrapped around the center of circulation and an eye appeared intermittently on visible satellite images on Thursday afternoon.  The improved organization of the inner core of Fernanda allowed it to intensify rapidly into a hurricane.  The distribution of thunderstorms become more symmetrical and circulation exhibited a more circular appearance.  Thunderstorms in the inner core began to generate strong upper level divergence which pumped out mass in all directions.  The divergence of mass allowed the surface pressure to decrease and the wind speeds to increase rapidly.

Hurricane Fernanda will move through an environment that will be favorable for further intensification during the next two days.  Fernanda will move over water where the Sea Surface Temperature (SST) is near 29°C.  An upper level ridge northeast of Fernanda is producing easterly winds which are blowing toward the top of the hurricane.  However, the speed of the upper level winds decreased on Thursday and there is less vertical wind shear.  A combination of a well organized inner core, warm SSTs and reduced vertical wind shear resulted in rapid intensification of Fernanda into a hurricane.  Rapid intensification could continue for another 24 to 36 hours and Fernanda is forecast to become a major hurricane on Friday.

A subtropical ridge to the north of Fernanda is steering the hurricane toward the west and a general westerly motion is expected to continue for several more days.  On its anticipated track Hurricane Fernanda will move farther away from Mexico.

TD 6E Strengthens Into Tropical Storm Fernanda

Tropical Depression Six-E strengthened into Tropical Storm Fernanda on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Fernanda was located at latitude 11.9°N and longitude 113.1°W which put it about 790 miles (1270 km) south-southwest of the southern tip of Baja California.  Fernanda was moving toward the west at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1004 mb.

Thunderstorms on the western side of the center of Tropical Storm Fernanda increased on Wednesday night.  Several bands of showers of thunderstorms formed in the western half of the circulation, but the distribution of convection remained asymmetrical.  There were few showers and thunderstorms in the eastern half of the circulation.  The thunderstorms in the western half of the were generating upper level divergence which was pumping out mass to the west of Tropical Storm Fernanda.

Tropical Storm Fernanda is currently in an environment that is moderately favorable for intensification.  It is moving over water where the Sea Surface Temperature (SST) is near 29.5°C.  An upper level ridge north of Fernanda is producing easterly winds which are blowing toward the top of the tropical storm.  Those winds are causing moderate vertical wind shear and the shear may be the cause of the asymmetrical distribution of thunderstorms.  Fernanda is likely to move into an area where the upper level winds are weaker and the shear will decrease.  Warm SSTs and less wind shear should allow Tropical Storm Fernanda to intensify into a hurricane later this week.  Once an eye forms, a period of rapid intensification will be possible and Fernanda could eventually become a major hurricane.

A subtropical ridge north of Fernanda is steering the tropical storm westward and a general westerly motion is expected to continue for the next few days.  On its anticipated track Tropical Storm Fernanda will move away from Mexico and it could move into the Central Pacific in a few days.

Tropical Depression Six-E Forms West of Mexico

The Eastern North Pacific basin continues to be active tropically.  Tropical Depression Six-E formed west of Mexico on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Depression Six-E was located at latitude 12.2°N and longitude 109.9°W which put it about 740 miles (1190 km) south of the southern tip of Baja California.  It was moving toward the west 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 1007 mb.

A center of circulation consolidated within a large area of thunderstorms south of Baja California on Tuesday.  A primary band of showers and thunderstorms wrapped around the western and southern sides of the center of circulation.  Additional bands of showers and thunderstorms were beginning to form north and west of the center.  There were not many showers and storms in the eastern half of the circulation.  The thunderstorms near the core of the circulation were beginning generate upper level divergence which was pumping away from depression.

Tropical Depression Six-E will move through an environment that will be favorable for intensification.  It will move over water where the Sea Surface Temperature (SST) is near 29°C.  Tropical Depression Six-E is near the western end of an upper level ridge and the upper level winds are relatively weak.  Warm SSTs and little vertical wind shear should allow the depression to strengthen during the next several days.  Tropical Depression Six-E is likely to become a tropical storm on Wednesday and it could become a hurricane later this week.

Tropical Depression Six-E is moving south of a subtropical ridge which is steering the depression toward the west.  The subtropical ridge is expected to continue to steer the depression toward the west during the next few days.  On its anticipated track the depression is expected to move away from the coast of Mexico.

Tropical Storm Orlene Develops Rapidly West of Mexico

Tropical Storm Orlene developed rapidly southwest of Baja California on Sunday.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Orlene was located at latitude 16.6°N and longitude 118.3°W which put it about 700 miles (1125 km) southwest of the southern tip of Baja California.  Orlene was moving toward the northwest at 9 m.p.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 Orlene organized quickly on Sunday.  A primary rainband wrapped around the center of circulation and an eye appears to be forming.  Additional spiral bands are rotating around the core of Orlene.  Thunderstorms in the core of Tropical Storm Orlene are generating upper level divergence which is pumping out mass in all directions.  The circulation of Orlene is symmetrical and well formed.

Tropical Storm Orlene is moving through a very favorable environment.  It is moving over water where the Sea Surface Temperature is near 29°C.  The upper level winds are weak and there is little vertical wind shear.  Tropical Storm Orlene will continue to intensify on Monday and it could intensify rapidly for another 24 hours.

Tropical Storm Orlene is moving northwest toward a weakness in the subtropical high and that general motion is expected to continue for another day or two.  Eventually, the subtropical ridge is expected to strengthen and turn Tropical Storm Orlene toward the west.

Hurricane Lester Passing North of Hawaii

Hurricane Lester passed north of Hawaii on Saturday.  All Hurricane Watches were cancelled, although the surf on the north coasts of the islands should be increased by the waves generated by Hurricane Lester.  At 5:00 p.m. EDT on Saturday the center of Hurricane Lester was located at latitude 22.4°N and longitude 155.4°W which put it about 175 miles (285 km) east-northeast of Honolulu, Hawaii.  Lester was moving toward the west-northwest at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 85 m.p.h. (140 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 985 mb.

Hurricane Lester weakened slowly on Saturday as it moved north of the Hawaiian Islands.  An upper level trough northwest of Lester produced southwesterly winds that blew across the top of the hurricane.  The vertical wind shear tilted the circulation toward the northeast with height.  The wind shear also inhibited the upper level divergence to the south of the center of Lester.  Less upper level divergence meant that the hurricane could not pump out as much mass and the surface pressure slowly rose.

Hurricane Lester is moving through an environment that is likely to weaken it further.  Lester is moving over water where the Sea Surface Temperature (SST) is 27°C.  So, there is enough energy to support the hurricane.  However, the upper level trough will continue to create vertical wind shear and the shear will continue to weaken Hurricane Lester.

Hurricane Lester is moving around the western end of a subtropical ridge which is steering toward the west-northwest.  That general motion is expected to continue for several more days.  When Hurricane Lester gets farther north the westerlies in the middle latitudes will turn it toward the northeast.  On its anticipated track Hurricane Lester will stay north of the Hawaiian Islands.

Hurricane Watch Issued for Hawaii as Hurricane Lester Moves Closer

As Hurricane Lester moved steadily closer to Hawaii on Thursday, a Hurricane Watch was issued for Hawaii County and Maui County including Maui, Molokai, Lanai and Kahoolawe.

At 8:00 p.m. EDT on Thursday the center of Hurricane Lester was located at latitude 18.5°N and longitude 145.4°W which put it about 640 miles (1030 km) east of Hilo, Hawaii.  Lester was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 145 m.p.h. (235 km/h).  The minimum surface pressure was 960 mb.

The symmetrical circulation of Hurricane Lester is very well organized.  There is a circular eye with a diameter of 25 miles (40 km).  A ring of strong thunderstorms completely surrounds the eye.  Multiple spiral rainbands are rotating around periphery of the circulation.  Hurricane Lester is generating strong upper level divergence which is pumping mass out in all directions.

Hurricane Lester is currently moving through a favorable environment.  It is over water where the Sea Surface Temperature is near 27°C.  The upper level winds are light and there is little vertical wind shear.  Hurricane Lester will be moving over some of the same water that Hurricane Madeline passed over a few days ago.  If Madeline stirred any cooler water to the surface, it could cause Hurricane Lester to weaken.  When Hurricane Lester gets closer to Hawaii an upper level trough will produce stronger upper level southwesterly winds and the wind shear will increase.  Lester should weaken as it gets closer to Hawaii.

A subtropical ridge has been steering Hurricane Lester toward the west.  The western end of the ridge is expected to weaken and that will cause Lester to move more toward the west-northwest.  On its anticipate track Hurricane Lester could approach Hawaii on Saturday morning.

Hurricane Warning for Hawaii as Madeline Moves Closer

The Central Pacific Hurricane Center issued a Hurricane Warning for Hawaii County (i.e. the Big Island of Hawaii) as Hurricane Madeline moved steadily closer on Tuesday.  A Tropical Storm Watch has been issued for Maui County including Maui, Molokai and Lanai.

At 11:00 p.m. EDT on Tuesday the center of Hurricane Madeline was located at latitude 19.3°N and longitude 150.3°W which put it about 315 miles (505 km) east of Hilo, Hawaii.  Madeline was moving toward the west at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 972 mb.

A subtropical ridge has been steering Hurricane Madeline toward the west.  The ridge is expected to strengthen and steer Madeline more toward the west-southwest for the next day or two.  On its anticipated track Hurricane Madeline could approach the island of Hawaii in about 30 hours.

An upper level trough north of Hawaii has been producing westerly winds which are causing vertical wind shear.  The westerly winds are restricting the upper level divergence to the west of Hurricane Madeline.  However, thunderstorms in the core of the hurricane have strengthened periodically and reduced the impact of the wind shear.  The shear is expected to continue and Hurricane Madeline is forecast to slowly weaken.  However, Madeline is moving over water where the Sea Surface Temperature is near 27°C, and it could move over warmer water if it moves toward the west-southwest.

Madeline is expected to be a hurricane when it moves past the island of Hawaii.  On its anticipated track the greatest threat would be to the southern half of the island.  Madeline is a compact hurricane and winds to hurricane force only extend out about 25 miles (40 km) from the center.  Hurricane Madeline will be capable of causing localized serious wind damage.  It may also produce heavy rain and flash flooding, especially where the wind blows up the slopes.

Major Hurricanes Madeline and Lester Moving Toward Hawaii

Hurricanes Madeline and Lester intensified quickly on Monday into Major Hurricanes as they moved toward Hawaii.  The approach of Hurricane Madeline prompted the Central Pacific Hurricane Center to issue a Hurricane Watch for Hawaii County.  Both hurricanes have the potential to affect the weather around Hawaii during the next few days.

At 5:00 p.m. EDT on Monday the center of Hurricane Madeline was located at latitude 18.6°N and longitude 145.5°W which put it about 630 miles (1015 km) east of Hilo, Hawaii.  Madeline was moving toward the west-northwest at 10 m.p.h. (16 km/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).  That made Hurricane Madeline the equivalent of a Category 3 hurricane on the Saffir-Simpson Scale.  The minimum surface pressure was 966 mb.

At 5:00 p.m. EDT on Monday the center of Hurricane Lester was located at latitude 18.0°N and longitude 130.5°W which put it about 1375 miles (2210 km) west of the southern tip of Baja California.  Lester was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  That made Hurricane Lester a Category 4 hurricane on the Saffir-Simpson Scale.  The minimum surface pressure was 951 mb.

Both Hurricanes Madeline and Lester are relatively compact hurricanes and the winds to hurricane force only extend out about 30 miles (50 km) from the center of circulation.  In Hurricane Madeline the Hurricane Intensity Index (HII) is 20.6.  The Hurricane Size Index (HSI) is 11.4 and the Hurricane Wind Intensity Size Index (HWISI) is 32.0.  Hurricane Lester is stronger, but slightly smaller.  The HII for Hurricane Lester is 25.1, while HSI is 10.3 and HWISI is 35.4.

Both hurricanes have well formed symmetrical eyes surrounded by rings of tall thunderstorms.  Each is producing well developed upper level divergence which is pumping out mass in all directions.  Hurricane Madeline has more spiral rainbands, and Hurricane Lester shows some indications that the structure might be assuming more of the shape of an annular hurricane.

Hurricanes Madeline and Lester responded to a favorable environment by intensifying rapidly on Monday.  The maximum sustained wind speed in Hurricane Madeline increased from 65 m.p.h. (105 km/h) to 115 m.p.h. (185 km/h) during the past 24 hours.  The maximum sustained wind speed in Hurricane Lester increased from 85 m.p.h. (140 km/h) to 130 m.p.h. (215 km/h) during the past 24 hours.

Hurricanes Madeline and Lester will remain in a favorable environment during the short term.  They are moving over water where the Sea Surface Temperatures (SSTs) are near 27.5°C.  The upper level winds are light and there is little vertical wind shear.  Thus, both hurricanes could maintain their intensity for another 12 to 24 hours.  When the hurricanes move closer to Hawaii, they will move over slightly cooler SSTs.  In addition, an upper level trough approaching from the northwest could increase the vertical wind shear later this week.  Hurricane Lester may also move over some cooler water mixed to the surface by Hurricane Madeline.

A subtropical ridge is steering Hurricanes Madeline and Lester toward the west and that general motion is expected to continue for the next several days.  On its anticipated track Hurricane Madeline could approach Hawaii in a couple of days.  Hurricane Lester could approach Hawaii in about five days.

 

Tropical Storm Madeline Forms East of Hawaii

A cluster of thunderstorms between Hawaii and Mexico developed enough organization on Friday night that the National Hurricane Center designated the system as Tropical Storm Madeline.  At 11:00 p.m. EDT on Friday the center of Tropical Storm Madeline was located at latitude 13.9°N and longitude 137.4°W which put it about 1235 miles (1990 km) east-southeast of Hilo, Hawaii.  Madeline 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 50 m.p.h. (80 km/h).  The minimum surface pressure was 1006 mb.

The circulation of Tropical Storm Madeline is still organizing.  A primary spiral band wraps around the western side of the circulation.  There are additional spiral bands of the thunderstorms in the southern part of the tropical storm.  The thunderstorms in the primary rainband are generating upper level divergence which it pumping mass out primarily to the west of tropical storm Madeline.

Tropical Storm Madeline is moving through an environment that is favorable for intensification.  It is moving over water where the Sea Surface Temperature (SST) is near 29°C.  The upper level winds are light and there is not much vertical wind shear.  Tropical Storm Madeline is expected to intensify steadily and it could become a hurricane by the end of the weekend.  In a few days Madeline will move over cooler SSTs and into an area where the is more vertical wind shear.  When that happens, Madeline will start to weaken.

A subtropical high is steering Tropical Storm Madeline toward the west-northwest and a general west-northwest or westerly motion is expected to continue during the next few days.  On its anticipated track Madeline could approach the Hawaiian Islands in about five days.

Tropical Storm Lester Forms West of Mexico

Tropical Storm Lester became the 12th named tropical storm to form over the Eastern North Pacific Ocean during 2016 on Thursday.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Lester was located at latitude 16.9°N and longitude 113.4°W which put it about 470 miles (760 km) south-southwest of the southern tip of Baja California.  Lester was moving toward the west-northwest at 10 m.p.h. (16 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.

Tropical Storm Lester formed when a distinct center of circulation developed within a tropical wave.  The core of the tropical storm is still consolidating.  There are thunderstorms near the center of circulation and there are spiral bands rotating around the core of Tropical Storm Lester.  The thunderstorms near the center are generating upper level divergence which is pumping away may to the south of the tropical storm.  There are hints of the possible formation of an eye on some satellite images.

Tropical Storm Lester is moving through an environment that is generally favorable for intensification.  It is moving over water where the Sea Surface Temperature is around 30°C.  An upper level ridge northwest of Lester is generating northerly winds which are blowing across the top of the tropical storm.  The northerly winds are producing some vertical wind shear, but the shear is only slowing the intensification process.  Tropical Storm Lester is expected to continue to intensify and it could become a hurricane.

A subtropical ridge is steering Tropical Storm Lester toward the west-northwest and that general motion is expected to continue.  On its anticipated track Tropical Storm Lester will move farther away from Mexico and it currently poses no threat to land.