Category Archives: Tropical Cyclones

Information about tropical cyclones

Ana Reaches Hurricane Intensity Near Hawaii

The structure and internal organization of Tropical Storm Ana has increased during the past 12 hours and it has intensified into a hurricane.  At 5:00 p.m. EDT the center of Hurricane Ana was located at latitude 16.4°N and longitude 155.2°W which put it about 230 miles south of Hilo and about 380 miles south-southeast of Honolulu, Hawaii.  Ana was moving toward the west-northwest at 14 m.p.h.  The maximum sustained wind speed was 75 m.p.h. and the minimum surface pressure was 987 mb.

The high pressure system that was steering Ana toward the west is weakening as an upper level trough approaches from the northwest.  The result of the interaction of the two systems is to steer Ana more toward the northwest.  Guidance from numerical models suggests that the center of Ana could stay south of the Hawaiian islands.  A new high pressure system is expected to build north of Ana and turn it back onto a more westward track in a couple of days.  The timing of that turn could determine how much of an effect Ana has on Hawaii.  A deviation of the track farther to the north would cause Ana to have a greater impact.  Tropical Storm Watches have been issued for Hawaii County, for Maui County including the islands of Maui, Molokai, Lanai and Kahoolwe, for Oahu, and for Kauai County including the islands of Kauai and Niihau.

The wind shear over Ana has decreased and some further intensification is possible.  When the upper level trough gets closer to Ana, the wind shear will increase and the hurricane should start to weaken.

Eyewall of Hurricane Gonzalo Is Rapidly Approaching Bermuda

The northern eyewall of Hurricane Gonzalo is approximately 45 miles (72 km) south-southwest of Bermuda.  The strongest winds in a tropical cyclone are normally found in the eyewall and so the weather conditions over Bermuda are likely to deteriorate rapidly during the next few hours.  At 5:00 p.m. EDT the weather station on Bermuda was reporting easterly winds at 45 m.p.h. with gusts to 67 m.p.h.  Heavy rain was falling and the pressure was falling rapidly.  Based on the current motion of Gonzalo, hurricane force winds could reach Bermuda during the next two or three hours.

At 5:00 p.m. EDT the center of Hurricane Gonzalo was located at latitude 31.7°N and longitude 65.3°W which put it about 50 miles southwest of Bermuda.  The maximum sustained wind speed was 115 m.p.h. and the minimum surface pressure was 949 mb.  A Hurricane Warning remains in effect for Bermuda.  The Canadian Hurricane Center has issued a Tropical Storm Watch that extends from Arnolds Cove to Chapels Cove, Newfoundland.

As of 5:00 p.m. EDT the maximum sustained wind speed in Gonzalo was 115 m.p.h.  Southwesterly winds in the upper levels are creating wind shear over Gonzalo, but it is still likely to strike Bermuda as a major hurricane.  A storm surge and wave action could pose a significant risk to the south coast.  High winds could also do damage, especially to exposed structures at higher elevations.

 

Gonzalo Threatens Bermuda As a Major Hurricane

Hurricane Gonzalo completed an eyewall replacement cycle on Wednesday and it is now stronger than it was.  At 8:00 a.m. EDT on Thursday the center of Gonzalo was located at latitude 25.5°N and longitude 68.7°W which put it about 525 miles south-southwest of Bermuda.  Gonzalo was moving toward the north at 9 m.p.h.  The maximum sustained wind speed was 140 m.p.h. which made Gonzalo a Category 4 hurricane on the Saffir-Simpson Scale.  It had a Hurricane Intensity Index of 28.3, a Hurricane Size Index of 13.9 and a HI of 42.2, which means it was capable of producing regional serious damage.  The minimum surface pressure was 940 mb.  A Hurricane Warning has been issued for Bermuda.

Gonzalo is moving around the western end of a high pressure system located toward its east.  Southwesterly winds on the leading edge of an upper level trough over the eastern U.S. are expected to turn Gonzalo toward the north-northeast.  The stronger winds in the upper level trough will also make Gonzalo start to move faster.  Gonzalo is likely to approach Bermuda on Friday afternoon.

Gonzalo is still in a environment that can support a major hurricane.  It is over warm Sea Surface Temperatures (SSTs) and the upper level winds are relatively light.  When the upper level trough begins to affect Gonzalo, stronger winds will generate more wind shear and the hurricane should begin to weaken.  However, Gonzalo could still be a Major Hurricane when it reaches Bermuda.  After Gonzalo moves north of Bermuda, the weakening trend will continue as cooler SSTs and drier air affect the hurricane.  Gonzalo will make a transition to a strong extratropical cyclone as it moves across the North Atlantic.

Gonzalo is forecast to take a track very similar to the one taken by Hurricane Fabian in 2003.  Fabian was a Major Hurricane that hit Bermuda.  Fabian did much damage to roofs and vegetation and it did an estimated 300 million dollars of property damage.  Winds speeds were greater at higher elevations.  Fabian also generated large waves and a storm surge of ten feet on the south shore of Bermuda.

 

Gonzalo Becomes a Major Hurricane

Hurricane Gonzalo intensified more rapidly on Tuesday and it reached Major Hurricane intensity on Tuesday afternoon.  At 11:00 p.m. EDT the center of Hurricane Gonzalo was located at latitude 22.2°N and longitude 66.6°W which put it about 705 miles south of Bermuda.  Gonzalo was moving toward the northwest at 13 m.p.h.  The maximum sustained wind speed was 125 m.p.h., which made Gonzalo a Category 3 hurricane on the Saffir-Simpson Scale.  The minimum surface pressure was 954 mb.  Gonzalo is now the strongest Atlantic hurricane so far in 2014.  A Hurricane Watch has been issued for Bermuda.

Gonzalo is still being steered by the subtropical high pressure system.  As it reaches the western end of the high, it will turn more toward the north.  Numerical models continue to indicate that southwesterly winds on the eastern side of a large upper trough moving over the eastern U.S. will turn Gonzalo toward the northeast later this week.  Gonzalo could be approaching Bermuda by Friday.

A smaller upper low located west of Gonzalo is creating some wind shear over the hurricane, but clearly the shear did not inhibit rapid intensification on Tuesday.  Gonzalo will be moving over warm Sea Surface Temperatures and so some further intensification is possible.  There could be some fluctuations in intensity if an eyewall replacement cycle starts to develop.  Eventually, the same upper level trough that should turn Gonzalo toward the northeast will generate stronger upper level winds and more wind shear.  Current guidance indicates that Gonzalo will still be a hurricane when it approaches Bermuda.

 

Gonzalo Becomes a Hurricane As It Moves Across the Northern Leeward Islands

Tropical Storm Gonzalo is moving through an environment favorable for intensification and it has become a hurricane.  At. 5:00 p.m. EDT the center of Hurricane Gonzalo was located at latitude 17.9°N and longitude 62.9°W which put it about 20 miles southeast of St. Martin and about 140 miles east-southeast of St. Thomas.  Gonzalo was moving toward the northwest at 12 m.p.h.  The maximum sustained wind speed has increased to 75 m.p.h. and the minimum surface pressure decreased to 984 mb.

Gonzalo is moving over Sea Surface Temperatures (SSTs) that are warmer than 29°C.  An eye has formed and there appears to be well developed upper level outflow to pump out mass.  Conditions favor further intensification and Gonzalo could reach Major Hurricane intensity.  There is an upper level low to the northeast of Gonzalo, but it does not appear to be generating significant wind shear.  In fact, the upper level outflow from Gonzalo appears to flowing over the top of the upper low.

Gonzalo is moving northwest as it curves around the western end of a subtropical high pressure system over the central Atlantic.  It is likely to gradually turn more toward the north as it gets to the western end of the high.  Numerical models are indicating that a large upper level trough that is contributing to severe weather over parts of the eastern U.S. will move eastward and turn Gonzalo to the northeast later in the week.

Hurricane Warnings have been issued for the British Virgin Islands and St. Martin.  Hurricane Watches and Tropical Storm Warnings have been issued for Puerto Rico, Culebra, Vieques, the U.S. Virgin Islands, St. Maartin and Anguilla.  Tropical Storm Warnings are in effect for St. Barthelemy, Saba, St. Eustatius, Barbuda, Antigua, St. Kitts, Nevis and Monteserrat.

 

Tropical Cyclone Hudhud About to Make Landfall in India

The center of Tropical Cyclone Hudhud is getting very near the coast of India.  At 8:00 p.m. EDT the center was located at latitude 17.2°N and longitude 84.2°E which put it about 70 miles east-southeast of Visakhapatnam, India.  Hudhud was moving toward the north-northwest at 8 m.p.h.  It had maximum sustained winds to 125 m.p.h. and there were gusts to 155 m.p.h.

Hudhud is likely to bring strong winds and locally heavy rainfall to parts of eastern India as it moves inland during the next 24 hours.  The center will pass near the city of Visakhapatnam which has a population of over two million people.  Hudhud could also generate a significant storm surge  along the coast.

 

Fay Transitions to a Tropical Storm

Thunderstorms developed near the center of Fay and an inner core of convection formed.  The thunderstorms released enough latent energy in the middle and upper troposphere to create a warm core.  As a result the structure of Fay changed from a subtropical storm into a tropical storm.  At 11:00 a.m. EDT the center of Tropical Storm Fay was located at latitude 27.9°N and longitude 65.3°W which put it about 305 miles south of Bermuda.  The maximum sustained wind speed was 70 m.p.h. and the minimum surface pressure was 991 mb.

The upper level outflow around Fay is well developed on the west side of the circulation.  It is over warmer Sea Surface Temperatures and some further intensification is possible.  When Fay gets farther north it will run into stronger upper level winds from the west.  Those winds will generate wind shear and start to weaken the storm.

Fay is moving around the western end of a subtropical high pressure system and it should continue to move northward today.  Eventually the upper level westerly winds will force Fay to turn toward the northeast.

The Tropical Storm Watch for Bermuda has been changed to a Tropical Storm Warning.

Subtropical Storm Fay Forms South of Bermuda

A large upper level low pressure system interacting with  the northern end of a tropical wave has produced a subtropical cyclone.  A reconnaissance plane investigated the system this afternoon and found that it had enough organization to be classified as a subtropical storm.  At 5:00 p.m. EDT the center of Subtropical Storm Fay was located at latitude 24.7°N and longitude 64.0°W, which put it about 525 miles south of Bermuda.  Fay was moving toward the north-northwest at 12 m.p.h. The maximum sustained wind speed was 40 m.p.h. and the minimum surface pressure was 1002 mb.

Fay is moving around the western end of a high pressure system located to its east.  It should turn more toward the northeast when it gets farther north and start to feel the influence of the midlatitude westerlies.

Fay currently has the typical hybrid structure of a subtropical cyclone the consists of one long band that coils about half to three quarters of the way around the system.  More thunderstorms are developing closer to the center of circulation.  If an inner core of thunderstorms develops and they release enough energy into the middle and upper levels of the storm to create a warm core, then Fay could make a transition to a tropical storm.

Fay is over warm Sea Surface Temperatures which create a potential for intensification, but it is also experiencing some wind shear from the nearby upper level low.  It could intensify some, especially if it develops an inner core.  Wind shear will increase as Fay moves farther north and it gets closer to upper level westerly winds.

A Tropical Storm Watch has been issued for Bermuda.

 

Typhoon Vongfong Approaching Okinawa

Typhoon Vongfong is approaching Okinawa and the island is already feeling the effects of the large circulation around the typhoon.  Kadena Air Force base has been reporting sustained winds to tropical storm force for 12 hours.  At 4:00 p.m. EDT the current observation at Kadena was heavy rain with northeast winds sustained at 47 m.p.h. and gusts to 71 m.p.h.

At 2:00 p.m. EDT the center of Typhoon Vongfong was located at latitude 23.8°N and longitude 128.9°E which put it about 200 miles south-southeast of Okinawa.  Vongfong was moving toward the north-northwest at 10 m.p.h.  The maximum sustained wind speed was 125 m.p.h. and there were gusts to 155 m.p.h.

Vongfong is starting to experience a little more wind shear and it is moving into a less favorable environment.  However, it is a large typhoon and the weakening process is likely to occur slowly for the next day or so.  As a result Vongfong will bring high winds and heavy rain to Okinawa for another 12-24 hours.

When Vongfong gets north of Okinawa, it will encounter strong westerly winds.  Those stronger winds will turn it toward the northeast.  The westerly winds will also increase wind shear over Vongfong and cause it to weaken more rapidly in a couple of days.  Vongfong could still be a typhoon when in approaches southwestern Japan.

 

Tropical Cyclone Hudhud Intensifying As It Get Closer to India

Tropical Cyclone Hudhud continues to move toward the eastern coast of India and it is not intensifying more rapidly.  At 2:00 p.m. EDT the center of Hudhud was located at latitude 15.9°N and longitude 86.5°E, which put it about 230 miles east-southeast of Visakhapatnam, India.  Hudhud was moving toward the northwest at 7 m.p.h.  The maximum sustained wind speed was 100 m.p.h. and there were gusts to 120 m.p.h.

A high pressure system located northeast of Hudhud is likely to continue to steer it toward the west-northwest or northwest until it reaches India.  Wind shear over Hudhud has decreased and the tropical cyclone is intensifying and it could intensify steadily until it makes landfall.  Hudhud will approach the coast of India near Visakhapatnam in about 36 hours and it will be a strong tropical cyclone when it gets there.  In addition to strong winds and heavy rain, Hudhud could also produce a significant storm surge along the coast.