Category Archives: Atlantic, Caribbean, and Gulf of Mexico

Atlantic TCs

Potential Tropical Cyclone Developing Over Bay of Campeche

A reconnaissance plane found a small center of low pressure within a broader area of low pressure over the Bay of Campeche on Tuesday afternoon.  The plane also found winds to near tropical storm force.  At the 3:00 p.m. EDT the low was centered at latitude 19.3°N and longitude 93.7°W which put it about 350 miles northwest of Campeche, Mexico and about 850 miles west-southwest of Key West, Florida.  The low was moving toward the east at 6 m.p.h.  The maximum sustained wind speed was 38 m.p.h. and the minimum surface pressure of 1001 mb.

Thunderstorms are forming mainly on the southern and eastern sides of the center.  The low could be pulling in some of the drier air over the northern Gulf of Mexico, which may be limiting convection on the northwest side of the low.  Westerly winds in the upper levels are also generating wind shear, which is inhibiting the development of the low.  On the other hand, the low is over Sea Surface Temperatures (SSTs) that are warmer than 29°C and there is plenty of energy in the ocean to support the development of a tropical cyclone.  The pressure has fallen about 5-6 mb in the past 12 hours and so the low appears to be getting stronger.  If more thunderstorms form around the center of the low, it could be classified as a tropical depression or a tropical storm.

The westerly winds in the upper and middle levels are pushing the low slowly toward the east.  Guidance from the forecast models seems to be divided into two main possibilities.  One group of models keeps the low relatively weak and forecasts it to move eastward across the Yucatan peninsula and into the northwestern Caribbean Sea before turning it northeastward and moving the low across the Bahamas.  A second group of models predicts that the low will be a bit stronger and that the upper level flow will turn it northeastward sooner and move the low across southern Florida.  If that second scenario occurs, the low could bring stronger winds and heavy rainfall to parts of south Florida.

 

Possible Tropical Development Over Southern Gulf of Mexico

A low pressure system has formed at the surface along the western end of a stationary front over the Bay of Campeche.  It is possible that this low pressure system could intensify into a tropical cyclone and the National Hurricane Center has tasked a reconnaissance plane to investigate the low tomorrow, if necessary.  At 8:00 a.m. EDT on Monday the low was centered at latitude 19.5°N and longitude 95.5°W which put it about 50 miles east of Veracruz, Mexico and about 940 miles west-southwest of Key West, Florida.  The low as moving toward the northeast at 3 m.p.h.  The maximum sustained wind speed was 30 m.p.h. and the minimum surface pressure was 1008 mb.

The low is over Sea Surface Temperatures (SSTs) that are warmer than 29°C and the southern Gulf of Mexico is a location where we see tropical cyclones develop late in the hurricane season.  On the other hand, westerly winds in the upper levels are creating wind shear over the low pressure system and there is drier air over the northern half of the Gulf of Mexico.  Those two factors will inhibit intensification of the system and so tropical development of the low could be slow.  If thunderstorms do develop near the center of the low, it will remain over warm SSTs while it is in the Gulf of Mexico and it could become a tropical storm.

There is westerly flow in the middle and upper levels over the Gulf of Mexico and that flow is likely to push the low pressure system toward the east.  The low could move slowly during a period while it is organizing.  If an area of deep thunderstorms forms, then the middle and upper level winds could push the low eastward more quickly.  The low could approach southwestern Florida later this week.

 

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.

 

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.

 

Edouard Becomes a Major Hurricane

The maximum sustained wind speed in Hurricane Edouard is now 115 m.p.h. which makes it a Category 3 hurricane on the Saffir-Simpson Scale and a Major Hurricane.  Edouard is the first Major Hurricane of the 2014 Atlantic hurricane season.  It is the first hurricane to reach Major Hurricane intensity over the Atlantic basin since Hurricane Sandy briefly was a Major Hurricane south of Cuba in 2012.

At 11:00 a.m. EDT on Tuesday the center of Hurricane Edouard was located at latitude 31.1°N and longitude 57.8°N which put it about 420 miles east of Bermuda, about 1060 miles east-southeast of Cape Hatteras and about 1720 miles west of Fayal Island in the Azores.  Edouard was moving toward the north-northwest at 13 m.p.h.  The minimum surface pressure was 955 mb.

Edouard is moving around the western portion of the subtropical high pressure system.  It should gradually turn more to the right until it reaches the upper level westerlies which should accelerate it eastward.  Some model guidance suggest that Edouard could approach the Azores during the weekend, while other models forecast a track north of the Azores.

Edouard could intensify a little more today, but cooler Sea Surface Temperatures and stronger westerly winds will begin to weaken the hurricane when it turns eastward.