Tag Archives: Jamaica

Matthew Rapidly Intensifies Into Category 4 Hurricane

Hurricane Matthew intensified very rapidly into a Category 4 hurricane on the Saffir-Simpson Scale as it moved across the southern Caribbean Sea on Friday.  At 5:00 p.m. EDT on Friday the center of Hurricane Matthew was located at latitude 13.5°N and longitude 71.6°W which put it about 75 miles (120 km) north of Punta Gallinas, Colombia.  Matthew was moving toward the west-southwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 140 m.p.h. (220 km/h). and there were wind gusts t0 165 m.p.h. (265 km/h).  The minimum surface pressure was 949 mb.

The Hurricane Size Index (HII) was 28.3.  The Hurricane Intensity Index (HII) was 13.2 and the Hurricane Wind Intensity Size Index (HWISI) was 41.5.  The indices mean that Hurricane Matthew is very similar in size and intensity to what Hurricane Ike was when Ike was northeast of the Leeward Islands in 2008.  The indices also mean that Hurricane Matthew is capable of producing regional significant wind damage.

Hurricane Matthew is very well organized and it efficiently extracted energy from the warm water of the Caribbean Sea to intensify rapidly on Friday.  It has a circular eye with a diameter of about 15 miles (24 km).  The eye is surrounded by a ring of very tall thunderstorms.  The thunderstorms are pumping out large quantities of mass which allowed the surface pressure to decrease by 44 mb during the past 24 hours.  There additional bands of thunderstorms, mainly in the eastern half of the circulation.

Hurricane Matthew will remain in a very favorable environment while it is over the Caribbean Sea.  It could intensify further.  When hurricanes become as strong as Matthew strong, they sometimes undergo eyewall replacement cycles.  During an eyewall replacement cycle, a hurricane first weakens and then strengthens again when the innermost eyewall dissipates.  If eyewall replacement cycles occur in Hurricane Matthew, then the intensity will fluctuate.

A strong subtropical high pressure system north of Matthew is steering the hurricane toward the west-southwest.  That general motion is expected to continue for another 24 hours.  When Matthew reaches the western end of the subtropical high, it will start to move toward the north.  Guidance from numerical models is still divergent about the details of the turn toward the north.  If the turn is sharper, it could mean that Hurricane Matthew moves toward Haiti.  If the turn is more gradual, it could mean that Matthew heads for Jamaica and eastern Cuba.  The uncertainty is the reason why watches have been posted for both Jamaica and Haiti.

Matthew is a very powerful hurricane.  It is capable of causing regional significant wind damage.  In addition Matthew will produce very heavy rain and the potential for dangerous flash flooding.  There is also the possibility of a significant storm surge along the coast.

Tropical Storm Earl Forms over the Western Caribbean

Based on data collected by an Air Force Reserve Hurricane Hunter reconnaissance plane, the National Hurricane Center designated a system previously known as Invest 97L as Tropical Storm Earl.  At 12:00 p.m. EDT on Tuesday the center of Tropical Storm Earl was located at latitude 16.3°N and longitude 80.2°W which put it about 535 miles (860 km) east of Belize City, Belize.  Earl was moving toward the west at 22 m.p.h. (35 km/h).  The maximum sustained wind speed was 45 m.p.h. (70 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1001 mb.

A Hurricane Watch and a Tropical Storm Warning has been issued for the portion of the coast from Punta Allen, Mexico to the Belize/Guatemala border.  A Tropical Storm Warning has been issued for the portion of the coast from Cabo Gracias a Dios to the Honduras/Guatemala border.

The recon plane found a small closed low level center of circulation on the western edge of a cluster of thunderstorms.  The circulation around Tropical Storm Earl is very small.  Winds to tropical storm force only extend out about 80 miles (130 km) from the center of circulation.  Most of the thunderstorms are occurring in the eastern half of the tropical storm.  Those thunderstorms are generating upper level divergence which has pumped out enough mass to allow the surface pressure to decrease a few millibars during the past 12 hours.

The environment around Tropical Storm Earl is somewhat favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 29°C.  An upper level low centered near the western tip of Cuba is producing southwesterly winds which are blowing over the western side of Tropical Storm Earl.  Those westerly winds are producing some vertical wind shear, which is why most of the thunderstorms are in the eastern half of Earl.  The wind shear is inhibiting intensification, but the upper low is forecast to move farther from Earl, which would reduce the shear.  If Earl move north of the coast of Honduras, it should intensify.  However, if the center of circulation moves over Honduras, then Earl could weaken fairly quickly because of its small size.

The subtropical high over the Atlantic Ocean is steering Tropical Storm Earl toward the west at a fairly rapid speed.  The high is expected to continue to steer Earl toward the west during the next several days, but the tropical storm is expected to move a little more slowly on Wednesday.  On its anticipated track the center of Tropical Storm Earl is expected to pass just north of the coast of Belize.  Earl could be very close to Belize in about 36 hours.

Earl is a small tropical storm and the greatest risks are locally heavy rainfall and flash flooding.