Hurricane Matthew continued its rapid intensification on Friday night and it became the first Atlantic hurricane to reach Category 5 on the Saffir-Simpson Scale since Hurricane Felix did so in 2007.  At 11:00 p.m. EDT on Friday the center of Hurricane Matthew was located at latitude 13.3°N and longitude 72.3°W which put it about 440 miles (710 km) southeast of Kingston, Jamaica.  Matthew was moving toward the west at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 190 m.p.h. (305 km/h).  The minimum surface pressure was 941 mb.

The Hurricane Intensity Index (HII) for Matthew was 35.0.  The Hurricane Size Index (HSI) was 13.7 and the Hurricane Wind Intensity Size Index (HWISI) was 48.7.  These indices indicate that Hurricane Matthew is not as intense and slightly smaller than Hurricane Wilma was, when Wilma was a Category 5 hurricane over the northwestern Caribbean Sea in 2005.

A Hurricane Watch is in effect for Jamaica.  A Tropical Storm Watch is in effect for the portion of the coast from the Haiti/Dominican Republic border to Port-Au-Prince, Haiti.  A Tropical Storm Warning is in effect for the portion of the coast from the Colombia/Venezuela border to Riohacha, Colombia.

Hurricane Matthew remains in a very favorable environment of minimal vertical wind shear and warm Sea Surface Temperatures.  The intensity may fluctuate as a result of eyewall replacement cycles.

A strong subtropical high is steering Hurricane Matthew toward the west.  Matthew is slowing as it approaches the western end of the subtropical high.  It will turn toward the north when it reaches the western end of that high pressure system.  However, the location, time and sharpness of the turn to the north are still uncertain.  That uncertainty means that the longer term track of Hurricane Matthew is also uncertain.  We should get more clarity about the future direction of Hurricane Matthew during the next several days.