Matthew’s Impacts on the United States

Hurricane Matthew (Source:  U.S. Naval Research Laboratory)

As Hurricane Matthew bears down on the East Coast of the United States, it’s important to reflect on how damaging and deadly Matthew has been in the Caribbean.  Not only has Matthew taken an unusual track along the Southeast Coast of the U.S., it has also set a slew of records since it developed last week.

Matthew is the first major hurricane to impact the east coast of Florida since Hurricane Jeanne in 2004.  A “major” hurricane is defined as a Category 3 or higher storm on the Saffir-Simpson scale.  Matthew also became the first major hurricane to effect any U.S. coastline since Wilma in October 2005 – the same year as other devastating storms such as Katrina and Rita.  Fortunately, Matthew’s highest winds have remained offshore just east of the Florida coast.

Prior to Matthew, the last Category 4 hurricane to harm Florida’s east coast in October was Hurricane King in 1950.  Matthew was also the longest lasting Category 4-5 hurricane on record in the Caribbean Sea after September 25.  The National Hurricane Center downgraded Matthew from a Category 4 to a Category 3 hurricane at 2 a.m. today.  As of 11 a.m. this morning, Matthew has sustained winds of 120 mph – keeping it at Category 3 intensity while the center is 35 miles ENE of Daytona Beach, Florida.

What’s contributed to making Matthew so formidable is where it formed.  The Caribbean Sea has exceptionally warm sea surface temperatures in the mid-80s.  Matthew has moved very slowly and that combined with favorable atmospheric conditions (i.e. a lack of wind shear) allowed it to intensify.  Normally, if a hurricane is slow moving, it will cause cooler water to reach the ocean surface which could slow intensification or lead to weakening.  However, the Caribbean Sea’s warm water is very deep so that did not happen.

The National Hurricane Center expects Hurricane Matthew to track Northeast near the coast of the United States bringing significant rainfall, gusty winds and coastal storm surge as far north as the Carolinas.  However, Matthew will continue to weaken over time.  Little to no impact from Matthew is expected in the Mid-Atlantic Region.  My colleagues and I on the WUSA9 weather team will continue to keep you up to date on this devastating storm.