Perspective on Hurricane Dorian

Dorian has become the Atlantic’s first major hurricane of 2019.  A “major” hurricane is defined as a Category 3 or greater on the Saffir-Simpson Hurricane Wind Scale with sustained winds of at least 111 mph.  Dorian ended a relatively quiet streak in the Atlantic Ocean Basin that had seen only three relatively weak storms prior to its development.  Although Hurricane Dorian largely spared Puerto Rico, the southeast coast of the United States isn’t expected to be as fortunate.

The latest National Hurricane Center forecast has Dorian is poised to make landfall as a Category 3 or 4 hurricane on the east coast of Florida early next week.  Once it nears the Florida coast, there is some uncertainty with its track inland as steering currents are expected to weaken.  That’s bad news as it could allow Dorian to potentially linger over Florida after coming ashore or stalling near the coast.  While hurricanes weaken after making landfall or in close proximity to a given land mass, high winds and storm surge would be long-term issues.

For slow moving tropical systems, long-lasting heavy rainfall becomes the primary danger after the high winds and storm surge diminish.  Hurricane Harvey made landfall in Texas two years ago and lingered for days after making landfall, causing widespread and devastating flooding.  Many Florida cities such as Tampa, Sarasota and Orlando have already had above average rainfall this summer, so the copious rainfall that a slow-moving tropical system would bring is bad news.  That’s especially true given the flat topography of Florida combined with the sandy soil that doesn’t have the capacity to absorb large amounts of rainfall.

Since 2000, three hurricanes have made landfall on the east coast of Florida.  Hurricanes Frances and Jeanne were Category 2 and 3 storms, respectively, and made landfall just three weeks apart in September 2004.  Hurricane Katrina also made landfall in eastern Florida as a Category 1 hurricane in 2005.  

Following Hurricane Wilma in October 2005, the state of Florida wouldn’t see another hurricane until Hermine in 2016.  Although Hurricane Matthew tracked along the east coast of Florida later in 2016, it never made landfall in Florida.  Hurricanes Irma (2017) and Michael (2018) also impacted Florida, but didn’t make landfall on the east coast.  If Dorian makes landfall on Florida’s east coast as a Category 4, it would be the strongest hurricane to make landfall there since Category 5 Hurricane Andrew in 1992.

There is still a fair amount of uncertainty as to what the exact track and intensity of Hurricane Dorian will be as it nears the Florida coast.  That’s because the computer models meteorologists look at when forecasting are not yet in agreement about what will happen.  Making preparations now and heeding local evacuation orders is vital to protect life and property.  Stay tuned to your favorite meteorologists and local authorities for instructions.