Hurricanes rarely hit Key West but on October 24, 2005, we
experienced the worst storm in memory - Hurricane Wilma. The
entire island was told to evacuate. Business owners put up their
hurricane protective shutters and plywood. After the hurricane had
passed, the storm surge sent 8’ of water inland, literally putting most
of the Lower Keys and Key West underwater. Sixty percent of the
homes in Key West were flooded and the surge destroyed tens of
thousands of cars throughout the Lower Keys. Key West looked like
a ‘car graveyard’ and we saw tractor trailer loads of cars coming and
going on the Overseas Highway for months after Wilma. The storm
destroyed the piers at the clothing optional Atlantic Shores motel and
breached the shark tank at the Key West Aquarium, freeing its
sharks. Damage postponed Key West’s Halloween Fantasy Fest
until the following December.
In March 2006, the NOAA opened its National Weather Forecasting
Building on White Street. This building is designed to withstand a
Cat 5 hurricane and its storm surge.
The previous most intense hurricane was Hurricane George, a
category 2 storm in September of 1998.
Tropical Wave (African or Easterly Wave)
A tropical wave is a trough or cyclonic curvature maximum in the trade wind easterlies. These waves tend to reach
maximum amplitude in the lower to middle troposphere and may or may not be accompanied by thunderstorm
clusters. Although there is still some debate on the issue,these easterly waves are thought to originate or
become amplified as a result of meteorological conditions over the continent of Africa. Each hurricane season
approximately 60 of these waves cross the tropical North Atlantic. Although the majority of these waves pass
through the basin without any significant tropical cyclone development, passage of these waves is often
accompanied by squally weather with brief periods of higher sustained winds.
A tropical disturbance is a discrete tropical weather system with apparently organized convection (generally 100
to 300 miles in diameter) originating in the tropics or subtropics, having a nonfrontal migratory character, and
maintaining its identity for 24 hours or more.
Tropical cyclones in which the maximum sustained surface wind speed (1-minute mean) is 38 mph (33 KT) or
Iess. Tropical depressions must have a closed surface circulation in order to be classified in this category.
Tropical cyclones in which the maximum sustained surface wind speed (1-minute mean) ranges from 39-73
mph (34 KT to 63 1
Tropical cyclones in which the maximum sustained surface wind speed (1-minute mean) is greater than or equal
to 74mph (64 KT).
Hurricane Categories (Saffir-Simpson Hurricane Scale)
Hurricanes are further categorized according to the strength of their winds using the Saffir-Simpson Hurricane
A Category 1 storm has the lowest wind speeds, while a Category 5 has the highest. These are relative terms
because lower category storms can sometimes inflict greater damage than higher category storms, depending
on angle of approach, location, and many other aspects particular to each system. Even tropical storms can
produce significant damage & loss of life, mainly due to floods.
Category 1 Hurricane — winds 74-95 mph (64-82 kt)
No real damage to buildings. Damage to unanchored mobile homes. Some damage to poorly constructed signs.
Also, some coastal flooding and minor pier damage. Examples: Irene 1999 and Allison 1995
Category 2 Hurricane — winds 96-110mph (83-95 kt) Some damage to building roofs, doors and windows.
Considerable damage to mobile homes. Flooding damages piers and small craft in unprotected moorings may
break their moorings. Some trees blown down. Examples: Georges 1998 and Gloria 1985
Category 3 Hurricane — winds 111-130mph (96-113 kt) Some structural damage to small residences and
utility buildings. Large trees blown down. Mobile homes and poorly built signs destroyed. Flooding near the coast
destroys smaller structures with larger structures damaged by floating debris. Terrain may be flooded well inland.
Examples: Keith 2000,Fran 1996 Opal 1995,Alicia 1983 and Betsy 1965
Category 4 Hurricane — winds 131-155 mph (114-135 kt) More extensive curtainwall failures with some
complete roof structure failure on small residences. Major erosion of beach areas. Terrain may be flooded well
inland. Examples: Hugo 1989 and Donna 7960
Category 5 Hurricane — winds 156mph and up (135+ kt) Complete roof failure on many residences and
industrial buildings. Some complete building failures with small utility buildings blown over or away. Flooding
causes major damage to lower floors of all structures near the shoreline. Massive evacuation of residential areas
may be required. Examples: Andrew 1992, Camille 7969 and Labor Day 1935
Information about the Florida Keys and Key West
Tropical Cyclone Basics
Tropical cyclones are warm core, non-frontal low pressure systems of synoptic scale that develop over tropical or
subtropical waters and have a definite organized surface circulation. Tropical depressions, tropical storms, and
hurricanes are all forms of tropical cyclones, differentiated only by the intensity of the winds associated with them.