Much like any other tropical cyclone, Andrew originated as a tropical wave off the western coast of Africa on August 14. It began organizing the next day while south of the Cape Verde Islands, and by August 16, the wave's thunderstorm activity had organized enough to classify it as a tropical depression. It was named Tropical Storm Andrew the following day.
Over the course of the next several days, however, this steady strengthening plateaued as Andrew turned northwest and met up with an upper level trough of low pressure centered just east-southeast of Bermuda. Wind shear from the pressure system weakened Andrew's surface circulation, nearly causing its dissipation. (At one point, its central pressure rose to 1015 millibars--a reading more fitting of a high pressure system than of a tropical system.) By August 21, the low began to weaken. This decreased the wind shear over Andrew and cleared the way for it to begin strengthening. Around this same time, strong high pressure began to build to near the coast of the southeast U.S. and to the storm's north. This helped steer Andrew westward--a track it would maintain for most of its life.
Now traveling westward with favorable conditions ahead, Andrew quickly intensified. It became a Cape Verde hurricane on August 22 while located 650 miles southeast of Nassau, Bahamas. Between August 22 to 23 it's central pressure dropped by nearly 50 millibars (to a measurement of 922 mb) and its intensity increased from a category 1 to a category 5 hurricane--the highest possible rating. Despite its great strength, Andrew remained small in size. In fact, its tropical-storm-force winds (which extend outward beyond the most intense winds, termed hurricane-force) only extended outward 90 miles (140 km) from storm center.
Storm Track, Impacts, & Damage
Hurricane Andrew made landfall as a category 5 storm when its eye passed over northern Eleuthera Island on August 23. The next day, a slightly weaker Andrew passed over the southern Berry Islands with winds of 150 mph (240 km/h). While thousands were displaced and their homes destroyed, only 4 fatalities occurred. The low death toll was credited to the advanced hurricane watches and warnings--which were issued as early as a day and a half prior.
Damages across the islands totaled $250 million (1992 USD).
Continuing its westward track, Andrew rapidly re-intensified as it crossed the warm waters of the Gulf Stream with Florida in its aim. In preparation, nearly 1.2 million people were evacuated across 9 counties. On the morning of August 24, it struck Elliott Key, FL (part of the Florida Keys) as a category 5 storm with peak winds of 165 mph (266 km/h). This event qualified it as the first major hurricane to affect the U.S. since Hurricane Betsy in 1965.
Out of all the regions impacted by Andrew, South Florida saw the greatest devastation. Miami-Dade County (which was in the direct path of the storm) experienced a 17 foot (5.2 m)storm surge, and a peak rainfall total of 13.98 inches (355 mm). It's city of Homestead, FL was reportedly 99% destroyed.
In the four hour's time it took a fast-moving Andrew to pass over Florida, one million residents lost power, over 700,000 structures were damaged or destroyed, and 44 casualties occurred. An estimated $23 billion dollars--that is, roughly 90% of the total cost of damage inflicted by Hurricane Andrew--was caused in the state of Florida alone.
After striking Florida, Andrew moved northwest across the Gulf of Mexico. On August 26, it made landfall in St. Mary Parish near Morgan City, LA as a category 3 storm. While storm tide and heavy rains caused some minor flooding, Andrew did mostly agricultural damage in the Pelican state. Including the crops destroyed by high winds and the millions of freshwater fish that were killed by upwelling, cumulative losses across the state totaled $1.5 billion (1992 USD).
Within ten hours of making landfall in Louisiana, Andrew had weakened to a tropical storm. Now traveling northeast, it crossed Mississippi, Alabama, and Georgia bringing moderate rainfall and damaging tornadoes. By August 27, it had downgraded to a tropical depression near the Appalachian Mountains, and by midday on August 28, its remnants began to merge with a frontal system over the mid-Atlantic states.
With an overall price tag of $26.75 billion, Hurricane Andrew currently ranks behind Hurricanes Katrina (2005) and Ike (2008) as the costliest in U.S. history. Due to the level of catastrophic damage Andrew caused, the World Meteorological Organization's (WMO) hurricane committee retired the name from the hurricane list in the spring of 1993. It was replaced with "Alex."