Strength of Tropical Storms Should Not Be Underestimated

Washington, D.C. -- While it is hurricanes that historically cause the most damage to the eastern and southeastern United States (including the Gulf of Mexico) between June and November, the power of the tropical storm (TS) cannot be ignored.

Of the top 30 Atlantic cyclones that have struck the U.S. since 1938, four of them were tropical storms. TS Allison hit the Texas coast in 1989, causing $500 million in damage. The same amount of damage was brought about by TS Alberto, which struck parts of Florida, Georgia and Alabama in 1994. In 1979, TS Claudette caused $400 million in damages to north Texas. TS Gordon, which hit south and central Florida and parts of North Carolina in 1994, also caused damages in the neighborhood of $400 million. There are also two tropical depressions that qualify for the Top-30 list. They hit Olivia, CA in 1982 and Norman, CA in 1978, causing $325 million and $300 million in damages respectively.

Tropical storms have many of the same characteristics found in hurricanes - counter clockwise winds, low pressure, heavy rains and the potential for death and destruction. In fact, the only difference between a tropical storm and a Category I hurricane is one mile per hour. A tropical storm has winds of 39 to 73 mph. At 74 mph, the storm becomes a Category I hurricane.

TS Allison became a tropical storm June 24, 1989, and was downgraded to a tropical depression one week later. At its peak the highest winds were 45 mph and the lowest pressure was 999mb. The storm moved north from its point of origin in the Gulf of Mexico east of Corpus Christi and traveled over much of the far eastern portions of Texas.

TS Alberto - June 30 to July 7, 1994 - began its life along the western tip of Cuba. The heavy rains associated with this storm brought severe flooding to Florida, Georgia and Alabama, and were responsible for 28 deaths in Georgia and two in Alabama. Alberto's strongest winds were 65 mph.

Like Alberto, TS Gordon - Nov. 8 to Nov. 21, 1994 - produced torrential rains, flooding and mudslides as it made its way through the western Caribbean Sea and later into the North Atlantic. An estimated 2,000 people died when the storm slammed into Haiti. Its path over Florida resulted in seven deaths and significant damage to crops in that state. Alberto crossed over Florida and moved north along the east coast of the U.S. Near the Outer Banks of North Carolina the storm strengthened to hurricane status, only to revert to a tropical storm before making landfall along the coast of the Tar Heel State. Gordon ranks 30th in the list of the deadliest tropical storms which resulted in 25 or more deaths since 1492.

TS Claudette was active from July 15-29, 1979. The storm had maximum sustained winds of 45 mph and a low pressure of 997mb. (information sources: National Hurricane Center, National Centers for Environmental Prediction)