Remembering Agnes 43 Years Later

Mid-Atlantic Rainfall Totals from Agnes  (Source: NOAA)

On this date in 1972, the Nation’s Capital saw its largest June daily rainfall on record and experienced severe flooding because of former Hurricane Agnes.  In fact, the entire Mid-Atlantic Region got record breaking rainfall that caused devastating flooding.  Although Agnes was only a minimal Category 1 hurricane when it made landfall along the U.S. Gulf Coast, winds were never its most damaging component.

In the DC Metro Region, Agnes brought a total of nearly 8.2” of rain to National Airport (with 6.11” falling on June 21) while Dulles Airport in nearby Sterling, Virginia, saw a storm total of 13.65” (including a daily record of 10.67” of rain on June 21).  This copious rainfall flooded an untold number roads and washed away some area bridges.  The Potomac River at Little Falls crested more than 12 feet above flood stage according to the U.S. Geological Survey.  As bad as the flooding was in the Nation’s Capital, it was even worse in Pennsylvania where it caused a dike to breach in Wilkes-Barre that almost destroyed the entire town.

Although most of the flooding and damage from Agnes resulted when it was no longer a hurricane, Agnes was the first Category 1 hurricane to have its name retired.  Agnes claimed 122 lives in the United States and caused $2.1 billion in damage (unadjusted for inflation) that made it the costliest natural disaster in U.S. history at the time.  Agnes demonstrated that tropical storms and hurricanes do not have to be intense to have a high death toll or cause a lot of damage.  

Just yesterday, the remnants of Tropical Storm Bill contributed to the copious amount of rainfall in the Mid-Atlantic Region.  A daily record 2.37” of rain fell at National Airport yesterday during what has also been a wetter than average June.