Though the Atlantic Hurricane season officially begins on the first of the month, June hurricanes tend to be few and far between. However, in 1972, one of the most impactful June hurricanes on record began to form in the Gulf of Mexico: Hurricane Agnes. 

On June 11, an unusual area of convection was spotted in the northwest Caribbean Sea as a polar front dropped into the region. Over the course of June 12 and 14, thunderstorm activity  over the Yucatan peninsula in Mexico began to converge and form a tropical depression that would eventually evolve into Hurricane Agnes. By the night of June 15, Agnes developed into a tropical storm as it continued to move northward into the Gulf of Mexico. As the storm continued straight for the Gulf Coast, it evolved into a hurricane, gaining speed and becoming increasingly dangerous. When Agnes struck the Florida panhandle on June 18, the hurricane had reached its peak intensity. Agnes weakened as it continued to move inland, passing through Georgia on June 20 as a tropical depression. Though it began to regain strength as it moved over North Carolina and Virginia, Agnes drifted offshore at Norfolk, Virginia -- but the storm wasn’t through just yet.

After moving up the coast, Agnes continued to strengthen as a tropical storm off the coast of New Jersey before swinging back inland near Long Island, New York. While Agnes’ circulation was absorbed by another system over Pennsylvania, the storm’s remnants brought unprecedented rainfall to the area. Agnes’ torrential rains followed an abnormally wet May for the area, resulting in devastating flooding across the Mid-Atlantic states.  

Throughout the region rainfall amounts ranged from 6 to 12 inches -- in some areas, 18 inches of rainfall occurred over 36 hours. The states of Pennsylvania, Virginia, and New York were battered with rain, causing rivers to rise at rates never before observed. In particular, communities located along the Susquehanna and Potomac rivers experienced disastrous flood conditions that led to widespread evacuations. As a result of the subsequent flooding, levees failed, and several towns were soon underwater. More than 100,000 people across the region lost their homes, and even more were without power and fresh water. Roads, railroads, and bridges were destroyed by the unyielding rain, resulting in almost $13 billion in damages. Ironically, some towns even battled extensive fire damage in flooded neighborhoods. All told, there were 122 deaths reported nationwide as a result of the flooding and rainfall caused by Hurricane Agnes. 

In the decades since Hurricane Agnes, the National Weather Service has continued to make forecasting and preparing for hurricanes a priority. With the help of advancing technologies and communication, it is our mission to protect lives and property in the face of dangerous weather.

Additional Reading:

• https://www.weather.gov/marfc/Agnes_45th

• https://www.wpc.ncep.noaa.gov/tropical/rain/agnes1972.html

• https://www.weather.gov/ctp/Agnes