Hurricane Esther was the first large tropical cyclone to be discovered by satellite imagery. The fifth tropical cyclone, named storm, and hurricane of the 1961 Atlantic hurricane season, Esther developed from an area of disturbed weather hundreds of miles west-southwest of the southernmost Cape Verde Islands on September 10. Moving northwestward, the depression strengthened into Tropical Storm Esther on September 11, before reaching hurricane intensity on the following day. Early on September 13, Esther curved westward and deepened into a major hurricane. The storm remained a Category 3 hurricane for about four days and gradually moved in a west-northwestward direction. Late on September 17, Esther strengthened into a Category 5 hurricane with sustained winds of 160 mph (260 km/h) on September 18. The storm curved north-northeastward on September 19, while offshore of North Carolina. Esther began to weaken while approaching New England and fell to Category 3 intensity on September 21. The storm turned eastward early on the following day, and rapidly weakened to a tropical storm.

Esther then executed a large cyclonic loop, until curving northward on September 25. Early on the following day, Esther struck Cape Cod, hours before emerging into the Gulf of Maine. Later on September 26, the storm made landfall in southeastern Maine, before weakening to a tropical depression and becoming extratropical over southeastern Quebec. The remnants persisted for about 12 hours, before dissipating early on September 27. Between North Carolina and New Jersey, effects were primarily limited to strong winds and minor beach erosion and coastal flooding due to storm surge. In New York, strong winds led to severe crop losses and over 300,000 power outages. High tides caused coastal flooding and damage to a number of pleasure boats. Similar impact was reported in Massachusetts. Additionally, some areas observed more than 8 inches (203 mm) of rainfall, flooding basements, low-lying roads, and underpasses. Overall, damage was minor, totaling about $6 million (1961 USD). There were also seven deaths reported when a United States Navy P5M aircraft crashed about 120 miles (190 km) north of Bermuda.



The National Hurricane Research Project (NHRP) was initiated in 1955 by the United States Weather Bureau in response to the devastating 1954 hurricane season, which saw hurricanes Carol, Edna, and Hazel bring destruction and flooding to New England and the Mid-Atlantic States. Robert Simpson, a Weather Bureau meteorologist who had participated in Air Force hurricane reconnaissance flights as an observer, was appointed as the first director of NHRP and organized the Research Operations Base at Morrison Air Force Base (now Palm Beach International Airport) in West Palm Beach, FL in 1956.