Tropical Storm Four of 1970 on August 18th. At the time of the picture, the storm displayed many features similar to those of hurricanes, leading to the possibility of "Four" being a hurricane. Source: http://docs.lib.noaa.gov/rescue/mwr/099/mwr-099-12-0966.pdf

This image is in the public domain because it contains materials that originally came from the U.S. National Oceanic and Atmospheric Administration, taken or made as part of an employee's official duties. العربية ∙ čeština ∙ Deutsch ∙ Zazaki ∙ English ∙ español ∙ eesti ∙ suomi ∙ français ∙ hrvatski ∙ magyar ∙ italiano ∙ 日本語 ∙ 한국어 ∙ македонски ∙ മലയാളം ∙ Plattdüütsch ∙ Nederlands ∙ polski ∙ português ∙ română ∙ русский ∙ sicilianu ∙ slovenščina ∙ Türkçe ∙ Tiếng Việt ∙ 简体中文 ∙ 繁體中文 ∙ +/−

The NOAA emblem is the property of the U.S. Government and a trademark of the United States Department of Commerce.