Tropical Depression Four - July 24-30, 1981 

A tropical disturbance formed south of Cuba, in association with a tropical wave.  The system moved westward
towards the northeast Yucatan peninsula, when it began to interact with an upper level low to its west.  A surface
circulation formed, and this system became a tropical depression on July 26th.  Moving west-northwest, the depression
made landfall across northeast Mexico, and its surface circulation quickly dissipated.  Its circulation aloft maintained
integrity, and recurved into western Texas.  Thunderstorm activity formed near its center, as well as along a draping
stationary front across northern Texas and Oklahoma, causing additional convective development.  The remnant
circulation dissipated by the morning of the 30th.  Below are the storm total rainfall maps for the depression, using data
provided by the National Climatic Data Center and the Comision Nacional del Agua, parent agency of Mexico's national
weather service.   The main portion of the track was provided by the National Hurricane Center, then extended based on
satellite imagery archived at the National Climatic Data Center.

Tropical Depression Four (1981) Rainfall Tropical Depression Four (1981) Rainfall Tropical Depression Four (1981) Rainfall