Scientists used SST data acquired from old ship records to create starting conditions for the computer models. They let the model run on its own, driven only by the observed monthly global sea surface temperatures. The model was able to reconstruct the Dust Bowl drought quite closely, providing strong evidence that the Great Plains dry spell originated with abnormal sea surface temperatures.

This sequence shows the warmer than normal SST (red-orange) in that the Atlantic Ocean and colder than normal SST (blues) in the Pacific Ocean, followed by a low level jet stream that shifted and weakened reducing the normal supply of moisture to the Great Plains.