Warm Water and Strange Weather May Be Connected

http://earthobservatory.nasa.gov/IOTD/view.php?id=85714

The weather in North America, particularly in winter, has been unusually extreme for much of the past two years. The western half has endured record-setting heat and, in many places, persistent and debilitating drought. The eastern half of North America has faced record cold and snow.
The causes are complex and have provoked lively discussion in the scientific community. Are ocean circulation and warming patterns in the Pacific altering atmospheric patterns over land? Or are atmospheric conditions driving the unusual conditions in the water? Are these short-term anomalies or decades-long changes at work? The answer has yet to be teased out, but it is probably a muddle of all of these things.
One thing is clear: the eastern Pacific Ocean has been warmer than normal since the winter of 2013–2014. The maps above show sea surface temperature anomalies in the Pacific in April 2014 (top) and March 2015 (bottom). The maps do not depict absolute temperatures; instead, they show how much above (red) or below (blue) water temperatures were compared to the long-term average from 2003 to 2012.