This is an interesting correlation. I don't know what the winter sea water temperatures have been like but over summer New Zealand sea water was warmer than usual.
"If winter and spring sea surface temperatures around New Zealand are below average, chances are it's going to rain in the south-west United States (SWUS) in three months' time.
It seems the two climate features are connected, with the link particularly strong with southern parts of the SWUS.
Researchers from the University of California, Irvine explain the link - apparently via a "a western Pacific ocean-atmosphere pathway" - in a paper recently published in Nature Communications.
Predicting rainfall in the SWUS was challenging, and had significant implications for the economy, water security and ecosystem management, the paper said. With climate change expected to modify precipitation patterns, the need for improved seasonal and even sub-seasonal predictive skill became critical.
The discovery is important because weather patterns, such as El Nino, that have been used up to now to predict rainfall in the SWUS - California, Arizona, Nevada and Utah - aren't great, and are becoming less accurate.
On the other hand, the link - or "teleconnection" - between the rainfall and what's being called the "New Zealand Index" has been growing stronger over the past four decades. It also allows predictions to be made three months before the rain starts falling."