If you haven’t heard, we are currently in an El Niño watch, meaning warmer waters have formed in the Equatorial Pacific and if they last for 3 months we will find ourselves in an official El Niño. And while El Niño winters are typically warmer in southern Alaska, the relation between El Niño and snowfall in Anchorage is a little less correlated than that between temperatures and the cycles of the El Niño Southern Oscillation (ENSO)
ENSO refers to the periodic warming or cooling of surface waters in the Equatorial Pacific. Trade winds near the equator (winds that blow east to west) typically push the warmer surface waters of the ocean westward. As the sun heats the surface of the ocean, those winds blow that warmth west, but it isn’t always steady.
When trade winds weaken, that warm water hangs out in the middle of the Pacific Ocean instead of moving west. This warming of the waters in the Equatorial Pacific is most prominent in late December. Long ago, fishermen started calling it El Niño because it correlated with the arrival of the Christ Child, or baby Jesus.