Cold and snowy January after La Nina developed

It's official: La Nina is here, but not for long. After coming down from a record-breaking El Nino we will only see a brief cooldown into La Nina.

La Nina and El Nino are phases of a fluctuating cycle between the atmosphere and the ocean that can have local and global impacts. This pattern is observed over the Pacific Ocean near the equator, where sea surface temperatures warm or cool and subsequently alter weather conditions.

When La Nina develops, sea surface temperatures cool in the tropical Pacific and the trade winds blow stronger. This leads to a large-scale pressure difference and changes to weather near and far. In North America during a La Nina winter, we can expect to see colder-than-average temperatures in the far north and warmth and dryness to the south. Precipitation is harder to predict but La Nina can increase rain or snow near the Ohio Valley and the Pacific Northwest. 

Matthew Beitscher with the National Weather Service in St. Louis says that the climatological impacts from La Nina can be hard to connect locally but that doesn't mean it isn't happening. "It doesn't mean that we won't see a colder or warmer winter than average because of La Nina. It just means that there's no discernible pattern, from all the past La Ninas that we've seen."

This is especially true for precipitation which is harder to predict than temperatures. "There isn't a huge change in precipitation trends compared to normal during La Nina years. There is a slight increase, but it's pretty negligible across our area." Beitscher says.

This recent La Nina still may have helped to deliver the nearly foot or more of snow that Central Missouri saw just this month. Columbia has recorded 9.7 inches of snow in recent weeks, more than twice our average snow for January.

Long-term forecasts for the rest of winter are following a La Nina pattern which may continue to drive precipitation near the Ohio Valley and our area into the early spring.