AMES, Iowa (WNAX) – An ongoing weather driver is still active, but not following previous scripts.

Dennis Todey, head of the Midwest Climate Hub (in Ames Iowa) says a La Nina advisory continues.

Todey says the longer range outlooks don’t track like previous La Nina’s.

Todey says the milder weather into late December was not totally unexpected.

A La Nina occurs when Pacific Ocean surface temperature cool. That can influence weather across North America.