(Des Moines) Weather experts continue to wait for the weather phenomenon La Nina to develop to give us an idea of what kind of pattern may or may not develop over the next few months. State Climatologist Dr. Justin Glisan says La Nina means warmer sea surface temperatures in the western Pacific, which could fire thunderstorms that impact rain and temperature across Iowa.
Glisan is noticing two different signals. He says since 1950, La Nina Falls has been dryer than normal. However, Glisan says there has been a wetter signal over the past 30 years in La Nina in the Autumn months.
Dr. Glisan says that in La Nina years, moving into wintertime, we generally see below-average temperatures in the upper Midwest, dryer conditions in the Gulf States, and wetter conditions in the Ohio Valley and Great Lakes. He says Iowa happens to be on that interface. So, it depends on whether the Jet Stream stays farther north or south.