Fall 2023 weather outlook for central Indiana

INDIANAPOLIS (WISH) — Meteorological fall began just a few days ago and will run through the end of November.

The big story heading into this fall is the El Niño conditions that have been observed and have a 95% chance of lasting through this upcoming winter.

ENSO is a large-scale climate pattern involving changes in the temperature of waters in the central and eastern tropical Pacific Ocean. El Niño is when warmer than normal temperatures are in the eastern tropical Pacific Ocean. This pattern acts as a domino effect that impacts the jet stream for us in the United States.

The Climate Prediction Center says a moderate El Niño is likely for this fall, with a chance of this El Niño being strong in this timeframe.

Over the last three moderate El Niño patterns, Indianapolis has had a drier-than-normal meteorological fall. Average temperatures did not have a distinct pattern in these few years. Keep in mind that these are moderate El Niño falls. There have been plenty of falls that have had strong or very strong El Niño influences since 1963.

Also, in the years of the strongest El Niño effects (2015, 1997, 1982), Indianapolis finished with below-average precipitation in the fall.

Fall outlook from U.S. Climate Prediction Center

In central Indiana, there is no strong signal for either precipitation or average temperatures this fall. This basically means there is an equal chance of above- or below-normal temperatures or precipitation, which means it could be an average fall. We will see how this pans out, especially considering three similar years all had below-normal precipitation.

Nearby, above-normal temperatures are expected, stretching the entire east coast. Precipitation is forecasted to be above average in the Carolinas.

Although we are already in meteorological fall, the autumnal equinox will be at 2:49 a.m. Sept. 23.