August 16, 2004 | By: Aimee Heald-Nielson

Kentucky hasn’t seen the effects of El Niño in nearly two years, but weather experts recently have noticed a small warming of sea surface temperatures east of the International Date Line, indicating the beginning of a weak El Niño period. 

In the past, El Niño has been responsible for milder, wetter conditions in Kentucky’s colder months. University of Kentucky Agricultural Meteorologist Tom Priddy said however, El Niño cannot be blamed for this summer’s wet and mild conditions.

“This summer’s weather is not because of El Niño or La Niña,” said Priddy. “We are in a neutral pattern and we have been since late 2003. Typically there is a lag once you get into an El Niño pattern before you start to see the shift of the jet stream, so we’re talking mid-fall before we see any impact.”

Priddy said it’s too early to say what the impact will be since that is determined by the position of the jet stream. History shows that El Niño usually has more of an effect on the southern tier states of the United States because it usually sets up a southern branch to the jet stream.

The National Oceanic and Atmospheric Administration (NOAA) is reporting that El Niño conditions will build over the next three months and could impact the weather by late fall. For Kentucky that could mean above normal temperatures and increased precipitation for the winter months.

“It just all depends where the jet stream goes,” Priddy said. “The jet stream determines where the active weather occurs. We may see more cloud cover and moisture if it settles over Kentucky. We tend to be right in the middle of weather types with the southern areas having colder weather and then warmer, drier conditions in the plains.”

There is a possibility that El Niño could affect the latter part of the 2004 hurricane season. Priddy said that El Niño tends to suppress hurricane activity in the Atlantic Ocean. Depending on how fast El Niño conditions build in the equatorial Pacific, it could decrease the intensity and number of tropical storms and hurricanes that hit the United States.

El Niño typically lasts 9 to 12 months and reaches peak intensity in December through April, but there have been El Niño episodes that have lasted as long at two to four years.

The El Niño episode of 1997 and 1998 wreaked havoc on weather conditions across the globe, not just Kentucky, Priddy said. It was associated with major flooding and landslides in California, and generally caused an increase in active weather in southern tier states that sometimes moved into Kentucky.

For more information on weather conditions, visit the UK College of Agriculture Weather Center.


Writer: Aimee D. Nielson 859-257-4736, ext. 267

Source: Tom Priddy 859-257-3000, ext. 245