El Niño increases the likelihood of drier conditions
BOWLING GREEN, Ky. (Sept. 21, 2015) — An El Niño weather pattern could mean this winter in Kentucky won’t be a repeat of last year’s cold and snowy conditions, state climatologist Stuart Foster said.
Dr. Foster, director of the Kentucky Mesonet and director of the Kentucky Climate Center at Western Kentucky University, was part of a team of climatologists and meteorologists who assisted in producing NOAA’s Midwest Region El Niño Impacts and Outlook for September. The report highlights the climatological aspects of El Niño and potential societal impacts.
“As Kentucky transitions from summer to fall and with last winter’s subzero temperatures and snowstorms fresh on their minds, many people are starting to ask what this winter may hold for the region,” Foster said. “The El Niño that developed last spring is taking shape as a rather strong event. This year is likely to be very interesting.”
An El Niño develops when sea surface temperatures are warmer than average in the equatorial Pacific for an extended period of time. El Niño impacts North America’s weather patterns, especially in winter, when the polar jet stream is typically farther north while the Pacific jet stream remains across the southern U.S. Some moderate to strong El Niños in the recent past include those of 1982-83, 1997-98 and 2009-10.
“While El Niño raises the likelihood of heavy rainfall capable of producing flooding and landslides along the West Coast, it could help to alleviate extreme drought conditions there,” said Foster. “In our region of the country however, the climatic signal El Niño is weaker. Still, El Niño increases the likelihood of drier conditions through the winter months including a reduced chance of precipitation amounts that could lead to widespread flooding.”
As for temperatures, Foster said, “there’s not a strong temperature signature with El Niño in Kentucky, but the expected northward shift of the polar jet stream implies a lower probability of extended cold snaps.”
However, he cautioned, that doesn’t mean Kentucky won’t see snow or cold temperatures this winter.
“With the expectation of an active storm track to our south and natural fluctuations in the jet stream, there would be a risk that we could have heavy snow events but all in all we would expect less snow during an El Niño winter,” he said.
Benefits of a drier, milder winter could include lower home heating costs, lower operating costs for livestock operations, reduced expenditures for snow and ice removal, and fewer lost work days for construction projects.