June 13, 2016
Indiana summer weather outlook: Drought looming again
WEST LAFAYETTE, Ind. - Indiana could be headed for another drought this summer, according to the Indiana State Climate Office. Some northern Indiana counties already are abnormally dry.
It depends on the strength of a developing La Niña weather pattern. Stronger La Niña conditions in summer typically result in hotter and/or drier Midwest summers, such as what happened during the historic drought in the summer of 2012.
Changes in large-scale weather patterns such as the demise of El Niño and strong possibility of La Niña conditions in coming months are leading to local scale impacts of reduced rainfall and hotter landscapes, said Dev Niyogi, state climatologist based at Purdue University.
"This, combined with the need by plants to replace water lost through evaporation, is setting a classic scenario for a regional drought," he said.
If La Niña does develop quickly and with at least moderate intensity, drought conditions may develop in Indiana by August, said Ken Scheeringa, associate state climatologist.
"In recent years, there has been a trend to fall droughts in Indiana," he said. "For example last year, moderate drought occurred from late September into late December."
The climate office expects the second half of June to be drier than normal, followed by equal chances that July and August will be wetter, drier or near normal in precipitation across the Midwest and a slightly higher chance of drier-than-normal conditions over Indiana.
Neutral weather conditions began in late May after what the climate office said was one of the strongest El Niños on record. The El Niño generated eight consecutive months of above -normal temperatures in Indiana through April and a mix of above- and below- normal precipitation.
"Historically, a quickly developing La Niña after a strong El Niño can be moderate to strong in intensity," Scheeringa said.
La Niña conditions occur when Pacific sea surface temperatures in a specific area near the equator persist cooler than normal by about 1 degree Fahrenheit. The "signature" impacts of La Niña are Indiana summers with above-normal temperatures and less-than-normal precipitation.
Signs of extended dryness have been reported in the June 9 update of the U.S. Drought Monitor, with several counties in the far north and northeast portions of Indiana abnormally dry. (A map of Indiana as part of the Drought Monitor is available at http://droughtmonitor.unl.edu/Home/StateDroughtMonitor.aspx?IN.)
Extended periods of dry conditions are nothing new to Indiana. In addition to the moderate drought in some parts of the state last year, other areas were abnormally dry before and during it. Heavy spring rains that killed or severely damaged some crops and dry conditions in the summer took a toll on Indiana's corn crop, which was the smallest since the devastating drought of 2012. Soybean crops fared better, recovering enough after the spring to produce a stronger crop.
"We will monitor the situation," Niyogi said. "Droughts don't always mean lowered yields. The timing, intensity, duration and area covered matter."
Writer: Keith Robinson, 765-494-2722, firstname.lastname@example.org
Sources: Dev Niyogi, 765-494-6574, email@example.com
Ken Scheeringa, 765-494-8105, firstname.lastname@example.org