The Edmond Sun

May 10, 2014

Lack of rainfall projects tough, dry summer for Central Oklahoma

Exceptional drought on the way to area

James Coburn
Special to The Sun

EDMOND — Central Oklahoma should have had more rainfall by now, said Steven Root, president and CEO of WeatherBank Inc., located in Edmond. Drought conditions resulting in dry brush did not help firefighters in their effort to quell a wildfire in Logan County this week.

With only 4-inches of rainfall received in Edmond as of Thursday, it’s not too far down the trail that central Oklahoma will go from a severe drought to an exceptional drought, Root said.

According to the National Weather Service, Will Rogers World Airport in Oklahoma City as of Thursday had received 3.94 inches of rain this year. Ten inches of rainfall would be normal for the year, showing a deficit of 6.27 inches.

“If we don’t get rain, and I’m not just talking rain for Western Oklahoma,” Root said. “I’m talking for Texas, New Mexico, Oklahoma, Southern Colorado — all of that — we’re going to turn off the source of water that we normally see.”

Monsoon moisture flow usually comes into Old Mexico, Arizona and parts of New Mexico in June or July, Root said. Indications are that the monsoon will be weaker this year, Root said.

A weak monsoon combined with the existing severe drought encroaching on Oklahoma will make matters worse, Root said. As a result, the drought will be hard to stop, he said.

May and June are the top months for rainfall, with nearly 50 percent of the annual rainfall coming in May, June, August and September or October, depending on location, Root said.

Rainfall in Edmond totaled 2.11 inches Wednesday night, making it the largest 24-hour total since Aug. 9, 2013, when it recorded 3.2 inches of rain.

“Also, there has only been two days of rainfall since the middle of last October,” Root said.

Based on predictive data that year-to-date rainfall will total 4 inches on May 31, then 2014 year-to-date rainfall will be the driest for Edmond since 1996, Root said.

The Palmer Drought Index measurement of dryness is based on recent precipitation and temperature and is most effective in determining long-term drought of more than several months, Root said.

“It uses a 0 as normal, and drought is shown in terms of negative numbers; for example, negative 2 is moderate drought, negative 3 is severe drought, and negative 4 is extreme drought,” he said. The Palmer drought data for Oklahoma City is shown using a 30-day running average up to a 120-day running average.

“The disturbing observation here is, when the PDI is -2.0 or lower (moderate drought), there has only been one instance out of four previous instances (2009) where the drought conditions quickly reversed direction and improved,” Root said. All other instances (2006, 2011 and 2012), the drought worsened. That does not bode well for 2014.”

A burn ban issued by Gov. Mary Fallin remains in effect for Edmond and a large part of Oklahoma. Visit OFS website for a complete list of burn bans and compliance guidelines. | 341-2121