Warm, dry winter spells drought for much of Oklahoma, forecasters predict
Just months after summer rains gave way to one of the state's driest autumns on record, extreme drought crept back into Oklahoma last week.
Forecasters say it isn't likely to leave anytime soon.
A strengthening La Nina weather pattern is bringing increased odds for a warmer- and drier-than-average winter in Oklahoma, according to seasonal forecasts released Thursday by the National Oceanic and Atmospheric Administration's Climate Prediction Survey.
Forecasters expect that the warm and dry trend will cause the drought that's been developing in southeast and far northwest Oklahoma to spread across the state in the coming months.
During a conference call with media Thursday morning, Stephen Baxter, a seasonal forecaster at the Climate Prediction Center's Operations Prediction Branch, said forecasters expect the La Nina weather pattern will persist through February.
La Nina is a cooling of ocean surface temperatures in the central and east-central Pacific Ocean near the equator. That cooling trend drives a number of weather patterns around the world.
Although La Nina's results in Oklahoma can vary from one episode to the next, the pattern generally leads to relatively warm, dry conditions in the state, said state climatologist Gary McManus.
Those conditions are exactly the ones NOAA forecasters say the southern United States can expect to see this winter. According to Thursday's seasonal forecast, forecasters are predicting increased chances for a warmer-than-average December across the southwest and southern Great Plains.
Forecasters expect that warming trend to continue through the winter, with increased odds for warmer- and drier-than-average conditions continuing through February.
Those forecasts don't rule out isolated episodes of cold weather and rain or snow, but rather indicate that the coming winter overall is likely to be relatively mild and dry. Those conditions are likely to exacerbate a drought that has already been brewing in southeastern Oklahoma, McManus said.
About 14 percent of the state, all of it in southeast Oklahoma, was in severe drought last week, according to the U.S. Drought Monitor. A small area of land in southern McCurtain County, in far southeastern Oklahoma, is in extreme drought, according to the drought monitor. That's the most severe drought classification the state has seen since October 2015.
Since the beginning of September, southeastern Oklahoma has seen an average about 4.25 inches of rain — just over a third of what it would typically expect to see during that period, making it the fourth-driest such period on record.
Forecasters expect that drought to persist where it already exists and spread across most of the rest of the state this winter, according to a Climate Prediction Center seasonal drought outlook released Thursday.
McManus said that dry trend could make this winter's wildfire season more severe than usual. The state's most active wildfire season typically runs from November through early spring, when vegetation is dormant and humidity is low. Adding unusually dry conditions to that combination can lead to extreme fire danger, he said.
There's no way for climate scientists to know for certain if this year's drought will turn into a crippling multiyear trend like the one that gripped southwestern Oklahoma from 2010-2015, McManus said. But in the short term, the drought doesn't appear likely to ease anytime soon.
“We can say with a little bit of confidence that we might see it stretch through to next spring," he said.