Record-breaking warm temperatures in Louisiana during Christmas week that had residents putting away their festive sweaters and jackets and pulling out summerwear capped off a year of weather extremes.
In Baton Rouge, high-temperature records were broken on Dec. 24 at 83 degrees, Dec. 26 at 84 degrees and Dec. 27 at 82 degrees.
New Orleans residents also experienced unseasonably warm temperatures with four straight days — Dec. 24 through Dec. 27 — of record-breaking high temperatures in the low 80s, according to information from the National Oceanic and Atmospheric Administration’s Regional Climate Centers. Lafayette also broke high-temperature records on Dec. 24, 25 and 26.
In fact, the state averaged 19 degrees above normal for the entire Christmas week, said Barry Keim, the state climatologist.
“That’s the largest temperature departure (for a week) that I can remember in my 12 years as state climatologist,” Keim said. “It was a pretty big deal.”
However, the biggest weather story of the year didn’t happen in a day or a week. It’s been going on all spring, all summer and now the start of winter.
El Niño weather conditions helped keep tropical storms away from Louisiana during the late spring and summer months and is now bringing extremely mild temperatures at the start of winter.
NOAA noted that El Niño began in March and has continued to strengthen, becoming one of the strongest in the past 60 years, rivaling those of 1982-83 and 1997-98, Keim said. With sea surface temperatures in the central Pacific Ocean becoming warmer for an extended period of time, El Niño influences temperature, rainfall and other weather around the world.
In Louisiana, the weather condition typically results in more rain, which causes cooler temperatures because of the cloud cover and wetter weather. At the same time, El Niño conditions also allow fewer arctic blasts to blow over the state, Keim said.
“We’re running well above normal for the last 10 to 12 weeks,” Keim said of the warm weather.
Louisiana also tends to get more storms during the winter and spring when an El Niño is present, he said. “It’s not like a one-time thing. Its climatic impacts are over the whole region,” the climatologist said.
In April, a month after NOAA reported an El Niño was in place, south Louisiana residents watched as the skies darkened and a powerful line of storms pushed through, bringing tornadoes, heavy rain and straight-line winds.
“It was one of my scariest brushes with weather,” said Keim, who described being on his way to LSU at 9:15 a.m. on April 27 when the sky kept getting darker and darker. “It was like midnight.”
Heavy rains and strong winds downed power lines across Baton Rouge, flooded roads, uprooted trees and spawned five tornadoes in the state.
The winds were strong enough — measuring 70 mph gusts at Louis Armstrong New Orleans International Airport — to push railroad cars off the Huey P. Long Bridge.
Louisiana also experienced drought conditions in 2015.
“The state was in and out of drought in the winter but nothing too serious,” Keim said. “Things started to get serious in the later part of the summer.”
Hot, dry weather lingered in the summer, and by October, 86 percent of the state was in some level of drought. More than half of the state was in the two worst drought categories of extreme or exceptional. Yet, by the end of October, the drought conditions were erased by heavy rainfall during three consecutive weekends.
That included the stormy conditions of Oct. 26 and Oct. 27 that resulted in more than 10 inches of rain in many areas in south Louisiana.
Follow Amy Wold on Twitter, @awold10.