State climatologist Barry Keim calls it the obvious: Hurricane Ida ranks at the top of its five major weather events – plus a sixth larger climate development – for Louisiana this year.
“It was clearly the biggest event for Louisiana for 2021,” Keim said.
Category 4 hurricane made landfall at Port Fourchon on August 29, marking the 16th anniversary of Hurricane Katrina, with maximum sustained winds of 150 mph. That put him in a tie three for the state’s strongest storm ever, with Hurricane Laura in 2020 and Hurricane “Last Island” of 1856 wiping out a coastal resort village. parish church of Terrebonne.
Ida has so far caused $ 64.5 billion in damage in the United States, according to the National Centers for Environmental Information. That’s still well short of Hurricane Katrina of 2005, which is said to have caused at least $ 125 billion in damage, making it the costliest hurricane in U.S. history.
Ida is believed to be responsible for 96 direct deaths, including at least 26 in Louisiana.
Almost all of the residences in Grand Isle were damaged, 40% of which were destroyed. Storm surges and winds also devastated the Jean Lafitte sector and considerably damaged the parishes of Terrebonne and Lafourche and Kenner. The community of Plaquemines Parish in Braithwaite was also severely damaged by the storm, as was the case during the major Katrina floods and Hurricane Isaac in 2012.
“It’s quite transformative for these communities,” said Keim, a meteorologist and professor in the geography and anthropology department at Louisiana State University. “When they are affected in the short term like that, people make the decision not to come back.”
A storm surge from Pontchartrain and Maurepas lakes, combined with heavy precipitation totaling over 17 inches, inundated portions of St. John and St. James parishes. Several days later, as Ida’s remains reached New York, New Jersey and Pennsylvania, record-breaking rainfall resulted in the first-ever flash flood emergency, with New York’s Central Park registering a record 7.13 inches rain on September 1st.
The power outages attributed to Ida have approached 2 million people nationwide, including nearly 900,000 in Louisiana, where some areas have been without power for more than two weeks.
Ida is also blamed for the loss of at least 106 square miles of wetlands in the Barataria Basin south of New Orleans.
N ° 2: The gel
Second on Keim’s list of most significant weather events is the arctic outbreak February 10-20, which resulted in low temperatures on February 16 of 16 degrees in Lake Charles, 20 degrees in Baton Rouge and 25 in New Brunswick. -Orléans. Shreveport saw a low of 1 degree that day.
“The polar vortex has reared its ugly head again, one of those arctic plagues where the jet stream plunges far south and we get this air that’s either coming from Siberia or the North Pole and making its way across the plains. Canada and the Great Plains of the United States, “he said.
While Keim is unsure of a link between the ice outbreak and global warming, a September article in the journal Science linked the February event to a 40-year-old model of the polar vortex – a basin very cold air that normally stays about 10 to 30 miles above the North Pole – most frequently extending south. Temperature changes caused by global warming have disrupted atmospheric conditions in the Arctic, in part due to increased annual melting of its ice cap, the newspaper concludes.
Much of the country’s attention during the cold snap was focused on Texas, where much of the power transmission grid failed for a day. But electrical problems were also prevalent in Lake Charles and other parts of Louisiana.
“Freezing rain was the biggest problem, cutting off power for days or weeks, depending on which part of the state you were in,” Keim said.
The National Center for Environmental Information attributes $ 20.8 billion in damage to the cold snap and estimates that up to 10 million people are without electricity. The lack of electricity contributed to a nationwide death toll of 172, which helped make the cold the costliest winter storm on record in the United States.
N ° 3: Thunderstorms
The third event on Keim’s list is a series of thunderstorm lines between May 15 and 19, with the worst rains occurring on May 17, resulting in dramatic flash floods. At Lake Charles, 8 to 17 inches fell in short stretches in several places, while parts of the Baton Rouge area recorded totals of 10 inches.
“It’s obviously large amounts of rain, but most of that rains fell in about 3 hours, which caused most of the problems,” Keim said. “There were estimates of between 400 and 500 flooded structures in the southern half of Lake Charles, and even in Baton Rouge there were significant areas with flood damage.”
The National Center for Environmental Information estimated that storm damage in Texas and Louisiana totaled $ 1.4 billion, including homes, businesses and vehicles in Lake Charles and Baton Rouge. The event is also blamed for 5 deaths.
It’s always difficult to associate individual precipitation with the effects of climate change, Keim said. “But you can at least say it’s consistent with what is expected from climate change,” he said. “You can argue that warmer sea surface temperatures and more evaporation and more water can be stored in the atmosphere, which produces events like this.”
According to data from the National Center for Environmental Information, Gulf water temperatures were on average continuous up to 9 degrees above average during the year, compared to water temperatures in 1981. to 2010.
N ° 4: Tornadoes
The fourth on Keim’s list is a tornado outbreak on April 6-7. There have been a dozen separate reports of tornadoes that have landed across the state, which Keim said could actually include instances where a single tornado touched down for a brief period, ascending to the top. in the sky for a while, then landed again several miles away.
Some of the most important affected include:
- EF1 tornado damaged charter school in Marksville
- An EF1 tornado which tore off the roof of a barn in Lecompte and overturned a mobile home.
- Possibly three tornadoes north of Bastrop, including one damaging a house and trapping at least one person inside, a second estimated at an EF1 force which injured one person, and a third which damaged a house and trapped several people there. inside.
- The one that damaged several houses near Kilbourne.
Two days later, a second storm system spawned a tornado near Palmetto, north of Lafayette. He destroyed several homes and rolled over a large mobile home several times, killing one and injuring seven, according to National Weather Service reports.
This same system caused wind damage along Interstate 10 from Baton Rouge to Sorrento, including power lines and downed trees, and damaged several homes. Wind damage was also reported in Lacombe and Slidell.
N ° 5: Claudette
Fifth on Keim’s list is Tropical Storm Claudette, which has the unusual merit of having formed on June 19 at 4 a.m. after made landfall on the Louisiana coast near Morgan City as a tropical depression.
“It has gotten stronger from the force of tropical storms over the swamp,” Keim said, the result of what forecasters call the “brown swamp effect,” where there is still enough warm water under the swamp. system in the wetland to allow it to intensify.
“It can probably happen more on the Louisiana coast than anywhere else due to the amount of swamp,” he said. “There is so much water it really is like being over the ocean or the gulf.”
Claudette caused extensive flood and rainfall damage in southeast Louisiana and the Gulf Coast states to the east, resulting in insured losses estimated at $ 350 million, according to AON Benfield, a insurance service company.
The heaviest rains in Louisiana occurred in Slidell, which saw 9.6 inches, resulting in widespread flooding that damaged a number of homes. The far east of New Orleans at Lake Catherine saw 7.7 inches.
N ° 6: incessant rain
Keim’s sixth weather event is not really an event, but rather the pattern of storms throughout the year that will result in New Orleans, Baton Rouge and Lake Charles registering much above average precipitation for 2021.
Louis Armstrong International Airport measured 86.08 inches of rain for the year on Wednesday, compared to an average of 63.35 inches. The record is 102.37 inches in 1991.
Baton Rouge Ryan Airport had recorded 79.85 inches, compared to an average of 61.94 inches for the year. Its record is 90.54 inches, set in 2016, the year of the historic August flooding.
Lake Charles had seen 72.26 inches on Wednesday night, up from an average of 59.75 inches. This record is 85.16 inches, set in 2002.
Most of the heaviest precipitation in all three locations fell in the spring and summer. At the start of the year, all three locations had totals near or below average.
“As we neared the end of March, the switch flipped the other way and it rained and rained and rained and rained,” Keim said.
The change in pattern is the result of an unusual number of west-to-east frontal systems that have plunged deep into southern Louisiana, which usually does not happen, Keim said.
“Once we get to mid-May, the fronts stop coming in southern Louisiana, which is why we stay in this very hot regime from around mid-May to mid-September,” a- he declared.
Precipitation in New Orleans reached the annual average on August 13. Repeated thunderstorms this week didn’t really add much to the total.