Mississippi River Flooding
The Mississippi River entered flood stage on February 17, 2019 and remained in flood stage in New Orleans for a record 292 days. In an average year, the river runs around three to five feet deep through New Orleans heading into Hurricane Season. This week, the river just dropped under eleven feet deep. A large hurricane, like Katrina, can add twelve feet to the river depth, which would push well beyond the levee height and cause widespread flooding.
Beyond flooding, the extended duration of the river being above flood stage translates to a higher likelihood of levee damage. During an interview with the Associated Press, Nicolas Pinter, an expert on river flood risks and levees, described the risk. “The big threat is water getting through or underneath. The longer the duration, the greater the threat.” Experts now worry about possible underwater damage to the levies as we head into Hurricane Season. The Army Corps of Engineers has conducted over 200 inspections on the levee system this year, but repairs are difficult and limited while the river is at flood stage.
Hurricane Season Outlook
National Hurricane Center, 08/08/2019
In addition to high river levels, forecasters are now predicting for a surge in hurricane activity this year. NOAA’s Climate Prediction Center increased the likelihood of an above-normal Atlantic hurricane season from 30% to 45%, a change from the previous outlook published in May. The number of predicted named storms has also increased to 10-17, of which 5-9 will become hurricanes (winds of 74 mph or greater), including 2-4 major hurricanes (winds of 111 mph or greater). Two named storms have already impacted the southern states ahead of the peak hurricane months, August through October.
The FEMA Ready Campaign released videos this week that show the potential impacts of a tropical storm, specifically hurricane storm surge and flooding. The videos emphasize the importance of following state and local authorities’ instruction ahead of a storm.
Sources:
https://weather.com/safety/floods/news/2019-07-29-record-long-mississippi-river-flood-ends
https://www.apnews.com/34b034b6e0904529a958f57398b06c71
https://www.noaa.gov/media-release/noaa-increases-chance-for-above-normal-hurricane-season
