Weather Update For Thursday 5/20/21 7 PM CST

Emergency Managers of Southeast Louisiana and Southern Mississippi

Here is an update concerning the potential for tropical cyclone development in the Gulf of Mexico as well as changes to coastal flood warnings and the wind advisory.

Changes from previous update:

• There is a low (20%) chance of tropical development in the Gulf of Mexico over the next 5 days.

• Coastal Flood Warning is now in effect for portions of Tangipahoa, Livingston, and St. John the Baptist Parish

• Wind Advisory is extended through tonight and is now in effect through 7 PM CDT tomorrow.

Overview:

There is a LOW (20%) chance of tropical cyclone development over the next 5 days.  

• This system is forecast to move generally northwestward over the next 1 to 2 days.

Coastal flooding of 2 to 3 feet above ground level is expected during high tide tonight into tomorrow morning along the shores of Lake Pontchartrain and Maurepas in Tangipahoa, Livingston, and St. John the Baptist Parishes.

Winds of 20 to 25 mph with gusts over 35 mph will be possible through Friday evening across coastal portions of Mississippi and Louisiana including all of metro New Orleans.

Confidence:

• Since this system has not yet developed, there is low confidence in the forecast impacts from any tropical development.

• Confidence is high that coastal flooding and gradient wind impacts will continue through tomorrow.

Impacts:

• The tropics currently pose no immediate threat to the local area, but should continue to be monitored.

• Coastal flooding of 2 to 3 feet above ground level will cover low lying coastal roadways and potentially flood non-elevated structures.

• Strong winds of 20 to 25 mph with gusts over 35 mph could cause loose objects to blow around, knock down tree branches, and produce scattered power outages. High profile vehicles will experience difficulties while travelling on area bridges.

The graphics below highlights the ongoing coastal flood and wind impacts as well as the area of concern in the tropics.

Additional Information and Resources:

NWS New Orleans Website: www.weather.gov/neworleans

NWS New Orleans DSS Website: http://www.weather.gov/lix/embrief

NWS New Orleans Tropical Page: https://www.weather.gov/srh/tropical?office=lix

River Gauges and Forecasts: http://water.weather.gov/ahps2/index.php?wfo=lix

NWS New Orleans Facebook: www.facebook.com/NWSNewOrleans

NWS New Orleans Twitter: https://twitter.com/NWSNewOrleans

Online Severe Weather Reporting: https://www.weather.gov/lix/submit_storm_report