New Orleans could get 10 inches of rain from tropical system

Axios

2 days ago

New Orleans and Jefferson Parish officials are preparing for up to 10 inches of rain as a tropical system heads toward Louisiana.
Why it matters: That's more rain than New Orleans typically gets in the entire month of July.
Some parishes are preparing for the threat by setting up sandbag locations and encouraging residents to prepare for the possibility of street flooding.
The big picture: The system was moving over Florida on Tuesday and expected to reach the Gulf on Wednesday, the National Hurricane Center said.
A tropical depression could form while it moves west in the Gulf, per NHC. It will be named Dexter if it strengthens into a tropical storm.
It's expected to approach Louisiana's coast on Thursday, NHC said.
Between the lines: It's the Gulf Coast's first storm threat of the 2025 hurricane season.
The biggest concern for southeast Louisiana is flooding, according to the National Weather Service's Slidell office.
It's too early to tell where the heaviest rain will fall.
The latest: Multiple rounds of heavy rainfall are expected to start Wednesday in New Orleans and continue through at least Saturday morning, NWS said.
It's "not out of the question" for some places to get more than 10 inches, NWS wrote in its Tuesday forecast.
New Orleans is most likely to get 3 to 4 inches by Sunday, with higher totals on the coast, per NWS.
Rainfall rates in some storms could be more than 4 inches per hour, which is faster than the pumps can drain streets.
A flood watch is in effect for southeast Louisiana and south Mississippi from Wednesday through Saturday morning.
What to do now: Leaders are asking residents and businesses to clear catch basins in front of their properties now. Clean your gutters, too.
It's also a good time to check your emergency kit and charge your phone and electronics in case there's an outage. Make sure you have a way to get info (Ex. NOLA Ready texts or a weather radio).
Sandbag sites are open in St. Tammany and Terrebonne parishes, WDSU says.
Once the rain arrives, stay off the roads if there's flooding. It's dangerous for you and can push water into homes and businesses.
Drainage prep
Zoom out: Drainage pumps in New Orleans and Jefferson Parish can handle 1 inch of rain the first hour and 0.5 inch per hour after that when the systems are working at full capacity.
When rain falls too quickly, it overwhelms the pumps, causing street flooding.
The Sewerage & Water Board said 86 of 93 major pumps (map) were working as of Tuesday. Two of its power turbines were down and available only for emergency use.
SWBNO crews are drawing down canals and cleaning catch basins in anticipation of the rain, spokesperson Ceara Labat tells Axios New Orleans.
All the underpass pumps were working, SWBNO said, with the exception of one of the three that drain the Carrolton Avenue/I-10 underpass.
In Jefferson Parish, all 194 pumps were working as of Tuesday, per drainage director Ben Lepine.
Employees have also tested all the generators and were ready to staff pumping stations 24 hours a day if needed, he said in a statement.
Public works employees are focusing on cleaning catch basins until the rain arrives.
Entergy said it is monitoring the storm and preparing for severe weather in south Louisiana.
The company has materials, supplies and staffing available if needed, a spokesperson tells Axios New Orleans.
What we're watching: Meteorologists are monitoring where the system goes once it enters the Gulf, which will give them a better idea where the heaviest rain will fall.