In the latest hurricane forecast news, Tropical Storm Barry heading westward is expected to hit the Louisiana coast Saturday and lash metropolitan New Orleans as well with a “life-threatening storm surge.”

According to the National Hurricane Center’s warning, heavy rainfall will grace the north-central Gulf Coast. In case of a hurricane, the greatest danger comes from storm surge or water rushing from the ocean. Storm surge will push up water levels as winds start lifting the water and start throwing them onto the shore. As ocean water gushes onto land, flooding conditions will worsen.

The NHC said the storm may graduate into “Hurricane Barry” by late Friday or early Saturday. At present Barry is 85 miles from the mouth of the Mississippi River and moving at a speed of 50 mph. The speed may increase in the next 48 hours.

High crest in Mississippi River

The NHC alert said the Mississippi River at New Orleans may rise to 19 feet Saturday evening. In that case, it will be breaking a record of 70 years, according to the National Weather Service.

“There is a danger of life-threatening storm surge inundation along the coast of southern and southeastern Louisiana,” the NWS warned.

Following the hurricane warnings, a state of emergency was declared in Louisiana and evacuations were ordered in some parts. Though onslaught of the tropical storm Barry was anticipated over the Gulf of Mexico, no evacuation orders were out for New Orleans.

Barry’s time spent on Gulf of Mexico matters

Barry’s landfall along the Louisiana coast Friday night or Saturday may be as a tropical storm.  But it's scaling up into a hurricane just before landfall depends on its stay over the Gulf of Mexico, according to an expert.

“Whether Barry becomes a hurricane before landfall or not will depend on the amount of time it can spend over the warm water of the Gulf of Mexico,” said AccuWeather Hurricane Expert Dan Kottlowski.

Louisiana Governor warns of significant weather event

“This is going to be a significant weather event,” Louisiana Governor John Bel Edwards tweeted and urged residents to monitor updates and heed the directives of local authorities.

Edwards announced that the Louisiana National Guard was instructed activated to spare 3,000 personnel for any Barry-related emergencies.  Location of Tropical Storm Barry Roughly half of both the oil output and gas output in the Gulf is shut in because of Barry, but the United States no longer depends on the region for its supply of oil and gas as it did a dozen years ago.  Photo: National Weather Service

However, J. David Rogers, author of a 2015 study on the flooding of New Orleans during Hurricane Katrina in 2005, said the new levees installed in 2011 will secure the city with greater protection from major flooding.

New Orleans cautions residents

New Orleans Mayor Latoya Cantrell said the city's anti-flood water pumps were working fine. However, she said, it will be impossible to “pump our way out of the water levels and waterfalls that are expected to hit the city of New Orleans.”

Meanwhile, New Orleans Police Superintendent Shaun Ferguson asked people to remain in their homes and advised against driving cars through standing water as the danger of being swept away or getting stranded is too high.