The unimaginable energy of Hurricane Ida was on show on Sunday because the storm reversed the course of the mighty Mississippi.

The river quickly flowed from south to north on Sunday afternoon after Ida made landfall as a Category 4 storm that underwent speedy intensification. Data from the U.S. Geological Survey exhibits {that a} river gauge at Belle Chasse, simply southeast of New Orleans, recorded the gorgeous about-face of the Mississippi River.

The Mississippi was discharging roughly 350,000 cubic ft (9,910 cubic meters) of water per second within the days previous to Ida’s arrival. Water moved upstream at a price of 40,000 cubic ft (1,132 cubic meters) per second. That’s a staggering quantity of water to show round. Ida is predicted to push 16 ft (5 meters) of storm surge inland, with the very best inundation masking an space from the petrochemical hub of Port Fourchon to the mouth of the Mississippi. The turnaround of the river is indicative of how highly effective that surge has been.

It’s a phenomenon we’ve seen with different storms, notably Hurricane Florence in 2018. That contributed to what’s referred to as compound flooding the place storm surge pushes water inland the place rain is falling. With water pushing ashore, there’s nowhere for the rain to empty.

With Ida, that might turn out to be an even bigger concern as day turns into night and the storm lingers. The National Hurricane Center famous in its most up-to-date forecast dialogue that “Ida’s forward motion has slowed.” Slower movement means bands of rain can repeatedly sweep over a given location, resulting in greater rainfall totals and extra flooding.

Despite spending hours over land, Ida has additionally did not weaken considerably. The storm can be nonetheless packing winds of 130 mph (209 kph), owing partially to what’s known as the brown ocean impact, which happens when storms are in a position to suck up moisture from the land itself and keep their energy whilst they transfer inland. (The impact has even helped maintain a tropical cyclone all the best way to the Great Lakes, albeit in a a lot weaker state than Ida.)

In the case of southeast Louisiana, “land” could be a beneficiant assertion; the area is generally bayous and barrier islands which have turn out to be much more fragmented and watery due to the fossil fuel industry inflicting subsidence (along with the ocean stage rise brought on by burning stated oil and gasoline). The levee system and containment of the Mississippi River have led to further sinking in what scientists have stated is a “worst case” state of affairs for the state.

There are a lot of causes to fret about that in the long run. But what it means now could be which means there’s loads of heat, shallow water to maintain Ida fueled up because it crawls northward. And though the Mississippi has since un-reversed course, the storm nonetheless has loads of injury left in its system.