National Weather Service forecasters warned that heavy rain Saturday afternoon and evening could cause flooding in the New Orleans area, in advance of the possibility of more severe weather Sunday.

The Weather Prediction Center in Oklahoma — which tracks thunderstorms — told the local forecast office that storms passing the metro New Orleans area could do so with a train effect, meaning multiple storms could traverse the same locations as if on railroad tracks.

In response, city officials in New Orleans announced they had temporarily lifted parking restrictions on neutral grounds and sidewalk so that residents can move their cars to higher ground.

Neutral ground, sidewalk parking restrictions lifted in New Orleans due to severe weather threat New Orleans officials have made changes to parking restrictions in the city with another round of severe weather set to move through the area …

Local Weather Service forecaster Robert Ricks said the area has been dry in recent weeks, so drainage pumps meant to protect the community from flooding have capacity to do so effectively. Nonetheless, Ricks said the office has been seeing rainfall amounts of 1 inch per hour, which could complicate the pump’s operations if that rate is prolonged.

Ricks’ office also warned that wind speeds associated with strong storms could exceed 30 miles per hour. Communities that could be affected include New Orleans, the east and West Banks of Jefferson Parish, St. John the Baptist Parish, northern St. Charles Parish, northwestern St. Bernard Parish, northwestern Plaquemines Parish and areas headed west.

Meanwhile, forecasters have placed the New Orleans area under a slight risk of severe weather on Sunday. That is the second-lowest severe risk of a scale with five categories.

A slight risk can mean wind gusts in excess of 60 mph, which can down trees and slightly damage buildings. Also, hail greater than an inch in diameter and isolated tornadoes are possible.

Forecasters have placed communities north of Covington and Slidell under higher risks for severe weather on Sunday. The fitful weekend weather arrives in advance of a warm front.

Staff writer Mark Schleifstein contributed to this report.