FARGO, N.D. — With its ominously titled slideshow, ‘‘Get ready for a big one,’’ the National Weather Service told flood-weary residents in the Fargo area Thursday to prepare for one of the Red River’s five largest crests this spring, an outlook that prompted city and county officials to ask for permanent flood protection.
The latest Weather Service flood outlook for Fargo and neighboring Moorhead, Minn., includes a 50 percent chance that the river would top 38 feet this spring, which would surpass the fifth-highest crest of 37.34 feet in 1969. There’s a 10 percent chance of an all-time record.
‘‘It’s March madness again,’’ said Fargo city administrator Pat Zavoral. He noted that it would be the fourth major flood in five years, including a record crest of 41 feet in 2009.
Chances of a top-five flood increased with near-record cold temperatures that have delayed the snowmelt, which isn’t expected to begin until the first week of April, Weather Service officials said. The chances of major rainfall totals also increase around that time.
‘‘That’s a volatile mix,’’ said Greg Gust, a meteorologist with the agency. He added, ‘‘The bottom line is that we have a way above normal snowpack sitting out there right now.’’
The flood threat comes as Congress is to consider whether to help fund a nearly $2 billion diversion channel around the Fargo-Moorhead area, a project that has come up against roadblocks.
Residents downstream of the river are protesting about a holding area that would flood homes and farmland in times of high water.