In the latest blow for Metairie’s Carnival celebration, Jefferson’s longest-parading krewe is decamping for Kenner.

The 200-member, all-female Krewe of Isis will take its show west in 2020, abandoning the Metairie route it has used for the last four decades, according to sources familiar with the decision.

The move is the latest in a series of setbacks for the much-diminished Metairie Carnival schedule, which has lost parades and attendance in recent years as the number and size of krewes in New Orleans have grown.

Earlier this year, another longtime parading krewe, Caesar, said it would no longer roll on Veterans Memorial Boulevard on the first Saturday of Carnival. Of the nine krewes that paraded in Metairie this year, only seven remain as potential parades for 2020.

The exact reasons for Isis’ decision have not been disclosed. Captain Sherrell Gorman declined Tuesday to confirm the move, saying that any changes would be announced at a Wednesday press conference at the Esplanade Mall. 

Kenner Mayor Ben Zahn said he too would reserve comment for the press conference.

Whether the move is a win for Kenner remains to be seen, said Carnival historian Arthur Hardy. There are no krewes that currently parade in Kenner during Carnival.

"They (Metairie) have lost two parades, but there are so many rumors about new parades jumping in, it's an incomplete story at this point," Hardy said. "I think it's really good for Kenner if it works."

Isis is the oldest parading Jefferson krewe, having held its 47th procession in March. For the first seven years of its existence, it was a Kenner parade.

The departures of Isis and Caesar may have been fueled, in part, by pressure from parish leaders for Metairie parades to adopt a new route that brings floats west along Veterans Memorial Boulevard to the Clearview shopping center, instead of the traditional west-to-east route.

The change, the parish leaders said, would help lure more families to the Bonnabel Boulevard section of the route and would boost the annual Family Gras concert series, which was moved to the shopping center.

Metairie’s Mardi Gras celebration has flagged in recent years as New Orleans krewes have proliferated and grown.

Three decades ago, when Jefferson’s Carnival celebration was at its height, the largest New Orleans krewes had about 1,000 members, Hardy said.

Now, three of them have more than 3,000, with many members siphoned away from suburban krewes by the lure of parading down St. Charles Avenue, Hardy said. Caesar, one of Jefferson’s largest krewes, had about 500 members.

Since Hurricane Katrina in 2005, at least nine Metairie-based krewes have folded or abandoned parading.

The new east-to-west route was offered as an option to krewes in 2019. But both Caesar and Isis opted to travel the traditional route, which started at Clearview shopping center and headed east along Veterans, taking short jogs up both Severn and Bonnabel before ending near Martin Behrman.

Both are night parades. Caesar has paraded on the first Saturday of Carnival, and Isis on the second. Their departures leave two gaping holes in Jefferson’s parade schedule.

At least one new krewe, Mad Hatters, has already applied for a parade permit in Jefferson. Applications are due July 31.

Follow Faimon A. Roberts III on Twitter, @faimon.