Question: Will the up-river flooding mean a return of flood threats for Louisiana later in the summer?
Answer: Not likely, and fortunately, based on what has occurred thus far.
I have yet to see projections beyond 4-weeks for the Mississippi in Louisiana, but I seriously doubt the water will come anywhere near what we saw in the spring.
The biggest reason: even though large sections of the upper Mississippi and Missouri (and other rivers) are experiencing flooding right now, the majority of the Mississippi flow that passes through Louisiana is due to water conditions on the Ohio River. The Ohio is a much larger contributor to our flow than the other sub-basins. Fortunately, there has not been widespread flooding in the Ohio Valley.
So we WILL see a summer rise on the Mississippi, but its highly unlikely that we'll have another "top 10" flow like earlier this spring. The current 4-week outlook keeps all sites in Louisiana well-below flood stage (and remember that flood stage is well below the tops of the levee protection), but we need an outlook that extends beyond 4 weeks to be better prepared as to what to expect.
Once I have a better handle on some longer-range projected numbers, I'll let you know.