El Nino did it.
A new analysis of the Midwestern flooding says the unusual Pacific Ocean warming known as El Nino was probably a leading culprit.El Nino is part of a complex phenomenon known as ENSO, which causes the water in the central Pacific Ocean to warm up every three to seven years.
The ultimate fault of the flooding may lie in a combination of factors, but the El Nino anomaly was "a direct influence," according to a report Thursday by the federal Climate Analysis Center in nearby Camp Springs, Md.
This summer's flood damage totaled more than $10 billion and 48 people lost their lives along the upper Mississippi and related rivers as persistent heavy rains deluged a region already soaked from winter snowmelt.
And wet soils continue to pose a problem for farmers in the region as well as raising the specter of more flooding next year.
This year's wetness means that the ground will have a limited capacity to absorb snowmelt next spring, so heavy winter snows or spring rains next year could mean a recurring threat, the report says.
The direct cause of the 1993 flooding was a persistent and unusual weather pattern causing storm after storm after storm to inundate the region.
And the pattern that brought those storms to the Midwest was encouraged by the ENSO, according to the report.
ENSO stands for El Nino-Southern Oscillation. El Nino is the warming of the Pacific waters, while southern oscillation refers to changes in air pressure over the Pacific Ocean that occur at the same time.