Storm unleashed a disastrous deluge in Louisiana

Storm unleashed a disastrous deluge in Louisiana

Storm unleashed a disastrous deluge in Louisiana: With the terrible Ellicott City flash flood fresh on our minds, another nearly unimaginable flood unfolded over southern Louisiana, beginning Aug. 11 and continuing to today.
While the Ellicott City flood had laserlike focus (6 to 8 inches of rain in just three hours), the relentless torrent across Louisiana created a regional-scale disaster to the tune of 25 to 30 inches accumulating over three to four days.
How does the atmosphere create such astounding waterworks over a short period of time?
The answer: Combine a sopping-wet air mass, featuring record-setting humidity levels, with a peculiar type of cyclonic storm running against the grain of the mid-latitude, westerly air current. You end up with a rogue vortex operating in a near-infinite water supply, creating both hell and high water for many, many thousands of people.
Cyclonic vortices — some people just call them storms — are the bread-and-butter weather-makers in both the tropics and middle-latitudes. At one end of the…