Unusual Meteorological Phenomenon — a “Monsoon Depression” — to Blame for Louisiana Flooding


The storm’s angry gray clouds settled in over Louisiana and like a grumpy house guest, it simply refused to leave.

Meteorologists call it a “monsoon depression.”

The rare weather event dumped more than 20 inches of rain on southwest Mississippi and coastal Louisiana, causing massive flooding in Baton Rouge and Lafayette, La.

As meteorologist Tim Destri with the NWS New Orleans/Baton Rouge office explains it, a low pressure system forms near the surface bringing deep tropical moisture from the warmer water in the Caribbean — almost like a hurricane but without the wind and the name.

“Everything came together just right like it would with a tropical weather system,” Destri said.

And the no-name storm isn’t done yet.  The NWS in Baton Rouge forecasts at least a 50% chance of rain through Wednesday, though drier conditions are expected in the later portion of the week and into the weekend. That rain will come by way of more “pop-up” variety of storms rather than from the system, though leftover moisture will increase rain chances, Destri said.

Destri called it one of the biggest flooding events in the area’s recorded history, recalling the damage wrought by Katrina, the massive hurricane that nearly wiped out New Orleans in 2005.

“This probably ranked up there with some of the top rainfall-producing systems in history, ” Destri said. “Damage is really significant, I mean extreme, because it’s been so devastating with some houses just completely inundated, just scenes like Katrina almost.”

Click here to continue reading…

SOURCE: Chris Bonanno
Florida Today