Mar 11, 2016

Floods From up to 20 Inches of Rain Create State of Emergency in Louisiana

Ouachita Parish, LA
USA
by
Jeff Masters
,
Weather Underground
A bridge collapsed on Louisiana Highway 557 in Ouchita Parish, Louisiana, on March 10, 2016. Photo: Louisiana DOTD
A bridge collapsed on Louisiana Highway 557 in Ouchita Parish, Louisiana, on March 10, 2016. Photo: Louisiana DOTD

The upper low over Mexico responsible for the deluge was able to tap into an atmospheric river of moisture from both the Western Caribbean and the Eastern Pacific, and was still bringing record amounts of water vapor to the Gulf Coast on Friday morning. The 7 am EST Friday March 11, 2016 upper-air balloon sounding from Jackson, MS set a new record for most precipitable water on record for any day during the December - March period: 1.97". New Orleans, LA set a record on Friday morning for most precipitable water of any astronomical winter date: 2.14". The record atmospheric moisture this week has led to rainfall amounts one would expect to occur only once every 200 years (a 0.5% chance of occurrence in a given year) over portions of northern Louisiana. According to the latest NOAA Storm Summary, as of 9 am EST Friday, a rain gauge two miles from the city of Monroe, Louisiana had received 20.90" of rain since Monday, and Shreveport, Louisiana had picked up 19.00" at Barksdale Air Force Base. Over a foot of rain was recorded at several locations in Southern Arkansas