Very intense convection continues to impact portions of southern Louisiana this morning as an area of low pressure (non-tropical, but with a tropical connection) plods slowly west near the MS/LA border. Intense rain rates of 3″-3.5″ per hour have been observed in the past 24 hours with some areas accumulating 10″-11″ of rain in a short period of time. This has wreaked havoc near and east of Lafayette and Baton Rouge where motorists have been stranded on interstates 55 and 10.
*Update as of 2200 UTC on 08/12/16: One co-0p observer near Livingston, LA (east of Baton Rouge) has recorded 17.09″ of rain since midnight, but much of that feel in the first six hours!
The 1130 UTC Weather Prediction Center (WPC) Mesoscale Precipitation Discussion (MPD) mentioned the continued influx of deep moisture near and south of the low center with sufficient instability to keep convection organized. Andrew Orrison (WPC forecaster/satellite focal point) mentions HIRES guidance indicating an additional 10″ of rain is possible in this highlighted area between 1200 UTC and 1800 UTC.
Conversations with Andrew reveal how useful the GOES-14 SRSOR imagery has been in monitoring this evolving heavy rain/flash flooding threat. The animation above shows one way that forecasters utilize the high frequency data provided by SRSOR and Vaisala GLD-360 lightning. Notice how the lightning activity around sunrise is quite intense and as the sun rises, the details in the evolution of the cloud canopy and deep convection becomes more apparent. This really helps the forecasters identify the regions that may be more susceptible to extreme rain rates when compared to radar.
The CIMSS Satellite Blog also has an entry on this event that looks into the Total Precipitable Water (TPW) and Infrared signals from GOES-14: https://cimss.ssec.wisc.edu/goes/blog/archives/21729
For more GOES-14 SRSOR animations and information: http://cimss.ssec.wisc.edu/goes/srsor2016/GOES-14_SRSOR.html
Thanks for reading!