Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
455 PM EDT Mon May 10 2021
 
Day 1
Valid 2055Z Mon May 10 2021 - 12Z Tue May 11 2021 

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS 
OF THE LOWER MISSISSIPPI VALLEY...

21 UTC Special Update...
Earlier convection that developed over the lower Mississippi 
Valley/central Gulf Coast region has now propagated south into the 
northern Gulf along with the associated outflow boundaries.  With 
organized redevelopment not expected through 12 UTC Tuesday, the 
Marginal and Slight Risk areas were removed.  

Still monitoring elevated convection developing near the ArkLaTex 
region.  While there is not a signal for widespread heavy amounts 
across this region, locally heavier amounts may impact areas 
impacted by recent heavy rains and with low FFG values.  
Therefore, the Margial Risk was left in place.  

Pereira

Previous Discussion...

Maintained the Marginal risk across portions of southwest TX from 
approximately Del Rio south towards Zapata. Extreme instability is 
forecast to develop over this region, with PWs increasing towards 
the climatological 90th percentile as well. Convection should 
initiate near the intersection of a stationary front and dry line 
this afternoon over TX and also over the terrain of northern 
Mexico. Given the degree of instability and southeasterly 
inflow...these cells should survive eastward into southwest TX 
this evening. Possible we see some upscale growth or at least some 
convective clusters evolve. Localized 3-5" rainfall may pose an 
isolated flash flood risk across this region.

Chenard/Jackson
 
Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt