Day 2 Outlook >
WPC Day 1 Excessive Rainfall Outlook
Risk of 1 to 6 hour rainfall exceeding flash flood guidance at a point
Updated: 2101 UTC Mon May 10, 2021
Valid: 2100 UTC May 10, 2021 - 12 UTC May 11, 2021
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
455 PM EDT Mon May 10 2021
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.
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.
Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt