Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
817 PM EDT Sun May 17 2026
Day 3
Valid 12Z Tue May 19 2026 - 12Z Wed May 20 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM THE SOUTHERN
PLAINS THROUGH THE LOWER OHIO VALLEY...

.19Z Update...

Forecast remains on track with a Marginal Risk area in effect from
the southern Plains to the Mid-Mississippi and Lower Ohio Valleys.
The frontal system will push southeast and stall over these
regions, with showers and storms capable of producing locally
heavy rainfall. Localized flash flooding will be a concern,
especially for areas of Central and East Texas where model
guidance is starting to indicate the higher rainfall totals may
be.

Dolan

.Previous Discussion...

The inherited Slight Risk for the southeastern half of Oklahoma was
removed with this update. Guidance has been understandably
struggling with the placement of expected rainfall/convection
across this region. Since there's excellent agreement that the axis
of heaviest rainfall will shift well south of the area expected to
be hit with heavy rain in days 1 and 2, the region of greatest
impact is an area where soils have dried out and will likely be
very receptive to beneficial rainfall. Since guidance is in poor
agreement on where the storms will be most persistent, instead
broad brushing much of the Marginal Risk area with anywhere from a
half inch to 1.25 inches, have opted to leave the large Marginal in
place. None of the guidance particularly favors southeastern
Oklahoma for any heavier amounts than anywhere else, especially
further south into Texas. Expect that should a new Slight be needed
with a future update, it will be over a portion and not into
Oklahoma, which sits at the back/northwestern edge of the heavier
rain axis.

Wegman

Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt