Mesoscale Precipitation Discussion 0190
NWS Weather Prediction Center College Park MD
1008 AM EDT Tue May 19 2026
Areas affected...Southeast Oklahoma and Northeast Texas into Arkansas
Concerning...Heavy rainfall...Flash flooding possible
Valid 191407Z - 191930Z
Summary...Isolated flash flooding possible over southeast Oklahoma
into northeast Texas and southwest Arkansas through the early
afternoon. Slowing progression of organized thunderstorms should
allow hourly rainfall of 1 to 3 inches with up to 4 inches
possible in three hours over this previously parched area.
Discussion...Prefrontal organized activity over southeast OK is
oriented parallel to the southwesterly low level flow. This has
caused a slowing to progression and longer duration of heavy rain
over east-central OK. Continued new development merging in with
this line will allow a flash flood threat to shift to northeast TX
through midday. MLCAPE of 3000 J/kg and PW of 1.6 inches will
maintain rapid development and heavy rainfall rates of 2 to
possibly 3 inches per hour. This area has been dry for the past
week, so flash flood guidance is quite high. Flash flooding should
be restricted to the areas with the highest rainfall and in
urbanized areas that get at least a few inches. Recent RRFS runs
have been heavier than the HRRR which seem reasonble as the HRRRs
have been underdoing current activity. Areas ahead of the cold
front will continue to be monitored given the unstable and moist environment.