Mesoscale Precipitation Discussion 0637
NWS Weather Prediction Center College Park MD
525 AM EDT Wed Jul 17 2024

Areas affected...southwestern Missouri, northwestern Arkansas,
northeastern Oklahoma, southeastern Kansas

Concerning...Heavy rainfall...Flash flooding likely

Valid 170925Z - 171425Z

Summary...Multiple cell mergers and slow overall storm speeds will
result in a continued flash flood threat through at least 13Z this
morning.

Discussion...Recent radar mosaic imagery shows a substantial
increase in convective coverage across the discussion area in
tandem with a couple of convective complexes - one propagating
westward across northern Arkansas and another migrating slowly
eastward across northeastern Oklahoma.  As earlier anticipated,
convective cells have developed along and south of a surface
boundary near the Kansas/Oklahoma border.  Storms are still
benefiting from 2000 J/kg MLCAPE, minimal CIN, and 2 inch PW
values within the pre-convective airmass near the front.  Weak
steering flow aloft has allowed for slow and at times erratic
movement driven by local mesoscale processes.  Slow
movement/propagation and mergers along with abundant moisture and
instability have enabled development of multiple areas of 1-3
inch/hr rain rates especially southeast of Branson and
north/northeast of Tulsa.  These rates have occasionally exceeded
local FFG thresholds (in the neighborhood of 2 inches/hr - lowest
across Missouri and north-central Arkansas).

Ongoing convective trends (with multiple cell mergers and heavy
rain rates) will likely continue for at least another couple of
hours.  With weak low-level advection and multiple areas of
convective overturning, however, cells are expected to undergo a
weakening trend eventually (after 13Z or so) as available
surface-based instability is exhausted.  Again, this process will
take a few hours to unfold.  Flash flooding remains likely where
heavy rainfall is most persistent and 1+ hours of rainfall have
occurred.  Mid-level forcing associated with a weak vortex aloft
over northern Arkansas may aid in prolonging heavy rain potential
beyond 13Z, although this potential is currently unclear.

Cook

ATTN...WFO...EAX...ICT...LZK...MEG...OUN...PAH...SGF...TOP...
TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...NCRFC...NWC...

LAT...LON   38149542 38149358 37739170 36979092 36059081
            35259149 35169361 35279600 36829722 37849662