Mesoscale Precipitation Discussion 0742
NWS Weather Prediction Center College Park MD
523 AM EDT Fri Jul 18 2025

Areas affected...Southern & Southeastern KS...Northeast
OK...Soutwest MO...Far Northeast AR

Concerning...Heavy rainfall...Flash flooding possible

Valid 180925Z - 181500Z

SUMMARY... Solid WAA isentropic ascent into increasingly veering
steering flow may allow for 2"/hr rates training resulting in a
few spots of localized flash flooding.

DISCUSSION...09z surface map shows a surface wave just southwest
of Enid, OK with the stationary front crossing through the OK/MO
border where a weak meso-low could be analyzed from older
convective complex over NE AR/NE OK in the early overnight hours.
The older outflow has retrograded west past OWP and OKM steepening
the isentropes across NE OK.  VWP and RAP analysis depict
southerly surface flow veering through 850mb before becoming
westerly at 700mb; displaying over 90 degrees of WAA veering
though winds are only 20-30kts at the core of the LLJ and
convective initiation level around 850mb.  MUCAPE above the level
is over 2000 J/kg and surface to 500mb PW is near or slightly
above 2" suggesting updrafts will be capable of efficient rainfall
production over 2"/hr with broader cores.  Given the front extends
southeastward due to the outflow, a few cells may track closely to
areas already affected by flash flooding from Delaware county, OK
into NW AR; though best ascent/instability aloft is generally
along and north of the OK/KS line.  

As noted, the 700mb flow is generally parallel to the development
region but is also weaker/slower than near the surface; this will
allow for some increased duration but also some subtle
upwind/flanking development for some additional duration of heavy
rainfall due to back-building/repeating cells.  Given this
repeating potential, spots of 2-4" are possible especially over SE
KS, which coincidentally has the lower FFG values at 1-1.5"/hr and
1.5-3"/3hrs.  Limitation is going to be directly tied to the
strength of the LLJ and moisture convergence through isentropic
ascent.  While, slow weakening is expected; hi-res CAMs are
typically are too fast to weaken WAA/convection from LLJ ascent,
but timing is likely to be within the 13-15z time period and so
risk of flash flooding can extend into SW MO as well.   

Gallina

ATTN...WFO...ICT...SGF...TSA...

ATTN...RFC...KRF...ORN...TUA...NWC...

LAT...LON   37959690 37889576 37619452 37179399 36629369
            36199406 36029469 36239552 37019648 37279791
            37789793