Mesoscale Precipitation Discussion 0547
NWS Weather Prediction Center College Park MD
444 PM EDT Wed Jul 03 2024

Areas affected...South-central & Southeastern MO into Lower Ohio
River Valley...

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

Valid 032045Z - 040200Z

SUMMARY...Intense rates of to 2.5"/hr and favorable deep layer
flow for potential training may overcome ground/soil conditions
resulting in some possible localized flash flooding prior to
higher potential into the overnight period. 

DISCUSSION...20z surface analysis denotes cold front sagged across
central IL into central MO and into southeastern KS; however, a
pre-frontal trough/outflow boundary from last evening
intersects/parallels the boundary from south-central MO across SE
MO into the Ohio River Valley and through SW to central OH.  Solid
cloud cover has strengthened frontogensis across the area with a
20-25 degree gradient from central MO to S MO/N AR where temps are
in the low 90s though surface Tds remain in the mid to upper 70s
throughout he zone.  Full insolation has resulted in a strong
instability gradient that orients to the outflow boundary
favorably.  MLCAPE of 2500-3500 J/kg exist across S-SE MO and into
W KY but remain in close proximity to the deeper q-axis that
exists in/just along the southern boundary of the cloud line. 
Total PWat values of 2-2.25" are well above normal and with some
weak northerly flux and combination with low level high moisture
values in the area, should allow for high flux convergence to
support 2.5"/hr rates with perhaps an occasional 3" value, though
inflow is still weak at 5-10kts.

Favorable right entrance divergence will be increasing through the
late evening providing broader scale ascent and sufficient outflow
to maintain stronger updrafts; however, it is the orientation of
the mean flow that may allow for cell repeating/training in the
evening and incidents of 3-4" in 1-3hrs.  Hydrologically, high
rates of this magnitude usually overcome most ground conditions;
however, there are some moderately dry conditions and naturally
higher FFG values in the region that even 3-4" total may be at the
limit of the FFG values.  Still, drier than normal conditions, may
make for harder grounds and limit infiltration.  So scattered
incidents of flash flooding are possible, especially if low level
flow strengthens and propagation vectors support back-building, at
worst, these rainfall totals will set the stage for the next round
later into tomorrow morning.

Gallina

ATTN...WFO...LSX...PAH...SGF...

ATTN...RFC...LMRFC...MBRFC...NCRFC...OHRFC...NWC...

LAT...LON   38638988 38638901 38338790 37778755 37198804
            36838951 36579121 36649333 37489359 38219205
            38469109