Mesoscale Precipitation Discussion 0094
NWS Weather Prediction Center College Park MD
1107 PM EDT Tue Mar 12 2024

Areas affected...Central Missouri...

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

Valid 130305Z - 130745Z

SUMMARY...Slow moving, possibly rotating elevated convection
overcoming dry atmospheric conditions for moderate rainfall and
hail production.  Short-term training crossing dormant soils and
therefore nearing 1-3hr FFG values suggesting isolated low-end
flash flooding conditions may be possible over the next few hours.

DISCUSSION...A compact, but well defined mid-level shortwave can
be seen in GOES-E WV suite this evening across MO. EIR 10.3um also
denotes a cluster of thunderstorms continuing to expand with small
overshooting tops continuing to percolate along the
southwest/upwind edge of the complex.   This wave remains well
defined through the mid, lower levels including at the surface
where a 1004 low sits within the the KC Metro with an slowly
advancing cold front angling SSW through the Flint Hills and a
stationary front extending through NW to north-central MO toward
SE IA.  VWP and RAP analysis suggest the the LLJ along/ahead of
the cold front has been accelerating up to 40-45kts across SW MO
before slowing/becoming convergent and isentropically ascending
along and east of the deeper cyclone in proximity to I-70. 

While surface Tds are modest in the low to mid 50s, the LLJ does
have some increased moisture through depth, but still remains even
seasonably average at best with total PWATs reaching 1".  Though
modest 30-35 kts of Effective Bulk Shear along this elevated
925-850 effective warm front/WAA axis has resulted in a few
updrafts picking up weak updraft rotation.  This further increases
isallobaric moisture flux, while concurrently reducing forward
propagation speeds.  Bunkers' right moving supercell vectors
suggest 15-20kts of east to east-southeast motions generally along
the effective warm frontal axis.  As such, this allows for cells
that have already observed 1-1.5"/hr rates and 2" totals per local
observations in proximity to I-70.  Mid-level drying and
evaporative cooling should allow for cold pool generation as well
as hail generation (which is likely contaminating MRMS
rain-rates/FLASH response); however, observational trends in KEAX
and further upstream backbuilding noted along the upstream edge of
the EIR canopy, suggests at least another round of thunderstorms
and therefore training/repeating and slowed cells motions in
proximity to I-70 over the next few hours is becoming a bit more
likely.  

While soil conditions per AHPS/NASA SPoRT are below average, they
are also dormant suggesting low FFGs of ~1.5/hr or ~2/3hrs may be
in range for one, maybe two isolated incidents of FFG exceedance,
and therefore possible low-end flash flooding conditions over the
next few hours.

Gallina

ATTN...WFO...EAX...LSX...SGF...

ATTN...RFC...MBRFC...NCRFC...NWC...

LAT...LON   39779335 39559256 39249172 39029139 38679114
            38249118 37989155 37969209 38179296 38539393
            39019414 39399433 39729417