Flood potential KA/MO/NE
From
Mike Powell@618:250/1 to
All on Tue Sep 23 08:43:57 2025
AWUS01 KWNH 231000
FFGMPD
MOZ000-KSZ000-NEZ000-231500-
Mesoscale Precipitation Discussion 1123
NWS Weather Prediction Center College Park MD
600 AM EDT Tue Sep 23 2025
Areas affected...Northeast Kansas...Northwest Missouri...Far
Southeast Nebraska...
Concerning...Heavy rainfall...Flash flooding possible
Valid 231000Z - 231500Z
SUMMARY...Broad scale over-turning of remaining unstable air will
have short-term rates of up to 2"/hr and localized totals to 2-3"
in 1-3 hours, resulting in possible localized flash flooding.
DISCUSSION...GOES-E WV suite depicts broad diffluent region
downstream of strengthening deep layer cyclone over the central
Rockies. An embedded shortwave is sharpening and vertically
stretching within the divergent pattern aloft, providing solid
DPVA across northeast KS into far southeast NEB and northwest MO.
This area has remained conditionally unstable and capped through
the early overnight period with broad 2000 J/kg MUCAPE reservoir
along and southwest of the Missouri River Valley.
Outflow boundary and southward sinking cold front out of IA and
east-central NEB initially provided sufficient convergence along
the northeast edge of the instability core and rapid expansion has
occurred over the last hour or so as southwesterly WAA has further
impinged on the area. Strong ascent and ample deep layer moisture
has supported localized rates of 1.5-2"/hr and with very
slow/stationary cell motions, generally only moving due to
outflow/propagation, an hour or so of intense rainfall may again
result in widely scattered 2-3" totals in 1-3 hours.
Additionally, as the southern stream shortwave melds with the
northern stream feature, effectively elongating the mid-level
trough toward a longer negative tilt orientation, but also
strengthened southwesterly flow and deep layer convergence with
the core of the southerly LLJ and effective moisture flux.
Leading edge convergence is also building a west to east oriented
arc of thunderstorms along the southwestern edge of the unstable
air, slow northward migration and intersection with the convective
outflow from the northwest will see a larger slab ascent with
broad overturning of the remaining 1.5-1.75" total Pwats in the
column and likely result in similar hourly rates up to 2"/hr but
likely to diminish quickly thereafter, likely resulting in widely
scattered pockets of 2-3" totals further southwest across
northeast KS toward the KC Metro. The sheer rates may result in
localized flash flooding conditions, especially near urban centers.
Gallina
ATTN...WFO...EAX...GID...OAX...TOP...
ATTN...RFC...KRF...NWC...
LAT...LON 40709689 40639608 40299516 39759444 39249384
38599419 38469488 38769571 39159679 39429830
40279804 40599744
$$
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