844
AWUS01 KWNH 310139
FFGMPD
MNZ000-IAZ000-NEZ000-SDZ000-310730-

Mesoscale Precipitation Discussion 0353
NWS Weather Prediction Center College Park MD
939 PM EDT Thu May 30 2024

Areas affected...Central & Northeast NEB...Southeast SD...Far
Northwest IA...Southwest MN...

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

Valid 310140Z - 310730Z

SUMMARY...Increasing moisture convergence along cold front with
slow cell motions pose spots of 1.75"/hr and spots of up to 3"
totals posing possible localized flash flooding.

DISCUSSION...VWP shows a steady increase of southeasterly flow
converging and veering as it nears the front across central to
northeast Nebraska.  Solid moisture of low 60s Tds and narrow
unstable axis along the front support 1000-1500 J/kg of MLCAPE.
Recent RADAR and 10.3um GOES-E EIR loop shows strengthening
updrafts with numerous overshooting tops dotting the front from
southeast SD across Northeast NEB.  An 850mb vorticity center
exists in central NEB and flow has backed a bit to increase
convergence and convection there as well.  Deep layer moisture is
modest but pooled along the same instability axis with 1.3-1.4"
total PWats.  As such, the strong flux convergence will allow for
solid rain rates of of 1.5-1.75"/hr.

The concern, though, is deep layer flow is generally parallel from
the southwest along the front and about 10-15kts through the
steering layer.  This may support some short-term training for
cells that may be in close proximity to each other before slow
eastward propagation.  This should allow for some increased
duration and potentail for spots of 2-3" totals along the eastern
periphary of the Sand Hills, espeically where the flow/front
flattens to the west-east propagation in central NEB.  As such,
lower FFG of 1-1.5/hr and 1.5-2.25"/3hr has the potential for
being exceeded through the early overnight period given the
aforemention rates/spotty totals; as such, localized flash flood
or two may be possible.

Gallina

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...FSD...GID...LBF...OAX...

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

LAT...LON   44459649 44309579 43719562 42829608 41419753
            40669906 40510062 41020071 42069863 43199766
            44249722