Mesoscale Precipitation Discussion 0371
NWS Weather Prediction Center College Park MD
528 AM EDT Sun Jun 02 2024
Areas affected...Eastern NE...Central to Northeast KS
Concerning...Heavy rainfall...Flash flooding possible
Valid 020928Z - 021500Z
SUMMARY...Heavy showers and thunderstorms across portions of
eastern NE down into central and northeast KS will continue over
the next few hours and will maintain a threat for isolated to
widely scattered instances of flash flooding.
DISCUSSION...Convective cloud tops continue to gradually cool
across areas of eastern NE down through portions of central to
northeast KS as low-amplitude shortwave energy ejecting east out
across the central Plains interacts with a moist and unstable 30
to 40 kt southerly low-level jet.
MUCAPE values are as high as 1000 to 2000 J/kg, and much of the
convection has been elevated and aligned in a general north/south
fashion along the cool side of the instability gradient as warm
air advection continues to impinge on the region.
Warm air advection will continue throughout the morning ahead of
the approaching shortwave energy and this coupled the sustained
pooling of moisture and instability with the low-level jet should
maintain a regional threat of heavy shower and thunderstorm
activity through mid-morning across eastern NE and down into areas
of central and especially northeast KS with a gradual shift of the
convective threat off to the east with time.
Rainfall rates with the stronger storms should be capable of
reaching 1.5 to 2.0"/hour, and the latest HREF guidance suggests
that some additional upscale growth/concentration of convection
will be possible going through the 12Z time frame with some
localized repeating/back-building of convective cells.
Some additional rainfall amounts of as much as 3 to 4 inches with
isolated heavier totals are expected by mid-morning, and this will
foster concerns for at least isolated to widely scattered
instances of flash flooding.