282
AWUS01 KWNH 182059
FFGMPD
MNZ000-IAZ000-KSZ000-NEZ000-SDZ000-190257-

Mesoscale Precipitation Discussion 0461
NWS Weather Prediction Center College Park MD
458 PM EDT Tue Jun 18 2024

Areas affected...Portions of the Upper Midwest and Central Plains

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

Valid 182057Z - 190257Z

Summary...Widespread convective initiation is underway along a
slow moving cold front traversing the Central Plains. As
additional convection fills in along the front, training of this
activity will support scattered flash flooding going into the
evening hours.

Discussion...Visible satellite and regional radar imagery this
afternoon depict a focused area of deep convection across the
Central Plains exhibiting training along and just behind a well
defined cold front. The pre-convective environment is very
supportive for robust organized convection, with recent
mesoanalysis and GPS estimates highlighting upwards of 3000-4000
J/kg of MUCAPE, 30-40 kts of effective shear, and 1.7-1.8" PWATS
(above the 90th percentile for parts of the region) pooling ahead
of the front for the emerging activity to tap into.

As coverage increases along the front over the next several hours,
expect the training character of these storms to continue given
the parallel orientation of the shear vectors to the front
combined with the slow overall movement of the boundary, with slow
10-15 kt Corfidi vectors noted. The reduced forward propagation of
this emerging complex may lead to rainfall totals locally
exceeding 3" per the HREF where convection can train the longest.
By 0Z tonight, HREF neighborhood probabilities suggest a 40-50%
chance of 3 hour FFG exceedence along the front across parts of
north-central Kansas through northwest Iowa. This suggests
scattered instances of flash flooding are possible going into this
evening, especially atop any urban areas including Omaha and
Lincoln, NE.

Asherman

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

ATTN...WFO...DDC...DMX...FSD...GID...GLD...ICT...MPX...OAX...
TOP...

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

LAT...LON   43999503 43699411 43329372 42549381 41279465
            40119655 39219814 38139963 38010028 38280062
            39030017 40299905 41559791 42299700 43319632
            43859578