Mesoscale Precipitation Discussion 0761
NWS Weather Prediction Center College Park MD
902 AM EDT Tue Sep 04 2018

Areas affected...Northeast Kansas...eastern Nebraska...northwest
Iowa...southern Minnesota

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

Valid 041254Z - 041854Z

Summary...An expanding area of heavy precipitation expected this
morning into this afternoon from portions of the Central Plains
into the Upper Mississippi Valley in an anomalous PW axis and very
favorable right entrance region of the upper jet.

Discussion...The latest regional radar imagery shows a broad
region of moderate to heavy rains stretching from eastern portions
of the Central Plains...northeastward toward the Upper Mississippi
Valley.  This precipitation area is expected to continue to remain
well defined this morning..continuing to be enhanced by large
scale lift ahead of several areas of shortwave energy forecast to
push northeastward in the above mentioned high PW axis...values
2.5 to 3+ standard deviations above the mean.  There is very good
model agreement on the potential for an axis of heavy precip this
morning into this afternoon across the risk area.  The simulated
radars from the 0000 utc hi res guidance (arw..nmmb...nsl wrf)
along with the latest hrrr are showing good depiction of the
current area of precipitation from east central Kansas...eastern
Nebraska into northwest Iowa...all showing potential for this area
of precip to continue to move in a general south to north across
the threat region.  There will be training of cells in this south
to north moving precip areas...with hourly rainfall rates of 1-2"
and totals of 3-5" possible in areas of training.  FFG values have
lowered from several days of heavy rains across north central
Kansas into southeast Nebraska.  Additional heavy rains moving
northward this morning will likely move over these lower FFG
areas...supporting additional runoff issues.

Oravec

ATTN...WFO...ARX...DMX...FSD...GID...ICT...MPX...OAX...TOP...

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

LAT...LON   44329314 44159257 43909258 43649310 43019424
            43019433 41859582 41269602 40559617 39749642
            38959663 38479680 38409728 38559778 38729806
            39749820 40929835 42199779 43359667 43839577
            44269447