Mesoscale Precipitation Discussion 0957
NWS Weather Prediction Center College Park MD
931 PM EDT Tue Oct 09 2018

Areas affected...Arkansas

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

Valid 100130Z - 100600Z

Summary...A band of heavy showers and thunderstorms will advance
gradually east over the next few hours. Some flash flooding will
be possible.

Discussion...The latest radar imagery shows a north/south axis of
heavy showers and thunderstorms advancing east across Arkansas
which is focusing along and ahead of a frontal zone. Deep layer
moisture and instability transport over the lower MS Valley ahead
of a large scale trough ejecting out across the Plains will
continue to favor a relatively organized axis of convection over
the next few hours.

PWATs are near 2 inches, and MLCAPE values are on the order of
1000 to 1500 j/kg which should continue to support enhanced
rainfall rates. Already there have been observed amounts of 1.5
inches/hr, and this coupled with relatively slow convective cell
motions off to the east will encourage some excessive amounts that
could reach 3 to 4 inches locally going through the late evening
hours. This is supported by the latest HRRR guidance. Some flash
flooding will be possible as a result, and especially over any
urbanized areas going through the late evening hours..

Orrison

ATTN...WFO...JAN...LZK...MEG...SHV...

ATTN...RFC...ABRFC...LMRFC...

LAT...LON   36449229 36199134 34669114 33629132 33109162
            33099238 33299278 34609300 35369300 36079282