Mesoscale Precipitation Discussion 0948
NWS Weather Prediction Center College Park MD
834 PM EDT Mon Oct 08 2018

Areas affected...Iowa

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

Valid 090030Z - 090630Z

Summary...Heavy showers and thunderstorms are likely over the next
few hours. Given the wet antecedent conditions, some flash
flooding will be possible.

Discussion...Radar imagery shows a band of heavy showers and
thunderstorms advancing from northwest MO up across southwest and
central areas of IA. Cloud tops have tended to cool overall over
the last couple of hours, and the activity is focusing along and
out ahead of a quasi-stationary frontal zone and within modest
instability with MUCAPE values of 1000 to 1500 j/kg. Some of the
convective support appears to also be tied in with a small scale
shortwave impulse that is embedded within the deep layer
south-southwest flow across the region, and in conjunction with a
wave of low pressure lifting up along the front toward southwest
IA.

PWATS remain anomalously high with values of 1.5 to 1.7 inches
which are well over 2 standard deviations above normal for this
time of the year. This will continue to favor efficient rainfall
processes for locally enhanced rainfall rates.

Expect as much as 2 to 3 inches of rain to be possible over the
next few hours at least locally as this cluster of storms lifts
northeast. Given the wet antecedent conditions, some flash
flooding will be possible.

Orrison

ATTN...WFO...ARX...DMX...DVN...EAX...

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

LAT...LON   43209165 43029110 42219077 41279131 40709205
            40579299 40619388 40689436 41069464 41539465
            42109418 42589353 43069256