Flash Flood Guidance

AWUS01 KWNH 191459

Mesoscale Precipitation Discussion 0100
NWS Weather Prediction Center College Park MD
1059 AM EDT Tue Mar 19 2019

Areas affected...Southeast NE...northeast KS...northern MO...far
southwest IA

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

Valid 191500Z - 192100Z

Summary...Convection developing ahead of an approaching short wave
is expected to produce hourly rainfall rates of 0.25 inches into
the mid afternoon hours, posing a flash flood threat in areas with
ongoing flooding.

Discussion...Regional radars over NE/KS into northern MO showed an
increasing areas of precipitation in advance of a short wave
approaching from the northern Rockies and northern Plains. Thus
far, the precipitation shield has been mainly stratiform, with
higher reflectivities  indicative of radars sampling mixed phase
precipitation near the melting level. Hourly rainfall rates have
averaged less than 0.20 inches through mid morning.

As the short wave approaches the Central Plains this afternoon,
mid level lapse rates steepen in response. This could allow low
topped convection to develop portions of southeast NE into
northeast KS and northern MO, especially toward 19/21z. The low
topped convection will have access to 0.60 inch precipitable water
air in the low level southerly flow, and the combination of
moisture and instability could be sufficient to support rainfall
rates of 0.25 inches (and possibly a but higher).

There is a high resolution model signal for local 1.00 inch
rainfall amounts, centered over southeast NE/northeast KS. Hourly
flash flood guidance values are as low as 1.00 inches over these
areas, where flooding is ongoing, and rainfall would hve no outlet
The additional rainfall could pose a flash flood threat in these
locations into the mid afternoon hours,


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



LAT...LON   41199650 40929469 40589388 40089347 39459432
            39289757 40739832