From Mike Powell@618:250/10 to All on Wed Jul 15 13:33:00 2026
AWUS01 KWNH 151118
FFGMPD
ARZ000-OKZ000-151615-
Mesoscale Precipitation Discussion 0726
NWS Weather Prediction Center College Park MD
717 AM EDT Wed Jul 15 2026
Areas affected...Arkansas
Concerning...Heavy rainfall...Flash flooding possible
Valid 151117Z - 151615Z
Summary...Convergence west of a surface low should continue to
produce the heavy rainfall through this morning over Arkansas into
eastern Oklahoma. Hourly rain amounts to 2.5" should lead to
localized flash flooding.
Discussion...A weak surface low pushing into eastern Arkansas has
aided heavy thunderstorms over western and southern portions of
the state. The cyclonic flow in a rather moist and sufficiently
unstable environment along with some frontal forcing should allow
enough repeating heavy rain to cause localized flash flooding rest
of this morning.
Easterly flow below a strong upper high centered over the Midwest
will continue to push activity westward over the Mid-South. A
mid-level low is apparent in WV imagery lifting north over
Mississippi. Moisture has pooled north and west of this low with
PW peaking at 2.2" just SW of Memphis and a gradient to 1.9" along
the OK border. Thunderstorms developed along the western flank of
the low and likely along a surface front wavering west from the
surface low. Instability is sufficient with MUCAPE around 1000
J/kg with estimated hourly rainfall of 2" estimated from KLZK and KSRX.
Recent HRRR/RRFS runs do not properly have the development that
has occurred, but generally depict cyclonic motion to cells they
develop through the morning. This area will continue to be
monitored.
This area of Arkansas has been fairly dry over the past week with
FFG around 2.5"/hr despite the terrain of central/western
Arkansas. Therefore flash flooding should be localized only
through the morning hours.