Mesoscale Precipitation Discussion 0931
NWS Weather Prediction Center College Park MD
326 AM EDT Sun Oct 07 2018

Areas affected...West-Central to Northwest TX...South-Central to
Northeast OK

Concerning...Heavy rainfall...Flash flooding likely

Valid 070725Z - 071325Z

Summary...Slow-moving and repeating showers and thunderstorms will
continue through dawn, and with the ground becoming increasingly
saturated, flash flooding will become increasingly likely.

Discussion...The latest WV satellite imagery over the last few
hours has been showing a gradual backing of the mid and
upper-level flow across the broader Southern Plains region which
is response to a sharply amplifying trough over the Southwest U.S.
This is resulting in an increase in deep layer ascent/forcing
across west-central to northwest TX and up across central/southern
OK where convection has been active throughout the night.

The activity continues to focus in vicinity of a quasi-stationary
frontal zone with modest instability characterized by MUCAPE
values of 1000 to 1500 j/kg. PWATS across the region are running
between 1.6 and 1.8 inches which is again about 2 standard
deviations above normal for this time of the year.

Given an increasingly diffluent flow pattern aloft and favorable
upper-level right-entrance region jet dynamics on the larger
scale, the ongoing convective activity will be sustainable and
actual may tend to expand a bit in coverage and intensity going
through 12Z.

The latest HRRR guidance favors as much as 3 to 5 inches of
additional rain locally going through 12Z, and there is some
moderate support for this from the 00Z ARW/ARW2 solutions as well
despite some differences with the placement of the heaviest
rainfall.

Given the additional rainfall potential and with the ground
becoming increasingly saturated, the threat for flash flooding is
expected to become more likely this morning.

Orrison

ATTN...WFO...FWD...LUB...OUN...SJT...TSA...

ATTN...RFC...ABRFC...WGRFC...

LAT...LON   36749526 36339492 35419504 34459571 33679658
            33129769 32879844 32679933 32760002 33130019
            33690001 34249948 34719848 35339729 36539595