Mesoscale Precipitation Discussion 0973
NWS Weather Prediction Center College Park MD
218 AM EDT Sat Oct 13 2018

Areas affected...Western and Central Texas

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

Valid 130607Z - 131145Z

Summary...Thunderstorms continue to increase in areal coverage
ahead of Sergio's remnants.  Hourly rain totals to 1.75" and local
amounts to 4" are possible overnight.

Discussion...Satellite imagery reveals the remains of Sergio were
moving into west Texas from southeast New Mexico.  The environment
ahead of the system is moistening, with precipitable water values
now in the 1.50 to 1.75 inch range based on Blended TPW satellite
imagery.  The activity is near and just north of a boundary lying
across the region.  While inflow at 850 hPa is 10-15 kts per VAD
wind profile data, effective bulk shear of 30-55 kts lies here. 
For the most part, the convection has been more severe in nature
than a pronounced flash flood concern, especially given the fact
that the storms have generally been forward propagating. 

The expectation is for convection to continue to fill in and
increase in intensity overnight with convergent low-level inflow
expected to increase which should import greater moisture into the
region. The portion of the boundary is western TX has started to
lift northward while an separate weak boundary extends southward. 

The HRRR/RAP guidance still appears to be well behind the curve
concerning the recent uptick near the Concho Valley, so the heavy
rainfall could occur sooner than advertised.  Hourly rain totals
to 1.75" with local amounts to 4" are anticipated through early
morning.  Soils have been saturated by recent rainfall totaling
over 300% of normal so flash flooding remains a concern.

Bann

ATTN...WFO...EWX...FWD...MAF...SJT...

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

LAT...LON   32799984 32449811 31819794 30360017 30270028
            30020072 30050163 30050176 30200237 30510325
            30800385 31370400 32060402 32640289