ZCZC SPCSWOMCD ALL
ACUS11 KWNS 280339 
SPC MCD 280339 
TXZ000-NMZ000-280545-

Mesoscale Discussion 0444
NWS Storm Prediction Center Norman OK
1039 PM CDT Tue Apr 27 2021

Areas affected...Parts of the Pecos Valley into Texas South Plains

Concerning...Severe Thunderstorm Watch 115...

Valid 280339Z - 280545Z

The severe weather threat for Severe Thunderstorm Watch 115
continues.

SUMMARY...A period of rapid thunderstorm development and
intensification is possible around the Midland area by Midnight-1 AM
CDT, if not before.  This may include the evolution of a supercell
or two, which could pose a risk for large, damaging hail, along with
potentially damaging wind gusts.

DISCUSSION...A south-southeasterly low-level jet is in the process
of strengthening to the east of the Pecos River.  Downstream of the
primary short wave trough now turning east-southeastward near the
Southwestern international border area, this is forecast to continue
into the 05-07Z time frame.  At the same time, it appears that
another more modest preceding perturbation may emerge from the
northern Mexican Plateau, and contribute to increasing forcing for
ascent across the Pecos Valley into South Plains vicinity. 

A general increase in convection is already underway across this
region, focused along the dryline and the southern fringe of a zone
of stronger warm advection (around 700 mb).  Inhibition associated
with warm elevated mixed-layer air may still be suppressing
convective development, but various model output suggests that this
may weaken considerably during the next few hours.  The increasing
large-scale ascent, coupled with deepening boundary-layer moisture
return beneath steep mid-level lapse rates, may support a period of
rapid thunderstorm development and intensification by 05-06Z, if not
before.  Initially this may include supercells around the Midland
area, before activity tends to consolidate and grow upscale while
propagating east-northeastward near the Interstate 20 corridor.

..Kerr.. 04/28/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...SJT...LUB...MAF...

LAT...LON   32030307 32700227 33290085 32270080 31620204 30570308
            32030307 

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