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ACUS11 KWNS 132057
SPC MCD 132057

Mesoscale Discussion 0176
NWS Storm Prediction Center Norman OK
0257 PM CST Mon Feb 13 2017

Areas affected...Portions of central TX

Concerning...Severe potential...Watch unlikely

Valid 132057Z - 132330Z

Probability of Watch Issuance...20 percent

SUMMARY...The area is being monitored for a possible increase in
isolated severe-thunderstorm potential. Present indications are that
Watch issuance is unlikely, though convective and environmental
trends will continue to be monitored.

DISCUSSION...Surface mesoanalysis places a 1014-mb low west of Hondo
TX with a warm front extending from the low east-southeastward to
the Middle TX Coast south of Victoria. Insolation on either side of
the boundary is permitting destabilization in its proximity and to
its south, and the warm front should continue to advance northward
toward central TX where 2-hour pressure falls on the order of
2.0-2.5 mb are ongoing. Given diurnally enhanced boundary-layer
circulations amidst the weakly capped and moist environment
(dewpoints in the lower/middle 60s near and south of the boundary),
small convective elements are developing in proximity to the warm
front and along a surface trough extending north/south through the
low. Broad low-level isentropic ascent is also aiding the
development of this activity.

The aforementioned moisture, supporting around 500-1500 J/kg of
MLCAPE, will continue to develop northward, potentially allowing
some intensification of the ongoing convection as it also develops
northward. While low-level hodographs are modest in length, deep
veering wind profiles coupled with adequate midlevel flow supporting
30-45 kt of effective shear, may foster isolated supercell
structures. If a sustained supercell were to evolve, severe hail and
wind, and perhaps a tornado, could occur. However, with stronger
deep ascent located well to the west of the region, sustenance of
surface-based convection is uncertain, and severe-thunderstorm
coverage will likely be limited. Regardless, some severe risk may be
increasing during the next few hours, perhaps continuing into the

..Cohen/Hart.. 02/13/2017

...Please see for graphic product...


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