Mesoscale Discussion 1040
NWS Storm Prediction Center Norman OK
0203 PM CDT Thu Jun 15 2017
Areas affected...Portions of the TX Panhandle and South
Plains...western OK...far south-central KS
Concerning...Severe potential...Watch possible
Valid 151903Z - 152130Z
Probability of Watch Issuance...60 percent
SUMMARY...The area is being monitored for an increase in the
potential for severe thunderstorms, including the risk for
significant severe hail. The issuance of a Severe Thunderstorm Watch
DISCUSSION...Towering cumulus development continues along a
northeast-southwest-oriented dryline across the TX Panhandle. The
dryline arches southward near the NM/West TX border, and additional
high-based cumulus fields are becoming evident over western sections
of the TX South Plains. Despite an overall dearth of deep ascent,
baroclinic circulations along the dryline are being amplified by
intense surface heating, with temperatures near 100F in some
locations on the immediate dry side of the dryline. Convection will
likely deepen, with isolated to widely scattered thunderstorms
developing in the next couple of hours.
Long, straight mid/high-level hodographs associated with 25-40 kt of
effective shear will foster splitting supercells. Large normalized
CAPE in the hail-growth zone aloft associated with very steep
midlevel lapse rates, along with MLCAPE around 2000-3500 J/kg,
suggest intense updrafts should evolve with severe hail -- and
baseball-size hail will be possible. Storms will develop into far
south-central KS and into western OK with time into the evening
hours. Large DCAPE amid the well-mixed boundary layer will support a
risk for severe wind gusts -- locally bolstered when congealing cold
pools facilitate convective clustering.
Given the lack of stronger deep ascent, there is some uncertainty
regarding the timing of more substantial increase in severe risk.
Moreover, anticipated severe coverage is somewhat unclear,
especially given only weakly convergent low-level flow. However,
appreciable conditional severe risk is in place for this afternoon
into the evening.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 33260248 34060259 35890068 37349942 37049878 35419901
33740006 33130154 33260248