000
ACUS11 KWNS 182005
SWOMCD
SPC MCD 182004
MOZ000-ARZ000-OKZ000-182130-

Mesoscale Discussion 1523
NWS Storm Prediction Center Norman OK
0304 PM CDT Fri Aug 18 2017

Areas affected...Southwest MO...Northwest AR...Far
Northeast/East-central OK

Concerning...Severe potential...Watch unlikely

Valid 182004Z - 182130Z

Probability of Watch Issuance...20 percent

SUMMARY...Storm coverage may increase over the next hour or two with
a few of these storms capable of large hail and/or damaging wind
gusts. Overall coverage of severe is uncertain but trends will be
monitored closely for possible watch issuance.

DISCUSSION...Convective initiation was recently realized within the
moist and moderately unstable airmass along the southern periphery
of the cyclonic flow aloft extending from the upper MS valley into
the southern Plains. Thunderstorm activity last night likely
augmented the vorticity near the KS/OK border within this cyclonic
flow and recent water vapor imagery appears to show the resulting
vorticity maximum moving into the OK/KS/MO border vicinity. Lift
associated with this feature and continued airmass destabilization
will likely result in increased thunderstorm activity across the
region with widely scattered to scattered coverage possible over the
next few hours.

This region is on the northeastern fringe of the northward moisture
 return and the areal extent of instability is confined by more
stable conditions across south-central/southeast MO and northeast
AR. Even so, anticipated southeasterly storm motion would keep
storms within the region of the best instability. Shear is
sufficient for updraft organization with isolated severe hail and/or
damaging wind gusts possible. Uncertainty regarding severe coverage
currently precludes higher watch probability but trends will be
monitored closely for upscale growth and the need for a watch.

..Mosier/Goss.. 08/18/2017

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

ATTN...WFO...LZK...SGF...TSA...

LAT...LON   36949401 36879304 36449242 35629248 35289347 35639461
            36489452 36949401