Mesoscale Discussion 0951
NWS Storm Prediction Center Norman OK
0656 AM CDT Sun Jun 21 2020
Areas affected...Parts of southern Oklahoma into north central Texas
Concerning...Severe Thunderstorm Watch 289...
Valid 211156Z - 211400Z
The severe weather threat for Severe Thunderstorm Watch 289
SUMMARY...Occasional, isolated severe hail may continue in slow
moving strong storms across the region through 8-10 AM CDT.
Although a new watch will not be issued in the near term, there is
at least some potential for storms to continue to consolidate and
gradually organize. This could eventually be accompanied by
increasing potential for strong wind gusts by mid morning, and
trends will have to continue to be monitored for the possibility of
a new severe weather watch.
DISCUSSION...Weak lower/mid-tropospheric warm advection continues to
contribute to a gradual increase in convective development near the
Red River between Sherman/Denison and Wichita Falls TX,
northwestward into the Fort Sill OK area. At the same time,
vigorous convective development is spreading southward into the
Oklahoma City metro area, to the southwest of a mesoscale convective
vortex which is migrating southeastward around 20-30 kt.
Through 13-15Z, merging convection and a continued gradual upscale
growth appears possible, aided by inflow of seasonably moist air
characterized by sizable CAPE on the order of 2000-3000 J/kg. Into
mid morning, there may be a tendency for activity to increasingly
root within a warming boundary layer with surface dew points in the
lower 70s, contributing to intensifying updrafts. As this occurs,
there is potential for surface pools to strengthen and consolidate,
and eventually begin to surge more rapidly southeastward in
conjunction with the development of strengthening rear inflow. If
this occurs, it probably would be accompanied by increasing
potential for strong wind gusts.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 34119561 33809453 32429542 32119680 32729799 33719773