MD 1312 CONCERNING SEVERE POTENTIAL…SEVERE THUNDERSTORM WATCH LIKELY FOR PORTIONS OF NORTHERN OK INTO SOUTHERN KS
Mesoscale Discussion 1312
NWS Storm Prediction Center Norman OK
0700 PM CDT Tue Jun 27 2023
Areas affected...Portions of northern OK into southern KS
Concerning...Severe potential...Severe Thunderstorm Watch likely
Valid 280000Z - 280130Z
Probability of Watch Issuance...95 percent
SUMMARY...Significant severe wind gusts (75+ mph) will become an
increasing concern as thunderstorms spread eastward this evening.
Downstream watch issuance will be needed.
DISCUSSION...Convection is strengthening early this evening across
the OK Panhandle and far northern TX Panhandle as it encounters
greater MLCAPE with eastward extent along/near a front, with
multiple reports of 4 inch hail with a supercell in Texas County OK.
This activity is already showing signs of upscale growth, and this
trend is expected to continue this evening as a southerly low-level
jet strengthens to around 30-40 kt. 40+ kt of deep-layer shear will
easily support continued convective organization of the developing
MCS.
There is some concern with the axis of greatest severe wind
potential this evening across southern KS and northern OK, as the
surface boundary/front has not advanced as far north as some
guidance suggested earlier. The greatest instability axis currently
extends from southwestern KS into northwestern and central OK. While
some northward advance of rich low-level moisture (70+ surface
dewpoints) appears possible with the low-level warm advection regime
tonight, the lack of a stronger surface mass response suggests that
the greatest instability will probably remain confined close to
where it is currently located. Adjustments to the higher severe wind
probabilities (30/45% wind areas) will likely be needed with the
forthcoming 01Z Day 1 Convective Outlook across southern KS and
northern/central OK to account for observational trends.
Even with these concerns, the potential for significant
severe/damaging winds (75+ mph) in a narrow corridor remains
apparent, as a very unstable airmass and strongly sheared
environment will likely support a small but intense bow moving
east-southeastward this evening. Isolated large hail will remain
possible with any embedded supercell. A tornado may also occur for a
couple more hours in a narrow corridor across southwestern KS into
northwestern OK, where low-level shear will be maximized near the
surface boundary. Downstream Severe Thunderstorm Watch issuance will
be required to address the increasing severe threat.
..Gleason/Guyer.. 06/28/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TSA...ICT...OUN...DDC...
LAT...LON 36049978 37739997 37869885 37719742 37359680 36839655
36229672 35969695 35829745 35839872 36049978
