Subj : MESO: Mesoscale Discussion 1312 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jun 28 2023 00:01:35 ACUS11 KWNS 280001 SWOMCD SPC MCD 280000=20 OKZ000-KSZ000-280130- 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=20 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 https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!_x0Nmae-D6PQiW54DlKd562C6xlGA9KsR80qygEdYtARCNP7jfkY69adH8R7gPAi7MxaOwOm-= Jh7NHcrC-hrEfHJ5p4$ for graphic product... ATTN...WFO...TSA...ICT...OUN...DDC... LAT...LON 36049978 37739997 37869885 37719742 37359680 36839655 36229672 35969695 35829745 35839872 36049978=20 =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .