Subj : MESO: Mesoscale Discussion 1348 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jun 30 2023 00:38:40 ACUS11 KWNS 300038 SWOMCD SPC MCD 300038=20 INZ000-KYZ000-ILZ000-300245- Mesoscale Discussion 1348 NWS Storm Prediction Center Norman OK 0738 PM CDT Thu Jun 29 2023 Areas affected...Parts of southern IL...southern IN...and western KY Concerning...Severe Thunderstorm Watch 420... Valid 300038Z - 300245Z The severe weather threat for Severe Thunderstorm Watch 420 continues. SUMMARY...Risk of large hail and perhaps locally severe gusts continues across parts of southern IL and IN this evening, and could persist for another few hours. A new watch issuance is not currently expected upon the expiration of WWs 417 and 420. DISCUSSION...Latest water vapor imagery depicts a low-amplitude shortwave impulse overspreading parts of central IL/IN this evening -- accompanied by 60-70 kt of midlevel flow (per regional VWP data). A strengthening low-level jet impinging on a remnant cold pool over southern IL/IN is favoring regenerative convection along/atop the outflow-cooled air. While surface observations and RAP forecast soundings suggest this activity should remain elevated given the increased boundary-layer stability, 70-80 kt of effective shear is still favoring semi-discrete supercells capable of large hail. And, given the potential for strong midlevel mesocyclones which could locally modify the near-storm environment, locally damaging gusts cannot be entirely ruled out. With a reservoir of elevated instability and the aforementioned deep-layer shear, the severe threat could continue for a few more hours. Currently, a new watch issuance is not expected upon the expiration of Severe Thunderstorm Watches 417 and 420 given the limited areal coverage and uncertainty on convective intensity, though convective trends will be monitored. ...Weinman/Hart.. 06/30/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!5YxNnDjNpkFUunTHJknbWtFJHcv9t224j6wxemmHMzfN014DgufdtAfcd9aj15ha7u0SalfFv= Oy-zdzAPbSQYfKO8X0$ for graphic product... ATTN...WFO...LMK...IND...PAH...ILX...LSX... LAT...LON 37878793 38348868 38598877 38788873 38998847 39048820 38738730 38538675 38238631 37938618 37378645 37338692 37488739 37878793=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) .