Subj : MESO: Mesoscale Discussion 2168 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Sep 21 2023 19:09:21 ACUS11 KWNS 211909 SWOMCD SPC MCD 211908=20 NEZ000-KSZ000-212115- Mesoscale Discussion 2168 NWS Storm Prediction Center Norman OK 0208 PM CDT Thu Sep 21 2023 Areas affected...Portions of southern Nebraska and northern Kansas Concerning...Severe potential...Watch likely=20 Valid 211908Z - 212115Z Probability of Watch Issuance...80 percent SUMMARY...The threat for all severe hazards will exists with storms that develop this afternoon. A watch is likely for parts of southwestern Nebraska into northwestern Kansas. DISCUSSION...An effective warm front is situated from the Nebraska Panhandle southeastward into south-central Nebraska, reinforced by convection in northeast Nebraska earlier today. A dryline also extends southward from a surface low in southwestern Nebraska into western Kansas. While upper-level forcing is nebulous/subtle, cumulus development has been noted near the surface low and more recently along the dryline along the Kansas/Nebraska border. Storm initiation appears probable in the next couple of hours with the most likely location being in parts of southwestern Nebraska. Steep lapse rates (sampled by the 12Z LBF sounding) and dewpoints in the low 60s F will support 2000-2500 J/kg MLCAPE. Shear is currently modest, but is expected to increase later this afternoon as the large-scale trough continues slowly eastward. All severe hazards will be possible with storms that develop this afternoon, although the primary risks will be large to very-large (1-3 in.) hail and severe wind gusts (60-70 mph). The tornado threat will generally be maximized along the warm front where surface winds remain more backed. However, the threat will initially be modulated by modest low-level winds. Storms that can remain discrete later into the afternoon will potentially pose a greater tornado threat as the low-level shear increases, particularly in western Kansas. Storms in western Kansas would likely be more discrete, but their development is more conditional due to overall weaker forcing. A watch is likely to be issued this afternoon. ...Wendt/Hart.. 09/21/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!_fQq5WNu0P-hMTYs8MoD0nsmazeW9gZVq_8die8sAOI0ZFuQRBhjV8RB64tfzhtBBVjvN3f3N= IdaLRiLHuWHvc3vebM$ for graphic product... ATTN...WFO...GID...LBF...DDC...GLD... LAT...LON 39060133 39920136 40720164 41300225 41670229 41700074 40959915 40239815 39779829 39349914 38789983 38360084 38540132 39060133=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) .