Subj : MESO: Mesoscale Discussion 1638 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jul 20 2023 12:48:08 ACUS11 KWNS 201248 SWOMCD SPC MCD 201247=20 TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-201445- Mesoscale Discussion 1638 NWS Storm Prediction Center Norman OK 0747 AM CDT Thu Jul 20 2023 Areas affected...much of Tennessee and adjacent portions of southern Kentucky...southeastern Missouri Concerning...Severe potential...Watch possible=20 Valid 201247Z - 201445Z Probability of Watch Issuance...40 percent SUMMARY...Intensifying thunderstorm development posing a risk for severe hail and wind appears possible as early as mid morning into midday (10 AM-Noon CDT). Trends are being monitored for the possibility of a severe weather watch. DISCUSSION...A remnant westerly mid-level jet streak (including speeds of 40-50 kt), generated or enhanced by now decayed convection initially near the Kansas/Oklahoma border earlier this morning, appears likely to continue propagating east-southeastward across the Ozark Plateau, toward the Tennessee Valley, through midday. To the north of this feature, where seasonably moist low-level air has been maintained, and mid-level inhibition associated with elevated mixed-layer air is weaker, forcing along the leading edge of outflow and/or gravity waves, has been supporting renewed thunderstorm development.=20=20 More recently, cooling tops have been observed near the leading of this jet, along its axis, near Poplar Bluff MO. During the next few hours, a corridor of strengthening differential surface heating beneath this regime, across far southeastern Missouri into middle Tennessee, may provide a focus for considerable boundary-layer destabilization and weakening inhibition, which could allow for increasing and intensifying thunderstorm development. With mixed-layer CAPE forecast to increase in excess of 2000 J/kg, in the presence of strengthening deep-layer shear, this could include supercell structures initially, then one or two upscale growing clusters. ...Kerr/Guyer.. 07/20/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!4J_HWi_tI7rqgD4VXsJBpKWHwBttzsC1df4UNsrFnQcM2ljypSeB2j03nkeWBaP8SIhm1GA2C= n9cao4F-neYwlp0Wfs$ for graphic product... ATTN...WFO...MRX...LMK...OHX...HUN...PAH...MEG... LAT...LON 37258932 37188736 37018605 36068370 35548412 35338536 35318707 35838827 35968992 36659038 37258932=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) .