Subj : MESO: Mesoscale Discussion 1997 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Dec 07 2022 02:05:07 ACUS11 KWNS 070205 SWOMCD SPC MCD 070204=20 KYZ000-INZ000-TNZ000-ILZ000-MOZ000-070300- Mesoscale Discussion 1997 NWS Storm Prediction Center Norman OK 0804 PM CST Tue Dec 06 2022 Areas affected...Northwest Tennessee into northern Kentucky Concerning...Severe potential...Watch unlikely=20 Valid 070204Z - 070300Z Probability of Watch Issuance...20 percent SUMMARY...A severe wind and weak tornado threat may emerge over the next 1-2 hours across northwest Tennessee and into western/northern Kentucky. However, this threat will be conditional on establishing convection rooted in the boundary layer, which remains uncertain. Regardless, the severe threat will remain too limited overall to warrant watch issuance. DISCUSSION...A gradual uptick in convection has been noted in IR imagery and echo-top data across parts of northwest TN into western and northern KY over the past hour as lift associated with a weak upper-level impulse overspreads a warm frontal zone draped over the mid-MS and lower OH River Valleys. Thus far, the north/northeasterly propagation vectors of the stronger cells (including a supercell near Louisville, KY) along the frontal zone suggest this convection is most likely elevated in nature. However, latest RAP forecast soundings and mesoanalysis estimates suggest MLCAPE may be as high as 500 J/kg along and to the south of the boundary across northwest TN/southwest KY. Convection that can become rooted in the boundary layer within this zone may access the 200-300 J/kg 0-1 km SRH observed in regional VWP observations and take on better structure.=20 If this occurs, the potential for damaging winds, and perhaps a tornado, will increase; however, mixed-layer buoyancy is expected to diminish over the next few hours amid gradual nocturnal cooling. Consequently, it is unclear if the deepening convection will intensify sufficiently to realize the low-level wind shear and pose a severe threat prior to the loss of adequate near-surface buoyancy. The ongoing organized cells near the Louisville, KY area are quickly propagating into a cooler air mass and away from the better MLCAPE, which should limit their access to boundary-layer buoyancy. ...Moore/Edwards.. 12/07/2022 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!7rpubaOr9KmDqiGebTPb4PjgJOn2GhJTaXI4GF0324hN6A2Ra7m7Uf5iItpjD1q3-ZoIFo9Tm= _RuAq8U9tHfty-QFrQ$ for graphic product... ATTN...WFO...ILN...LMK...OHX...PAH...MEG... LAT...LON 36528945 37108883 37538793 38108680 38638567 38718493 38558425 38128419 37538459 36888564 36658612 36388684 36148735 35928798 35788853 35758929 36008966 36528945=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) .