Subj : MESO: Mesoscale Discussion 1157 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jun 18 2023 22:31:56 ACUS11 KWNS 182231 SWOMCD SPC MCD 182231=20 MSZ000-TNZ000-MOZ000-ARZ000-190030- Mesoscale Discussion 1157 NWS Storm Prediction Center Norman OK 0531 PM CDT Sun Jun 18 2023 Areas affected...Eastern Arkansas...Far Southwest Tennessee...Northwest and North-central Mississippi Concerning...Severe potential...Watch likely=20 Valid 182231Z - 190030Z Probability of Watch Issuance...80 percent SUMMARY...The severe threat is expected to gradually increase across northeastern Arkansas and may impact areas further south across eastern Arkansas and northwest Mississippi, especially as convective initiation becomes more likely. Weather watch issuance will be likely over the next couple of hours. DISCUSSION...The latest water vapor imagery shows an upper-level trough over the Ozarks. At the surface, a moist airmass is located across much of the lower to mid Mississippi Valley. The RAP has moderate instability across southeastern Arkansas and north-central Mississippi with weaker instability further north into northeast Arkansas and western Tennessee. A severe threat has recently developed in far northeast Arkansas, near a mid-level vorticity max associated with the upper-level trough. The severe threat will likely continue as storms gradually intensify southward across northeast Arkansas. As the vorticity max moves east-southeastward, additional convective initiation is expected from east-central Arkansas eastward across northwest Mississippi. The moderate instability, strong deep-layer shear and strengthening low-level shear will make supercell development possible later this evening. Large hail and wind damage will initially be possible, but an tornado threat may also eventually develop especially across northern Mississippi. ...Broyles/Grams.. 06/18/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!-sRXMC7iSGyC1GXJt65dVPl6airKwZjsW7qYD4vU90xBZgGPG8JQQt-EHt14O9yuxdm8pV6dn= PTijRDuH8a0fqtbdCk$ for graphic product... ATTN...WFO...MEG...JAN...LZK... LAT...LON 33558956 33399068 33429124 33569188 33859205 34559186 35879103 36209021 36028953 35638907 35258878 34618874 33978904 33558956=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) .