Subj : MESO: Mesoscale Discussion 2250 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Oct 13 2023 17:12:40 ACUS11 KWNS 131712 SWOMCD SPC MCD 131712=20 IAZ000-131845- Mesoscale Discussion 2250 NWS Storm Prediction Center Norman OK 1212 PM CDT Fri Oct 13 2023 Areas affected...Parts of central IA Concerning...Severe potential...Watch possible=20 Valid 131712Z - 131845Z Probability of Watch Issuance...40 percent SUMMARY...A few brief tornadoes and isolated hail are possible this afternoon. DISCUSSION...A deep-layer cyclone currently centered near the IA/NE border will move eastward across western/central this afternoon. A surface front extends northeastward from the low into northwest IA, then arcs southeastward across central IA into northern MO. Widespread cloudiness is noted along/ahead of the front, though some thinning and cloud breaks have recently developed across parts of north-central and south-central IA.=20 As pre-frontal temperatures warm through the 60s F within a modestly moist boundary layer, MLCAPE will increase into the 300-700 J/kg range. Weak convection has already developed in Pocahontas County, with additional development expected by early/mid afternoon southward along the frontal boundary. A band of storms is expected to evolve by mid afternoon, with modestly favorable effective shear (generally 30-35 kt) potentially supporting embedded supercell structures, especially from central into south-central IA.=20 A combination of modestly favorable low-level shear/SRH and ambient vertical vorticity associated with the cyclone will support a threat of a few brief tornadoes this afternoon, both within a hybrid/marginal supercell environment across central/south-central IA, and a landspout environment into parts of north-central/northwest IA. Cool temperatures aloft may also support isolated hail with the strongest storms. While coverage and magnitude of the threat may remain relatively limited, tornado watch issuance is possible this afternoon if confidence in the potential for multiple tornadoes increases. ...Dean/Thompson.. 10/13/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!8-BkKyRxFgY1oH1rLFmefie3cHaWbRuYkw-CD0elUuDUpp14QTMP9m8DQYB_mbHWcn2rnPReF= EgxsIuMo01tGnNxQCY$ for graphic product... ATTN...WFO...DVN...DMX... LAT...LON 42619475 42959474 42939397 42269255 41609231 40939237 40939268 41049319 41499361 41829388 42259436 42619475=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) .