Subj : MESO: Mesoscale Discussion 1749 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jul 30 2024 20:03:54 ACUS11 KWNS 302003 SWOMCD SPC MCD 302003=20 NDZ000-SDZ000-302200- Mesoscale Discussion 1749 NWS Storm Prediction Center Norman OK 0303 PM CDT Tue Jul 30 2024 Areas affected...North and South Dakota Concerning...Severe potential...Watch possible=20 Valid 302003Z - 302200Z Probability of Watch Issuance...60 percent SUMMARY...Thunderstorm development is anticipated in the next 1-2 hours across the western Dakotas. Storms are expected to intensify as they migrate east into central North and South Dakota. Watch issuance is possible later this afternoon/evening as the severe threat becomes more prominent. DISCUSSION...Recent GOES visible imagery shows a gradual increase in cumulus along a surface trough and within the Black Hills in western SD. Mid to upper-level cirrus overspreading the region from the west is indicative of gradually increasing synoptic-scale ascent ahead of a mid-level shortwave trough over ID/MT. Thunderstorm development appears likely in the coming hours as ascent continues to increase and continued daytime heating erodes any lingering MLCIN.=20 Initial thunderstorms across the western Dakotas will develop within a relatively dry/well-mixed environment with LCL heights between 3.0 to 3.5 km. This environment will favor strong downdraft accelerations and rapid cold pool development/expansion with an attendant severe wind risk. Convection is expected to intensify as it moves east through the evening hours and encounters a reservoir of richer low-level moisture (well-sampled by a recent 19 UTC ABR sounding). Adequate deep-layer wind shear (around 30-35 knots) should support organized convection. Storm coverage remains somewhat uncertain given weak forcing for ascent. While the environment may support a supercell or two this evening, clustering of initial cells is possible and may promote upscale growth and a more robust wind threat. Trends will be monitored and watch issuance may be needed later this afternoon or evening to address this concern. ...Moore/Gleason.. 07/30/2024 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!7xy2YeWp6JQv1r-d4J5oYlFePwSd0bcYfnSnXpobE3EZk0f6tHWuEbKRpKEdnpyq44Ier2-mv= 7dir961d-xIeMAn5EE$ for graphic product... ATTN...WFO...ABR...BIS...UNR... LAT...LON 44930049 44030188 43840218 43790254 43850287 44170313 44510327 44810330 46100323 46540311 46740298 47060283 47900222 48380147 48400078 48060016 47429973 46649967 46039979 45490003 44930049=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .