Subj : MESO: Mesoscale Discussion 0458 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 04 2023 20:07:02 ACUS11 KWNS 042006 SWOMCD SPC MCD 042006=20 MOZ000-ARZ000-TXZ000-OKZ000-KSZ000-042200- Mesoscale Discussion 0458 NWS Storm Prediction Center Norman OK 0306 PM CDT Tue Apr 04 2023 Areas affected...portions of North Texas...eastern Oklahoma...western Arkansas into southwestern Missouri and southeastern Kansas Concerning...Severe potential...Watch possible=20 Valid 042006Z - 042200Z Probability of Watch Issuance...40 percent SUMMARY...Thunderstorms may pose a risk initially for hail across portions of North TX/OK into portions of western AR. Additional development along the dryline is possible in eastern KS and western MO. Uncertainty on the exact timing and location of storm development is very high. Trends are being monitored for a possible weather watch. DISCUSSION...As of 2000 UTC, afternoon observations showed a broad plume of cirrus, associated with a deep western US trough, overspreading a warming and moistening air mass across much of the ArkLaTex and southern Plains. Within the broad cirrus, several CI attempts have been noted along and east of a confluence band ahead of the dryline in North TX. Surface temperatures near 80 and dewpoints in the upper 60s to low 70s F are supporting moderate instability with MLCAPE of 2000 J/kg. With the main trough lagging to the west, forcing for ascent is rather nebulous over much of the region through the afternoon. This is evident in SPC mesoanalysis which shows considerable inhibition still in place below a robust EML. Despite the inhibition, strong flow aloft is supporting long elongated hodographs with effective shear of 50-60 kt favorable for supercells with the potential for large hail. Weaker low-level shear may limit the initial tornado threat if supercells are able to mature. However as forcing increases toward the evening, a greater threat for tornadoes may evolve. Recent visible and radar trends show several weak, likely elevated=20 updrafts over the Red river are persisting despite the inhibition. As updrafts cluster and shift north, a more sustained/sustained storm may evolve from these initial attempts. Diurnal heating/weak ascent may also support additional, isolated development around the dryline from east/northeastern OK into eastern KS. Poor handling of the situation by Hi-res guidance and nebulous forcing lends low confidence in additional convective development and the overall evolution. None the less, the strongly sheared and destabilizing air mass appears conditionally favorable for large to very large hail and possibly tornadoes late this afternoon into the evening. A greater threat will likely evolve overnight as the main trough ejects eastward. Trends will be monitored or a possible weather watch this afternoon but uncertainty is high. ...Lyons/Hart.. 04/04/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!9llzrV8bCv1ChR1WJqNn_E75UEB8uC3MMfQxMkIYWJv0oUzL89HfERp0eNS6L9xUclubwbuZ8= Fafk851KfPKwhinhiA$ for graphic product... ATTN...WFO...LZK...SGF...SHV...EAX...TSA...TOP...ICT...FWD... OUN... LAT...LON 32889550 32639719 32699788 33149825 33799804 34069798 34409764 34819718 35429671 36009641 36699624 38009569 38139522 38209434 38059368 37199279 36109280 34689342 34099372 33479434 33179477 32889550=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) .