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 

   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 
   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 www.spc.noaa.gov 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