ZCZC SPCSWOMCD ALL ACUS11 KWNS 271029 SPC MCD 271029 OKZ000-TXZ000-271200- Mesoscale Discussion 0537 NWS Storm Prediction Center Norman OK 0529 AM CDT Sat Apr 27 2024 Areas affected...Parts of northwest TX into western OK Concerning...Severe potential...Watch likely Valid 271029Z - 271200Z Probability of Watch Issuance...80 percent SUMMARY...Severe storm development is possible toward sunrise. Large hail will be possible initially, but the tornado threat will increase through the morning. Watch issuance is likely prior to 7 AM CDT. DISCUSSION...Rich low-level moisture is streaming into parts of the TX South Plains and northwest TX this morning, in response to a strong southerly low-level jet noted on regional VWPs. Meanwhile, a strong mid/upper-level shortwave trough and attendant mid/upper-level jet are approaching the southern Rockies. A cirrus plume now moving over far west TX may be indicative of increasing ascent in advance of the shortwave. As this ascent begins to impinge on returning moisture across northwest TX, thunderstorm development is expected near or just before sunrise, with increasing storm coverage expected with time into parts of western OK. Initial storm development will likely be somewhat elevated, but MUCAPE of greater than 2000 J/kg and strong effective shear will support supercell potential with an initial threat of large hail (potentially in the 1.5 - 2 inch diameter range). As storms spread into western OK, a transition to surface-based convection will be possible later this morning, as MLCINH quickly erodes with even modest diurnal heating. A transition to one or more clusters is possible as storm coverage increases with time this morning, but increasingly favorable low-level moisture and wind profiles will support embedded supercells with an increasing tornado threat. Watch issuance is likely prior to 7 AM CDT. ..Dean/Thompson.. 04/27/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN...LUB...AMA... LAT...LON 34029986 33970016 33960083 34230093 35110009 36019945 36869914 36939846 36549794 36019782 35349799 34419848 34029986 NNNN