ZCZC SPCSWOMCD ALL ACUS11 KWNS 180113 SPC MCD 180113 MOZ000-ARZ000-OKZ000-KSZ000-TXZ000-180315- Mesoscale Discussion 1339 NWS Storm Prediction Center Norman OK 0813 PM CDT Tue Jun 17 2025 Areas affected...Parts of southern KS...northern OK...far southwest MO...and far northwest AR Concerning...Tornado Watch 429... Valid 180113Z - 180315Z The severe weather threat for Tornado Watch 429 continues. SUMMARY...A general increase in thunderstorm coverage is expected across the area during the next several hours. One or more MCSs may evolve out of this activity, posing a risk of scattered severe wind gusts. A new watch will likely be issued before 03Z to replace Tornado Watch 429. DISCUSSION...A persistent upscale-growing supercell cluster continues tracking east-southeastward along the KS/OK border -- along the immediate cool side of a large-scale outflow boundary extending across northern OK. These storms should continue moving along a related east/west-oriented instability gradient, where around 60 kt of 0-6 km shear (per nearby VWP) and ample low-level hodograph curvature will continue to support large hail, severe wind gusts, and possibly an embedded tornado. Farther west, an intense semi-discrete supercell is moving southeastward over far northwest OK and the northeastern TX Panhandle. Very strong surface-based instability and a large clockwise-curved hodograph (around 300 m2/s2 effective SRH) will continue to favor a risk of tornadoes (some possibly strong) and large hail in the near-term. Over the next several hours, a general increase in thunderstorm coverage is expected along outflow boundaries, as a midlevel wave (evident in water-vapor imagery) moves into the region. While overall convective evolution is uncertain, a strongly unstable air mass remains in place along/south of the large-scale outflow boundary in northern OK/southern KS (see OUN 00Z sounding). This, combined with the increasing large-scale ascent and a focused low-level jet, should support the development of one or more organized MCSs -- capable of producing scattered severe wind gusts. A new watch will likely be issued prior to the expiration of Tornado Watch 429 at 03Z. ..Weinman/Mosier.. 06/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...TSA...TOP...ICT...OUN...DDC...AMA... LAT...LON 35389951 35570005 35890028 36310030 36810019 37549949 37789888 38089768 38159659 37979525 37549427 37009392 36499412 36089458 35699528 35459663 35389951 MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH MOST PROBABLE PEAK WIND GUST...75-90 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN NNNN