ZCZC SPCSWOMCD ALL ACUS11 KWNS 310340 SPC MCD 310340 KSZ000-OKZ000-TXZ000-310545- Mesoscale Discussion 0581 NWS Storm Prediction Center Norman OK 1040 PM CDT Wed May 30 2018 Areas affected...Eastern Texas Panhandle...Eastern Oklahoma Panhandle...Northern Oklahoma...Southern Kansas Concerning...Severe Thunderstorm Watch 135... Valid 310340Z - 310545Z The severe weather threat for Severe Thunderstorm Watch 135 continues. SUMMARY...A severe threat will likely continue late this evening into the overnight period across northern Oklahoma and southern Kansas. Large hail and wind damage will be possible as a line of storms moves eastward across WW 135. Additional counties may need to be added to the watch across parts of western and central Oklahoma. DISCUSSION...The latest surface analysis shows a 999 mb low across northwest Texas with the moist sector wrapping around the low on the east side. Surface dewpoints increase with eastward extent reaching the mid 70s F across the central and eastern part of WW 135. In response, MLCAPE values are in the 2500 to 4000 J/kg range according to the RAP across the watch. This will help to sustain a linear MCS as it moves across northern Oklahoma and southern Kansas late this evening into the overnight period. The Vance, OK WSR-88D VWP shows moderate deep-layer shear and forecast soundings have steep mid-level lapse rates of 7.5 to 8.0 C/km. This will be favorable for large hail with the stronger cores of the linear MCS. Also, an eastward movement of the MCS in the 40 to 50 kt range will also be favorable for wind damage along the leading edge. Given the recent development near the Texas and Oklahoma state line, Roger Mills and Custer counties may need to be added to the watch. Canadian and Oklahoma counties may eventually need to be added depending upon how much development occurs along the southern flank of the MCS. ..Broyles/Thompson.. 05/31/2018 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TSA...ICT...OUN...DDC...AMA... LAT...LON 37000036 36190049 35730017 35609968 35759741 35939605 37279586 37869637 37879709 37659804 37349875 37289955 37000036 NNNN