ZCZC SPCSWOMCD ALL ACUS11 KWNS 092334 SPC MCD 092334 MNZ000-NDZ000-100100- Mesoscale Discussion 1454 NWS Storm Prediction Center Norman OK 0634 PM CDT Mon Aug 09 2021 Areas affected...East-central North Dakota and far northwestern Minnesota Concerning...Severe Thunderstorm Watch 418... Valid 092334Z - 100100Z The severe weather threat for Severe Thunderstorm Watch 418 continues. SUMMARY...Supercells across WW418 will continue to pose a risk for all hazards. Additional development is expected over the next few hours with an increasing risk for hail/damaging winds later this evening. DISCUSSION...Ahead of the compact upper low across the northern Plains, a cluster of supercells has become established across central North Dakota. Recent storm reports of golf ball and baseball sized hail indicate these storms continue to pose a risk for large to very large hail as they track to the north and east. Ongoing near a warm front with dewpoints in the mid 60s F, SPC mesoanalysis shows 2000-3000 J/kg of MLCAPE across much of North Dakota. Regional VWPs also show robust shear profiles with 50-60 kts of effective shear. With strong instability and vertical shear in place, the environment will remain highly favorable for supercells capable of large to very large hail and damaging wind gusts this evening. As the cluster of storms continues to track to the north and east, they will approach a southwest to northeast oriented warm front in the vicinity of Grand Forks, ND. Along and north of this boundary, low-level flow is strongly backed, favoring enlarged low-level hodographs. KMVX VAD data shows 200-300 ESRH in place, suggesting some potential for tornadoes if storms can remain discrete. However, additional development and continued upscale growth into one or more clusters/short line segments may shift the threat towards damaging winds later this evening. Until then, a tornado or two will remain possible near the front. ..Lyons.. 08/09/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...BIS... LAT...LON 47479976 48969973 49109936 49119723 49099667 48719653 48119646 47929652 47059710 46319921 46419950 46969960 47479976 NNNN