ZCZC SPCSWOMCD ALL ACUS11 KWNS 170412 SPC MCD 170412 INZ000-ILZ000-IAZ000-NEZ000-170615- Mesoscale Discussion 0646 NWS Storm Prediction Center Norman OK 1112 PM CDT Thu May 16 2019 Areas affected...South-central Iowa...Northern Illinois...Far Eastern Nebraska...Far Northwest Indiana Concerning...Severe Thunderstorm Watch 170... Valid 170412Z - 170615Z The severe weather threat for Severe Thunderstorm Watch 170 continues. SUMMARY...A threat for wind damage and isolated large hail will continue across WW 170 for a few more hours. A southward extension may become necessary as cells move toward the southern edge of WW 170. DISCUSSION...The latest radar imagery shows numerous thunderstorms ongoing south of a front from near the vicinity of Omaha eastward to just south of Chicago. This activity is located along the northern edge of moderate instability where surface dewpoints are in the lower 60s F and MLCAPE values are estimated to be in the 1000 to 2000 J/kg range. The MCS will continue to move slowly southeastward into the stronger instability at the south end of the watch. The instability combined with steep mid-level lapse rates and moderate deep-layer shear, evident on regional WSR-88D VWPs, will be favorable for an isolated severe threat. Wind damage and hail will be possible with the stronger cells. ..Broyles/Guyer.. 05/17/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...DVN...DMX...FSD...OAX... LAT...LON 41139112 41189592 41379590 41399688 41759689 41759706 42039705 42019629 42239640 42189397 42559395 42529254 42639254 42609199 42289204 42279067 42429064 42379050 42209037 42158860 41748860 41748804 41628800 41618787 41558792 41528774 41448776 41428751 40738752 40728711 40488710 40508793 40358794 40398843 40618845 40648853 40778861 40788889 40908891 40998997 41148995 41179043 41049039 41039113 41139112 NNNN