Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
031 ACUS02 KWNS 191734 SWODY2 SPC AC 191733 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Jul 19 2026 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM IOW ACROSS WISCONSIN AND INTO WESTERN UPPER MICHIGAN... ...SUMMARY... Severe thunderstorms are probable across portions of the Upper Midwest and Great Lakes vicinity on Monday. Swaths of damaging winds, large hail, and a few tornadoes will all be possible. Isolated strong to damaging gusts may occur over parts of the Carolinas. ...From IA across WI and into Upper MI... A substantial shortwave trough will dive southeastward across the upper MS Valley and toward the Great Lakes, with a broad area of 50-70 kt midlevel northwesterlies. Upper-level winds will be stronger, with over 100 kt at 300 mb from MN into WI. Cool temperatures aloft will also result in steep midlevel lapse rates over 7 C/km. A few early day storms may produce hail over eastern MN into western WI as elevated instability will be strong and effective shear over 50 kt. This activity is expected to wane during the day, with new storms developing along the cold front as it pushes into western Upper MI, WI, and northern IA. Initial storms should primarily be supercells given such strong shear. A corridor of tornado risk is evident east of the instability axis from IA across WI and into Upper MI, and effective SRH may exceed 300 m2/s2. Surface winds may veer with time, but any rightward movement off the hodograph may lead to a large increase of effective SRH for some of the larger supercells. A conditional risk of a strong tornado also exists from far northeast IA across much of WI. Here, 0-3 km shear will be strong, with 50 kt winds at 700 mb. Several models indicate a VGP at or above 0.4. With time, some of the cells may bow southeastward with corridors of significant wind damage and hail possible. ...Southern VA into NC... Daytime heating, 70s F dewpoints and surface convergence near a weak low will aid storm formation from western into central NC after 20Z. MLCAPE over 2000 J/kg, PWAT over 2.00", and westerly flow aloft near 20 kt will lead to multicellular storm mode with locally damaging wind gusts. ..Jewell.. 07/19/2026 $$