Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
616 ACUS02 KWNS 010602 SWODY2 SPC AC 010601 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Wed Jul 01 2026 Valid 021200Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST... ...SUMMARY... Strong to severe storms will be possible from the northern Plains into the Midwest and Great Lakes regions on Thursday. Isolated strong to severe storms may also occur in the Tennessee Valley/Southeast as well as parts of the Northeast. ...Northern Plains into Mid-Missouri Valley... Broad cyclonic flow aloft across the Rockies will promote a lee trough and a modest surface low in the vicinity of the Black Hills. A surface boundary will arc from eastern Montana into northern South Dakota and southern Minnesota. Moisture advection into the High Plains will couple with higher terrain of MT/WY/SD as well as the surface boundary to initiate convection during the afternoon. Supercells will be likely initially with an attendant risk of large to very-large hail, severe winds, and a tornado or two. Mid-level lapse rates of 8-9 C/km will promote rapid intensification and strong downdrafts. Couple this with modest effective shear of 40-45 kt and upscale growth will be likely with time. An MCS is possible and would likely track along the surface boundary. Wind gusts of 75+ mph would be possible with this activity. While most guidance does not show development along the surface boundary towards the mid-Missouri Valley, there will be weak warm advection ongoing through the day that will increase by late afternoon. Should storms develop here, they would likely be more isolated/cellular. A similar threat for large/very-large hail and severe gusts would exist along with a locally greater tornado threat. This would especially be the case if storms can remain discrete into the evening when low-level shear increases. Depending on whether this activity develops/evolves, this will have an impact on the spatial extent of a greater threat for severe winds into the evening and beyond. Given that uncertainty, the Slight Risk will be maintained with potential increases in wind probabilities in subsequent outlooks as confidence increases. ...Midwest... Convection is expected to be ongoing in parts of the region. At least an isolated threat for damaging winds and large hail would exist with this activity. There remain some potential for intensification to occur as storms move east during the day. The Slight Risk remains in place into far western Lower Michigan to account for this potential. Later in the afternoon, redevelopment is possible along the outflow from earlier activity. The most robust model signals are in Iowa and parts of Wisconsin. Large hail would be possible especially in Iowa where mid-level lapse rates would be steeper. Otherwise damaging winds would be the main threat. A tornado or two could occur, but low-level shear will be rather weak. ...Northeast... Strong buoyancy and modest shear will again be in place across the region. At least isolated storms are possible during the afternoon. Damaging winds should be the main threat with this activity. Isolated large hail may occur with the strongest storms, but modest mid-level lapse rates will limit this threat. Some guidance does show more organized activity moving into the region from Ontario/Quebec, but this may not occur until late afternoon. Confidence in that scenario occurring is too low for an increase in wind probabilities. ...Tennessee Valley/Southeast... Strong heating of a very moist airmass will promote scattered to numerous storms during the afternoon. Congealing outflows will help to organize activity even with very weak shear. Given mid-level lapse rates of 7-7.5 C/km, at least marginally severe storms will be possible. Damaging winds are the expected hazard. ..Wendt.. 07/01/2026 $$