Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
606 ACUS02 KWNS 020549 SWODY2 SPC AC 020547 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1247 AM CDT Tue Jun 02 2026 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS INTO UPPER MISSISSIPPI VALLEY... ...SUMMARY... Thunderstorms with large to very large hail and severe wind gusts will be possible Wednesday afternoon into night in parts of the northern Plains into upper Mississippi Valley. More sporadic occurrences of large hail and severe wind gusts appear possible across parts of the central High Plains and southwest Texas. ...Synopsis... A mid/upper-level low initially over southern Saskatchewan Wednesday morning is forecast to shift east into southern Manitoba through the forecast period. At the same time, an attending belt of enhanced mid/upper-level winds will overspread the northern Plains into upper MS Valley, along with a corridor of modest height falls. Elsewhere, a lower-latitude short-wave trough will drift north-northeast from the southern into central High Plains. At the surface, low pressure linked with the Canadian upper low will move through the same areas, while a trailing cold front pushes through the northern Plains into the upper MS Valley. A secondary surface low is expected to form along the front in central SD Wednesday afternoon with the trailing portion of the boundary settling into the NE Panhandle and southeast WY. ...Northern Plains into the upper Mississippi Valley Wednesday afternoon/night... Showers and thunderstorms may be ongoing Wednesday morning across portions of ND in association with a subtle short-wave trough moving through the area. Model guidance is suggestive that a subset of the early-day convection could linger through the morning into early afternoon across portions of eastern ND into northwest MN, which could ultimately limit the degree of air mass destabilization in those areas. However to the south of the associated cloud debris/convective outflow, stronger daytime heating in conjunction with boundary layer dewpoints in the 60s and steep mid-level lapse rates will support a moderately unstable air mass with MLCAPE of 1500-2500 J/kg. Modest height falls aloft will combine with convergence along the cold front and preceding convective outflow boundary to support robust thunderstorm development by mid/late afternoon across portions of south-central and southeast ND into central and northeast SD. Forecast soundings indicate the presence of a vertically veering wind profile with 35-40 kt of effective bulk shear, which will support organized storm modes, including supercells. Elongated hodographs resulting from the presence of relatively strong flow above 8-9 km will favor a conditional threat for two-inch or greater hail with any sustained supercells. In addition, some tornado threat could materialize by late afternoon into early evening across portions of southeast ND into northeast SD from the vicinity of the expected outflow boundary to ahead of the secondary surface low, where some enhancement of low-level shear is forecast. Increasing convergence along coalescing cold pools owing to a strengthening low-level jet is expected to support upscale growth of storms into an MCS Wednesday evening across portions of eastern SD and western MN, with an associated risk for damaging wind gusts. ...Southern and Central High Plains Wednesday afternoon/evening... The models indicate the potential for early-day storms across portions of the southern High Plains owing to forcing for ascent associated with the short-wave trough. Associated cloud cover is expected to limit destabilization potential in those areas, with comparably greater instability developing across the central Plains, and across portions of southwest TX. The migration of the short-wave trough into the central high Plains by afternoon into evening will support clusters of diurnally enhanced thunderstorms in those areas, with an attendant risk for sporadic large hail and damaging winds. Weakening vertical shear with southward extent from the northern into central Plains is expected to limit the potential for a more organized severe-weather episode. Additional strong to severe storms appear possible along the favored terrain of southwest TX, where isolated occurrences of large hail and damaging winds may occur. ..Mead.. 06/02/2026 $$