390 ACUS01 KWNS 241232 SWODY1 SPC AC 241230 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0730 AM CDT Mon Aug 24 2026 Valid 241300Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS/UPPER MIDWEST...CENTRAL HIGH PLAINS...LOWER MISSISSIPPI VALLEY/CENTRAL GULF COAST...AND COASTAL CAROLINAS... ...SUMMARY... Severe thunderstorms capable of producing large hail and damaging winds will be possible this afternoon and evening across the Dakotas and northwest Minnesota as well as the central High Plains. Other severe thunderstorms with mainly a damaging wind threat may focus across the lower Mississippi Valley and coastal Carolinas. ...Dakotas/Upper Midwest into the Central High Plains... A mid-level shortwave trough over Alberta/Saskatchewan will move eastward across the Canadian prairie provinces through tonight, with a belt of moderately strong flow aloft and multiple MCVs influencing the northern Plains to Upper Midwest. Residual/ongoing convection this morning and lingering cloud cover will be complicating factors for thunderstorm development and evolution later today. Even so, widely scattered thunderstorms should develop by late afternoon or early evening within a moist/unstable airmass near an eastward-moving front and weak surface wave across central/eastern ND. Other convection may initiate and then move southeastward from south-central Canada. Around 35-45 kt of deep-layer shear will support supercells initially with a large hail threat. The development of east/southeastward-moving clusters should eventually occur this evening, with scattered severe/damaging winds possible. Farther south and a bit more removed from the stronger cyclonic flow aloft, additional high-based thunderstorms are expected to form by late afternoon/early evening across the Black Hills/western NE in the vicinity of the surface front. Strengthening and sufficient veering of winds with height through mid levels should support initial supercells capable of large hail, prior to a clustering of these southeastward-moving thunderstorms. Scattered severe/damaging winds may occur with this activity through mid/late evening across the central High Plains before increasing MLCIN encourages gradual weakening. ...Coastal Carolinas... The Carolinas will be influenced by modestly enhanced cyclonic flow aloft today, with a moist and moderately to strongly unstable environment forecast along the coastal plain to the east of a slow-moving front. This favorable instability and around 30-40 kt of effective bulk shear should support initial supercells with some hail risk this afternoon. However, scattered damaging winds will probably become the primary concern as thunderstorms increase in coverage. Severe potential should tend to wane by early evening as convection moves offshore and/or weakens with the loss of daytime heating. ...Lower Mississippi Valley/Central Gulf Coast... Widely scattered elevated convection has developed this morning from southeast KS into AR in a low-level warm advection regime. This convection will shift south-southeastward today, potentially becoming surface based into the afternoon as diurnal heating supports downstream destabilization of a rather moist low-level airmass. Even though deep-layer shear will remain weak, an upscale-growing/forward-propagating cluster may evolve during the afternoon, with scattered damaging wind potential increasing across the ArkLaMiss south-southeastward toward the central Gulf Coast. ...Northern Great Basin into the Central Rockies... Isolated to scattered high-based thunderstorms are expected to develop this afternoon across parts of the northern Great Basin into the central Rockies amid steepening low-level lapse rates with a very well-mixed boundary layer. Since this convection will develop along the periphery of stronger flow aloft, modest organization is possible even though low-level moisture and related instability should remain weak. Occasional dry microbursts may occur, some of which could pose an isolated threat for severe gusts. ...Maine... Across northern ME, partially clearing skies this afternoon should encourage surface temperatures to rise into the 70s, resulting in weak instability (up to 250-500 J/kg MLCAPE) given relatively poor mid-level lapse rates. Even so, a southerly mid/upper-level jet will overspread northern New England during the afternoon, resulting in highly elongated hodographs and 30-40 kt of effective bulk shear. Any thunderstorms that can develop and be sustained could become organized multicells capable of producing isolated damaging gusts and perhaps marginally severe hail. ..Gleason/Broyles.. 08/24/2026 $$