


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
975 ACUS02 KWNS 101720 SWODY2 SPC AC 101718 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE MONDAY AFTERNOON AND EVENING ACROSS PARTS OF EASTERN NORTH DAKOTA...NORTHWESTERN MINNESOTA...EAST CENTRAL NEW MEXICO AND NORTHWESTERN TEXAS... ...SUMMARY... Strong thunderstorms accompanied by at least some risk for severe wind and hail may impact parts of eastern New Mexico into the Texas South Plains, as well as parts of eastern North Dakota into northwestern Minnesota, late Monday afternoon and evening. ...Discussion... While the westerlies generally remain confined to the higher latitudes, one significant embedded short wave trough is forecast to continue digging southeast of the Canadian Prairies through the international border vicinity, to the west of the Great Lakes, during this period. It appears that this will be accompanied by one initial surge of cooler/drier boundary layer air across much of the Dakotas and portions of the Upper Midwest/adjacent Great Lakes region by late Monday night. Otherwise, weak mid-level troughing likely will linger across much of the remainder of the interior U.S., to the east of the Rockies, between large-scale mean ridging centered offshore of both the Pacific and Atlantic coasts. An associated weak surface frontal zone, still reinforced by convective outflow in some locations, is likely to linger across the Great Lakes through lower Missouri Valley and Texas South Plains into early Monday, before generally continuing to weaken through the period. Seasonably high boundary-layer moisture content probably will be maintained ahead of the stalled/slow moving remnant front, across much of the Southwest, as well as in a corridor along and to the north it. Some of this moisture across the lower/middle Missouri Valley may begin to advect northward ahead of the lead reinforcing cool intrusion late Monday into Monday night. ...Southern Great Plains into Great Lakes... The seasonably high boundary-layer moisture content, along/just north of the weakening front, may provide support for the development of moderate to locally higher CAPE with insolation Monday. As this occurs, it appears that a number of convectively generated or augmented perturbations within the generally weak southwesterly deep-layer mean flow could contribute to scattered thunderstorm development during and after peak heating. Some of this could pose a risk for localized potentially damaging wind gusts, but the coverage of any such activity still seems likely to remain rather sparse in nature. One possible exception may develop along a modifying segment of the boundary across parts of east central New Mexico into the Texas South Plains by late Monday afternoon or evening, beneath steeper mid-level lapse rates associated with the remnants of a plume of warm elevated mixed-layer air. There appears a general consensus within the various model output that a digging short wave impulse, within a weak northwesterly mid-level regime, may provide support for a relatively notable upscale growing/southeastward propagating thunderstorm cluster. Farther northeast, the NAM, perhaps more so than other model output, suggests that a notable MCV may emerge from Sunday night convection over the central Great Plains, before slowly migrating across the lower Missouri Valley toward the Great Lakes Monday through Monday night. It is possible that a perturbation of the strength suggested by the NAM could, at some point, support another notable evolving cluster with potential to produce strong wind gusts. At this point, however, the potential for this still seems low, with too much uncertainty to introduce 5 percent probabilities without unduly large false alarm area. ...Northern Great Plains... A moistening boundary-layer, aided by evapotranspiration and perhaps the onset of better low-level moisture return on strengthening southerly low-level flow, may contribute to moderate CAPE within a corridor of stronger pre-frontal surface heating by late afternoon. Coupled with strengthening deep-layer mean wind fields and shear, downstream of a digging 50+ kt 500 mb jet, it appears that the environment may become conducive to vigorous convective development capable of producing small to marginally severe hail and strong surface gusts. Potential for gusts approaching or exceeding severe limits appears highest during the late afternoon and early evening across parts of eastern North Dakota into northwestern Minnesota, where warm, unsaturated low-level thermodynamic profiles with steep lapse rates will aid downward momentum transfer via enhanced melting and evaporative cooling in downdrafts. ..Kerr.. 08/10/2025 $$