


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
304 ACUS03 KWNS 020730 SWODY3 SPC AC 020729 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Sat Aug 02 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS...AND IN THE NORTHERN ROCKIES... ...SUMMARY... An isolated severe threat will be possible on Monday across parts of the central and northern Plains, and in the northern Rockies. ...Central ad Northern Plains... A mid-level ridge is forecast to move across the central Rockies on Monday, as a trough remains in place from the upper Mississippi Valley. At the surface, an axis of low-level moisture is forecast from eastern Nebraska northward into the eastern Dakotas. As surface temperatures warm and instability increases during the day along and near the moist axis, isolated to scattered thunderstorms are expected to develop. More isolated cells may also form southwestward into Nebraska, ahead of the central Plains ridge. Any severe threat will likely be co-located with areas that have the strongest instability. Forecast soundings in the late afternoon from southern South Dakota into northern Nebraska have MLCAPE peaking in the 1500 to 3000 J/kg range, and have moderate deep-layer shear in place. This would be sufficient for isolated severe gusts and hail. However, the overall pattern will be diffuse, suggesting that any severe threat the develops will remain localized. ...Northern Rockies... At mid-levels, a shortwave trough is forecast to move northeastward across the northwestern U.S. on Monday, as flow remains southwesterly over the northern Rockies. At the surface, upslope flow should be in place over the northern High Plains extending westward into the northern Rockies. As surface temperatures warm during the day, scattered thunderstorm are expected to develop from northern Idaho into western and central Montana. NAM forecast soundings in western and central Montana by late afternoon have MLCAPE peaking near 1200 J/kg, with 0-6 km shear of 40 to 50 knots. This could support an isolated severe threat. Large surface temperature-dewpoint spreads and nearly dry adiabatic lapse rates from the surface to 700 mb should result in high-based storms capable of isolated severe gusts. Hail will also be possible. ..Broyles.. 08/02/2025 $$