


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
988 ACUS03 KWNS 150724 SWODY3 SPC AC 150723 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Sun Jun 15 2025 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS AND LOWER TO MID MISSOURI VALLEY... ...SUMMARY... Thunderstorms with an isolated large hail and wind-damage threat will be possible on Tuesday across parts of the central Plains and lower to mid Missouri Valley. Outside of this area, marginally severe storms may develop over parts of the central U.S. An isolated severe threat is also expected across parts of the Central Appalachians and Mid-Atlantic. ...Great Plains/Lower to Mid Missouri Valley/Mid to Upper Mississippi Valley... At mid-levels, a shortwave trough is forecast to move into the Rockies on Tuesday, as a ridge remains in place over the southern Plains. At the surface, a cold front will advance southward through the central U.S., likely reaching southern Kansas, northwest Missouri and southeast Iowa by afternoon. To the south of the front, surface dewpoints in the lower to mid 70s F will contribute to moderate to strong instability across much of this moist airmass by afternoon. As low-level convergence increases, convection is expected to initiate along and near the front, with scattered strong to severe thunderstorms moving southeastward toward the instability axis in the late afternoon and early evening. Model forecasts suggest that an impressive thermodynamic environment will be in place ahead of the front by Tuesday afternoon. From 21Z to 00Z, NAM forecast soundings along parts of the instability axis have MLCAPE peaking between 4000 and 5000 J/kg. Moderate deep-layer shear is also forecast, mostly due to speed shear in the mid-levels. This environment should support supercells with large hail, especially early in the event when storms are more likely be discrete. A wind-damage threat is also expected to develop as storms congeal, and as a line gradually organizes. The severe threat should persist through much of the evening, with MCS development possible. Further northwest into parts of the central High Plains, upslope easterly flow is forecast within a post-frontal airmass. Surface dewpoints will be mostly in the 50s F. As surface temperatures warm during the day, pockets of moderate instability are expected to develop over parts of the region. Thunderstorms are expected to initiate in the higher terrain during the early to mid afternoon, with storms moving eastward into the lower elevations. Steep mid-level lapse rates and moderate deep-layer shear should be sufficient for a marginal severe threat. ...Central Appalachians/Mid-Atlantic... At mid-levels, a subtle shortwave trough is forecast to move eastward across the southern and central Appalachians on Tuesday. Ahead of this feature, a very moist airmass will be in place with surface dewpoints in the lower to mid 70s F over much of the Atlantic Coastal Plain. By afternoon, moderate instability is expected to develop within most of this airmass. Convection will initiate in the higher terrain of the Appalachians, and move eastward into the lower elevations during the afternoon. Moderate deep-layer shear and steep low-level lapse rates, evident on forecast soundings, will contribute to a marginal wind-damage threat. ..Broyles.. 06/15/2025 $$