Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
630 ACUS03 KWNS 040637 SWODY3 SPC AC 040636 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0136 AM CDT Fri Sep 04 2026 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHEAST...AND THE NORTHERN PLAINS... ...SUMMARY... Strong wind gusts are possible across the Southeast Sunday afternoon and early evening. A more uncertain and conditional risk for severe wind and hail is expected across parts of the northern Plains. ...Northern Plains... An amplified upper ridge will remain in place from the central Plains to the Upper Midwest on Sunday. Some modest weakening of the ridge may occur as an upper shortwave trough digs across the Northwest and weak shortwave disturbances crest the ridge through the period. At the surface, low pressure will persist across the western Dakotas. Boundary layer moisture will spread across eastern MT on the back side of the surface low, while deep low-level moisture extends across ND into eastern SD and the Mid-MO Valley along another surface boundary. Capping will be a main limiting factor for storm development. However, if the cap can be overcome, or if elevated convection develops during the day into evening, strong wind gusts and large hail will be possible given supercell wind profiles and corridor of moderate to strong instability. Deep-layer southwesterly flow is forecast to increase with the approach of the Northwest upper shortwave trough late in the period across parts of the northern Rockies toward the northern High Plains. This could also support possible severe convection overnight into parts of MT, but timing and overlap of stronger shear and better instability remains uncertain. Overall, severe potential appears conditional on Sunday across portions of the northern Plains. But, if storms can develop, some risk for severe wind/hail will be possible. ...Southeast... Weak northwesterly flow aloft will persist on Sunday as a surface front develops south/southwest into the Southeast. Ahead of the surface boundary, a very moist airmass will support a corridor of moderate to strong instability focused across southern GA. Thunderstorms are expected to develop during the afternoon. Vertical shear will remain weak, but high PW values could support sporadic wet microbursts and locally strong wind gusts. Some guidance suggests sufficient clustering and outflow consolidation could occur such that a forward propagating cluster could spread south/southwest across the area. If this occurs, damaging wind potential could increase. ..Leitman.. 09/04/2026 $$