SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon May 12 2025 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN MONTANA AND NORTHWEST NORTH DAKOTA... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the Southeast today, where a tornado or two, localized damaging winds, and hail could occur. Isolated severe wind gusts are also possible in northeast Montana to northwest North Dakota around early evening. ...Southeast... Vertically stacked cyclone persists over the Mid-South this morning. Expectation is for this system to become more progressive today, ejecting into western TN by early tomorrow morning. A moist airmass remains in place downstream of this cyclone across the Southeast, and numerous showers and thunderstorms are currently ongoing within the warm conveyor of this system from FL into GA and the Carolina. Moderate southwesterly/southerly will persist within this warm sector, and effective shear should be sufficient for multicell clusters and transient updraft rotation. However, only modest destabilization is anticipated across much of the region, limiting the overall severe potential. Expectation is for occasionally strong storms in areas of sufficient destabilization, with damaging downbursts and hail as the primary risk. A corridor of greater severe potential could be developing across southern GA and northern FL where some heating is occurring. ...Northeast Montana/northwest North Dakota... Deep shortwave trough will continue to push eastward across the Pacific Northwest today, with associated southwesterly flow aloft extending from northern CA into the northern High Plains. Deeply mixed thermodynamic profiles are expected across the region as the airmass destabilizes this afternoon. Isolated thunderstorms are most probable from mid-afternoon into evening with development near/behind an eastward-advancing front. Convective coverage off the higher terrain of southern Montana should be less than in recent days. However, the potential will still exist for a few dry microbursts producing localized severe-caliber wind gusts as the storms move off the terrain into more of eastern MT. ..Mosier/Halbert.. 05/12/2025