A low-pressure system and associated warm front, combined with high precipitable water values exceeding 2 inches along the I-95 corridor, drove scattered showers and thunderstorms across the Southeast and Mid-Atlantic on September 12, 2026. National Weather Service observations recorded measurable rainfall in Atlanta (thunderstorms noted) and portions of the Ohio Valley, while Miami saw lower totals amid more variable coverage. Model consensus from the HREF highlighted efficient warm-rain processes and localized heavy bands, consistent with climatological patterns for early-September moisture surges. Official NWS climate summaries and QPF discussions confirm these events as the key drivers behind market-implied probabilities for affected cities, with resolution hinging on station-specific daily totals.