Day 2 Convective Outlook
Issued: · Valid: –
Summary
Scattered strong thunderstorms capable of producing small hail and damaging wind gusts may impact parts of the Ohio Valley to the Northeast during Sunday afternoon and evening.
Product Text
000 ACUS02 KWNS 121700 SWODY2 SPC AC 121658 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1158 AM CDT Sat Sep 12 2026 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE OHIO VALLEY TO THE NORTHEAST... ...SUMMARY... Scattered strong storms accompanied by small to marginally severe hail and potential for locally damaging wind gusts may impact parts of the Northeast through upper Ohio Valley Sunday afternoon and evening. ...Ohio Valley to the Northeast... A mid-level shortwave trough will amplify as it moves from the Upper Midwest to the eastern Great Lakes on Sunday. A primary surface low will move across Quebec with a cold front extending into the eastern Great Lakes. In addition, a lee trough will develop east of the Appalachians with weak surface low development along the coast. A large area of showers and embedded thunderstorms will likely be ongoing at the beginning of the period across the Mid-Atlantic to the Northeast. West of this activity, modest heating and mid 60s dewpoints will support weak to potentially moderate instability. This instability, combined with moderate to strong deep-layer shear will support the potential for strong to severe storms. However, storm coverage remains uncertain. A warm nose around 2km should limit storm development away from the front. Even along the front, storm coverage/intensity remains uncertain. Convergence will not be that strong as the surface low-develops along the coast. Therefore, a conditional severe weather environment remains from the Ohio Valley to the Northeast, but concerns with storm coverage preclude anything more than a Marginal Risk at this time. ...Central High Plains... Lee troughing will strengthen across the central Plains Sunday afternoon. As this occurs, upslope flow will strengthen across eastern Wyoming and vicinity. A cluster of storms will likely develop during the evening and move across South Dakota during the overnight period. Marginal instability will likely preclude any severe weather potential with this activity. ...North-central Montana... A mid-level jet streak will eject northeast from the base of a mid-level trough across the Northwest and overspread western Montana. Showers and a few thunderstorms will develop across western Montana during the afternoon and evening amid modest surface heating. Strong flow above 3km may occasionally mix to the surface with some gusty winds. If greater heating/instability can develop, an isolated severe wind threat may be possible with the strongest storms. ..Bentley.. 09/12/2026 $$