


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
998 ACUS03 KWNS 110730 SWODY3 SPC AC 110729 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Fri Jul 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC NORTH INTO WESTERN AND UPSTATE NEW YORK AS WELL AS ACROSS THE SOUTHERN GREAT PLAINS NORTHEAST INTO THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Marginally severe thunderstorms will be possible across the eastern US from the mid-Atlantic region northward into upstate New York. Additional strong-to-severe thunderstorms will be possible across the southern Great Plains northeast into the Mid-Mississippi Valley. ... Synopsis ... Broadly cyclonic mid-level flow will overspread the northeast United States on Sunday. At the same time, a surface cold front will slowly move east across the eastern US. Farther southwest, across the southern Great Plains, the aforementioned cold front will make little southward progress as southerly low-level flow increases in response to surface cyclogenesis across the northern High Plains late in the period. ... Mid-Atlantic northward into Upstate New York ... Numerous thunderstorms are expected to develop from late morning into the early afternoon associated with a modest increase in large-scale ascent and surface convergence along the cold front. Ahead of the front, surface dewpoints in the mid 60Fs to low 70Fs will combine with diurnal heating to result in most-unstable CAPE values in excess of 1500 J/kg. Despite the better effective-layer shear remaining north of the US, the degree of instability and the very moist airmass will support sporadic wind damage with the strongest thunderstorms. ... Southern Great Plains into the Mid-Mississippi Valley ... Multiple MCVs from the preceding days convection will likely be located across the region through the forecast period. A very moist airmass -- precipitable water values in excess of 2 inches in places -- and diurnal heating will result in a strongly unstable and weakly capped airmass. Although thunderstorms will be possible across the totality of the delineated area, it is likely that pockets of more concentrated thunderstorm activity will develop in the vicinity of the aforementioned MCVs. Some severe potential -- likely damaging wind gusts -- will be possible with the strongest storms. ..Marsh.. 07/11/2025 $$