Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
928 ACUS02 KWNS 111731 SWODY2 SPC AC 111729 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Jun 11 2026 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FRIDAY AFTERNOON AND EVENING ACROSS THE APPALACHIANS VICINITY INTO THE MID ATLANTIC... ...SUMMARY... Clusters of thunderstorms may develop across the Appalachians into Mid Atlantic Friday afternoon through Friday evening, accompanied by potential to produce damaging wind gusts. ...Discussion... Downstream of building mid-level ridging within the mid-latitudes, offshore of the Pacific coast, it still appears that flow will remain largely zonal across the northern tier of the interior U.S. through at least this period, between subtropical ridging centered over the northern Gulf Basin and a quasi-stationary mid-level low centered to the southwest of Hudson Bay. Across the Atlantic Seaboard, it appears that generally modest to weak, though difluent and splitting, flow will prevail, as the most substantive upstream short wave perturbations pivot across and to the northwest of the lower Great Lakes, around the periphery of the low. In lower levels, a surface cyclone is forecast to migrate north/northwestward into the Hudson Bay vicinity and occlude Friday through Friday night, with the trailing cold front advancing southeastward through much of the Mid Atlantic by 12Z Saturday. Across the lower Ohio through southern Great Plains Red River Valleys, the front, initially reinforced by convective outflow, is forecast to weaken, while a another influx of cooler/drier air slowly spreads south of the central Canadian/U.S. border vicinity, through the northern Great Plains/Upper Midwest and adjacent Great Lakes region. ..Appalachians/Mid Atlantic... There still appears a general consensus within model output that seasonably high boundary-layer moisture content will support sizable potential instability (including CAPE in excess of 2000 J/kg) with insolation by early Friday afternoon, from portions of the Cumberland and Allegheny Plateau into the lee of the Blue Ridge and perhaps Poconos/Catskills. Coincident with at least subtle to weak mid-level height falls, and modest strengthening of flow in the 700-500 mb layer to 20-30 kt, the environment may become conducive to the evolution of modestly organizing clusters with potential to produce swaths of strong to severe wind gusts. ...Southern Rockies and adjacent Great Plains... Moistening southerly low-level flow, in the presence of steepening low-level lapse rates with daytime heating, may contribute to sizable CAPE in excess of 2000 J/kg along/east of the Guadalupe and Sacramento Mountains, through the Sangre de Cristo Mountains and Raton Mesa vicinity by early Friday evening. This may become supportive of scattered thunderstorm development with potential to produce severe hail and localized strong surface gusts. Particularly closer to the southern periphery of the westerlies, near and east of the Raton Mesa, shear may become supportive of an organizing cluster propagating off the higher terrain, as a nocturnal low-level jet strengthens Friday evening. It might not be out of the question that probabilities for severe wind will need to be increased further across parts of northeastern New Mexico into southwestern Kansas and the Texas/Oklahoma Panhandle region in later outlook updates for this period. ..Kerr.. 06/11/2026 $$