Day 2 Convective Outlook
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000 ACUS02 KWNS 060532 SWODY2 SPC AC 060530 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 AM CDT Sat Jun 06 2026 Valid 071200Z - 081200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ... ...SUMMARY... Scattered severe storms capable of large to very large hail, severe wind gusts, and perhaps a tornado or two are possible across the northern Plains. More isolated severe storms capable locally damaging wind gusts may occur across portions of the Mid-Atlantic. A brief tornado or two appears possible in eastern Oklahoma and western Arkansas. ...Synopsis... A vorticity maximum and associated mid/upper-level jet streaks within the base of broader-scale troughing from the lee of the Canadian Rockies into northern Intermountain Region Sunday morning are forecast to accelerate northeast through the northern High Plains, ahead of an upstream jet segment moving onto the Pacific Northwest coast. Elsewhere, an amplified short-wave trough will progress through the Northeast, while a more loosely organized trough progresses through the central and southern Plains through the Ozarks and mid MS Valley. At the surface, an area of low pressure and associated pre-frontal trough over the western Dakotas will be overtaken by a cold front moving out of the northern Rockies. That frontal system will continue east into the ND-MN Red River Valley, and southeast into the central High Plains by Monday morning. Elsewhere, more of a backdoor cold front will progress south/southwest through the Northeast into Mid-Atlantic. ...Montana and Wyoming into the Dakotas... A hot, deeply mixed boundary layer is expected to develop ahead of the pre-frontal trough over the western Dakotas Sunday afternoon, with the presence of steep low/mid-level lapse rates contributing to an axis of moderate to strong instability. Moderate instability is expected to extend into eastern MT and northeast WY, owing to low-level moisture wrapping around the surface trough. Initial storm development is expected by mid afternoon along the western fringe of the instability axis across southeast MT into north-central and northeast WY as lift is enhanced by terrain, the cold front, and forcing tied to the vorticity maximum and attending jet streaks. A separate thunderstorm regime is expected to evolve by late afternoon into evening over the western Dakotas as the cold front merges with the pre-frontal trough. The MT/WY storms are expected to mature in a strongly sheared environment, which will favor supercells capable of large hail. Initially marginal vertical shear with the western Dakotas storm regime is expected strengthen through the evening, supporting the potential for supercells capable of large to very large hail and severe wind gusts as the primary hazards. Some tornado threat may materialize by mid/late evening across portions of north-central ND where strengthening low-level shear will coincide with a more moist, lower-LCL boundary layer. The magnitude of the threat will be contingent on storm mode at that time, given the tendency for more linear forcing along the cold front. ... Central Virginia into the Chesapeake Bay Area... Daytime heating coupled with dewpoints in the 60s will contribute to a moderately unstable air mass by afternoon, ahead of a pre-frontal wind shift moving into the area from the north. Convergence along that boundary along with the glancing influence of the mid-level trough passing to the immediate north are expected to support isolated to widely scattered thunderstorms during the afternoon across the discussion area. Relatively warm mid-level temperatures are expected to limit the potential for large hail; however, the presence of steep, low-level lapse rates and 30-35 kt of northwesterly deep-layer shear appear supportive of locally damaging wind gusts through the afternoon into early evening. ...Eastern Oklahoma and Western Arkansas... Forcing for ascent attendant to a vorticity maximum moving through the base of broader-scale troughing is expected to contribute to an increase in thunderstorm coverage early in the day. That scenario would tend to limit air mass destabilization through the afternoon, leaving severe-storm potential in question. However, there is a signal in some guidance that a low-level jet will strengthen during the afternoon into evening, leading to an increase in low-level shear. A concurrent risk for a brief tornado or two may materialize, especially with any storms on the southern or western fringe of the larger convective footprint. That notion is generally supported by the 00z HREF mean 0-1 km SRH, which shows values increasing to 100-150 m2/s2 by Sunday evening. ..Mead.. 06/06/2026 $$