Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
418 ACUS02 KWNS 170550 SWODY2 SPC AC 170549 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1149 PM CST Mon Feb 16 2026 Valid 181200Z - 191200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Widely scattered areas of low probabilistic potential for thunderstorm development may evolve across the U.S. Wednesday through Wednesday night, but any storms that do form are expected to remain generally weak. ...Discussion... Notable spread persists within the latest model output concerning short wave (and related lower-level) developments within a cyclonic regime evolving inland of the Pacific coast through the Mississippi Valley by Wednesday. In general, one initial perturbation and associated surface troughing, pivoting through the Upper Midwest and adjacent Great Lakes region by the beginning of this period, are still forecast to undergo substantive weakening Wednesday through Wednesday night. It is possible that a residual area of lower/mid-tropospheric forcing for ascent, coupled with limited moisture return, may maintain sufficient strength to support continuing convective development capable of producing lightning while spreading through the lower Great Lakes vicinity into the day Wednesday. This seems likely to remain rooted above an initially stable boundary layer, with little risk for severe weather before diminishing. Upstream, another fairly significant short wave perturbation is forecast to accelerate east-northeast of the southern Sierra Nevada, as another digs toward the Oregon/northern California coast. Beneath strong mid-level cooling, models indicate that boundary-layer warming will probably contribute to weak destabilization supportive of convective development across the eastern Great Basin through the mountains of Colorado and Wyoming during the day. It doesn`t seem entirely out of the question that some of this activity may become capable of producing lightning, particularly where surface temperatures are able to warm above freezing. However, this probably will remain very sparse in coverage. Otherwise, thunderstorm probabilities marginally sufficient for a categorical thunderstorm area are likely to linger near Pacific coastal areas, mainly from Oregon into and just south of San Francisco Bay. It does still appear that the short wave trough emerging from the West will support notable cyclogenesis from the lee of the Colorado Rockies into the central Great Plains late Wednesday through Wednesday night. However, low-level flow, above the boundary-layer, across and east of the southern Great Plains is forecast to maintain a pronounced westerly component through the period. Modest inland moisture return off a gradually modifying Gulf boundary layer appears likely to remain focused east of the lower Mississippi Valley, into the Southeast, around the western periphery of low-level ridging centered over the southern mid- to subtropical latitudes of the western Atlantic. It is possible that a weak mid/upper impulse rapidly progressing eastward across parts of the Tennessee Valley and southern Appalachians, and/or low-level warm advection farther west into the vicinity of the confluence of the Mississippi and Ohio Rivers, could support weak thunderstorm development Wednesday night. But, probabilities appear near or below the minimum threshold for a categorical thunder area at the present time. ..Kerr.. 02/17/2026 $$