Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
555 ACUS02 KWNS 040535 SWODY2 SPC AC 040533 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 AM CDT Mon May 04 2026 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST TEXAS...SOUTHEAST OKLAHOMA...ARKANSAS...AND SOUTHEAST MISSOURI... ...SUMMARY... Isolated to scattered strong to severe storms are possible Tuesday afternoon and evening across portions of eastern Oklahoma and northeast Texas into the Mid-South. Additional strong storms are possible across parts of the Northeast. ...Synopsis... Upper troughing centered on the north-central U.S. will phase with an upper shortwave trough over the Southwest on Tuesday. As this occurs, strong deep-layer west/southwesterly flow will develop across the southern Plains to the Ohio Valley and into the Northeast. At the surface, a cold front is forecast to extend from southern Lower MI to a surface low over central OK. A dryline will extend southwestward from the central OK low into central/southwest TX. The cold front is expected to develop east/southeast through the period, becoming oriented from the Northeast to southern AR and northern TX by Wednesday morning. Two areas of severe potential are expected to be focused ahead of the surface cold front, one across parts of the southern Plains to the Mid-South and the second across the Northeast. ...Southern Plains to the Mid-South... Southerly low-level flow will transport 60s F dewpoints northward to the east of the surface dryline and as far north as the MO Bootheel vicinity. Some morning convection or cloud cover is expected across parts of southern MO toward the MO/OH River confluence. Persistent warm advection may result in scattered cloudiness across much of the ArkLaTex and Ozarks vicinity as well. Nevertheless, modest cooling aloft by late afternoon will aid in steepening midlevel lapse rates atop the moist boundary layer, supporting MLCAPE in the 1000-2000 J/kg range. Instability will decrease with northeast extent into the Mid-South. Scattered thunderstorm development is expected by late afternoon ahead of the surface cold front. Convection may tend to become linear more quickly across the Mid-South where shear vectors are parallel to the surface boundary. Further south across parts of AR into northeast TX closer to the surface triple point, low-level flow may be less veered and shear vectors supporting initially discrete cells. Any convection that can remain semi-discrete/cellular will pose a risk for large hail, strong wind gusts, and a tornado or two. With time, convection will evolve into linear segments as a low-level jet increases and the front begins to develop southeastward. The risk is more conditional along the dryline with southwestward extent across TX. Forcing for ascent will be weaker across this area and the main initiation mechanism will be mixing/dryline circulations. If storms can develop, hail and strong gusts will be possible. ...Northeast... A shortwave upper trough over the Great Lakes will develop east/northeast across Ontario and Quebec through the evening. Strong deep-layer southwesterly flow will overspread the Northeast as this occurs. Boundary layer moisture will be modest, with dewpoints generally in the 40s to low 50s. However, cold temperatures aloft will foster steep midlevel lapse rates, supporting modest destabilization during the afternoon/evening (generally less than 1000 J/kg MLCAPE). Increasing large-scale ascent and the approach of the surface boundary will result in isolated to scattered thunderstorm development. Strong gusts will be the main risk with storms given the strength of deep-layer flow and a well mixed boundary layer. However, isolated hail also will be possible given 35+ kt effective shear and 500 mb temperatures near -18 C. ..Leitman.. 05/04/2026 $$