Subj : DAY1 2/5 Risk Area Posted To : All From : Mike Powell Date : Tue Sep 23 2025 08:43:57 ACUS01 KWNS 230600 SWODY1 SPC AC 230559 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Tue Sep 23 2025 Valid 231200Z - 241200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS AND OZARKS TOWARD THE MID MISSISSIPPI VALLEY... ....SUMMARY... Severe storms are possible from the southern Plains to the Mid Mississippi Valley today and tonight. Supercells capable of all severe hazards are possible mainly from eastern Oklahoma into the Ozarks. Additional isolated severe storms with damaging gusts are possible over the Mid Atlantic. ....Eastern Oklahoma into the Ozarks and northeast Texas... A positive tilt large-scale trough will amplify over the southern Rockies and High Plains today, as several small-sale features embedded within the stronger westerly flow pass across KS/OK, over the Ozark Plateau and into the mid MS Valley today and tonight. Accompanying the lead shortwave, a 40-50 kt mid-level jet will aide in surface cyclogenesis along a southward moving cold front across the KS/OK border. Near the surface low, an early morning MCS will likely be moving into northwest AR and southwest MO ahead of a 30-40 kt low-level jet. Isolated damaging winds and perhaps some hail will be possible with this initial activity. Some resurgence is possible through the morning along the AR/MO border with diurnal destabilization, especially along the southern flank. Regardless, outflow from the morning convection will likely develop into an east-west oriented effective boundary intersecting with the developing surface low from the AR/MO border region into eastern OK. As the shortwave trough approaches, robust destabilization is expected over much of the warm sector owing to heating amidst 70s F surface dewpoints. Afternoon MLCAPE of 2000-3000 J/kg should support rapid thunderstorm development along the per-frontal surface trough/wind shift and near the effective boundary. Semi-discrete supercells are expected with a continued 30+ kt southwesterly low-level jet helping to expand hodographs. Damaging gusts and some hail (occasional 2+ inch) are possible with initial storms from eastern OK into northeast TX where low-level flow is more veered and lapse rates are steeper. Tornado potential (conditionally significant) is likely to be maximized near the effective triple point and modifying outflow boundary from northeastern OK into western AR. Here, backed low-level flow, ESRH of 200-300 m2/s2 and the potential for higher low-level buoyancy could support locally stronger low-level mesocyclones. Higher tornado probabilities may be needed as confidence in final boundary positioning and destabilization, post MCS, becomes more clear. Upscale growth into one or more clusters is expected into the early overnight hours across eastern AR into the Mid MS Valley. Some risk for damaging winds and perhaps an embedded tornado or two may persist. However, increasingly strong low-level warm advection ahead of the deepening surface low should support widespread thunderstorm development which may limit instability. ....Mid Atlantic... Downstream of a broad mid-level trough, widely scattered thunderstorms are expected to develop by early afternoon within a moist/moderately unstable air mass east of the central Appalachians toward the mid Atlantic. Around 20-30 kt of deep-layer shear may promote a couple loosely organized clusters with a risk of locally damaging gusts before weakening into the evening hours. ....Central TX... As the surface low deepens and moves eastward, the cold front will continue southward across the TX Panhandle into central TX overnight. The primary upper trough over the southern Plains will pass overhead with moderate height falls and cooling aloft. Low-level isentropic ascent could support a few elevated storms along and north of the front with damaging wind and hail potential overnight. ...Lyons/Hart.. 09/23/2025 $$ --- SBBSecho 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1) .