Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Sep 23 2025 12:38:45 ACUS01 KWNS 231238 SWODY1 SPC AC 231236 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0736 AM CDT Tue Sep 23 2025 Valid 231300Z - 241200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN OKLAHOMA/NORTHEAST TEXAS INTO MUCH OF ARKANSAS AND FAR SOUTHERN MISSOURI... ....SUMMARY... Severe thunderstorms should occur this afternoon and evening from parts of the southern Plains to the Mid-South. The greatest severe risk, including the potential for a few tornadoes, should exist from parts of eastern Oklahoma into western Arkansas and vicinity. ....Southern Plains into the Ozarks and Mid-South... Convection ongoing across eastern KS, northeast OK, and western MO this morning is largely being aided by ascent with a 30-40 kt southwesterly low-level jet over the southern Plains. This activity has generally remained sub-severe over the past few hours, with substantial MLCIN present. Recent surface analysis shows a weak low (around 1006 mb) over northwest OK. This low should develop slowly eastward through the day, while a trailing cold front continues slowly southeastward across the central/southern High Plains. Westerly mid-level flow is not forecast to be overly strong today, but it should gradually strengthen this afternoon as a weak perturbation translates eastward from the central/southern Plains into the Ozarks and mid MS Valley by this evening. A rather moist airmass, with surface dewpoints in the low to mid 70s, will be present along/south of a convectively reinforced boundary that should be draped across northern OK into southern MO/northern AR this afternoon. Daytime heating and modestly steepened low/mid-level lapse rates (reference 12Z observed OUN sounding) will easily foster 2000-3000 J/kg of MLCAPE in a pre-frontal corridor across eastern OK and northwest AR, with locally stronger instability possible. It appears increasingly likely that robust thunderstorms, including the potential for multiple supercells, will develop by 18-22Z as convective temperatures are reached. While not overly strong, gradual veering and strengthening of the wind field through low/mid levels should support sufficient low-level and deep-layer shear for organized updrafts. Initial convection should pose a threat for severe hail, before quick upscale growth into one or more clusters occurs with associated threat for scattered damaging winds continuing into parts of the Ozarks and Mid-South through at least early evening. There may be a focused/mesoscale area of greater tornado potential this afternoon/early evening along/south of the surface boundary in east-central/northeast OK into northwest AR, where effective SRH should become locally enhanced amid a 20-30 kt southwesterly low-level jet and slightly backed surface winds. Even so, there is still considerable uncertainty regarding convective mode (how long supercells can remain at least semi-discrete), and some signal for veered/southwesterly low-level winds with time and southward extent that could reduce low-level SRH. Have therefore held off on introducing an Enhanced Risk for this area with this update. But, trends will continue to be monitored. Additional thunderstorms are expected to develop this afternoon and evening along/south of the cold front across parts of southeast OK into north TX. This activity will be mostly displaced to the south of stronger westerly mid-level flow. Still, isolated to widely scattered hail and severe gusts may occur with the more robust cores given moderate instability and modest deep-layer shear forecast. ....Mid-Atlantic... Downstream of a broad/weak mid-level trough over the eastern CONUS, scattered thunderstorms should develop by early afternoon within a moist/weakly unstable air mass east of the central Appalachians toward the southern Mid-Atlantic region. Around 20-25 kt of deep-layer shear may support loosely organized clusters with a risk of locally damaging winds before this activity weakens this evening with the loss of daytime heating. ...Gleason/Grams.. 09/23/2025 $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .