Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Sep 23 2025 20:02:17 ACUS01 KWNS 232002 SWODY1 SPC AC 232000 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Tue Sep 23 2025 Valid 232000Z - 241200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN OKLAHOMA INTO WESTERN ARKANSAS... ....SUMMARY... Scattered severe thunderstorms are probable this afternoon into the evening over portions of eastern Oklahoma into western Arkansas. The primary severe-weather risk will be the threat for a few tornadoes, with one or two of these tornadoes potentially being strong. Scattered damaging wind gusts will be possible as well. ....20Z Update... The primary change with this update was an expansion of the Enhanced Risk in east-central OK and west-central AR -- driven by 30-percent wind probabilities. Along/south of the convectively reinforced baroclinic zone draped across northeast OK into northwest AR, temperatures have warmed into the lower 90s amid middle 70s dewpoints. The resultant strong surface-based buoyancy will favor scattered damaging wind gusts (possibly up to 75 mph on an isolated basis) with a mix of semi-discrete supercells and upscale-growing clusters through the afternoon. For details on the near-term severe risk here, reference MCD #2123. Elsewhere, the Marginal Risk was expanded slightly northward into southern IL ahead of a band of approaching convection. Diurnal heating of a moist air mass beneath high-level clouds has contributed to weak surface-based buoyancy, which combined with strengthening deep-layer shear, will support a couple loosely organized storms capable of locally damaging winds. ...Weinman.. 09/23/2025 ..PREV DISCUSSION... /ISSUED 1129 AM CDT Tue Sep 23 2025/ ....Southern Plains into the Ozarks and Mid-South... Water-vapor imagery shows an elongated, positively tilted mid-level trough centered over the eastern Great Basin/central Rockies. Of particular note, a mid-level vorticity maximum is indicated moving east from the OK-TX Panhandle region and embedded within a belt of slightly stronger 30-45 kt westerly flow. Radar/lightning data late this morning shows a few thunderstorm clusters over the Ozark Plateau along and north of a psuedo warm front/outflow boundary. This boundary has become quasi-stationary and is draped west to east from northeast OK across far northern AR east to the MS River. Surface streamline analysis indicates a 1007 mb low has begun to become better defined over north-central OK and this low will develop east along the boundary towards northwest AR by early evening. South of the composite outflow/warm front, a very moisture-rich airmass continues to heat/destabilize in eastern OK with surface temperatures and dewpoints in the mid 80s and mid 70s deg F, respectively. Model forecast soundings shows 1000-2000 J/kg MLCAPE over western and northern TX to upwards of 3000 J/kg over eastern OK. The latest model guidance shows sufficiently enlarged hodographs (150-250 m2/s2 effective SRH) near the west-east oriented boundary. This environmental setup will support robust supercell development, especially in the Enhanced Risk (level 3/5) area. A few tornadoes, one or two which may be strong, are possible mainly during the mid-late afternoon through the early evening. Large hail will be possible with the more intense updrafts and scattered wind damage may occur where clustering of storms becomes more prevalent. Storms will likely continue eastward into the evening with some risk for severe being maintained before more substantive weakening occurs with storm activity as it nears the MS Valley late. 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 to mid afternoon within a moist/weakly unstable airmass. 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. $$ = = = 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) .