Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Dec 15 2024 19:31:51 ACUS03 KWNS 151931 SWODY3 SPC AC 151930 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0130 PM CST Sun Dec 15 2024 Valid 171200Z - 181200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... Thunderstorms are expected from the southern Plains to the Mid-Mississippi Valley and across Florida on Tuesday. Severe thunderstorms appear unlikely at this time. ....Synopsis... On Tuesday, a fast moving jet streak will move from the Inter Mountain West to the central Plains. This will lead to some weak lee cyclogenesis with this surface low drifting south along the Front Range through the day. The positively tilted upper trough will sharpen by Tuesday evening, and a surface low will start to develop into the Plains and eventually move somewhere near the Mid-Mississippi Valley by the end of the period. A reservoir of moderate instability will be present across the southern half of Texas on Tuesday morning with slow northward movement toward the Red River through the day. Neutral to slightly rising heights aloft will likely keep thunderstorm activity limited during the day. However, during the evening and overnight hours as the upper trough sharpens and ejects into the Plains, height falls and increasing vorticity advection combined with increasing isentropic ascent should provide ample lift for scattered thunderstorm activity Tuesday night. Forecast soundings show weak to moderate elevated instability and moderate mid-level lapse rates. As mid-level flow strengthens with the approaching jet streak, 30 to 35 knots of effective shear will likely be present along and to the north of the front. Isolated large hail may be possible in this zone after 03Z. The better chance for surface based thunderstorms will be farther south near the ArkLaTex. However, forecast soundings show weak shear that far south which would likely limit storm intensity even if surface-based convection can develop within a more unstable environment. A marginal risk may be needed for portions of the southern Plains/Ozarks in later outlooks if overlap between forcing, instability and shear becomes more clear. ...Bentley.. 12/15/2024 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .