Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Feb 14 2025 19:39:26 ACUS01 KWNS 141938 SWODY1 SPC AC 141937 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0137 PM CST Fri Feb 14 2025 Valid 142000Z - 151200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... Widely scattered weak thunderstorm development is likely across parts of the southern Great Basin into Four Corners vicinity, and across parts of the lower Mississippi Valley, late this afternoon into evening. More widespread weak thunderstorm development is probable across Arkansas into the lower Ohio Valley late this evening into early Saturday. ....20Z Outlook Update... Above a residual cold/stable boundary-layer, a moistening southerly return flow is in the process of developing off the western Gulf Basin. Associated destabilization, rooted around the 850 mb level, has supported the initiation of some thunderstorm activity within a broader convective band across parts of southern Louisiana into southeastern Texas, in the presence of forcing for ascent aided by warm advection. However, warming farther aloft is ongoing, and likely to increasingly suppress thunderstorm development near northwestern Gulf coastal areas into this evening. To the north-northeast of this regime, strengthening lower/mid-tropospheric warm advection and destabilization are likely to support a more concentrated area of thunderstorm development focused across the Arkansas into lower Ohio Valley vicinity, downstream of the significant short wave trough forecast to dig across the southern Rockies and adjacent portions of the northern Mexican Plateau by 12Z Saturday. Beneath the mid-level cold core of this trough, ongoing insolation is contributing to boundary-layer destabilization across the southern Great Basin through Four Corners region. Forecast soundings continue to suggest that thermodynamic profiles will become supportive of widely scattered convection capable of producing lightning, before this potential diminishes during the evening with the onset of diurnal boundary-layer cooling. ...Kerr.. 02/14/2025 ..PREV DISCUSSION... /ISSUED 1016 AM CST Fri Feb 14 2025/ ....Synopsis... Water-vapor imagery this morning shows a large-scale upper trough over the West. This feature will amplify through late tonight as a 100-kt 500mb speed max moves through the base of the trough and into northern Sonora and Chihuahua. A belt of strong southwesterly mid-level flow will extend downstream of this upper trough into the southern Great Plains northeastward through the OH Valley. The gradual moistening of a low-level conveyor belt from the northwest Gulf Coast into the lower OH Valley will facilitate shower/thunderstorm development beginning late this evening but mainly into the overnight. Despite lee cyclone development initially over eastern CO today but evolving into western OK tonight, a cool low-level airmass of continental origin will only slowly modify across the Mid South. As a result, the poleward transport of moisture atop a cool boundary layer will promote elevated buoyancy ranging from around 1000 J/kg MUCAPE over southeast OK to 250 J/kg in the lower OH Valley. Relatively marginal mid-level lapse rates will probably limit overall updraft vigor and thereby limit hail potential (perhaps locally sub severe) with the strongest storms. $$ = = = 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) .