Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Apr 19 2023 06:01:58 ACUS02 KWNS 190601 SWODY2 SPC AC 190600 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Wed Apr 19 2023 Valid 201200Z - 211200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSISSIPPI VALLEY...SOUTHERN OZARKS...ARK-LA-TEX AND SOUTHERN PLAINS.... ....SUMMARY... Severe thunderstorms associated with wind damage and large hail will be possible across parts of mid Mississippi Valley southwestward into the Ark-La-Tex and southern Plains Thursday afternoon and evening. ....Ozarks/Ark-La-Tex/Southern Plains... Southwest mid-level flow will remain established across the Great Plains and Mississippi Valley on Thursday, as an upper-level trough approaches from the west. At the surface, a cold front will move southeastward into the Ozarks and into north-central Texas. Ahead of the front, surface dewpoints will generally be in the 60s F, which will contribute to moderate destabilization by midday, from the southern Ozarks southwestward. Surface heating and increasing low-level convergence along the front will result in scattered thunderstorm development during the early afternoon, with convective coverage gradually expanding during the late afternoon. Thunderstorms will be likely along the front, but also could form southeastward across the moist sector. Several cell clusters and line segments are expected to move east-northeastward across southern Ozarks, Ark-La-Tex and east-central Texas during the late afternoon and evening. NAM forecast soundings at 00Z from southwest Arkansas southwestward to near Dallas, have MLCAPE in the 1500 to 2500 J/kg range with 700-500 mb lapse rates near 8.0 C/km. This, combined with about 40 knots of 0-6 km shear will be favorable for severe storms. Low to mid-level winds are forecast to be parallel to the front, suggesting that linear mode could be favored. Multicells that can organize could be associated with wind damage and hail. Further southwest into east-central Texas, instability is forecast to be even stronger, with MLCAPE peaking near 3500 J/kg. Low-level winds are forecast to be more backed with a gradual veering profile with height. This, along with 0-6 km shear around 40 knots could be favorable for supercells, especially if storms remain discrete. Hailstones of greater than 2 inches in diameter would be possible with the more dominant supercells in areas where strong instability develops. ....Mid to Upper Mississippi Valley... An upper-level low will move through the northern Plains on Thursday, as southwest flow remains strong at mid-levels across much of the north-central United States. At the surface, a cold front will move eastward into the mid to upper Mississippi Valley. Surface dewpoints ahead of the front are forecast to be mostly in the lower 60s F, which will contribute to weak destabilization by early afternoon. Large-scale ascent associated with the upper-level system will aid thunderstorm development early in the day, with these storms expanding in coverage and moving northeastward across the region. In spite of the weak instability, 0-6 km shear is forecast to be about 50 knots over much of the mid to upper Mississippi Valley. This, along with steep mid-level lapse rates will likely support isolated severe storms. Wind damage and hail will be possible with the stronger multicell line segments, although the potential for wind may be the greater of the two threats. ...Broyles.. 04/19/2023 $$ = = = 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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .