Subj : DAY1SVR: Day 1 Convective Outlook Corr 1 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jul 23 2023 01:03:59 ACUS01 KWNS 230103 SWODY1 SPC AC 230102 Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0802 PM CDT Sat Jul 22 2023 Valid 230100Z - 231200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... CORRECTED FOR 5% HAIL LINE ....SUMMARY... Thunderstorms associated with large hail and wind damage will be possible this evening in parts of the central Plains. Marginally severe storms will also be possible in the southern High Plains, mid Missouri Valley, upper Mississippi Valley, Southeast and Arizona. ....Central and Southern Plains/Mid Missouri and Upper Mississippi Valleys... Northwesterly mid-level flow is evident across the central U.S. this evening, with a subtle shortwave trough moving southeastward across the mid Missouri and upper Mississippi Valleys extending into the central Plains. Ahead of the trough, a moist and unstable airmass is in place from Kansas northeastward into Iowa, with surface dewpoints in the 60s F contributing to moderate instability. Scattered thunderstorms are ongoing within this airmass. The greatest convective coverage is located in the central Plains, where thunderstorm development will likely continue for much of the evening. An instability maximum is currently analyzed by the RAP in western Kansas, where MLCAPE is estimated to be around 2500 J/kg. The Goodland, Kansas WSR-88D VWP is near the instability max, and has had 0-6 km shear in the 55 to 65 knot range over the last hour. This will continue to support supercell development over the next few hours across western and northern Kansas. In addition, the RAP shows an elevated mixed layer extending from the central Rockies into the central Plains, where 700-500 mb lapse rates are estimated to be in the 7 to 7.5 C/km range. This thermodynamic environment will be favorable for large hail with the more intense cores. Hailstones of greater than 2 inches in diameter will be possible early this evening in parts of western Kansas. In addition, a wind-damage threat will accompany the more intense cells. Outside of the slight risk area, moderate instability is currently analyzed across parts of the southern High Plains, and in the mid Missouri and upper Mississippi Valleys. Although deep-layer shear will be adequate in these areas for a marginal severe threat, isolated convective coverage and decreasing instability will likely cause the severe threat to diminish by mid to late evening. ....Southeast... Westerly mid-level flow is located across much of the Southeast this evening. At the surface, a cold front is located from south-central Mississippi eastward into western Georgia. To the south of the front, surface dewpoints in the lower to mid 70s F are contributing to moderate instability, mainly along the immediate Gulf Coast. Strong thunderstorms are ongoing along the northern edge of this unstable airmass. Although deep-layer shear appears to be marginal for severe storms across much of the Gulf Coast, low-level lapse rates are steep in many of the coastal areas according to the RAP. This should be enough for an isolated wind-damage threat for another hour or two this evening. The greatest potential will be in southern Louisiana. ....Arizona... A mid-level anticyclone is currently located over the Desert Southwest. Scattered thunderstorms are ongoing from central New Mexico into southwest Arizona, where an axis of instability is located. Although deep-layer shear is relatively weak across this area, 0-3 km lapse rates are estimated to be in the 9 to 10 C/km range, according to the RAP. This will likely aid downdraft acceleration with a few of the stronger cells this evening, contributing to an isolated wind-damage threat. ...Broyles.. 07/23/2023 $$ = = = 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) .