Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu May 18 2023 12:30:38 ACUS01 KWNS 181230 SWODY1 SPC AC 181229 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0729 AM CDT Thu May 18 2023 Valid 181300Z - 191200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE TEXAS PANHANDLE AND WESTERN OKLAHOMA... ....SUMMARY... Strong to severe thunderstorms with hail and strong wind gusts may impact parts of the southern Great Plains, the Upper Midwest, and the Tennessee Valley this afternoon and evening. ....West TX/OK... Weak to moderately strong westerly mid-level winds are present today from the Great Basin eastward into the central/southern Plains, with several weak/subtle shortwave troughs embedded in the flow. Strong heating is expected to occur today from the southern TX panhandle southward, helping to form a weakly focused surface dryline from near Amarillo southward to the Big Bend region. Most overnight CAM solutions suggest that low clouds persist through much of the day in the central/northeastern TX panhandle, leading to a relatively strong baroclinic zone across the region. This boundary is likely to be the focus for strong/severe thunderstorms by late afternoon. Despite weak forcing mechanisms, scattered high-based thunderstorms are expected to build in vicinity/west of the dryline and move into the moist/unstable axis. Gusty winds will be possible in the stronger cores throughout the region. Enhanced low-level shear/convergence in vicinity of the baroclinic zone may result in more organized storms over the TX panhandle during the late afternoon and evening, where RAP forecast soundings show enlarged hodographs to support supercell structures. Hail and damaging winds are the main threat, although a tornado or two is possible. Therefore have added a small SLGT risk for that region. ....Eastern CO/Western KS... Easterly post-frontal low-level winds are expected today over much of eastern CO and western KS, maintaining 50s dewpoints across the region. Afternoon thunderstorms are expected to increase in coverage over the foothills and spread into the adjacent plains, with some interaction with the DCVZ. Forecast soundings in this area show MLCAPE values around 1000 J/kg and 25-30 knots of deep-layer shear. This suggests some potential for organized clusters of storms capable of gusty winds and hail. ....MN/WI... An upper trough over Manitoba will track southeastward today, with its associated surface cold front sagging into southeast MN and central WI. Scattered thunderstorms will form along this front by mid-afternoon and track across parts of central WI and northeast IA. Strengthening winds aloft and strong heating ahead of the front will support gusty/damaging winds in the strongest cores. The primary severe threat will only last few hours this evening due to a narrow instability axis and the onset of diurnal cooling. ...Hart/Gleason.. 05/18/2023 $$ = = = 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) .