Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Oct 03 2023 06:01:37 ACUS01 KWNS 030601 SWODY1 SPC AC 030559 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Tue Oct 03 2023 Valid 031200Z - 041200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN AND CENTRAL PLAINS... ....SUMMARY... Thunderstorms, associated with large hail, wind damage, and a few tornadoes, will be possible this afternoon and evening across parts of the Great Plains. ....Southern and Central Plains... An upper-level trough will move into the High Plains today, as an associated mid-level jet on the eastern side of the system moves through the central Plains. At the surface, a low will deepen and move across the northern Plains, as a cold front advances eastward into the central and northern High Plains. Strong low-level moisture advection in the central Plains will replenish low-level moisture ahead of the front. Surface dewpoints will likely reach the lower to mid 60s F by afternoon from northwest Texas northward into central Kansas and southern Nebraska. As surface temperatures warm during the day, moderate instability will develop along and near the moist axis. MLCAPE is forecast to peak in the 2000 to 3000 J/kg range. As low-level convergence increases ahead of the front, scattered thunderstorms will form from west Texas north-northeastward into west-central Kansas and central Nebraska. These storms will move northeastward into the stronger instability during the late afternoon and evening. MCS development will be possible. RAP forecast soundings at 00Z/Wednesday along the moist axis from northwest Texas to south-central Nebraska have 0-6 km shear generally in the 45 to 55 knot range, with 700-500 mb lapse rates near 7.5 C/km. This will support supercell development with large hail and wind damage likely in and around the stronger cores. Hailstones of greater than 2 inches will be possible in association with the more intense supercell updrafts along this corridor during the late afternoon. In addition, 0-3 km storm-relative helicity is forecast to increase into the 200 to 300 m2/s2 range by early evening, suggesting that tornadoes will be possible with the more intense supercells as well. Wind damage will also be likely with supercells and with short bowing line segments. The severe threat is expected to continue into the mid to late evening, as the low-level jet gradually strengthens across the region. Further south-southwest into parts of west Texas, isolated to scattered thunderstorm development will be likely late this afternoon into the evening. The environment will favor supercell development, with a potential for large hail and wind damage. ....Northern Plains... An upper-level trough will move into the northern Plains today, as an associated belt of strong mid-level flow on the eastern side of the system translates eastward. At the surface, a low will deepen and move north-northeastward across North Dakota during the day, as a cold front advances eastward in the northern High Plains. Surface dewpoints will initially be in the 50s F over much of the northern Plains, but a dry slot will cause drier air to advect into the region from the southwest. Due to this, a corridor of maximized low-level moisture will setup further east across eastern South Dakota and west-central Minnesota. Moderate instability may develop along the western edge of the moist corridor, where isolated to scattered thunderstorms will be possible during the late afternoon and early evening. In addition to the moderate instability, 0-6 km shear is forecast to be in the 50 to 60 knot range near the instability axis suggesting the environment will support supercells. There is some question concerning which mode will be favored. If supercell mode is favored, then large hail and wind damage can be expected with the cells. If linear mode becomes favored, then the wind-damage threat could be the greater of the two threats. The most likely corridor for severe storms will be across eastern South Dakota and far southwest Minnesota, where severe weather parameters are forecast to become maximized. ...Broyles/Lyons.. 10/03/2023 $$ = = = 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) .