Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Oct 02 2023 05:50:29 ACUS01 KWNS 020550 SWODY1 SPC AC 020549 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1249 AM CDT Mon Oct 02 2023 Valid 021200Z - 031200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN ROCKIES AND SOUTHERN HIGH PLAINS... ....SUMMARY... Thunderstorms, associated with large hail and wind damage, will be possible this afternoon and evening across parts of the southern Rockies and southern High Plains. Marginally severe storms will be possible in parts of the central Rockies, and in parts of the central and northern Plains. ....Southern Rockies/Southern High Plains... A relatively high amplitude upper-level trough will move across the western U.S. today. An associated mid-level jet will translate northeastward into the southern and central Rockies. Ahead of the system, low-level moisture advection and south-southeasterly upslope flow will be maintained across the southern High Plains. As a result, surface dewpoints are expected to be near 60 F in much of eastern New Mexico and west Texas by afternoon. In response to surface heating, moderate instability is forecast to develop by mid afternoon throughout much of eastern New Mexico. Scattered thunderstorms will likely develop in the higher terrain of central and eastern New Mexico, gradually spreading northeastward into the lower elevations. Several clusters of strong thunderstorms appear likely to develop during the late afternoon and persist into the early to mid evening. RAP forecast soundings late this afternoon suggest that the most favorable environment for severe storms will be in southeast New Mexico, where MLCAPE is forecast to peak in the 2000 to 2500 J/kg range. 0-6 km shear in this area is forecast to be in the 40 to 50 knot range, with an increase in shear likely as the eastern edge of the mid-level jet moves into the region. This will be favorable for supercells and organized storms. The instability, along with 700-500 mb lapse rates near 7.5 C/km, will make large hail likely with the more intense cores. As the storms mature and move northeastward into the lower elevations, a wind-damage threat is also expected to materialize. The severe threat will first develop in eastern New Mexico, but will spread northeastward into the southern High Plains by early evening. A severe threat will also be possible in far West Texas, but the threat will be increasingly marginal with southward extent there. ....Central Rockies/Central and Northern Plains... South-southwesterly mid-level flow will be in place today from the central Rockies into the northern High Plains. At the surface, a low will deepen in far southeast Wyoming. Moisture advection will continue across much of the central and northern Plains, with surface dewpoints remaining in the 50s F in most areas. As surface temperatures warm this afternoon, a corridor of moderate instability will develop across the central High Plains. Isolated to scattered thunderstorms appear likely to form near this axis of instability westward into the higher terrain of Colorado and Wyoming. The storms will move north-northeastward into the central and northern High Plains during the late afternoon and early evening. RAP forecast soundings near the instability axis have MLCAPE peaking near 2000 J/kg, with 0-6 km shear in the 25 to 30 knot range. Mid-level lapse rates near 7.5 C/km, combined with 0-3 km lapse rates increasing to near 8.5 C/km, will be favorable for hail and strong winds associated with organized multicells. The severe threat is expected to be marginal, but should persist into the early to mid evening as storm coverage gradually increases across the region. ...Broyles/Lyons.. 10/02/2023 $$ = = = 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) .