Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Oct 02 2023 20:00:34 ACUS01 KWNS 022000 SWODY1 SPC AC 021958 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Mon Oct 02 2023 Valid 022000Z - 031200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN AND CENTRAL HIGH PLAINS... ....SUMMARY... The greatest potential for scattered severe thunderstorms capable of producing a couple tornadoes, significant large hail, and severe wind gusts remains across parts of eastern New Mexico and far west Texas this afternoon and evening. ....20Z Update... No changes have been made to the Slight Risk across the southern High Plains. A few supercells posing a threat for large to perhaps very large hail have developed over parts of central/eastern NM. This convection is expected to spread east-northeastward across the southern High Plains through this evening, while posing a continued threat for isolated large hail, severe wind gusts, and perhaps a tornado or two given a favorable kinematic environment. See Severe Thunderstorm Watch 696 for more details. Isolated thunderstorms should also pose some threat for severe hail/wind gusts across southeastern CO and vicinity. Confidence in greater coverage of potentially severe convection was not high enough to expand the Slight Risk across NM into southeastern CO. Reference Mesoscale Discussion 2210 for more information on the severe risk for this area. Low-level moisture remains fairly limited across the western NE and northeastern CO vicinity this afternoon, although some locations are reporting surface dewpoints in the mid to upper 50s along/south of a front draped across SD. Thunderstorms should eventually move northeastward off the higher terrain of the central Rockies and into the adjacent High Plains, with other convection possibly developing over northeastern CO. Given the well mixed boundary layer, severe downdraft winds still appear to be the primary severe hazard. But, isolated hail may occur with any supercell that can be sustained. See recently issued Mesoscale Discussion 2209 for more details on the near-term severe threat across this area. ...Gleason.. 10/02/2023 ..PREV DISCUSSION... /ISSUED 1128 AM CDT Mon Oct 02 2023/ ....Southern High Plains... Low to mid 60s surface dew points are pervasive across eastern NM and west TX. This will support a broader plume of moderate buoyancy this afternoon relative to the past couple days with MLCAPE of 1500-2500 J/kg becoming common. Scattered to eventually widespread thunderstorms will develop off the higher terrain of central to eastern NM into the TX Trans-Pecos, initiating in the early afternoon. Several discrete supercells should evolve across east-central/southeast NM and the Permian Basin. Modest low-level curvature beneath a moderately elongated and straight mid to upper hodograph should favor large hail production, some of which should reach golf ball size with potential for a few 2-2.5 inch sizes as well. A couple tornadoes will also be possible, most probable in the east-central NM vicinity where low-level hodographs should be slightly more enlarged with lower LCL heights. Storms should consolidate into east-northeast moving clusters by late afternoon to early evening with a strong to isolated severe wind threat spreading across parts of west TX before weakening after sunset. ....Central High Plains to the Dakotas... A lee cyclone becoming established over northeast CO will track north-northeast into southwest SD this evening as mid-level height falls increase downstream of a vigorous shortwave trough moving from UT into WY. A strengthening baroclinic zone, aided by ongoing differential boundary-layer heating within the nearly cloud-free warm sector and stratus lingering behind the front, will support intensifying thunderstorms that develop northeast off the Front Range. Consensus of 12Z HREF guidance supports a scenario of an organized cluster peaking across the western NE Panhandle vicinity in the late afternoon to early evening with a severe wind and isolated hail threat along the baroclinic zone. The severe wind/hail potential should decrease after sunset, but may continue tonight on an isolated basis across parts of the Dakotas. $$ = = = 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) .