Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
841 ACUS02 KWNS 091734 SWODY2 SPC AC 091732 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sun Jun 09 2024 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN HIGH PLAINS REGION... ...SUMMARY... Isolated severe storms with large hail and severe wind gusts will be possible on Monday in parts of the central and northern High Plains. Marginally severe thunderstorms will be possible in parts of the southern High Plains, and portions of the Southeast. ...Northern and central High Plains... A mid-level short-wave trough is forecast to advance eastward across the northern Intermountain Region Monday, allowing surface lee troughing to persist over the northern High Plains. As an axis of modest (50s dewpoints) low-level moisture advects northward ahead of this upper system, near and ahead of the surface trough, daytime heating will permit 1000 to 2000 J/kg CAPE to develop during the afternoon. Ascent associated with the advancing upper system and associated surface trough, combined with the destabilizing environment, will result in development of isolated to scattered thunderstorms -- perhaps initially near the higher terrain of northern and central Wyoming, but more robustly thereafter nearer the surface trough. As a belt of enhanced (around 40 kt) westerly mid-level flow spreads atop the region, beneath low-level southerlies, shear sufficient for organized/rotating storms suggests potential for supercells initially, along with attendant risks for locally damaging wind gusts and hail. Some upscale growth of storms is expected by evening, as congealing of cold pools occurs, and storms shift east-southeastward off the higher terrain. Severe potential -- increasingly in the form of locally damaging gusts -- will likewise spread eastward, before storms begin to diminish in tandem with nocturnal stabilization of the boundary layer. ...Southern High Plains... A weak upper low forecast to drift across the southern Rockies area, while afternoon heating leads to a destabilizing airmass across the southern High Plains region and vicinity, will lead to development of afternoon thunderstorms across the area. While shear will remain generally weak across most of the area, and thus storms generally disorganized, some enhancement of northwesterly mid-level flow on the southwest side of the low will spread southeastward out of central New Mexico and into Far West Texas through the afternoon and evening. As such, a small zone of greater severe risk could evolve across parts of the South Plains region and adjacent Permian Basin/Transpecos areas of Texas during the late afternoon and early evening hours. Indeed, a few CAMs suggest some upscale growth of storms into a southeastward-moving MCS -- which could yield somewhat greater potential for strong wind gusts. At this time, will refrain from a SLGT risk upgrade, due to uncertainty regarding this scenario. ...Parts of the Southeast... As a cold front sags southward across the Southeast, and becomes situated from the South Carolina Coast westward to the central Gulf coast, heating of the moist boundary layer near and south of the front should result in widely scattered storm development, focused along the frontal zone. With rather weak low-level flow but some enhancement of the mid-level westerlies atop the front, a few stronger storms -- capable of producing marginal hail and/or locally damaging gusts -- are expected during the afternoon hours, before storms weaken after dark. ..Goss.. 06/09/2024 $$