Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Aug 24 2024 05:53:38 ACUS01 KWNS 240553 SWODY1 SPC AC 240552 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CDT Sat Aug 24 2024 Valid 241200Z - 251200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE FOUR CORNERS REGION INTO THE CENTRAL HIGH PLAINS...PARTS OF WESTERN MO...AND PARTS OF THE SOUTHERN PLAINS... ....SUMMARY... Strong to locally severe storms are possible today from the Four Corners region northeastward into the central High Plains. Strong to severe storms are also possible across western Missouri and also across western Oklahoma. ....Synopsis... A deep mid/upper-level trough will remain in place over the West today. An embedded mid/upper cyclone is forecast to move southeastward from northern CA into the Great Basin. Downstream, an upper-level anticyclone will remain anchored over the southern Great Plains. One surface low is forecast to gradually deepen across the northern High Plains, while another weak surface low may develop across the south-central High Plains. ....Four Corners region into the central High Plains... The eastern fringe of stronger southwesterly flow aloft (associated with the deep upper trough) will overspread a plume of midlevel moisture from the Four Corners region into the central Rockies. Scattered thunderstorm development is expected across the region this afternoon. Effective shear of 30-40 kt and modest but sufficient buoyancy will support potential for a few loosely organized cells and/or clusters, with a threat of isolated strong to severe gusts. Richer low-level moisture and stronger instability will develop this afternoon across parts of the central High Plains, where moist easterly flow is maintained to the north of a nearly stationary surface boundary. With capping and weaker large-scale ascent expected, storm initiation within this more-unstable regime may be suppressed. However, high-based convection that develops over the higher terrain could spread into the central High Plains by early evening, potentially accompanied by an isolated strong to severe gusts and perhaps some hail. ....Western MO and vicinity... Most guidance suggests an increase in elevated convection near and after 12Z across parts of western MO, driven by low-level warm advection and moistening in the 850-700 mb layer. Effective shear will not be particularly strong, but relatively steep midlevel lapse rates and moderate elevated buoyancy will support potential for a few robust storms. Isolated hail cannot be ruled out with the strongest storms. Also, despite the elevated nature of the convection, initially rather dry profiles below the moist layer could support locally strong gusts. Depending on the coverage and intensity of morning convection, cold-pool development will be possible, which could lead to a southward-propagating cluster across western MO. This scenario remains quite uncertain, but there will be some potential for an isolated damaging-gust threat to spread into southwest MO from late morning into the afternoon. ....Parts of western OK into northwest TX... Despite generally weak large-scale ascent, some guidance suggests potential for isolated to widely scattered thunderstorm development within a very hot/well-mixed environment across parts of western OK into northwest TX late this afternoon into the early evening. With weak deep-layer shear and the influence of the upper ridge, storms will likely remain disorganized, and coverage of storms remains uncertain. However, any stronger storm within this environment would pose a conditional microburst threat. A 5% wind area has been added where relative confidence in storm development is currently greatest. ....Northeast MT into northwest ND... Moderate to locally strong instability may develop this afternoon from far northeast MT into northwest ND, with sufficient deep-layer shear to support storm organization. However, large-scale ascent is expected to remain rather weak across the region, and there is only a very weak signal for diurnal storm development. Some threat for severe hail and/or wind could accompany any robust storm within this regime, but confidence in storm coverage is too low for probabilities at this time. ...Dean/Karstens.. 08/24/2024 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .