Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Aug 14 2024 19:56:44 ACUS01 KWNS 141956 SWODY1 SPC AC 141954 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS MIDDLE MO VALLEY... ....SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across portions of the middle Missouri Valley. ....20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ...Thornton/Thompson.. 08/14/2024 ..PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ....MO Valley area this afternoon through tonight... An MCV over northwest IA will continue eastward today, while clusters of thunderstorms are ongoing this morning from central MO to northern AR within a low-level warm advection regime. Warm advection will slowly weaken through the day, but convective outflow with the central MO storm cluster may result in those storms persisting well into the afternoon while spreading southward. Otherwise, outflow from the morning convection will slowly modify from eastern KS into southeast NE, in advance of a midlevel shortwave trough over the central High Plains, and an associated surface cold front moving southeastward across northwest KS. The cold front and the front/outflow intersection will focus thunderstorm development late this afternoon/evening from central KS to southeast NE/southwest IA, and storms will subsequently spread eastward tonight as one or more storm clusters/MCSs across northern MO/southern IA. Low-level shear/hodograph curvature will be maintained this afternoon within the modifying outflow across the SLGT risk area, where semi-discrete supercells and a couple of tornadoes will be possible. Isolated very large hail (2-2.5 inches in diameter) will also with any persistent supercells, though the severe threat will transition primarily to damaging winds (60-75 mph) by late evening into tonight as storms grow upscale. Farther northwest, a separate clustering of storms is possible in central SD, south of the ongoing convection across southern ND. Surface heating in cloud breaks and weak ascent downstream from an ejecting midlevel trough will help focus thunderstorm development by 21-00z. Low-midlevel vertical shear will not be particularly strong and flow aloft will be strongly backed, which suggests a fairly quick growth into a line segment. Isolated damaging gusts and large hail will be possible for a few hours late this afternoon/evening. ....WY and vicinity this afternoon... An embedded vorticity maximum over southeast ID will progress eastward over WY this afternoon/evening. There will be sufficient low-midlevel moisture and surface heating for high-based thunderstorm development by early afternoon in advance of the vorticity maximum. Given steep low-level lapse rates and modest enhancement to midlevel flow (near 30 kt), strong outflow winds of 50-60 mph will be possible with this convection through the afternoon. $$ = = = 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) .