SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Wed Aug 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF EASTERN KANSAS INTO THE MID MISSISSIPPI VALLEY/MIDWEST... ...SUMMARY... Scattered severe thunderstorms appear possible across parts of the Midwest and mid Mississippi Valley on Thursday. Damaging winds and large hail should be the main threats, but a couple tornadoes may also occur. ...Midwest/Mid Mississippi Valley... A mid/upper-level trough should gradually amplify and deepen over the Upper Midwest on Thursday, eventually transitioning to a closed upper low. A gradual intensification of mid-level westerly flow is forecast across parts of the east-central Plains into the mid MS Valley vicinity through the day. At the surface, a weak low may gradually occlude beneath the upper cyclone through the period, with a trailing front extending southwestward from this low across parts of the Midwest into the central and southern Plains. In the wake of mainly elevated thunderstorms that should be ongoing Thursday morning, low-level southwesterly flow should support airmass recovery and robust destabilization Thursday afternoon from parts of the east-central Plains into the mid MS Valley and Midwest. Relatively steep mid-level lapse rates overlying rich low-level moisture (upper 60s to mid 70s surface dewpoints) will likely foster strong to locally extreme instability, with MLCAPE potentially in the 2500-4000+ J/kg range across the warm sector by late Thursday afternoon. Meanwhile, gradually strengthening mid-level flow will support effective bulk shear values around 30-45 kt, resulting in a conditionally rather favorable environment for severe thunderstorms. The details of convective initiation and evolution still remain rather uncertain due to weak low-level convergence along the synoptic front. Regardless, isolated to widely scattered thunderstorms should develop by late Thursday afternoon along this boundary, and potentially near any remnant outflow boundaries from earlier convection. Supercells with a threat of large hail, localized damaging gusts, and a couple tornadoes will be possible initially, with some upscale growth potentially leading to an increase in severe/damaging wind potential by Thursday evening, as thunderstorms move into parts of southern MO/IL and vicinity. ...Southern/Central Plains... With robust daytime heating, a deeply mixed boundary layer is expected to occur along/south of the front across parts of southern KS into OK. While deep-layer shear should remain weak across most of this region, moderate to strong instability and steepened low to mid-level lapse rates should support mainly an isolated severe wind threat with high-based thunderstorms that can develop. Occasional hail may also occur with the strongest cores. ..Gleason.. 08/14/2024
