000 ACUS01 KWNS 140550 SWODY1 SPC AC 140548 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue May 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL AND NORTHERN FLORIDA INTO EXTREME SOUTHERN GEORGIA... ...SUMMARY... Severe thunderstorms will be possible today over parts of central and northern Florida into extreme southern Georgia, with damaging gusts and a tornado or two the main threats. Isolated severe storms will also be possible across portions of the Ohio and Tennessee Valleys into the Carolina Piedmont, as well as the central Rockies/High Plains and parts of western Texas. ...Synopsis... A mid-level trough will slowly progress across the Southeast as a second, low amplitude trough traverses the central Rockies today. Multiple embedded impulses should pivot around the Southeast mid-level trough and eject into the Atlantic, providing multiple rounds of deep-layer ascent to support a few rounds of thunderstorms over northern into central FL. Accompanying the southeast mid-level trough is a weak surface low over the OH/TN Valleys, which will aid in the northward transport of low-level moisture and associated buoyancy. Given modest vertical wind shear in place, adequate buoyancy will support the organization of at least isolated strong to severe thunderstorms over the OH/TN Valleys, with a more concentrated severe risk possible in northern FL along a residual baroclinic boundary. Elsewhere across the central Rockies/High Plains, enough deep-layer ascent will support scattered thunderstorms atop a well-mixed, heated boundary layer to support an isolated severe threat. ...Central and northern FL into extreme southern GA... A baroclinic boundary will become reinforced somewhere over northern FL with the passage of an MCS at the start of the period. Along this boundary, the MCS should intensify as a 500 mb jet streak overspreads the moist, destabilizing boundary layer. 7+ C/km mid-level lapse rates overspreading 70+ F surface dewpoints will boost MLCAPE to the 2000-3000 J/kg range. Modest low-level hodograph curvature and some elongation suggests that embedded bowing structures and mesovortices could develop, accompanied by a damaging gust and tornado risk. After the first round of storms diminish by the afternoon, a second round of strong to potentially severe thunderstorms could develop over northern FL as a second mid-level impulse embedded in the upper trough overspreads the region. Severe coverage with this second round of storms will be more conditional on how much airmass recovery can occur between both rounds of storms. ...OH and TN Valleys into the Carolina Piedmont... Deep-layer moisture will advect northward ahead of the meandering surface low, beneath a nearly uncapped troposphere. As such, diurnal heating needs only to boost surface temperatures into the lower 70s F to initiate convection. These temperatures, along with low to mid 60s F dewpoints, will support around 1000 J/kg SBCAPE by afternoon. Flow aloft is not expected to be overly strong, with slightly curved and short hodographs likely resulting in mainly pulse cellular and multicellular storms. Damaging gusts and hail will be the main threats, though a brief tornado or two cannot be ruled out. ...Central Rockies into the Central High Plains... The approach of a low-amplitude mid-level trough, and diurnal heating of an uncapped boundary layer, will support scattered to numerous thunderstorms during the afternoon and evening hours. A deep and dry boundary layer should become established by afternoon peak heating, resulting in high-based pulse- and multicell storms capable of producing isolated severe gusts (given 7-9 C/km low and mid-level lapse rates). A couple instances of severe hail may also accompany storms over the central High Plains, where low-level moisture is slightly more favorable. ...Portions of western Texas... A narrow corridor of thunderstorm potential exists ahead of a diffuse dryline over western TX by afternoon peak heating, where the dryline circulation may be strong enough to assist in the initiation of isolated thunderstorms amid minimal CINH. Low-level moisture will be meager, with mid 80s F surface temperatures and low 50s F dewpoints contributing to over 30 F spreads, so any storms that develop will be high based. Somewhat elongated hodographs suggest that supercells would be the dominant mode of convection, accompanied by an isolated severe wind/hail risk. ..Squitieri.. 05/14/2024 $$