Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jun 12 2023 04:42:32 ACUS02 KWNS 120442 SWODY2 SPC AC 120440 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1140 PM CDT Sun Jun 11 2023 Valid 131200Z - 141200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TUESDAY INTO TUESDAY NIGHT ACROSS PARTS OF SOUTHEASTERN OKLAHOMA...NORTHEASTERN TEXAS...SOUTHERN ARKANSAS...NORTHERN LOUISIANA...MUCH OF CENTRAL MISSISSIPPI AND ALABAMA...CENTRAL AND SOUTHERN GEORGIA AND ADJACENT PORTIONS OF NORTHERN FLORIDA... ....SUMMARY... Organized clusters of thunderstorms may develop and pose a risk for severe wind and hail Tuesday into Tuesday night across parts of the southeastern Great Plains through the Gulf Coast states. ....Synopsis... It still appears that short wave developments within the prevailing split mid/upper flow will become more progressive during this period. As this occurs, models indicate that a couple of persistent, embedded, broad and deep mid-level lows will undergo a more notable eastward acceleration Tuesday through Tuesday night. While the lead circulation continues to shift away from the northern Atlantic Seaboard, the trailing one is forecast to redevelop eastward across the lower Great Lakes region. The southern periphery of the Great Lakes low will extend as far south as the lower Ohio and Tennessee Valleys, across the southern Appalachians, more or less in phase with broad southern stream troughing across the Gulf Coast states. The mid-level troughing may sharpen some in response to a short wave perturbation pivoting around the western through southern periphery of the Great Lakes low, and as the increasingly deformed remnants of a weakening mid-level low emerging from the Great Basin continue to develop eastward into the confluent regime to the south and southwest of the Great Lakes low. In response to these developments, seasonably strong westerly to west-northwesterly lower/mid-tropospheric flow will be maintained along a lingering near-surface frontal zone across the southern Great Plains through the Gulf Coast states. Seasonably moist boundary-layer air will generally remain confined to areas along and south of this frontal zone. However, beneath modestly steepening mid-level lapse rates, it appears that this moisture will contribute to moderately large mixed-layer CAPE with daytime heating. ....Southeastern Great Plains through the Gulf Coast states... Forcing for ascent along the quasi-stationary frontal zone, which may be reinforced in areas by convective outflow, remains uncertain due to model spread/uncertainties concerning smaller-scale perturbations progressing through the larger-scale flow. Areas of convective development may be ongoing at the outset of the period, and the impact of early period convection on potential latter period activity also remains uncertain. Due to these issues, among others, the potential for the evolution of one long-lived, progressive mesoscale convective system appears relatively low. However, the occasional development of organizing, progressive clusters which may become capable of producing swaths of potentially damaging wind gusts appears possible throughout Tuesday into Tuesday night. Given the strength of the deep-layer shear, more discrete thunderstorm development during the peak late afternoon/early evening boundary-layer instability may develop supercell structures capable of producing large hail and perhaps a tornado or two. ....Southeast Colorado into Texas/Oklahoma Panhandle vicinity... A remnant mid-level cold core emerging from the Great Basin is forecast to progress across and dig southeast of the Colorado Rockies by late Tuesday afternoon. It appears that this will contribute to thermodynamic profiles with steep lapse rates and modest CAPE supportive of thunderstorm development across and southeast of the Raton Mesa vicinity through Tuesday evening. Aided by modest deep-layer shear, stronger activity may become capable of producing marginally severe wind and hail. ...Kerr.. 06/12/2023 $$ = = = 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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .