Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jun 25 2023 17:34:17 ACUS02 KWNS 251734 SWODY2 SPC AC 251732 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sun Jun 25 2023 Valid 261200Z - 271200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS MID-ATLANTIC STATES... ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS NEAR THE BLACK HILLS... ....SUMMARY... Scattered severe thunderstorms are likely across the Mid-Atlantic states Monday afternoon through the evening. Damaging gusts and large hail will be the primary hazards. ....Eastern U.S.... A mid-level low over the Great Lakes and an associated trough over the Appalachians will slowly move east during the period. Moderate to strong cyclonic flow will move through the base of the trough and overspread a destabilizing warm sector east of the Appalachians. In the low levels, an effective front will push east across the upper OH Valley and Appalachians during the day with this convectively aided boundary pushing east of much of the Mid-Atlantic coast by early Tuesday morning. Scattered showers/isolated thunderstorms are forecast to be ongoing Monday morning across PA moving into southern NY and weakening by midday. In wake of this activity, strong heating from PA (where cloud breaks permit) southward into the western Carolinas will result in a moderate to strongly unstable airmass by early afternoon (1500-3000 J/kg SBCAPE). Weak capping will likely erode as scattered to numerous thunderstorms develop during the afternoon from NC north into PA. Model guidance shows 25-40 kt 500-mb flow over the Mid-Atlantic states which will aid in storm organization. Forecast hodographs shows backing of flow with height in the mid- to upper levels and will promote a fairly quick transition from a mix of cells and linear segments to a more extensive band of storms. The extensive coverage of the expected squall line and the quality of the mesoscale environment prompted an expansion in the 30-percent wind probabilities. Some model guidance shows slight low-level hodograph enlargement from parts of northeast PA into the lower Hudson Valley during the late afternoon/early evening. However, considerable uncertainty in the quality of the airmass precludes higher tornado probabilities across this region. By early to mid evening, much of the thunderstorm activity will push east of the coast across the Mid-Atlantic states with the remaining risk likely becoming more focused across NC. Farther south, more isolated storm coverage is expected over the northeast Gulf Coast with widely scattered storms expected over SC. Damaging gusts and perhaps large hail will be possible with the stronger storms. ....Northern WY into SD and northern NE... An upper-level ridge is forecast to move across the central and northern High Plains on Monday. Beneath the ridge, a narrow corridor of moderate instability is forecast to develop by afternoon. An easterly component to the low-level flow will facilitate 50s deg F dewpoints into northeast WY and western SD. Forecast soundings show steep lapse rates (7.5 deg C/km in the 700-500 mb layer) and elongated hodographs. The latest CAM solutions show widely scattered thunderstorms developing by early evening over northeast WY with some of this activity developing/moving east-southeast into southwest SD/northern NE by late evening into the overnight. Large hail/severe gusts are the primary hazards. .....Southeast OK/southern AR... Weak warm-air advection is forecast Monday night near a residual frontal zone forecast to be draped across southern AR into eastern OK. Isolated thunderstorms are possible within a very moist and conditionally unstable airmass will be in place with MUCAPE around 3000 J/kg. Strong mid to high-level northwesterly flow cresting the mid-level ridge will support storm-top venting and perhaps a localized large-hail risk. ...Smith.. 06/25/2023 $$ = = = 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) .