Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Apr 28 2023 20:01:50 ACUS01 KWNS 282001 SWODY1 SPC AC 282000 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Apr 28 2023 Valid 282000Z - 291200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL TO SOUTH-CENTRAL TEXAS... ....SUMMARY... Destructive hail (some at least as large as baseballs), thunderstorm gusts potentially exceeding 75 mph, and a couple tornadoes remain possible this afternoon and evening from north Texas southwestward into south-central Texas. ....20Z Update... The northern extent of the Enhanced Risk (across north TX) has been trimmed with this update. Intense convection, including a supercell, has recently developed along/just south of the surface triple point in central TX. Although a left-splitting supercell or two remains possible, it appears that the greater concentration of severe hail/wind will remain generally south of the Metroplex. Very large hail and a tornado remain a possibility with any supercell that can remain at least semi-discrete. The damaging wind threat will increase as convection eventually grows upscale into an MCS later this afternoon and evening, with some potential for isolated significant severe gusts. Otherwise, only minor changes have been made to the Marginal Risk across NC, based on recent surface observations showing a stalled wedge front draped east-west across much of the state. This area may have a somewhat better chance for an organized thunderstorm or two given a favorable combination of instability and deep-layer shear. But, confidence in any more than an isolated severe hail/wind threat remains too low to increase severe probabilities. See Mesoscale Discussion 649 for more information on the short-term threat for isolated wind/hail across the central Appalachians and vicinity, and Mesoscale Discussion 650 for more details regarding the isolated severe threat across NC. ...Gleason.. 04/28/2023 ..PREV DISCUSSION... /ISSUED 1125 AM CDT Fri Apr 28 2023/ ....TX this afternoon through tonight... A midlevel shortwave trough over the southern High Plains will continue eastward over central TX this afternoon/evening, as an accompanying cold front likewise surges southeastward. Low-level moisture return is underway from south into central and north TX, with boundary-layer dewpoints in the 65-70 F range from Waco southward as of 16z. Strong surface heating/mixing is expected along the western fringe of the returning moisture, near a remnant lee trough/dryline across the Edwards Plateau, prior to being overtaken by the cold front later this afternoon/evening. The surface heating, in combination with strengthening forcing for ascent along the cold front (with the approach of the midlevel trough) will support thunderstorm development by mid afternoon across central/north TX. The increasing low-level moisture and surface heating, beneath midlevel lapse rates in excess of 8 C/km, will result in large buoyancy in the warm sector this afternoon (MLCAPE greater than 2500 J/kg). Thermodynamic profiles will favor both strong updrafts and strong downdrafts, while wind profiles will become favorable for supercells as hodographs lengthen. There will be a window of opportunity for a couple of tornadoes from about 20-22z near the path of the surface wave along the cold front, where the stronger low-level shear/hodograph curvature will coincide with the north edge of the richer low-level moisture (a little south to southwest of the DFW area). The initial convection will likely be supercells with the aforementioned tornado potential, as well as very large hail near 3 inches in diameter. Forcing for ascent along the front will support upscale growth into more linear convection by this evening into central/south central TX. Isolated very large hail will be possible with any semi-discrete supercells, along with an increase in the potential for damaging outflow gusts (a few of which could reach or exceed 75 mph). The storms will continue southeastward overnight to the middle and lower TX coasts. ....OH Valley to the Southeast this afternoon... The trailing influence of a midlevel trough will move over OH/WV this afternoon, along with weak surface reflections. A few cloud breaks will allow modest surface heating, and destabilization could become sufficient for isolated strong storms with some hail/wind this afternoon. The trailing (southeast) influence of the midlevel trough, and a slow-moving wedge front, could focus a few strong storms this afternoon across NC. Farther south, the remnants of an overnight MCS are moving over central FL. Lingering clouds have slow surface heating in central FL, and the better chances for isolated strong storms with wind/hail will be in the zones of stronger surface heating across southeast FL with the sea breeze, and closer to the FL/GA border. $$ = = = 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) .