Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jan 23 2023 08:26:28 ACUS03 KWNS 230826 SWODY3 SPC AC 230825 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0225 AM CST Mon Jan 23 2023 Valid 251200Z - 261200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WEDNESDAY ACROSS PARTS OF NORTHERN FLORIDA...MUCH OF CENTRAL AND SOUTHERN GEORGIA...SOUTH CAROLINA...NORTH CAROLINA AND SOUTHEASTERN VIRGINIA... ....SUMMARY... Strong thunderstorms may impact portions of the southern through middle Atlantic Coast states Wednesday, accompanied by at least some risk for damaging wind gusts and tornadoes. ....Synopsis... As a deep mid-level low of Arctic origins begins to redevelop southwestward toward the Hudson Bay vicinity, and a subtropical high is maintained over the Caribbean, models indicate that mid-level troughing may continue to gradually encompass much of the U.S from the Great Basin eastward. Within persistent large-scale ridging over the eastern Pacific, a prominent new mid-level high is forecast to form to the west of the northern U.S. Pacific coast. As this occurs, downstream digging short waves will maintain mid-level troughing across the Four Corners states, while an initially much more prominent perturbation farther downstream accelerates toward an increasingly confluent regime across the lower Great Lakes region through Mid Atlantic by 12Z Thursday. ....South Atlantic Seaboard... The lead short wave will be accompanied by a significant surface cyclone, with secondary cyclogenesis forecast from the lee of the southern Appalachians into southern New England Wednesday through Wednesday night. Models indicate that this will coincide with substantive further strengthening of an intense west-southwesterly mid/upper jet, including speeds of 100-110+ kt around 500 mb, with a 50-70 kt south-southwesterly 850 mb jet also shifting northward to the lee of the southern Appalachians. Within the evolving warm sector, it appears that boundary-layer moisture characterized by dew points in excess of 60F will overspread much of the southern through middle Atlantic Seaboard, in the presence of the intense deep-layer mean wind fields and vertical shear. However, forecast soundings suggest that thermodynamic profiles will remain characterized by weak lower/mid tropospheric lapse rates. Weak CAPE could still support sustained convection and embedded thunderstorms, with the potential to organize, both along an initial warm front just ahead of the developing surface low across the Piedmont, and ahead of the trailing cold front as it advances toward coastal areas. The extent to which this activity may become capable of contributing damaging surface gusts, and perhaps a few tornadoes, remains unclear. Much will depend on the modification of the near-surface lapse rates. Guidance generally suggests these may remain moist adiabatic to more stable in at least a shallow surface-based layer, and the severe weather risk for this period still appears largely conditional. ...Kerr.. 01/23/2023 $$ = = = 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) .