Administrators NorthGeorgiaWX Posted January 12 Administrators Posted January 12 SPC 2000Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0135 PM CST Fri Jan 12 2024 Valid 122000Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN AL...SOUTHERN GA...NORTHERN FL...AND SOUTHERN SC... ...SUMMARY... Isolated damaging winds and a couple of tornadoes remain possible this afternoon into tonight across southern Alabama, southern Georgia, northern Florida, and southern South Carolina. ...20Z Update... A shortwave trough continues to push quickly northeastward across the Mid MS Valley, with its accompanying intense jet streak stretching from OK/north TX through the TN Valley into the central Appalachians. Evolution of this shortwave northeastward has lead to increased displacement between the primary forcing for ascent and the warm sector, which currently only reaching as far north as southern AL and southern GA. Based on 19Z surface analysis, the 56 deg F isodrosotherm runs from southern MS northeastward into central AL and then back southeastward across southern and off the far southern SC coast. Primary convective line extends from east-central AL southwestward through the western FL Panhandle. Some modest moisture advection is still anticipated ahead of this line, but displacement from the primary ascent will keep mid-level temperatures warm, resulting poor lapse rates and scant buoyancy. Consequently, despite very robust kinematic fields, updraft strength and duration will remain limited. Damaging gusts will remain possible, with a low-probability tornado threat persisting as well, particularly near the warm front across southern GA. Some severe potential remains across the Carolinas tonight as well where limited destabilization is possible ahead of the line. Very strong vertical shear and intense winds just above the surface suggest some potential for damaging winds with the line. ..Mosier.. 01/12/2024 .PREV DISCUSSION... /ISSUED 1015 AM CST Fri Jan 12 2024/ ...Southeast through tonight... The primary midlevel shortwave trough/jet streak is beginning to turn northeastward over the Mid South, and will continue toward the OH Valley this afternoon. An associated surface cyclone will deepen/consolidate across IN by late afternoon, as a surface cold front surges eastward across MS/AL/GA. It appears the main height falls/forcing for ascent will progress northeastward and away from the narrow surface warm sector that is now confined to southern MS/southwest AL. There will be some northward spread of the warm sector with boundary-layer dewpoints into the 60s across southern AL/GA through the afternoon. However, the lack of strong/deep ascent in the presence of very strong deep-layer shear and poor midlevel lapse rates casts doubt on the depth/intensity of any warm sector convection this afternoon. A conditional threat for wind damage and a couple of tornadoes will continue given the very strong vertical shear/long hodographs, but confidence in sustained supercells along the north edge of the surface warm sector is low. Otherwise, slightly elevated convection will be most common today into TN/AL/GA to the north of the remnant cool wedge. A shallow forced band of convection may persist along the surface cold front across the Carolinas into tonight. Very strong vertical shear and intense winds not far above the surface suggest some potential for damaging winds and/or a couple of tornadoes with the line. Still, the relatively weak deeper-layer forcing for ascent (as a result of the main shortwave trough passing northwest of the Carolinas) and the modest thermodynamic profiles both suggest uncertainty in the coverage/magnitude of any severe threat. Read more View the full article Quote
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