SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0105 AM CST Sat Jan 04 2025 Valid 051200Z - 061200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF LOUISIANA...MISSISSIPPI AND ARKANSAS... ...SUMMARY... Severe thunderstorms will be possible Sunday afternoon and evening from the Sabine River Valley into the lower to mid Mississippi Valley and central Gulf Coast states. Severe wind gusts, tornadoes and hail will be the primary threats. ...Sabine River Valley/Lower to Mid Mississippi Valleys... A mid-level trough will move eastward through the southern Plains on Sunday, as an associated jet streak translates eastward into the Ozarks. At the surface, a low will move across the Ozarks as a cold front advances eastward into the lower Mississippi Valley. A moist airmass will be located ahead of the front, with moisture advection taking place throughout the day. As surface temperatures warm, scattered thunderstorms are expected to develop late Sunday morning, with storm coverage increasing rapidly by early afternoon. The development of a linear MCS is expected as low-level convergence couples with strong large-scale ascent along and ahead of the front. A severe threat is expected to develop across a broad area Sunday afternoon. During the afternoon, NAM forecast soundings from southern Arkansas into northern Louisiana and central Mississippi increase MLCAPE to around 500 J/kg with 0-6 km shear reaching the 50 to 60 knot range. Stronger deep-layer shear will be likely as the mid-level jet passes through the region during the late afternoon. This will be favorable for severe storms, associated with the development of a linear MCS. The wind-damage threat will be maximized along the leading edge of the line, especially with bowing line segments. In addition, 0-3 km storm-relative helicity is forecast to peak in the 400 to 500 m2/s2 range ahead of the line, suggesting a tornado threat will be likely with any rotating elements within the line. If more discrete cells can develop ahead of the line, then supercellular tornadoes would also be possible. At this time, it appears that the wind-damage threat associated with the line will be great enough to warrant upgrading to Enhanced across parts of Louisiana, Arkansas and Mississippi. ..Broyles.. 01/04/2025