Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
700 ACUS02 KWNS 221729 SWODY2 SPC AC 221727 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sun Sep 22 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE OZARKS INTO PARTS OF THE TENNESSEE AND LOWER OHIO VALLEYS... ...SUMMARY... Isolated strong to severe thunderstorms are possible from the Ozarks into parts of the Tennessee and lower Ohio Valleys on Monday. ...Synopsis... A broad, positively-tilted trough will slowly progress eastward through the central Plains and into the Ozarks/lower Ohio Valley vicinity by Tuesday morning. A belt of moderate mid-level flow will stretch from near the Red River into Tennessee, Kentucky, and southern Illinois/Indiana. Given the nature of the trough, a rather weak surface pattern is expected. However, a cold front is expected to reside from the southern Great Lakes region into the Ozarks with a weak surface low in the Mid-South making some northward progress during the period. To the south of the front, a moist airmass should remain in place with mid 60s to low 70s F dewpoints. ...Ozarks Vicinity... Cloud cover and precipitation will likely be present Monday morning. The degree of destabilization during the afternoon will be uncertain. Model guidance has some confidence in heating into parts of central Arkansas, but the northern extent of stronger heating is the primary question. With the cold front taking on a more north-south orientation in this region, 35-45 kts of effective shear across the boundary could promote a more discrete storm mode. Should sufficient destabilization occur, isolated large hail and damaging winds would be possible. Poor mid-level lapse rates should tend to limit overall intensity of most storms. ...Portions of Tennessee/lower Ohio Valleys... As with areas farther west, there will be some potential for precipitation and cloud cover Monday morning, especially with northern extent. South of the surface boundary, at least broken cloud cover should allow for sufficient heating to promote around 1500 J/kg MLCAPE by the afternoon. 40-50 kts of shear parallel to the boundary will allow some potential for storm organization. Damaging winds would likely be the primary threat, though isolated large hail is possible in the strongest, discrete storms. As the trough moves east and the surface boundary slowly lifts northward into Tuesday morning, some stronger elevated activity could move into southern Illinois/Indiana during the overnight. There is spread in how far north the boundary moves and the degree of elevated buoyancy, but some potential for small to marginally severe hail and an isolated damaging wind gust will exist. ..Wendt.. 09/22/2024 $$