nWo Posted March 3, 2023 Share Posted March 3, 2023 Mesoscale Discussion 0242 NWS Storm Prediction Center Norman OK 0401 AM CST Fri Mar 03 2023 Areas affected...portions of northern MS/AL...western into Middle TN...western KY...far southeast MO...and far southern IL Concerning...Severe potential...Watch likely Valid 031001Z - 031230Z Probability of Watch Issuance...80 percent SUMMARY...A new tornado watch will likely be needed by 13-14z/7-8 am CST across portions of the Tennessee and Lower Ohio Valleys. Damaging gusts and a few tornadoes will be possible through midday/early afternoon. DISCUSSION...A quasi-stationary boundary is evident in surface analysis extending from west-central TN toward the TN/KY border vicinity north of Nashville. Meanwhile, the warm front, demarcating mid-60s F surface dewpoints from upper 50s to low 60s F dewpoints, is arcing from near Memphis into east-central MS (between Starkville and Tupelo) and central AL. Large-scale ascent ejecting into east TX, as the mid/upper trough becomes more negatively tilted as of 10z, will aid in deepening of the surface low over central AR as it tracks northeast toward the Lower OH Valley through midday. As this occurs, the warm front will lift northward, allowing for destabilization of the airmass downstream from WW 59 across parts of northern MS into western and Middle TN, and eventually northward toward the lower OH River. Ongoing precipitation across parts of western/Middle TN/southeast MO/western KY and vicinity lends to some uncertainty with respect to the northern extent of severe potential through the morning, and possible watch issuance. While a relative minimum in severe activity may exist in the short term, as the warm front surges northward through mid-morning, forecast soundings in addition to CAMs and deterministic guidance suggest organized convection will develop northeast from near the MS River through western KY. Where the more moist and unstable airmass evolves, sufficient low-level instability, in the presence of intense low-level shear (aided by a 50-60 kt 850 mb jet), will support organized linear convection with perhaps embedded or semi-discrete cells. Damaging gusts and a few tornadoes will be possible with this activity through midday/early afternoon. A downstream watch will likely be needed by around 13z-14z. Link to comment Share on other sites More sharing options...
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