Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Nov 28 2022 07:05:27 ACUS02 KWNS 280705 SWODY2 SPC AC 280703 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CST Mon Nov 28 2022 Valid 291200Z - 301200Z ....THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR NORTHEAST LOUISIANA...FAR SOUTHEAST ARKANSAS...NORTHWEST MISSISSIPPI AND FAR SOUTHWEST TENNESSEE... ....SUMMARY... Severe thunderstorms with tornadoes and wind damage, along with some hail, will be likely on Tuesday afternoon and evening, extending into the overnight period across parts of the lower to mid Mississippi Valley. Significant and/or long-track tornadoes will be possible. ....Regional Tornado Outbreak Possible Tuesday Afternoon and Evening Across Parts of the Lower to Mid Mississippi Valley... ....Lower to Mid Mississippi Valley/Sabine River Valley/Western Ohio and Tennessee Valleys... A progressive upper-level trough will move quickly eastward across the Rockies Tuesday and into the Great Plains. Ahead of the system, a moist airmass, with surface dewpoints in the lower to mid 60s F, will advect northward across the lower and mid Mississippi Valleys. Thunderstorm development will be likely during the day on the eastern edge of the most airmass, from the central Gulf Coast states northward into the western Ohio Valley. While elevated, an isolated severe threat will be possible with some of this convection. Further to the southwest, an axis of moderate instability is forecast to develop by mid to late afternoon from northwest Louisiana northeastward into far eastern Arkansas. This airmass should continue to destabilize during the evening, as rich low-level moisture streams north-northeastward, with MLCAPE reaching the 1500 to 2000 J/kg range by 03Z Wednesday across parts of northern Louisiana, southeast Arkansas and northwest Mississippi. Surface-based convective initiation appears likely to occur during the late afternoon and early evening in northern Louisiana, with these storms tracking northeastward across far southeast Arkansas and into northwest Mississippi. Throughout the day on Tuesday, deep-layer shear will steadily increase across the region as a 70 to 90 knot mid-level jet translates quickly eastward across the south-central U.S. This jet is forecast to move through the base of the trough at around 55 knots, which will help sustain a 40 to 60 knot low-level jet ahead of the system. NAM forecast soundings along the most favorable corridor from far northeast of Monroe, Louisiana to near Memphis, Tennessee at 03Z Wednesday, have MLCAPE in the 1500 to 2000 J/kg range, with 0-6 km shear near 70 knots, and 0-3 km storm-relative helicities around 400 m2/s2. Hodographs are forecast to be long and curved, suggesting the environment will be favorable for tornadic supercells. A long-track and/or significant tornadoes will be possible, with the most favorable corridor located from far northeast Louisiana northeastward across northwest Mississippi. An earlier and further southwest convective initiation would be most favorable for a tornado outbreak, which would give the storms more time to move northeastward through the most unstable air. Supercells will also have potential for wind damage and isolated large hail. During the mid to late evening, a strengthening low-level jet should help maintain the severe threat across the region. A threat for tornadoes, wind-damage and hail will be possible with supercells and with organized bowing line segments from mid evening into the early overnight period. Further northeast into north-central Tennessee, western Kentucky and far southern Illinois, moisture advection during the early to mid evening, will likely increase dewpoints into the lower 60s F. As a cold front approaches from the west, scattered thunderstorms are expected to develop across the moist sector. Although instability is forecast to be weak ahead of the front, large-scale ascent should be very focused due to the approaching trough. This combined with strong deep-layer shear should support a severe threat, with wind damage and a few tornadoes possible. ...Broyles.. 11/28/2022 $$ = = = 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) .