As of now this doesn’t look like an “outbreak” but if a few things come together, there could be a couple of strong tornadoes or even a higher end straight line wind damage threat. Will know more as the day goes on but I won’t be surprised to see parts of Tennessee upgraded to a “Moderate” risk for wind damage for tomorrow. As of now this looks like a later afternoon into the evening threat for Tennessee.
..Lower to Mid Mississippi Valley/Central Gulf Coast States/Ohio and Tennessee Valleys...
Southwest flow at mid-levels will remain in place on Tuesday from the Great Plains to the Eastern Seaboard. A broad low-level jet will move northeastward across the mid Mississippi and Ohio Valleys. At the surface, a cold front will advance southeastward through the Arklatex and mid Mississippi Valley. Ahead of the front, the airmass will be moist with surface dewpoints in the 60s F. Thunderstorms will likely be ongoing at the start of the period in the Ozarks along the western edge of a 60 to 70 knot low-level jet. This activity is forecast to move east-northeastward across the Ohio Valley during the afternoon. Further to the southwest, surface heating will result in an axis of instability by afternoon from western Mississippi northward into western Tennessee and far western Kentucky. Surface-based thunderstorm development appears likely to take place near the axis of instability from late afternoon into the mid evening.
NAM forecast soundings near the axis of instability by 00Z Tuesday evening show MLCAPE in the 500 to 1000 J/kg range. 0-6 km shear is forecast to be in the 60 to 75 knot range. Low-level shear is also forecast to be strong with 0-3 km storm relative helicity in the 250 to 350 m2/s2 range. This thermodynamic and wind profile should be favorable for supercells with wind-damage and isolated large hail. A tornado threat is also expected to develop as the low-level jet strengthens during the late afternoon and early evening. The potential for tornadoes is expected to increase from southeast Missouri into the lower Ohio Valley during the day on Tuesday, and then expand southward across the Tennessee Valley and into the central Gulf Coast States by late afternoon and early evening. Some models suggest there will be potential for linear MCS development during the evening across the Tennessee Valley and central Gulf Coast states. If a line of strong thunderstorms does develop ahead of the front, then the wind-damage threat could increase markedly during the evening. At this time, model spread in the convective still substantial which presents uncertainty concerning
..Lower to Mid Mississippi Valley/Central Gulf Coast States/Ohio and Tennessee Valleys...
Southwest flow at mid-levels will remain in place on Tuesday from the Great Plains to the Eastern Seaboard. A broad low-level jet will move northeastward across the mid Mississippi and Ohio Valleys. At the surface, a cold front will advance southeastward through the Arklatex and mid Mississippi Valley. Ahead of the front, the airmass will be moist with surface dewpoints in the 60s F. Thunderstorms will likely be ongoing at the start of the period in the Ozarks along the western edge of a 60 to 70 knot low-level jet. This activity is forecast to move east-northeastward across the Ohio Valley during the afternoon. Further to the southwest, surface heating will result in an axis of instability by afternoon from western Mississippi northward into western Tennessee and far western Kentucky. Surface-based thunderstorm development appears likely to take place near the axis of instability from late afternoon into the mid evening.
NAM forecast soundings near the axis of instability by 00Z Tuesday evening show MLCAPE in the 500 to 1000 J/kg range. 0-6 km shear is forecast to be in the 60 to 75 knot range. Low-level shear is also forecast to be strong with 0-3 km storm relative helicity in the 250 to 350 m2/s2 range. This thermodynamic and wind profile should be favorable for supercells with wind-damage and isolated large hail. A tornado threat is also expected to develop as the low-level jet strengthens during the late afternoon and early evening. The potential for tornadoes is expected to increase from southeast Missouri into the lower Ohio Valley during the day on Tuesday, and then expand southward across the Tennessee Valley and into the central Gulf Coast States by late afternoon and early evening. Some models suggest there will be potential for linear MCS development during the evening across the Tennessee Valley and central Gulf Coast states. If a line of strong thunderstorms does develop ahead of the front, then the wind-damage threat could increase markedly during the evening. At this time, model spread in the convective still substantial which presents uncertainty concerning
