11AM Day 2 Convective Outlook for Saturday, February 14. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST TX INTO LA AND SOUTHWEST MS
SUMMARY
Severe thunderstorms are possible from Saturday into Saturday night from parts of Texas into the lower Mississippi Valley. Isolated hail will be possible across parts of Texas during the day, with an increasing threat of damaging winds and a couple tornadoes expected Saturday night from east Texas into Louisiana and southwest Mississippi.
Synopsis
A vigorous mid/upper-level shortwave trough will move across the southern Plains during the day, before reaching the lower MS Valley vicinity Saturday night. This system will be accompanied by a strong midlevel jet (60-80 kt at 500 mb) and a consolidating surface low that is forecast to eventually deepen and reach the ArkLaTex region by evening. Relatively rich low-level moisture (with dewpoints in the 60s F) will already be in place Saturday morning across parts of TX/OK, and will eventually spread into parts of the lower MS Valley by evening, in conjunction with the advancing surface low.
Southern Plains into the lower MS Valley
Elevated storms will likely be ongoing Saturday morning from parts of west/northwest TX into southern OK, which could pose an isolated hail threat. Early-day convection may gradually evolve into a loosely organized QLCS across north TX and vicinity, with additional isolated strong to severe storm development possible into central TX as the primary mid/upper shortwave trough ejects eastward. Weak to locally moderate buoyancy and increasing deep-layer shear will support at least an isolated severe threat through the afternoon, though CAM guidance varies regarding the coverage and duration of organized storms through the first part of the period.
Guidance generally depicts increasing low-level mass response near/after 00Z, which should aid the development of a more organized QLCS during the evening across parts of east TX. This QLCS is expected move eastward into parts of LA and lower MS Valley during the late evening and overnight hours. While instability will become increasingly scant with eastward extent, strengthening low/midlevel flow and effective SRH will support development of one or more organized bowing segments, with an attendant threat of scattered damaging winds. Some increase in the tornado threat will also be possible Saturday evening/night, both with line-embedded mesovortices, and also potentially with any supercells within the warm-conveyor belt region that eventually merge into the primary QLCS.
Most guidance suggests some weakening trend prior to 12Z Sunday morning, with the stronger forcing potentially becoming displaced from the effective warm sector. However, some threat for locally damaging winds and a brief tornado could persist near the LA/MS coasts through the end of the forecast period.