1PM Day 3 Convective Outlook for Thursday, January 8. THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN OK/TX INTO THE OZARKS AND LOWER/MID MS VALLEY
SUMMARY
Isolated severe storms are possible on Thursday from eastern Texas and Oklahoma into parts of the Ozarks and lower/mid Mississippi Valley.
Eastern TX/OK into the Lower/Mid MS Valley and lower OH Valley
Guidance has come into relatively better agreement with the timing and overall evolution of a compact midlevel impulse and accompanying surface low ejecting northeastward from the southern Plains toward the Great Lakes through the period. This will result in the development of an expansive warm sector characterized by partially modified Gulf moisture and somewhat cool surface temperatures. Given poor/modest lapse rates, buoyancy will remain fairly limited -- especially with northward extent. Nevertheless, strong deep-layer flow/shear will overspread the warm sector, resulting in an expansive area of conditional severe potential.
Widely scattered elevated thunderstorms with a risk of marginally severe hail and locally damaging gusts will be spreading east-northeastward from the southern Plains into the lower/middle MS Valley at the start of the period. There will be some potential for this activity to become surface-based and intensify as it tracks east-northeastward though the afternoon, though this will be largely dependent on the degree of surface heating in the warm sector. If storms can root at the surface, a mesoscale corridor of higher severe potential will be possible -- posing a risk of severe wind gusts and perhaps a tornado.
Thunderstorms will generally spread northeastward toward the lower OH Valley in tandem with the surface low through the day, and severe potential becomes more uncertain with northward extent (given the low CAPE/high shear parameter space). A small northward expansion of severe probabilities was made where near-surface-based storms will be possible amid strengthening low-level flow/shear, and depending on destabilization, further expansions will be possible.