...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST TX
ACROSS THE LOWER MS VALLEY...
...SUMMARY...
Severe thunderstorms are possible today and tonight from east Texas
across the Lower Mississippi Valley. This includes the potential for
damaging winds, a few tornadoes, and possibly some hail.
...Synopsis...
Upper low currently moving into the southern High Plains is forecast
to continue eastward across the southern Plains today, becoming more
progressive and negatively tilted as it does. An associated surface
low is currently centered about 25 miles west of TYR in east TX,
along a slow-moving cold front.
This surface low is expected to deepen while gradually moving
northeastward this morning, before then accelerating northeastward
this afternoon and evening as the upper low also accelerates
eastward/northeastward. The cold front is also expected to quickly
move eastward in response, likely extending from the low over
northwest AR southward through southwest LA at 00Z. Additional
northeastward progress of the surface low is expected thereafter,
with the low likely centered over central IL by 12Z. At that tine,
the cold front will likely extend southward from the low through
middle TN and then more southwestward through southeastern LA.
...East TX through the Lower MS Valley...
Widespread warm-air advection showers and thunderstorms will likely
be ongoing from central TX into eastern OK/far western AR this
morning, along and behind the cold front expected to extend from
northeast TX back southwestward into central TX. Limited buoyancy
should temper any severe potential with this activity.
Low-level moisture advection is expected to persist across the warm
sector, likely resulting in a broad area of mid 60s dewpoints ahead
of the front by early afternoon. Pre-frontal convection will likely
increase during the late afternoon/early evening across LA as ascent
spreads across the region. Buoyancy will be tempered by widespread
cloud cover and limited diurnal heating. In contrast, moderate
deep-layer vertical shear will be in place, supported by a
strengthening low-level jet, and the potential exists for organized
storms capable of damaging wind gusts and tornadoes. However, a
slightly elevated and more multicellular mode is currently
anticipated, with storm interactions potentially limiting updraft
organization.
Additional thunderstorm development is expected along the front,
with the moderate vertical shear contributing bowing line segments
capable of damaging wind gusts, and perhaps a line-embedded
tornadoes. Greatest chance for tornadoes within the line appears to
be from north-central LA eastward into central MS, where slightly
higher buoyancy could overlap with strong low-level jet in the
presence of surface-based storms.
...Arklatex into the Lower OH Valley...
The deepening surface low is forecast to track northeastward from
the Arklatex across central AR and southeast MO into central IL.
Ascent attendant to this low will augment the already strong forcing
near the upper low and associated jet streak, contributing to
thunderstorms just ahead of the low as it progresses northeastward.
Bowing line segments capable of damaging wind gusts and maybe a
line-embedded tornado or two are possible across southern AR this
evening. Despite limited buoyancy, the strong forcing for ascent may
contribute to additional damaging wind gusts overnight across
southwest MO and into southern IL.
