Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0154 PM CST Thu Dec 26 2024
Valid 262000Z - 271200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON/EVENING IN SOUTHEAST TEXAS...
...SUMMARY...
Several tornadoes, including a strong (potentially EF2+) tornado or
two, will be possible this afternoon/evening across southeast Texas.
Damaging gusts of 60-70 mph and large hail of 1-1.75" in diameter
will also be possible from east Texas this afternoon into Louisiana,
southern Arkansas and far west central Mississippi overnight.
...20Z Update...
Severe probabilities in parts of central Texas have been adjusted to
account for the progression of ongoing convection. Quasi-discrete
supercells continue in parts of southeast Texas as well as to the
northwest of Houston. These storms will continue to post the
greatest threat for tornadoes (potentially strong). See MCD 2284 and
2285 for additional short-term, mesoscale details.
..Wendt.. 12/26/2024
.PREV DISCUSSION... /ISSUED 1013 AM CST Thu Dec 26 2024/
...East TX/LA/southern AR through tonight...
Elevated convection has already formed over north central TX this
morning in a band of ascent preceding a midlevel shortwave trough
moving eastward. New thunderstorm development is expected through
the afternoon farther to the south and east across east/southeast
TX, as the warm sector spreads northward in advance of a weak
surface cyclone. Boundary-layer dewpoints in the mid-upper 60s
beneath midlevel lapse rates near 8 C/km will drive MLCAPE ranging
from 500 J/kg a little south of I-20 to 1500-2000 J/kg across
southeast TX by late afternoon, where surface-based storms are
likely with small breaks in the stratus. Vertical shear profiles
will be characterized by sufficiently long hodographs (effective
bulk shear in excess of 45 kt) and low-level hodograph curvature
(effective SRH in excess of 200 m2/s2) for supercells.
The initial storms will be more cellular across southeast TX with a
gradual transition to a mixed mode/band of storms this evening into
tonight as the storms spread eastward/northeastward across
LA/southern AR. The surface-based supercells in southeast TX will
be capable of producing tornadoes from early afternoon into late
evening (including a strong/EF2+ tornado or two), along with
isolated large hail (1-1.75 inches in diameter). With the gradual
change in storms to a more linear mode, the potential for wind
damage (and embedded tornadoes) will persist into tonight.
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