Day 1 Severe Weather Outlook

Valid 241300Z – 251200Z


Thunderstorms, some producing marginally severe hail or wind, are
expected across central Texas this afternoon and evening.

…Central TX this afternoon/evening and Gulf coast overnight…
A midlevel trough over CO/NM will move slowly east-southeastward to
the southern High Plains by early tonight, while a surface cold
front continues to move southeastward into central TX this afternoon
and south/southeast TX overnight. Low-level moisture return is
underway across TX, with mid 60s boundary-layer dewpoints now
reaching the Edwards Plateau, and low-mid 70s reside along the lower
TX coast. Continued low-level moistening and surface heating
beneath 7-8 C/km midlevel lapse rates will contribute to moderate
buoyancy (MLCAPE of 1000-1500 J/kg) ahead of the cold front this
afternoon/evening across central TX.

Thunderstorm development is expected along the front by early-mid
afternoon, and storms will spread east-southeastward through late
evening and overnight with the cold front. The moderate buoyancy
and effective bulk shear of 35-45 kt will favor organized line
segments and possibly some embedded supercell structures within the
band of frontal convection. These storms may tend to be slightly
undercut and reside just above the shallow cool air mass at the
surface, which will somewhat temper the threat for large hail and
damaging winds. The expected predominant linear mode, undercutting
front, and relatively weak low-level shear in the warm sector
(related to a lack of cyclogenesis) are not supportive of tornadoes.

Overnight, convection across the northwest and north central Gulf of
Mexico could approach the upper TX and LA coasts in a weak warm
advection regime. However, low-level shear will not be particularly

..Thompson/Smith.. 10/24/2019


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