Severe Weather Threat 12.26-12.29.2024

Mesoscale Discussion 2301
NWS Storm Prediction Center Norman OK
1147 AM CST Sat Dec 28 2024

Areas affected...portions of eastern Texas into far western
Louisiana

Concerning...Tornado Watch 718...719...

Valid 281747Z - 281915Z

The severe weather threat for Tornado Watch 718, 719 continues.

SUMMARY...The severe threat continues across Tornado Watches
718-719. All severe hazards remain possible. The best chance for
tornadoes will exist with supercells embedded in confluence bands.

DISCUSSION...Multiple storms along a confluence band, including a
supercell with a history of producing at least one tornado, persist
along a Walker to Matagorda County, TX line while a QLCS is
developing farther to the west amid an increase in synoptic forcing.
Storms in both regimes are overspreading a destabilized boundary
layer, characterized by 70s F surface temperatures and dewpoints,
yielding over 2000 J/kg MLCAPE with minimal MLCINH per 17Z
mesoanalysis. Latest regional VADs show hodographs with elongation,
but modest low-level curvature, indicating an environment favorable
for damaging gusts, large hail, and perhaps a few tornadoes.

Latest mesoanalysis shows an 80+ kt 500 mb speed max pivoting the
base of the mid-level trough, and is poised to overspread the TX/LA
border over the next few hours. A low-level mass response is
expected, with intensification of the low-level jet to well over 40
kts likely. As this occurs, enlargement of the hodographs should
occur, especially closer to LA. Subsequently, the potential for
damaging gusts and tornadoes (including the risk of a strong
tornado) should increase later this afternoon. The best chance for
any strong tornadoes will likely be with any sustained supercell
structures associated with the confluence band, especially if a
supercell can avoid detrimental interference from nearby storms.
Otherwise, the damaging gust/tornado threat will also increase with
an approaching/intensifying QLCS, which will eventually overtake
preceding warm-sector confluence bands/storms.

Convection continues to oscillate in intensity farther east in the
free warm sector. Confidence is not overly high in robust severe
thunderstorms developing in this corridor. However, any storm that
manages to develop could become supercellular, posing a threat for
all severe hazards.

..Squitieri.. 12/28/2024
Click to expand...
 
You must log in or register to reply here.
Back
Top