ACUS02 KWNS 170649
SWODY2
SPC AC 170647

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1247 AM CST Mon Feb 17 2025

Valid 181200Z - 191200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST
TEXAS AND SOUTHERN LOUISIANA...

...SUMMARY...
A couple of strong to severe thunderstorms are expected to evolve
across southeast Texas and portions of southern Louisiana, mainly
Tuesday evening and into the overnight hours.

...Upper TX Coast and Southern LA...

An upper shortwave trough will move across the Plains to the MS
Valley on Tuesday. This will bring a swath of enhanced
mid/upper-level southwesterly flow across the south-central states.
At the surface, a weak low will traverse the western Gulf Coast
vicinity to southern MS through the period. Meanwhile, an Arctic
cold front will surge south/southeast across the region mainly after
00z and into Wednesday morning.

Ahead of the cold front, southerly near-surface flow and a
strengthening southwesterly low-level jet will transport 60s F
dewpoints northward. However, the northward extent of deeper
moisture return will be limited to near the I-10 corridor. A cool
boundary-layer beneath a warm layer between 925-850 mb will result
in little surface-based instability. Additionally, nebulous
large-scale ascent will preclude convective development until near
00z when the upper trough impinges on the area. Cooling aloft and
modestly steep midlevel lapse rates amid moistening low/midlevels
will support MUCAPE values up to around 1000 J/kg. Vertical shear
will be favorable for organized convection, with elongated/straight
hodographs forecast above the aforementioned warm layer. While the
warm sector will be rather limited, and the cold front will quickly
surge southeast after dark, a few stronger elevated storms will be
possible. This activity will mainly pose a risk for marginally
severe hail.

There is some conditional potential toward the end of the period for
near-surface based convection across parts of southern LA. However,
this is conditional on the northward extent of the warm sector,
which remains uncertain as the surface low is forecast to track very
near the coast. If near-surface based storms can develop, some
potential for strong gusts and a tornado or two will accompany
storms given very favorable low-level SRH and large/curved low-level
hodographs. Will include low tornado probabilities to encompass this
scenario, though this outcome remains uncertain.

..Leitman.. 02/17/2025

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