452
ACUS02 KWNS 261724
SWODY2
SPC AC 261723

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1123 AM CST Tue Nov 26 2024

Valid 271200Z - 281200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE LOWER MISSISSIPPI VALLEY AND NORTHERN ALABAMA...

...SUMMARY...
Isolated strong to severe storms are possible from the lower
Mississippi Valley into parts of Alabama, primarily from late
Wednesday night into early Thursday morning.

...Lower MS Valley into northern Alabama...
Low-level moisture will surge northeastward from the northwest Gulf
of Mexico Wednesday afternoon into Wednesday night, with upper 60s F
dewpoints reaching southern MS, and low/mid 60s F dewpoints
extending into central/northern MS/AL. A warm layer between 850-700
mb should tend to suppress surface-based storm initiation through
the day, though steep lapse rates above this layer will result in
MLCAPE increasing above 1000 J/kg (with somewhat greater MUCAPE
values) from LA into at least southern MS, while MLCAPE of near 500
J/kg may reach a larger portion of AL/MS. As noted previously, some
guidance (such as the NAM) remains much less aggressive with the
northern extent of favorable instability.

Low-level warm/moist advection will increase across the Marginal
Risk area late Wednesday night in advance of an eastward-moving
positively-tilted upper-level trough and surface cold front, and
isolated to scattered thunderstorm development will be possible as
larger-scale lift contributes to diminishing CINH. Strong
low/mid-level wind fields will result in a favorable kinematic
environment for organized thunderstorms, with a conditional risk for
large hail and damaging gusts with any storm that can develop and
remained sustained near and in advance of the front. A sustained
storm in advance of the front may also pose a risk for a tornado
given the favorable low-level hodograph structure. There may also be
some risk for isolated elevated/post-frontal storms, with an
attendant risk for hail.

Overall, there remains substantial variability in the 12z hi-res and
ML guidance regarding whether, and where, thunderstorm initiation
will occur Wednesday night. Given the environmental parameters that
are expected to be in place (especially during the 08z-12z time
frame), the current Marginal Risk area and associated severe
probabilities will be maintained. Have trimmed the General Thunder
area in line with the most recent 12z calibrated HREF guidance.

..Bunting.. 11/26/2024

$$