ACUS03 KWNS 131933
SWODY3
SPC AC 131932
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0232 PM CDT Fri Mar 13 2026
Valid 151200Z - 161200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER
MISSISSIPPI RIVER VALLEY TO THE OHIO VALLEY....
...SUMMARY...
A widespread damaging wind event with some tornado threat is likely
on late Sunday afternoon through Sunday night from northeast Texas
to southwest Lower Michigan. The greatest wind threat appears to be
from northeast Arkansas/western Tennessee to southern Indiana during
the evening and overnight hours.
...Synopsis...
A 100+ knot mid-level jet will lead to rapid amplification as it
rounds the base of the mid-level trough across the Central Plains on
Sunday. As the associated surface cyclone moves northeastward
through the day, strong low-level moisture transport will occur
across the warm sector. This will result in weak to potentially
moderate instability ahead of the cold front Sunday afternoon. This
cold front will accelerate east-southeastward from the Midwest to
the Mid-Mississippi Valley during the afternoon and from Ohio to
western Georgia/eastern Alabama by Monday morning.
....Ohio Valley...
Despite dewpoints only increasing to the mid to upper 50s, a very
favorable kinematic environment will be in place with a 70 knot
low-level jet and nearly 125 knot mid-level jet by Monday morning.
Given this wind field, any instability, combined with the strong
frontal forcing, will be sufficient for a powerful QLCS during the
evening and overnight hours. This squall line will likely have
widespread 60+ mph wind gusts with some stronger 75+ mph wind gusts
possible.
In addition, very long hodographs with 200+ m2/s2 0-500m SRH will
support a threat for line-embedded tornadoes, some of which could be
strong. Additionally, the strong shear may also allow for some
embedded supercells, also depicted by the 12Z RRFS, which also may
lead to a locally greater tornado threat. Pre-frontal development
cannot be ruled out, especially from northeast Arkansas to southern
Illinois at the nose of the 500mb jet and the northern extent of the
richer low-level moisture. This scenario is more uncertain, but
could pose a greater tornado threat if it were to materialize.
...Lower Mississippi Valley to the Southeast...
The squall line will form during the afternoon, perhaps with some
initial supercell/hail threat across Arkansas and northeast Texas
and then move northeastward through the overnight period. The
strongest low-mid level wind field will remain north of this region,
however, greater instability will compensate and should maintain the
damaging squall line through the overnight hours. The greatest STP
values within the entire risk area are forecast (by the 12Z NAM)
between 03Z and 12Z from western Tennessee to central Mississippi
and northwest Alabama. Therefore, expect a QLCS tornado threat to
accompany the damaging wind threat through the overnight and early
morning period.
...FL/AL Coast...
Toward the end of the period, richer low-level moisture will begin
to move inland across the FL Panhandle into southern Alabama. Within
this zone, discrete convection may develop after 08Z. If this were
to occur, strong shear would support supercells capable of
tornadoes.
..Bentley.. 03/13/2026
$$
= = =
To unsubscribe from WX-STORM and you already have a login, go to
https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at
cnovy@cox.net and ask to be removed from WX-STORM.
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (1:2320/107)