ACUS02 KWNS 041715
SWODY2
SPC AC 041713

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1213 PM CDT Fri Apr 04 2025

Valid 051200Z - 061200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EAST TEXAS
TO MIDDLE TENNESSEE...

...SUMMARY...
Severe storms, capable of producing damaging wind gusts, large hail
and several tornadoes are expected from Saturday into Saturday night
from the Sabine River Valley northeastward into the lower to mid
Mississippi and Ohio Valleys. Strong tornadoes, very large hail, and
severe gusts above 70 mph will be possible in parts of the lower to
mid Mississippi Valley.

...Synopsis...
A mid-level jet streak, situated near the southern axis of the
mid-level trough across northern New Mexico will shift northeastward
through the day and will be centered over Arkansas by 12Z Sunday. An
elongated surface frontal zone will run parallel to this deep-layer
flow from South Texas to the Mid-Mississippi Valley. A weak surface
low is forecast to develop along this frontal zone and move
northeast through the day Saturday. Large hail, severe wind gusts,
and tornadoes are possible along and southeast of this surface front
during the day Saturday and into Saturday night.

...East Texas into Middle Tennessee...
Widespread convection is anticipated Saturday morning along the
frontal zone from northeast Texas into the Ohio Valley. This
convection should reinforce the cold air north of the front which
may result in it continuing to move south through the day. This is a complicating factor to the overall forecast which could limit the
longevity of surface based storms and thus the overall severe
weather threat closer to the front from southern Arkansas into
western Tennessee and northern Mississippi. The HRRR and other CAM
guidance develops a strong enough surface wave along the front from
mid-morning to early afternoon which stalls and/or results in a
slight northward shift of the frontal zone by early afternoon. This
would result in longer residence time for any surface based storms
and at least some window for a strong tornado threat. However,
guidance has trended weaker with the surface wave over the last
several runs with slightly slower ejection of the mid-level jet max.
Therefore, am not confident that the front will stall/lift north,
with a preferred solution similar to the NAM which shows a continual
southeast movement of the frontal zone through the day Saturday.

Farther southwest, frontal orientation across east Texas should be
more supportive for surface-based supercells along and perhaps east
of the front. Therefore, have expanded 10% tornado probabilities
farther southwest to address this threat. A line of storms with
embedded supercells will continue southeast through the evening and
into the overnight hours across Louisiana and eventually into
Mississippi. The greatest significant tornado threat will likely be
associated with any storms which can remain more discrete, ahead of
the primary frontal development.

...Ohio Valley into parts of the central Appalachians...
The severe weather threat from western Kentucky to southern
Pennsylvania and western Maryland remains very conditional on
overnight/morning convection from the Day 1 period. 12Z guidance
varies greatly in the expansiveness of these thunderstorms tonight
with stratiform rain and a stable airmass depicted by the HRRR with
the NAM indicating minimal thunderstorm activity from northern
Kentucky and southern Ohio eastward which will permit some
instability and given the shear, potential for some severe weather
threat Saturday afternoon. A slight/marginal risk seems appropriate
to handle this conditional threat with some modifications likely
once Day 1 convective evolution becomes more apparent.

..Bentley.. 04/04/2025

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