SPC Mar 29, 2025 0600 UTC Day 2 Convective Outlook

SPC 0600Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
0115 AM CDT Sat Mar 29 2025

Valid 301200Z - 311200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS A BROAD
AREA CENTERED OVER THE OHIO/MID MISSISSIPPI/TENNESSEE VALLEYS...

...SUMMARY...
A widespread/substantial severe-weather episode is forecast across
an area centered on the Ohio/Mid and Lower Mississippi/Lower
Missouri/Tennessee River Valleys.  Very large hail, damaging winds,
and strong tornadoes are expected.

...Midwest/Ohio Valley south to East Texas and the central Gulf
Coast states...
A mid-level short-wave trough is forecast to shift northeastward out
of the central Plains into the Upper Great Lakes region through the
first half of the period, with an accompanying surface low deepening
slowly as it reaches the Lake Michigan vicinity by early evening. 
Meanwhile, a secondary short-wave trough -- comporised of several
vorticity maxima -- is forecast to move into/across the central and
southern Plains toward the Mississippi Valley through the second
half of the period, possibly driving weak frontal wave development
in the mid Mississippi/lower Ohio Valley vicinity by evening.  

As the cold front crosses western Illinois/Missouri during the day,
daytime heating will support destabilization, yielding scattered
thunderstorm development, as the main/initial short-wave trough
crosses this region.  Large hail and damaging winds will become
increasingly likely as the storms organize, and a few tornadoes will
also be possible.  This convection may evolve into one or more bands
of organized storms with embedded rotation, with risk for more
widespread strong/damaging gusts, in addition to embedded tornadoes,
as the convection shifts across Indiana/southern Lower Michigan, and
eventually western Ohio through the evening and into the overnight
hours.

Farther south, more uncertainty exists -- due to questions regarding
degree of cloudiness and precipitation ahead of the approaching
front.  NAM output suggests very steep lapse rates aloft will
overspread the area atop a capped/amply moist boundary layer.  As
the front approaches, and effects of the secondary upper troughing
impinge gradually on the Lower Mississippi Valley area -- and
eventually the Mid South/Tennessee Valley, developing storms would
pose substantial, all-hazards severe risk including very large hail,
strong/damaging winds, and potentially strong tornadoes.

However, some models -- particularly the RAP -- suggest that
widespread precipitation/weak convection will persist through much
of the period across the lower Ohio/lower Mississippi/Tennessee
Valleys through the first half of the period, substantially
affecting the thermodynamic environment.  Along with a
less-amplified upper flow field -- and weaker shear overall --
enough uncertainty exists to refrain from a higher-end outlook at
this time.  As such, will maintain ENH risk across a broad area at
this time, though an upgrade to MDT risk in the lower
Ohio/Tennessee/Mid Mississippi Valley corridor may be required in
later outlooks.

..Goss.. 03/29/2025

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