SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0237 PM CDT Thu Mar 14 2024
Valid 142000Z - 151200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NEAR THE
RED RIVER NORTHEASTWARD ACROSS THE OZARKS...
...SUMMARY...
Large damaging hail, wind gusts, and a few tornadoes are expected
from far northeast Texas to the Ohio Valley.
...Northeast TX/Eastern OK to the Mid MS/OH Valley region...
A large area of severe storm potential exists today due to a
expanding plume of instability, beneath strong westerlies.
Scattered severe storms are currently ongoing over eastern OK, and
as far south as the Red River. This region is characterized by
strong instability and deep-layer shear, but relatively weak
low-level shear. As such, large hail will continue to be the primary
concern. However, a brief tornado may still occur with complex
storm/outflow interactions.
Farther north, stronger low level shear currently exists from
central MO eastward across the OH Valley. Winds aloft in this region
are more westerly than southwesterly, resulting in rightward motion
and better low-level SRH. The area will continue to destabilize, and
scattered supercells are likely to develop soon over much of MO and
IL. Very large hail is likely with the strongest storms, and a
couple tornadoes may also occur where 0-1 SRH exceeds 100 m2s/2.
Veering low-level winds may tend to truncate low-level shear a bit,
trending toward straight-line hodographs. However, any
rightward-turning supercell should thrive in the diurnally favorable
and unstable environment, possibly with tornado threat.
Finally, a lone supercell, tornadic at times, persists on the nose
of the low-level theta-e plume over northern KY. This cell is near
the instability gradient, and may persist. For more information on
this area see mesoscale discussion 233.
..Jewell.. 03/14/2024
.PREV DISCUSSION... /ISSUED 1130 AM CDT Thu Mar 14 2024/
...Missouri eastward into Kentucky/Indiana/Ohio...
A complex scenario is unfolding for today, given rather subtle
large-scale ascent across much of the area, but with a very
favorable background thermodynamic environment coupled with strong
deep-layer shear.
A line of strong/locally severe storms is ongoing this morning
across Indiana, which will continue eastward this afternoon into
Ohio. Locally damaging wind gusts will be the primary risk with
these storms, continuing across western Ohio before some weakening
eventually occurs given weakening instability with eastward extent
into the upper Ohio Valley.
In the wake of these storms, but ahead of a sagging cold front,
airmass recovery is underway. Clouds have cleared across Illinois
and for the most part Missouri as well, ahead of the front and in
the wake of earlier storms. Ongoing heating, beneath steep lapse
rates aloft, will result in a moderately unstable warm sector this
afternoon. CAMs continue to suggest redevelopment of more cellular
-- eventually clustered -- convection across this region this
afternoon, and eventually (presuming ample airmass recovery can
occur) into Indiana and possibly/eventually western Ohio. Though
low-level flow behind the initial band of Indiana storms will likely
remain somewhat veered, which may limit more substantial tornado
risk, very large hail is expected, along with damaging winds and a
couple of tornadoes. Storms could eventually grow upscale this
evening, spreading across the Tennessee Valley region accompanied by
continued severe risk.
...North Texas and the eastern half of Oklahoma to the Mid
Mississippi Valley area...
Storms have developed rapidly over the past hour across portions of
far northern Texas and into south-central Oklahoma near the slowly
advancing front/dryline, where heating beneath steep mid-level lapse
rates has resulted in development of 2000 to 2500 J/kg mixed-layer
CAPE. With 50 kt mid-level southwesterlies across the region,
deep-layer shear is supportive of updraft rotation, and thus
associated potential for very large hail, along with locally severe
wind gusts. Low-level southerlies are contributing to sufficient
shear for a couple of tornadoes late this morning/early this
afternoon. However, gradual veering, and some weakening, of the
low-level wind field is expected, which should temper tornado risk
to some degree. Still, a couple of tornadoes are expected with
stronger/sustained supercells.
With time, severe/supercell storms will spread eastward across the
Ozarks/Arklatex, likely clustering to some degree into this evening,
though with supercell structures persisting. Very large hail,
locally damaging wind gusts, and potential for a couple of tornadoes
will continue, eventually reaching the Mid-Mississippi Valley area.
A few CAMs continue to suggest potential for overnight development
of storms across portions of central Texas, potential slightly
elevated atop of a slightly stable boundary layer. Given sufficient
shear and the steep lapse-rate environment, conditional risk for
very large hail remains evident.
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