Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1243 AM CDT Wed Mar 13 2024
Valid 131200Z - 141200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS AND LOWER MISSOURI VALLEY...
...SUMMARY...
Severe thunderstorms, associated with large to very large hail, wind
damage and a few tornadoes, are expected today across parts of the
central Plains and lower Missouri Valley. Isolated severe storms may
occur across parts of the southern Plains.
...Central Plains/Lower Missouri Valley...
An upper-level low will move into the Intermountain West today, as a
70 to 90 knot mid-level jet rounds the base of the system. In
response, a surface low will deepen across far southwest Kansas and
the Oklahoma Panhandle. To the east of the surface low, strong
moisture advection will occur. By afternoon, surface dewpoints are
expected to reach the mid to upper 50s F over eastern Kansas and
much of Missouri, where an east-to-west corridor of moderate
instability is forecast to develop. A dryline will likely setup
further west over south-central Kansas. Scattered convective
initiation appears likely along and near the instability axis by
late afternoon, with storm coverage expanding markedly during the
early evening. Multiple clusters of organized thunderstorms will
likely develop over parts of the central Plains and lower Missouri
Valley.
In response to the approaching mid-level jet, an area of very steep
mid-level lapse rates is forecast to spread northeastward into the
central Plains during the afternoon. RAP forecast soundings near the
instability axis by 00Z/Thursday have MLCAPE in the 2000 to 2500
J/kg range with 700-500 mb lapse rates around 8 C/km. This
thermodynamic environment, along with 40 knots of 0-6 km shear will
be favorable for supercells with large hail. Hailstones of greater
than 2 inches in diameter will be possible with the more dominant
and intense supercells. In addition, 0-3 km storm-relative helicity
is forecast to be near 300 m2/s2 suggesting that a tornado threat
will also likely develop. The greatest tornado threat is expected in
the early evening as the low-level jet strengthens. Wind damage will
also be possible.
...Southern Plains...
Strong moisture advection will take place today across the southern
Plains, as surface dewpoints increase into the 60s F across north
Texas and eastern Oklahoma. A dryline will develop along the western
edge of this moist airmass during the afternoon. RAP forecast
soundings near the moist axis increase MLCAPE to around 2000 J/kg by
afternoon, but have a capping inversion over most of the southern
Plains. This should keep convective initiation very isolated. RAP
forecast soundings by late afternoon to the east of the dryline have
0-6 km shear in the 50 to 60 knot range. The deep-layer shear and
instability will easily support supercell development with any
updraft that can grow upscale as the cap becomes weaker in the late
afternoon. If an organized cell can develop and persist, isolated
large hail, strong gusts and a marginal tornado threat would be
possible. However, this threat is expected to be highly conditional.
..Broyles/Thornton.. 03/13/2024
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