SPC AC 230554
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1254 AM CDT Thu Mar 23 2023
Valid 231200Z - 241200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EDWARDS
PLATEAU TO THE RED RIVER AND INTO THE NORTHERN OZARKS...
...SUMMARY...
Thunderstorms capable of hail, some very large, are possible
Thursday afternoon through Friday morning across parts of the
southern Great Plains.
...Synopsis...
A shortwave trough, seen on morning water-vapor imagery across
southern California will traverse the Southwest this morning and
move to the TX/OK Panhandle by 06Z Friday. In advance of this
shortwave trough, a surface low will develop across far West Texas
and deepen gradually through the day. A cold front which extends
from central Kansas to the southern tip of Lake Michigan this
morning will move slowly south through the day, and eventually will
stall early Friday morning as low-level flow strengthens in response
to the developing surface low.
...Southern Plains...
The eastward-advancing mid-level trough will lead to weak mass
response across the southern Plains as early as midday Thursday.
This will result in backing/strengthening 850mb flow and associated
isentropic ascent. Thunderstorm activity is expected near or
slightly to the cool side of the frontal boundary across Oklahoma
during the early afternoon period. Moderate instability, steep
mid-level lapse rates, and long/straight hodographs will support
supercells capable of large to very large hail.
The majority of convection-permitting guidance indicates
thunderstorm activity will be anafrontal and thus elevated. This is
the most likely solution since the front should be the primary
initiating source, and the mean wind will remain parallel to the
frontal orientation. Any storms along or ahead of this front would
pose a brief tornado threat.
Additional storms are expected after 04Z as weak DCVA ahead of the
approaching mid-level shortwave trough overspreads the warm sector.
Storms will be possible along the entire dryline from the Rio Grande
to southwest Oklahoma. However, this shortwave trough will be
dampening as it moves east, and therefore, its influence is unknown.
At least isolated supercell coverage is expected in the 03Z to 09Z
period across central Texas into southern Oklahoma. Large hail will
be the primary threat with this activity. Despite the strengthening
low-level jet, increasing inhibition and weak flow between 1-2 km
will be a limiting factor to the tornado threat, although it cannot
be ruled out.
...The Ozarks into southern Illinois/Indiana...
Early morning thunderstorms across Missouri and Illinois will
continue east across Indiana and Ohio by mid-day Thursday, but
should remain sub-severe due to limited instability with eastward
extent.
Elevated thunderstorms which develop in Oklahoma early Thursday
afternoon will continue northeast on the cool side of the front
through the afternoon and evening, with additional development
expected as the low-level jet strengthens further. A
southward-moving cold front and storm motion parallel to the surface
front should lead to mostly anafrontal/elevated convection. However,
on the mesoscale, any storms which remain latched to the front could
pose a threat for a tornado.
..Bentley.. 03/23/2023
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