SPC Sep 22, 2023 0730 UTC Day 3 Severe Thunderstorm Outlook

SPC Sep 22, 2023 0730 UTC Day 3 Severe Thunderstorm Outlook

SPC 0730Z Day 3 Outlook
Day 3 Outlook Image
Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0219 AM CDT Fri Sep 22 2023

Valid 241200Z - 251200Z


Thunderstorms, associated with large hail and wind damage, will be
possible on Sunday from parts of central Texas northeastward into
southeast Oklahoma.

...Southern Plains/Ark-La-Tex...
A shortwave trough is forecast to move eastward across the southern
Plains on Sunday. A cold front will likely advance southward into
west-central and north Texas by afternoon. Warming surface
temperatures ahead of the front will result in moderate to strong
destabilization by afternoon, with MLCAPE expected to peak in the
2000 to 3000 J/kg range in many areas south of the front. As
instability and low-level convergence increase near the front,
scattered thunderstorms will likely form in the mid to late
afternoon. These storms will move southeastward into the stronger
instability across north-central and northeast Texas, with several
cell clusters persisting into the early to mid evening.

Forecast soundings by 00Z/Monday near and to the southwest of the
Dallas/Fort Worth Metroplex show moderate deep-layer shear and steep
low to mid-level lapse rates. The moderate deep-layer shear is
mostly due to mid-level speed shear, although some directional shear
is evident in the low levels. 700-500 mb lapse rates are forecast to
be near 8 C/km. This environment should support supercells
associated with isolated large hail. Large temperature-dewpoint
spreads will result in high storm bases, and a nearly adiabatic
lapse rate below 850 mb will contribute to downdraft acceleration.
As a result, a wind-damage threat is also expected to develop during
the late afternoon and early evening. The cold front is forecast to
be a bit faster than some of the model solutions are suggesting. For
this reason, the faster model solutions are favored and the slight
risk has been placed accordingly.

..Broyles.. 09/22/2023

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