SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0630 AM CST Sun Dec 24 2023
Valid 241300Z - 251200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not forecast through tonight across the
contiguous United States.
...Synopsis/Discussion...
In mid/upper levels, a series of shortwave troughs will reinforce
mean troughing over the central CONUS through the period, with these
being the main influences:
1. A northern-stream perturbation -- apparent in moisture-channel
imagery across eastern/southern SK, west-central MT, to near Star
Valley in westernmost WY. The southern part of this perturbation
should move eastward then break south-southeastward from the main
northern-stream belt, and intensify considerably tonight. The net
result by 12Z should be a deepening, closed cyclone centered over
the BFF/SNY vicinity. The resulting large, synoptic cyclone will be
a dominant pattern feature over the central/eastern CONUS for
several more days.
2. A southern-stream trough now located near a CAO-CVS-PRS axis
and over northeastern Chihuahua. This feature should move eastward
and become negatively tilted today, reaching near a LBL-LTS-CLL axis
by 00Z. As heights fall and synoptic gradients strengthen in
advance of the northern Plains cyclogenesis, this trough will pivot
to near a SLN-FYV-GLH axis by 12Z tomorrow.
At the surface, 11Z analysis showed a low over west-central KS,
along an Arctic front extending from a separate low near FSD to
northeastern NM. A Pacific front was drawn from the KS low across
extreme western OK, northwest TX, to the Big Bend region and
west-central MX. By 00Z, the Arctic front should extend from
central MN to south-central OK and the Permian Basin region of west
TX and southeastern NM. The Pacific front should be moving more
slowly eastward over southern OK, central TX and the middle TX
Coast, with a wind shift and some surface veering ahead of the front
in east TX.
The strongest convective forcing should continue to occur over
prefrontal (both fronts) areas with diurnal heating substantially
restricted by clouds/precip, minimal to no surface-based buoyancy,
marginal elevated instability to support thunder, and mostly messy
convective modes. Areal/organized severe-thunderstorm potential
should remain (and shift eastward) over the open waters of the
northwestern and north-central Gulf, under the left-exit region of
a subtropical-jet segment. There, vertical shear will be favorable,
and sea-air fluxes should contribute to relatively maximized theta-e
and buoyancy in the storm environment. Over land, however, severe
potential appears to low for an unconditional outlook.
..Edwards/Broyles.. 12/24/2023
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