ACUS01 KWNS 081254
SWODY1
SPC AC 081252

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0652 AM CST Fri Nov 08 2024

Valid 081300Z - 091200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH-CENTRAL TEXAS...

...SUMMARY...
Severe-thunderstorm threat exists from north Texas to the Hill
Country and parts of central/east Texas through this evening.  The
most focused tornado, damaging-wind and hail potential appears to be
over north-central Texas.

...Synopsis...
The mid/upper-level pattern features a closed, temporarily cut-off,
synoptic-scale cyclone, initially centered over central NM.  As a
strong, basal shortwave trough pivots northeastward across eastern
NM and the TX Panhandle today, the 500-mb low will shift east-
northeastward toward CAO by 00Z.  Overnight, the low should track
north-northeastward, reaching the GLD vicinity by 12Z.  Height falls
should occur over central/north TX today, then becoming neutral to
slightly rising overnight.

The 11Z surface analysis showed a frontal-wave low near SWW, with a
cold front south-southwestward between DRT-6R6.  A warm front was
drawn from the low through some rain-cooled air to near MWL, then
east-southeastward over southern fringes of the Metroplex to between
LFK-ESF.  The low is expected to move northward to near the
northeastern corner of the TX Panhandle by 00Z and occlude, while
the occluded/cold front reaches western OK, north-central/central
TX, to near LRD.  The warm front should drift northward over north-
central/northeast TX, with its progress slowed by increasing
precip/convection to its north.  By 12Z tomorrow, the low should get
stacked with the 500-mb center over northwestern KS, with the cold
front reaching east TX and the shelf waters off the TX Gulf Coast.

Meanwhile, Hurricane Rafael is forecast to remain well-removed from
land this period, moving generally westward over the central to
west-central Gulf then slowing/meandering after this period.  See
NHC advisories for latest forecast track/intensity info on Rafael.

...North to central TX...
An ongoing area of convection over parts of north TX and southern OK
is expected to shift northward over increasingly elevated and less-
unstable inflow parcels and weaken through midday.  Meanwhile,
closer to the cold front, scattered thunderstorms are expected to
develop over the next several hours through early afternoon,
evolving into a nearly solid convective band with embedded
supercells and bow/LEWP formations possible.  This activity should
shift eastward over central and north TX through early evening,
offering at least marginal potential for all severe hazards.

Meanwhile, isolated to scattered thunderstorms are possible in the
warm sector and along/north of the warm front.  This activity should
move northward to northeastward.  Any sustained, relatively discrete
cells with prolonged access to surface-based parcels in the warm
sector, and especially interacting with the warm front, may rotate
with a threat for all hazards (hail, damaging to severe gusts and
mesoscale peak in tornado potential) also present.  The associated
theta-e/instability gradient is expected to align northwest/
southeast very near or even across the DFW Metroplex.  This will
yield an increased severe threat from north to south into more-
unstable inflow air, and within the southern part of the relatively
high-vorticity gradient itself.  Given the superposition of these
foci and the expected favorable parameter space, the north-central
TX part of the outlook is being upgraded for all hazards this cycle.

Upper 60s to low 70s F surface dewpoints already are present in the
warm sector, and will shift north slowly, in step with the warm
front, before the main north-south band overtakes the region.  This
should occur during the afternoon when low-level, warm-sector
instability is maximized away from convection.  Despite modest lapse
rates aloft (manifest in mid/upper-level stable layers sampled by
the 12Z FWD sounding), a northwestward-narrowing, triangular
corridor of 1000-1500 J/kg peak MLCAPE is expected.  Veering winds
with height are forecast to continue, with hodograph curvature/size
largest along the warm front, and enough deep shear (effective-shear
magnitudes 35-45 kt in central/north TX, weakening southward and
eastward) to support occasional supercell structures.  Overnight,
supportive large-scale ascent and the elevated LLJ each should shift
northward away from the area, while the main band of convective-
scale forcing shifts into east TX and weakens.

..Edwards/Bentley.. 11/08/2024

$$
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