ACUS01 KWNS 251950
SWODY1
SPC AC 251948

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0248 PM CDT Sat Apr 25 2026

Valid 252000Z - 261200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
CENTRAL AND SOUTHEASTERN OKLAHOMA INTO FAR NORTHERN TEXAS...

...SUMMARY...
Severe thunderstorms with very large to giant hail (2 to 4+ inches
in diameter), tornadoes (some EF2+), and scattered damaging winds
are expected late this afternoon through tonight across parts of the
southern Plains and ArkLaTex.

...20Z Update...

The previous forecast (see below) remains on track. The main
adjustments made to the outlook (albeit minor) were to slightly
extend the moderate risk-driven hail probabilities to the southwest
to align with the current position of the surface boundary. The
latest high-resolution guidance consensus has consistently depicted
some of the most robust storms to form and anchor along this
boundary. With current mesoanalysis already showing 4000+ J/kg
MLCAPE colocated across far south-central OK, the current thinking
is that intense supercells traversing this boundary will produce
severe hail in the 3-4 inch range, and a couple of stones above 4
inches in diameter cannot be completely ruled out. Tornadoes may
also occur, with the best chance of a strong to intense tornado
being with a boundary-anchoring supercell that can remain discrete
and dominant.

..Squitieri.. 04/25/2026

.PREV DISCUSSION... /ISSUED 1131 AM CDT Sat Apr 25 2026/

...Southern Plains and ArkLaTex...

While stratus remains semi-prevalent this morning along/north of the near-stationary front, strong to locally extreme instability (MLCAPE
2500-4000+ J/kg) is expected to develop along/east of the dryline in
Texas and Red River-vicinity triple point, and to the south of slow-northward-shifting warm front in Oklahoma by peak afternoon
heating. The presence of seasonably cool temperatures aloft and
7.5-8.5 C/km mid-level lapse rates will also support this very
unstable thermodynamic environment. While large-scale ascent
associated with the ejecting mid-level shortwave trough is not
expected to be overly robust, the arrival of a shortwave
trough/mid-level speed max will be favorably timed atop the warm
sector. At least widely scattered thunderstorm initiation is
expected by mid/late afternoon to early evening (around 20-23Z),
especially near the warm front/dryline intersection and a bit north
across south-central/east-central Oklahoma.

40-50 kt of generally westerly effective bulk shear will support
intense supercells, with multiple right/left splits expected. This
activity will quickly intensify shortly after convective initiation,
and very large to giant hail appears likely (2-4+ inches in
diameter). The potential exists for multiple intense supercells to
track east-southeastward along/near the warm front. A conditional
risk for supercells remains apparent farther south along the length
of the dryline in TX, although confidence in convective initiation
remains low, but at least isolated but intense deep convective
development is plausible, especially in closer proximity to the
surface triple point across North Texas.

Modest southerly low-level winds (around 20-30 kt at 850 mb) will be
present through this evening across the southern Plains. Locally
enhanced 0-1 km SRH will exist near the warm front with backed
near-surface winds. This will support a threat for tornadoes with
any right-split supercells that remain surface based. A slight
increase in the low-level jet this evening and presence of very
strong to locally extreme buoyancy also suggests some threat for a
few EF-2+ tornadoes. With time this evening, convection may
grow upscale and pose a threat for scattered severe/damaging winds
as storm clusters move southeastward across the Red River toward and
across the ArkLaTex.

...Central Plains including Kansas/Nebraska...

Farther north, instability and low-level moisture is expected to
remain weaker/more limited. But, some supercells/small clusters are
expected to develop this afternoon and move east-northeastward given
sufficient deep-layer shear for updraft organization. Isolated to
scattered severe hail and damaging winds should be the main threat
with this activity through mid-evening before eventually weakening.

...Lower Mississippi Valley/Middle Gulf Coast...

Strong to locally severe storms may redevelop later today as outflow
modifies in the wake of the early morning MCS, with the potential
that additional storms, potentially in the form of another MCS,
approach the region from the northwest late tonight.

$$


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