RSS Mesoscale Discussions from Storm Prediction Center
SPC 2000Z Day 1 Outlook
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.
Read more
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0230 PM CDT Sat Apr 25 2026
Valid 271200Z - 281200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR THE
MID-MISSISSIPPI VALLEY...MID-SOUTH...AND LOWER OHIO VALLEY...
...SUMMARY...
Widespread strong to severe thunderstorm development appears
probable across the middle Mississippi into lower Ohio and Tennessee
Valleys Monday afternoon and evening. At least initially, this may
include several evolving supercells potentially capable of producing
strong tornadoes across parts of southeastern Iowa into central
through southern Illinois and adjacent east central and southeast
Missouri.
...Synopsis...
A potent shortwave trough will move into the mid-Mississippi Valley
on Monday. A deepening surface low in the upper Mississippi Valley
will draw rich moisture northward into a very broad warm sector.
Strong deep-layer shear will promote numerous organized storms
capable of all severe hazards.
...Mid-Mississippi Valley...
A fairly well-timed shortwave trough will move into the region by
mid-afternoon. A deepening surface low will lift northeastward into
the upper Mississippi Valley. Associated with the cyclone, a cold
front/dryline composite will drape southwestward through central
Iowa/western Missouri. Within the warm sector, rich moisture
(dewpoints in the upper 60s F) and mid-level lapse rates around 8
C/km will promote MLCAPE of 2000-3000 J/kg. 60+ kts of effective
shear is expected as the mid-level jet overspreads the region.
Supercells are possible along the warm front, pre-frontal trough,
and even the open warm sector given the forcing for ascent. All
severe hazards will be possible including very-large hail,
significant winds, and strong tornadoes. Potential for longer track
tornadoes is not out of the question. There remains some uncertainty
as to how convection will ultimately evolve during the afternoon
given the potential for early morning thunderstorms. The NAM would
suggest this activity clears out relatively quickly and development
on the pre-frontal trough or front in the afternoon is probable. The
latest ECMWF depicts convection lingering into the later
morning/early afternoon, particularly in northern and parts of
central Illinois. This would act to shift the primary corridor of
severe risk farther south and east. The main zone of concern, when
taking all guidance into account, appears to be from far southeast
Iowa into central Illinois. With time, one or more stronger linear
segments are expected to evolve where damaging winds and QLCS
tornadoes would be possible. A categorical upgrade to Level
4/Moderate was considered, but will await additional guidance which
will hopefully clarify how early-day convection will evolve.
...Mid-South...
Though this area will be displaced from the strongest mid-level
ascent, rich moisture (upper 60s F to potentially low 70s F
dewpoints) will promote 2500-3000 J/kg MLCAPE. A broad mid-level jet
will nose into the region. Around 50 kts of effective shear can be
expected. Supercells capable of all severe hazards will be possible.
..Wendt.. 04/25/2026
Read more
