RSS Mesoscale Discussions from Storm Prediction Center
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0743 AM CDT Tue May 26 2026
Valid 261300Z - 271200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
SOUTHWEST AND SOUTH-CENTRAL TEXAS...
...SUMMARY...
Scattered severe thunderstorms are possible across parts of
southwest into south-central Texas. Large hail, severe wind gusts,
and a couple tornadoes are possible through this evening.
...Southwest into South-Central Texas...
Water-vapor imagery this morning shows a weak mid-level trough over
southern NM and Far West TX. This upper feature will slowly migrate
east into the Permian Basin and Concho Valley later this
afternoon/evening. Early morning showers/thunderstorms and their
associated outflow and relatively cool air have overspread the
Permian Basin. To the southeast of the rain-cooled airmass, the 12
UTC Del Rio, TX raob sampled moderately steep 700-500 mb lapse rates
(7.3 deg C/km) and 2200 J/kg MUCAPE. A weak area of low pressure
near the Big Bend will maintain a moist, easterly low-level fetch
into the Edwards Plateau. Heating via cloud breaks and surface
dewpoints in the upper 60s and lower 70s F will contribute to
1500-3000 J/kg MLCAPE by afternoon.
Strong veering of the low-level wind profile with 20-25 kt westerly
500-mb flow will support organized storms, including supercells with
the stronger updrafts. Some tornado threat may evolve with one or
two more intense supercells but this risk will largely be dependent
on mesoscale factors. Clusters of storms are eventually expected
with the severe risk continuing into the evening with the stronger
storms capable of wind/hail.
...Kentucky...
A seasonably moisture-rich airmass is located along and south of a
residual frontal zone draped from the confluence of the OH-MS Rivers
east-northeast across the OH Valley. Despite considerable cloud
cover, some heating will result in weak instability. Widely
scattered to scattered thunderstorms coincident with peak heating
are forecast. Modest southwesterly mid-level flow (20-30 kt) may
act to aid in some organization of cells. An isolated risk for
damaging gusts and perhaps a brief tornado are possible with this
activity.
...Upper Midwest...
A weak MCV was noted over the Mid MO Valley this morning embedded
within a weak westerly mid-level flow regime to the north of a
flattened mid-level anticyclone. In the low levels, a
quasi-stationary boundary will be draped generally west to east
across the region. South of this boundary, surface dewpoints in the
60s F will contribute to pockets of moderate instability by
afternoon. Model guidance indicates scattered storm coverage later
this afternoon in the wake of morning showers/storms over parts of
this region. Isolated wind/hail will be the primary hazards with
the stronger storms before this activity weakens by early evening.
...Northern Rockies...
A belt of south-southeasterly 20-30 kt mid-level flow will reside in
between a mid-level cyclone over northern CA and an anticyclone over
the Midwest. A lee trough over the northern High Plains will focus
thunderstorm development later today as the boundary layer
destabilizes. Low-level lapse rates will be very steep, which will
contribute to a potential for severe wind gusts. Hail will also be
possible, mainly over western Montana where instability is forecast
to be the strongest.
..Smith/Weinman.. 05/26/2026
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