SPC May 30, 2026 1300 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0725 AM CDT Sat May 30 2026

Valid 301300Z - 311200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL
HIGH PLAINS INTO CENTRAL KANSAS AND NORTH-CENTRAL OKLAHOMA...

...SUMMARY...
Scattered severe thunderstorms are possible this afternoon and
evening over the central Great Plains. The stronger thunderstorms
will potentially be capable of large to very large hail, severe
gusts, and perhaps a couple of tornadoes.

...NE Panhandle into the northern High Plains...
A mid-level trough along the UT/CO border will migrate slowly
northeast with a belt of 20-40 kt cyclonic 500-mb flow wrapping
cyclonically through the base of the trough into the NE Panhandle
and Black Hills. In the low levels, an elongated area of surface
low pressure/lee trough will focus thunderstorm development later
this afternoon/evening. The western part of a moisture plume
extending from the southern Great Plains northward into western
NE/SD will feature 50s to lower 60 F dewpoints. Strong heating and
large-scale ascent will combine to weaken the capping inversion and
result in widely scattered thunderstorms developing by mid-late
afternoon. Slightly stronger deep-layer shear across NE will favor
a mix of supercells and multicells with the stronger storms. Large
hail and severe gusts will be possible with the stronger
thunderstorms through the mid evening as this activity probably
grows upscale into a linear cluster or two.

...NE-KS and into OK-TX...
Models continue to show a sharp dryline across western/central
KS, western OK, and into west TX by late afternoon. Main lobe of
forcing for ascent associated with the upper trough will likely
glance the northwestern quadrant of KS into NE. Surface
mesoanalysis this morning shows a low over northeast CO near AKO and
an effective outflow boundary draped east along I-70 in
north-central KS. North of the boundary, easterly surface winds
will contribute to maintaining moist upslope flow.

Ample heating in wake of early morning convection and an
increasingly rich moisture plume arcing from north-central OK into
southwest NE, will favor a very unstable airmass developing by
mid-late afternoon (3500-4500 J/kg MLCAPE). Some forecast
uncertainty remains regarding low-level hodographs due to model
spread (e.g., RAP and HRRR time-lagged depictions favoring more
supercells vs. NAM with less favorable hodographs and indicative of
more multicellular structures). Furthermore, effective shear is
forecast to be only 25-35 knots and will likely straddle the
multicell-supercell spectrum. Where slightly stronger shear and
some enlargement of clockwise-curved hodographs are currently
expected, it is where supercells are more probable and the risk for
large to very large hail and a couple of tornadoes are increasingly
possible. Have opted to include a 5-percent tornado risk over
north-central KS into southwest NE, with this region being located
north of this morning's west-east boundary and in closer proximity
to the upper wave. Farther south, lower storm coverage (isolated)
is expected into OK and more sparse and widely spaced activity
farther south along the dryline in parts of west TX. Large hail and
severe gusts are the primary hazards with these storms.

...Southwest Missouri into central Arkansas...
A zone of isentropic ascent near 850 mb will become established
across the Ozark Plateau by late afternoon. Isolated to scattered
thunderstorms are likely within this corridor. Models show large
SBCAPE (3000 J/kg) and adequate deep-layer shear for some storm
organization. A few stronger cells may be capable of large hail and
perhaps strong/severe wind gusts.

..Smith/Kerr.. 05/30/2026


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SPC May 30, 2026 0600 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1249 AM CDT Sat May 30 2026

Valid 301200Z - 311200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL
HIGH PLAINS INTO CENTRAL KANSAS AND NORTH-CENTRAL OKLAHOMA...

...SUMMARY...
Thunderstorms with large hail and severe wind gusts are expected on
this afternoon and evening from parts of the central High Plains
into central Kansas and north-central Oklahoma. Isolated severe
gusts and hail will also be possible in the northern High Plains,
and across parts of western Texas.

...Synopsis...
Latest GOES imagery depicts a pronounced mid-level low over southern
UT with a modest (25-35 knot) subtropical jet emanating from
northern Mexico into the southern Plains. Several shortwave
vorticity maximum are noted along the MS River Valley and across the
Southeast within a broad upper-level deformation zone. Over the next
12-24 hours, the low over southern UT will drift northeast, likely
overspreading the central High Plains by late afternoon/early
evening. As this occurs, more focused surface pressure falls and lee
cyclone development will become apparent across eastern WY/CO and
into portions of western KS/OK and the TX Panhandle.

00 UTC RAOBs across the central to southern Rockies sampled very
steep (8-9 C/km) lapse rates, which should advect eastward in the
wake of ongoing convection through this afternoon given the
southwesterly mid-level flow regime. Additionally, late-evening
surface observations across the central CONUS reveal an expansive
reservoir of rich low-level moisture with dewpoints in the upper 60s
to mid 70s spanning from central OK into the Southeast. This
moisture will advect west/northwest through the morning and
afternoon hours in response to the surface pressure
falls/cyclogenesis over the central High Plains.

The combination of destabilizing thermal profiles aloft and
increasing low-level moisture content will promote a broad swath of
moderate to very high buoyancy from the central High Plains
southward into the southern Plains. Thunderstorm development within
this unstable air mass appears likely as ascent increases through
the day along the surface trough/sharpening dryline.

...Central High Plains...
35-45 knot southerly mid-level flow across the central High Plains
will yield elongated hodographs with deep-layer shear vectors
oriented off the dryline/surface trough. This will result in
high-based supercell development initially across northeast
CO/western NE into western SD with an attendant threat for large
hail and strong outflow winds. With time, upscale growth is
anticipated as convection spreads north/northeast across NE and SD
with an increasing threat for severe winds.

...Central/Southern Plains...
Most guidance depicts a sharpening dryline across western/central
KS, western OK, and into western TX through the afternoon hours.
More focused forcing for ascent across central KS to northern OK
ahead of a subtle low-amplitude upper wave will likely favor
scattered thunderstorm coverage with more isolated thunderstorms
likely with southward extent into western TX. Although ample
buoyancy will be in place (MLCAPE values between 3500-4500 J/kg),
the primary limiting factor across the central/southern Plains will
be modest deep-layer wind shear. Consensus among forecast guidance
suggests effective bulk shear values on the order of 25-35 knots are
likely, which will promote a combination of supercells and
multicells. However, the steep lapse-rate environment coupled with
sufficient deep-layer wind shear will support the potential for
large hail along with severe wind gusts.

A focused corridor for a tornado threat may emerge across northern
OK to central KS where southeasterly low-level flow should support
effective SRH on the order of 150-200 m2/s2. However, the tornado
threat will likely be highly conditional on achieving a sustained
supercell with balanced inflow/outflow. Given the increased
convective signal across northern OK/KS, 15% hail/wind
probabilities, as well as 2% tornado probabilities, have been
introduced.

...Southwest Missouri into central Arkansas...
A zone of isentropic ascent near 850 mb will become established
across the Ozark Plateau by late afternoon. Isolated to scattered
thunderstorms are likely within this corridor given MUCAPE values
upwards of 3000 J/kg, and sufficient deep-layer wind shear should be
in place for a few organized cells capable of large hail and perhaps
strong/severe downburst winds.

..Moore/Marsh.. 05/30/2026


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SPC May 30, 2026 0100 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 0100Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0759 PM CDT Fri May 29 2026

Valid 300100Z - 301200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
WESTERN TEXAS INTO NORTHERN OKLAHOMA...

...SUMMARY...
Widely scattered strong to severe storms capable of sporadic large
hail and severe winds will linger across the central and southern
Plains through the late evening hours before diminishing by early
morning. More isolated severe thunderstorms will also remain
possible across portion of north-central Montana through late
evening.

...Synopsis...
Regional radar mosaics show widely scattered convection from
northwest KS into north-central OK and across portions of western
Texas. Based on latest GOES imagery and recent RAP upper-air
analyses, modest diffluence aloft associated with the left-exit
region of a subtropical jet resides across northern OK/KS and should
continue to promote thunderstorm development across this region over
the next several hours. Further northwest across Montana, isolated
to widely scattered thunderstorms continue to percolate within the
higher terrain with little forward motion owing to weak mid-level
winds. Across both regions, thunderstorms will likely persist into
the late evening hours with some threat for severe gusts and perhaps
sporadic large hail.

...Kansas/northern Oklahoma...
New convection continues to develop across northwest to
south-central KS within the left-exit region of the upper jet and
within a zone of modest isentropic ascent focused near 850 mb.
Through the evening, additional thunderstorm development appears
likely as the nocturnal low-level jet gradually strengthens.
However, regional VWPs depict diminishing mid-level flow with
northward extent across KS, and dewpoint depressions on the order of
20-30 F coupled with weak low-level winds are favoring outflow
dominant convection with transient organization. Consequently, the
potential for a prolonged or intense severe threat across any one
corridor of the region appears limited - especially heading into the
late evening hours as nocturnal cooling/stabilization becomes more
pronounced. Nonetheless, severe gusts, and perhaps very sporadic
large hail, will remain possible with this activity for the next
several hours as it spreads east/northeast. 5% hail/wind
probabilities were expanded to account for this potential through
04-06 UTC.

...Western Texas...
Thunderstorm coverage has failed to materialize as expected thus far
across much of western TX, though a few thunderstorm clusters are
noted near the Amarillo, TX area, as is percolating convection near
Fort Stockton, TX. Given the dearth of more widespread convection -
likely owing to very weak forcing for ascent and the stabilizing
influence of residual cloud cover - confidence in the severe threat
through late evening is low. However, 00 UTC RAOBs and latest RAP
mesoanalysis estimates continue to show an environment supportive of
organized convection, and recent high-res guidance hints at further
development between the I-10 and I-20 corridors through roughly 04
UTC. The Slight risk has been bifurcated to highlight these two
corridors downstream of ongoing and/or developing intense
convection.

...Montana...
Convection continues to percolated across north-central MT with MRMS
imagery showing occasional periods of intensification to severe
limits with the deeper, more robust convective cores. Weak flow
below 5 km AGL is likely contributing to the slow storm motions and
poor organization, but as hinted by recent trends, convection that
can become sufficiently deep may be influenced by stronger flow
above 5 km and pose a brief threat for large hail and severe winds.
In general, this threat should wane through the late evening hours.

..Moore.. 05/30/2026


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SPC May 29, 2026 2000 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 2000Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0256 PM CDT Fri May 29 2026

Valid 292000Z - 301200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER WEST TEXAS
INTO WESTERN OKLAHOMA...

...SUMMARY...
Scattered strong to severe storms capable of sporadic large hail and
scattered severe winds are still expected this afternoon and evening
across portions of western Texas into northern Oklahoma. More
isolated severe thunderstorms remain likely across parts of the
central High Plains, southern Utah, and the northern Rockies.

...20Z Update...
The previous forecast (see below) remains generally on track. The
biggest change made to the outlook was to extend 15 percent wind and
hail probabilities (hence the Slight risk) farther east into OK.
Though speed and directional shear are not expected to be overly
abundant, some hodograph curvature and elongation, amid 2500-3000
J/kg MLCAPE will support multicells and transient supercells capable
of producing severe wind and hail (with a few stones potentially
exceeding 2 inches in diameter). Otherwise, more minor adjustments
were made to thunder and severe probabilities to account for
observations and the latest guidance consensus.

..Squitieri.. 05/29/2026

.PREV DISCUSSION... /ISSUED 1110 AM CDT Fri May 29 2026/

...Southern Plains...
Southwesterly flow aloft is present today over AZ/NM, with large
scale height falls and weak ascent overspreading west TX/OK.
Low-level southeasterly flow in this region is maintaining a moist
and potentially moderately unstable air mass, with breaks in the
clouds leading to pockets of CAPE over 2000 J/kg. By late
afternoon, clusters of thunderstorms will develop from the Davis
mountains northward into the TX Panhandle. Forecast soundings in
this area show a deeply mixed boundary-layer suggestive of a
damaging wind and large hail potential. These storms will congeal
and move eastward into western OK during the evening, spreading into
greater low-level moisture and CAPE profiles. The risk of hail may
increase as this happens.

...Northeast CO/Northwest KS...
Scattered afternoon thunderstorms are expected to develop along the
Palmer Ridge to the east of Denver, and over the plains of southeast
CO. These storms will track northeastward through the early
evening, with some increase in low-level shear expected. This may
result in a supercell or two capable of large hail, damaging winds,
or perhaps a tornado.

...MT...
A consensus of 12z model guidance continues to show that scattered
afternoon thunderstorms will form over the terrain of western and
central MT. This activity will spread northward toward the Canadian
border, through a region of 1000 J/kg CAPE and a deeply mixed
boundary-layer. This would support a risk of isolated damaging wind
gusts and perhaps hail in the strongest storms.


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