SPC Jun 27, 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
1233 AM CDT Sat Jun 27 2026

Valid 271200Z - 281200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE THIS
AFTERNOON INTO EARLY TONIGHT ACROSS EASTERN MT AND WESTERN ND...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS INTO WESTERN SOUTH
DAKOTA AND NEBRASKA...AND ACROSS NORTH CAROLINA...

...SUMMARY...
A mix of initial supercells and later storm clusters will produce
swaths of severe outflow winds and very large hail across the
northern High Plains late this afternoon into early tonight.
Isolated wind damage will also be possible from the Mid-Mississippi
Valley to the Carolinas, as well as across west Texas and the Texas
Panhandle.

...Northern High Plains this afternoon into tonight...
Embedded speed maxima will rotate northeastward over the northern
High Plains, around the eastern periphery of a close midlevel low
evolving over the northern Great Basin and northern Rockies.
Boundary-layer dewpoints in the 60s will continue to spread
northward from KS/NE to the Dakotas, east of a deep lee
trough/cyclone across the central/northern High Plains. The
moistening will occur beneath steep midlevel lapse rates, which
combined with daytime heating will result in large CAPE.

Thunderstorm development is expected this afternoon along both the
surface trough/lee cyclone near the MT/ND border and near the Big
Horn Mountains. The initial storms could be supercells with very
large hail (2-3 inch diameter) near the ND/MT border, and a couple
of tornadoes with any supercells anchored along the surface
boundary, though relatively large temperature-dewpoint spreads and
mode concerns could temper the tornado threat somewhat. By late
evening and early tonight, storms will likely grow upscale and move
northeastward across ND as one or more MCSs with severe outflow
winds (potentially 80+ mph) in the steep lapse rate environment.
More isolated supercells will also be possible farther south into
western SD/NE where isolated very large hail and significant severe
outflow gusts will be possible.

...TN/southern KY to NC this afternoon...
An MCV now over eastern KY will continue eastward near the VA/NC
border during the day, and additional MCVs are likely to emerge from
ongoing storm clusters moving eastward across OK, southwest KS and
the TX Panhandle. Ascent with the MCVs, as well as residual
outflow/differential heating zones, will help focus thunderstorm
development during the afternoon in a moist, unstable environment.
Occasional wind damage will be possible with storm clusters where
low-level lapse rates are relatively steep (south of persistent
clouds) and there is some enhancement of midlevel flow. An isolated
tornado may also occur in the warm advection zone with enhanced
low-level hodograph curvature across TN on the southwest flank of
the western MCV, though confidence in this scenario is low.

...TX Panhandle into west TX late this afternoon/evening...
Though forcing for ascent will be weak at best this far south,
strong surface heating/mixing along the lee trough/dryline could
support high-based thunderstorm development late this afternoon.
Inverted-V profiles will favor the potential for isolated severe
outflow gusts of 60-75 mph.

..Thompson/Chalmers.. 06/27/2026


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SPC Jun 27, 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
0802 PM CDT Fri Jun 26 2026

Valid 270100Z - 271200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS INTO EARLY TONIGHT
FROM THE HIGH PLAINS INTO NORTHERN OKLAHOMA AND SOUTHERN MISSOURI...

...SUMMARY...
Scattered severe thunderstorms with severe outflow gusts and large
hail will persist into early tonight across the High Plains and from
northern Oklahoma into southern Missouri.

...Northern OK to southern MO...
Multiple strong-severe storms formed late this afternoon along a
stalled front from the northeast TX Panhandle eastward into northern
OK into southern MO. Seasonably high moisture content in the
boundary layer (dewpoints in the low-mid 70s) and lingering warm
temperatures are contributing to MLCAPE near 3000 J/kg with only
weak convective inhibition, while vertical shear is sufficient for
supercells with large hail (1 to 2 inches in diameter). Storms will
likely persist into tonight as a result of cell interactions and an
increase in warm advection with a strengthening low-level jet,
immediately downstream from a subtle midlevel trough now approaching
northwest OK. The stronger cells/clusters will be capable of
isolated large hail and occasional severe outflow gusts of 60-70 mph
as storms spread slowly southeastward across
northern/central/northeast OK.

A similar environment extends into southern MO along and south of
the stalled front, with a few ongoing cells/clusters. There has
been some localized tornado threat across south central MO where a
discrete storm or two are interacting with a zone of slightly
enhanced low-level shear in a moist environment, though the tornado
threat will remain localized/marginal.

...High Plains...
Widely scattered storm clusters formed this afternoon and continue
to develop this evening with interacting outflows from MT across
eastern WY/NE Panhandle into eastern CO and the western OK Panhandle
on the west edge of the moisture in a largely upslope flow regime.
This corridor is downstream from a pronounced midlevel trough over
the Great Basin/Pacific Northwest, which will encourage a nocturnal
low-level jet to support some persistence of storms into early
tonight, despite weakening buoyancy and increasing inhibition with
eastward extent. Occasional severe outflow gusts and large hail
will be the main threats.

Potential for storms to maintain a wind/hail threat a little deeper
into the overnight hours will be across southwest KS and vicinity.
The storm clusters spreading eastward from CO will encounter
somewhat richer low-level moisture (mid-upper 60s dewpoints) on the
immediate cool side of a stalled front, coincident with a nocturnal
increase in the low-level jet and associated warm advection.

...KY area...
A remnant MCV is moving eastward over western KY with the primary
storm cluster from far southern IN into central KY on the leading
edge of the ascent. These storms have exhibited a primarily linear
mode with a trailing cold pool into western KY. Earlier discrete
storms have since weakened while moving atop the rain-cooled air,
though a few storms may persist into early tonight in the warm
advection regime on the southwest flank of the MCV. The primary
severe threat appears to be isolated wind damage with the leading
line segments across central/northern KY for the next 1-2 hours
before boundary-layer stabilization weakens the storms.

..Thompson.. 06/27/2026


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SPC Jun 26, 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
0300 PM CDT Fri Jun 26 2026

Valid 262000Z - 271200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
NORTHERN/CENTRAL HIGH PLAINS...SOUTHERN PLAINS TO THE LOWER OHIO
VALLEY...AND PARTS OF NEW ENGLAND...

...SUMMARY...
Scattered severe thunderstorm development is expected today,
particularly this afternoon into tonight across parts of the
southern Plains to Lower Ohio Valley and across parts of the
northern and central High Plains to the Black Hills vicinity. Other
severe storms are expected across portions of New England.

...20Z Update...
The forecast remains on track, and only minor changes were made with
this update.

The SLGT risk in the central High Plains was expanded southeastward
from southeast CO into southwest KS and parts of the OK/TX
Panhandles. Guidance is in relatively good agreement, depicting
thunderstorms evolving off the Raton Mesa and tracking
east-southeastward along a gradient of rich boundary-layer
moisture/moderate surface-based buoyancy this evening/tonight. Aided
by 40 kt of effective shear and increasing low-level hodograph
curvature amid a strengthening nocturnal LLJ, supercell clusters
will pose a risk for severe gusts, large hail, and possibly a
tornado.

Farther east, a minor westward expansion of the SLGT risk was made
into north-central OK. Ample diurnal heating/destabilization of a
very moist air mas (middle/upper 70s dewpoints) is yielding strong
surface-based buoyancy along an east/west-oriented surface boundary.
Current thinking is that a few organized clusters/supercells
developing along the boundary will be capable of producing severe
wind gusts and large hail later this afternoon/evening.

..Weinman.. 06/26/2026

.PREV DISCUSSION... /ISSUED 1147 AM CDT Fri Jun 26 2026/

...Ozarks and Lower Ohio Valley...
Multiple eastward-moving MCVs remain evident regionally in
observational data at midday, probably strongest across southeast
Missouri, but also the Oklahoma/Arkansas border vicinity and
northern Kentucky. A related observed enhancement to the
low/mid-level flow will persists from the Ozarks/Bootheel
east-northeastward parallel to the Ohio River, but cloud
cover/scattered precipitation remains fairly prevalent regionally as
well. Peripheral cloud breaks and insolation should allow for
gradual destabilization, particularly on the south/southwest fringes
of this early day activity. This should lead to severe storm
development into mid/late afternoon through the evening, potentially
including supercells given the flow enhancement. A couple of
tornadoes could occur aside from wind damage.

...High Plains...
A seasonably anomalous upper trough will continue to amplify and
spread eastward over the Pacific Northwest toward the Great Basin
and Intermountain West, with a lead disturbance ejecting
northeastward toward the northern High Plains. Pronounced lee
troughing is forecast with a surface low expected to evolve over
central and southeast Montana through tonight. A corridor of at
least weak to moderate boundary-layer destabilization is expected
across the High Plains. Strengthening large-scale ascent and ample
vertical shear downstream of the digging large-scale troughing will
favor organized severe thunderstorm development late this afternoon
through evening. Supercells and evolving organized clusters will
pose a risk for large hail and severe gusts, and perhaps a tornado.
Across the central into southern High Plains, isolated to widely
scattered storms will likely develop/mature and propagate east
during the evening. Hail and wind are the primary hazards with this
activity and this severe risk will probably linger into the late
evening.

...New England...
Have introduced a Slight Risk for portions of the region, primarily
focused near the advancing surface low/warm front. A shortwave
trough over Ontario/Lower Great Lakes will move east across New
England by this evening. Cloud cover, albeit abating this afternoon,
will limit the overall magnitude of destabilization, but upwards of
1000-1500 J/kg SBCAPE are forecast to develop along/south of a warm
front. Elongated hodographs beneath a 100+ kt 250-mb speed max will
aid in storm organization in the form of possibly a couple of
supercells and organized multicells. Isolated coverage of large hail
and damaging gusts are the primary risks with the stronger
thunderstorms, but the moist environment and low-level shear/SRH
could yield a tornado threat.

...Mid-Atlantic States to Carolinas...
The southern periphery of stronger mid to high-level westerly flow
is forecast across the region, atop northward-shifting low-level
moisture that is richest across the Carolinas into southern
Virginia, where near/above 70 F surface dewpoints are prevalent. The
overlap of moderate westerly flow and weak destabilization is
expected to support scattered thunderstorms capable of strong to
locally severe/damaging gusts (50-60 mph). Additional sea-breeze
influenced locally severe storms may occur across the coastal plain
of the Carolinas.


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SPC Jun 26, 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
0749 AM CDT Fri Jun 26 2026

Valid 261300Z - 271200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING ACROSS PARTS OF THE OZARKS PLATEAU INTO THE LOWER OHIO
VALLEY AND ACROSS PARTS OF THE NORTHERN HIGH PLAINS TO THE BLACK
HILLS...

...SUMMARY...
Scattered severe thunderstorm development is possible today,
particularly this afternoon into tonight across parts of the Ozark
Plateau into lower Ohio Valley and across parts of the northern High
Plains to the Black Hills vicinity.

...Ozark Plateau into lower Ohio Valley...
Radar-mosaic imagery this morning shows a trio of MCVs (e.g.,
western KY, southwest MO, east-central OK) moving east across the
general region. Ongoing linear clusters of thunderstorms associated
with the MO and KY MCVs cast considerable uncertainty regarding
destabilization across the Ozarks into the lower OH Valley.
Nonetheless, a residual baroclinic zone aided perhaps by
differential heating along the remnant outflow will favor renewed
storm development later this afternoon. A seasonably moist airmass
(lower 70s F dewpoints) in proximity to some enhancement of the
background westerly flow, will likely contribute to strong to severe
storms developing by mid to late afternoon through the evening. A
couple of tornadoes are possible with supercell activity as well as
scattered damaging gusts with the more organized multicells and
related clusters.

...High Plains...
A seasonably anomalous upper trough over the West will feature a
lead disturbance ejecting northeastward into the northern High
Plains during the Day 1 period. Pronounced lee troughing is
forecast with a surface low expected to evolve over southeast MT by
late tonight. Congruent with prior forecast thinking, a corridor of
at least weak to moderate boundary-layer destabilization is expected
across the High Plains. Strengthening large-scale ascent and ample
vertical shear downstream of the digging large-scale troughing will
favor organized severe thunderstorm development late this afternoon
through evening. Supercells and evolving organized clusters will
pose a risk for large hail and severe gusts, and perhaps a tornado.
Farther south, isolated to widely scattered storms will likely
develop/mature and propagate east during the evening. Hail and wind
are the primary hazards with this activity and this severe risk will
probably linger into the late evening.

...Mid-Atlantic states...
The southern periphery of stronger mid to high-level westerly flow
is forecast across northern Mid-Atlantic region. The northern rim
of richer low-level moisture (lower 70s F dewpoints) arches from
eastern NC into southeast VA. The overlap of moderate westerly flow
and weak destabilization will probably support scattered
thunderstorms capable of an isolated risk of strong to locally
severe/damaging gusts (50-60 mph).

...New England...
An upper shortwave trough over Ontario/Lower Great Lakes this
morning will move east across New England by this evening.
Considerable cloud cover will limit the overall magnitude of
destabilization, but upwards of 1000-1500 J/kg SBCAPE are forecast
to develop by midday. Elongated hodographs beneath a 100+ kt 250-mb
speed max will aid in storm organization in the form of possibly a
couple of supercells and organized multicells. Isolated coverage of
large hail and damaging gusts are the primary risks with the
stronger thunderstorms.

..Smith/Jewell.. 06/26/2026


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