RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1259 AM CDT Fri Jun 12 2026
Valid 121200Z - 131200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
APPALACHIANS...MID ATLANTIC...AND NORTHEAST...AND ALSO FOR PARTS OF
THE SOUTH-CENTRAL HIGH PLAINS...
...SUMMARY...
Strong to severe storms capable of damaging winds are possible
across parts of the Appalachians, Mid Atlantic, and Northeast,
mainly this afternoon and evening. Severe storms with a threat of
hail and severe gusts will also be possible across parts of the
south-central High Plains.
...Appalachians into the Mid Atlantic and Northeast...
A vigorous mid/upper-level shortwave trough is forecast to move
across Quebec later today, with weak midlevel height falls forecast
to extend south of this shortwave into parts of the Appalachians,
Northeast, and Mid Atlantic. The strongest deep-layer flow will
remain north of the international border, but modest effective shear
(generally 20-30 kt) will overlap relatively strong heating and
modest buoyancy across parts of the Northeast/Mid Atlantic.
Scattered outflow-driven clusters may develop with time and move
eastward, with an attendant threat of damaging wind and perhaps
isolated hail.
Deep-layer flow/shear will be even weaker into parts of the southern
Mid Atlantic/Carolinas vicinity. However, very strong heating of a
moist airmass will support potential for scattered thunderstorms
with downburst potential, and eventual evolution into loosely
organized clusters capable of damaging outflow winds from afternoon
into at least the early evening.
...South-central High Plains vicinity...
Moist southerly low-level flow beneath steepening midlevel lapse
rates will result in robust destabilization from the Raton Mesa
vicinity into the adjacent south-central High Plains, with MLCAPE
increasing to near/above 2000 J/kg by late afternoon. Modest
westerly mid/upper-level flow will support effective shear of 30-35
kt, conditionally supportive of organized convection. Large-scale
ascent will remain subtle, but eventual storms may develop by late
afternoon near the higher terrain, and spread east-southeastward
with time.
Initial storms could evolve into isolated supercells, with a threat
of hail, localized severe gusts, and possibly a tornado.
Consolidating outflow and a nocturnally strengthening low-level jet
will support some upscale growth during the evening, with an
attendant severe-wind threat expected to spread across parts of the
south-central High Plains.
Farther south, more isolated strong to severe storms will be
possible across parts of central/eastern NM into Far West TX, with a
threat of isolated hail and localized severe gusts.
...Upper Midwest...
Relatively low-topped convection may develop late this afternoon
from the eastern Dakotas into MN, as low-level lapse rates steepen
beneath seasonably cool temperatures aloft. Robust
west-northwesterly flow aloft will conditionally favor some storm
organization, if sufficient buoyancy can develop. However, most
guidance depicts MLCAPE generally below 500 J/kg, with an
inconsistent signal for where the deepest convection might develop.
Some threat for marginal hail and/or locally damaging wind could
evolve across some part of this region, and probabilities may be
needed if confidence increases regarding sufficient destabilization
and storm coverage.
...Parts of NE into western IA...
Elevated convection may develop late in the period from parts of NE
into western IA, within a warm-advection regime to the north of a
warm front. Guidance continues to vary regarding the magnitude of
elevated moistening/destabilization (which may be affected by MCS
development to the south across KS) and coverage of storms prior to
the end of the forecast period. Effective shear will be sufficient
for at least modest storm organization and an isolated hail threat,
if sufficient destabilization can occur. The aforementioned
uncertainties and likely very late timing of any severe threat
preclude the addition of hail probabilities at this time.
...Parts of OK/north TX...
In the wake of morning convection, robust redevelopment cannot be
ruled out across parts of OK/north TX, near a outflow-influenced
surface boundary. Guidance varies substantially regarding the
coverage/location of storms through mid morning, resulting in
considerable uncertainty. Moderate to strong buoyancy and modest
deep-layer shear could result in localized hail/wind potential, but
confidence in boundary placement and diurnal storm coverage is too
low for probabilities at this time.
..Dean/Weinman.. 06/12/2026
Read more
SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1257 AM CDT Fri Jun 12 2026
Valid 131200Z - 141200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN
KANSAS INTO WEST-CENTRAL ILLINOIS...
...SUMMARY...
One or two evolving thunderstorm clusters appear possible across
parts of the central Great Plains and lower Missouri Valley vicinity
Saturday afternoon through Saturday night, accompanied by potential
for strong, damaging wind gusts. Large to very large hail may also
occur early in storm development from Kansas into Iowa.
...Mid-MS Valley into KS/OK...
Generally low-amplitude mid/upper flow will extend across the
central/southern Plains to the Mid-MS Valley area initially Saturday
morning as the region is sandwiched between an upper trough over the
Upper Midwest and the northern periphery of upper ridging across the
Southeast. As the Upper Midwest trough modestly deepens and pivots
east, some strengthening of mid and upper westerly flow is forecast.
At the surface, southerly low-level flow will transport rich
boundary layer moisture northward across OK/KS into the Mid-MS
Valley ahead of northeast to southwest oriented cold front. Steep
midlevel lapse rates atop this moist airmass will support a corridor
of moderate to strong instability (2500-4000 J/kg MLCAPE) across KS,
MO into southern IA and perhaps IL.
Some uncertainty remains regarding possible ongoing convection
across parts of northeast OK/southeast KS early Saturday morning in
the form of a decaying MCS from the Day 1/Friday period. It is
possible an MCV associated with this feature could move across MO
during the day and pose some severe risk toward the MS River by
afternoon. However, confidence in this scenario is low given low
predictability of mesoscale feature at this time scale.
Confidence is somewhat higher that convection will develop during
the afternoon in the vicinity of the surface front from eastern KS
into IA. Initial supercells appear possible. Low-level shear will be
modest, but given rich boundary layer moisture and strong
instability, a couple of tornadoes are possible. More likely, a
large to very large hail risk will be possible with initial
supercells given steep midlevel lapse rates, strong instability and
elongated/straight forecast hodographs. As the surface front
develops southeast during the late afternoon into the evening, one
or more bowing MCSs are expected to develop, posing a risk for
scattered severe/damaging winds (isolated gusts to 70-80 mph will be
possible). This activity should continued southeast across the Lower
MO Valley toward the Ozarks vicinity through evening/overnight. The
northward extent of greater severe potential is uncertain, and this
portions of the outlook may need further refinement in subsequent
outlooks.
...Lake Michigan Vicinity...
Isolated thunderstorms are expected during the afternoon and early
evening along the advancing cold front. Cool temperatures aloft will
support steep midlevel lapse rates atop low 60s F boundary layer
moisture. This will foster MLCAPE values around 1500-2000 J/kg.
Isolated hail and gusty winds will be possible with these storms.
...Southern Plains vicinity...
A surface dryline will extend from southwest KS into eastern NM on
Saturday. Forecast guidance depicts a shortwave impulse ejecting
across the southern Rockies ahead of a western U.S. upper trough. As
this occurs, isolated to scattered storms will develop near the
surface boundary. This activity will likely be higher-based given
deep mixing and strong heating into the 90s. Isolated strong wind
gusts will be the main hazard with this activity, though a few
instances of hail also are possible.
..Leitman.. 06/12/2026
Read more
SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0153 AM CDT Fri Jun 12 2026
Valid 141200Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE MID-ATLANTIC REGION...
...SUMMARY...
Isolated severe thunderstorms are expected across portions of the
Mid-Atlantic on Sunday.
...Synopsis...
An upper shortwave trough will pivot across the Great Lakes to the
Northeast on Sunday. As this occurs, a belt of enhanced
southwesterly deep-layer flow will overspread much of the
northeastern U.S. At the surface, a cold front will be oriented from
Ohio to the Mid-South, then westward into north/central TX by
mid/late afternoon. A seasonally moist airmass will be in place
ahead of the front. Pockets of moderate to strong instability will
develop across parts of the southern Plains vicinity as the cold
front develops southward through the period. Additional areas of
moderate to strong destabilization are possible across the
Mid-Atlantic vicinity.
...Mid-Atlantic...
Currently, the best overlap of enhanced west/southwesterly shear and
MLCAPE near 2000 J/kg appears to be across the Mid-Atlantic from
eastern VA into southeast PA/southern NJ within a moist axis and
pre-frontal surface trough. Scattered thunderstorms may develop
within this area during peak heating and pose a risk mainly for
damaging gusts. Stronger southwesterly flow aloft is expected with
northward extent into PA/NY and portions of New England. However,
degree of destabilization is uncertain due to cloud cover and
possible remnant convection over the Ohio Valley from the Day
2/Saturday period moving across the Upper Ohio Valley early in the
period ahead of the surface cold front. Depending on model trends
and mesoscale details emanating from prior day convection, severe
probability could be adjusted northward in subsequent outlooks.
...Southeast NM into the ArkLaTex...
Convection will develop near the southward-advancing surface front
during the afternoon within a very moist and moderately unstable
airmass. Convection may tend to be anafrontal, and storms could
quickly become undercut by the front. Nevertheless, isolated strong
gusts and hail will be possible with stronger storms.
..Leitman.. 06/12/2026
Read more
Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0236 AM CDT Fri Jun 12 2026
Valid 151200Z - 201200Z
...DISCUSSION...
...Days 4-5/Mon-Tue...
A surface front will remain across south TX and the Gulf Coast
vicinity while broad upper troughing persists east of the Rockies.
As a result, severe potential is expected to remain limited as any
deep Gulf moisture and stronger instability will remain well removed
from any stronger mid/upper flow associated with the upper trough.
...Days 6-7/Wed-Thu - Southern Plains to Midwest...
A mid/upper shortwave trough will move from the northern Rockies to
the MS Valley on Wednesday, and the OH Valley to the Northeast on
Thursday. Deepening surface low pressure will shift from the central
Plains to the Northeast and southwesterly deep-layer flow increases.
This will result in northward transport of Gulf moisture into the
Plains/Midwest on Wednesday, and the Northeast by Thursday. This
could result in increasing severe potential for portions of these
regions. Currently, capping across the Plains my limit storm
coverage across that region on Wednesday. Furthermore, timing of
greater moisture return across the Midwest ahead of a surface cold
front is uncertain. Severe probabilities may be needed eventually,
but uncertainty remains too high to introduce unconditional
probabilities at this time.
...Day 8/Fri...
Upper ridging is expected to develop over the Rockies into the
Plains by the end of the forecast period. Meanwhile, upper troughing
will pivot northeast across New England. Some guidance suggests a
shortwave impulse could eject from the Rockies into the central
Plains within the broader scale upper ridging. This could support
some severe potential, but overall predictability is low given large
model spread.
Read more
