RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1250 AM CDT Sun Jul 05 2026
Valid 051200Z - 061200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE
MID-ATLANTIC AND NORTH DAKOTA SUNDAY AFTERNOON AND EVENING...
...SUMMARY...
Scattered wind damage is possible with thunderstorms across the
Mid-Atlantic Sunday afternoon and evening. Large to very large hail
may occur with thunderstorms in North Dakota with more sporadic
occurrences of hail and damaging winds from the southern High Plains
into the Tennessee Valley and in parts of the northern Rockies.
...Synopsis...
A series of weak mid-level disturbances (some of convective origin)
will contribute modest trough amplification from the OH Valley into
the TN and lower MS Valleys on Sunday while another disturbance
approaches the Mid-Atlantic from the west. Elsewhere, a short-wave
trough and associated 50+ kt mid-level jet streak will move through
southern parts of British Columbia and Alberta with downstream
height falls overspreading the northern Rockies into northern High
Plains.
At the surface, a weak front is forecast to become established from
an area of low pressure over OH into the DE River Valley. A
secondary surface low may materialize over the Delmarva near the
intersection of the front and a lee trough extending south-southwest
into the Carolina Piedmont. Farther west, a cold front will settle
southeast into the northern High Plains.
...Upper Ohio Valley into Mid-Atlantic and the Carolinas...
A hot and very moist air mass is expected to exist from the vicinity
of the surface front in eastern PA and NJ south along the lee trough
into the Carolinas with MLCAPE increasing to 1500-3000+ J/kg.
Convergence near the surface low and attending boundaries may be
augmented by weak forcing for ascent ahead of a subtle short-wave
trough to yield scattered thunderstorm development by early to mid
afternoon.
The strongest deep-layer shear of 30-35 kt is forecast in the
vicinity of the surface front in eastern PA and NJ, where episodic
supercell structures are possible with an attendant risk for
marginally severe hail and damaging winds. Otherwise, the
expectation is for pulse-type and multicell storms to merge into
clusters or line segments with the hot, well-mixed PBL and
resultant, steep low-level lapse rates enhancing damaging wind
potential from mid afternoon into evening.
Damaging wind potential is expected to be more sporadic with
southward extent into the Carolinas owing to decreased vertical
shear and forcing for ascent.
Farther west in the upper OH Valley, a remnant MCV may focus an
additional cluster of afternoon thunderstorms near the surface low
and associated front. Both vertical shear and instability are
expected to be weaker than the segment of the front nearer to the
Mid-Atlantic Coast. Nonetheless, some 00Z CAM guidance suggests the
potential for brief cold-pool organization with an associated risk
for locally damaging wind gusts.
...Northern Rockies into the Northern Plains...
Modest height falls are forecast Sunday afternoon into evening to
the east and southeast of the short-wave trough mentioned in the
synopsis. And while the boundary-layer is forecast to remain
relatively dry ahead of the cold front, the presence of steep
low/mid-level lapse rates will largely contribute to pockets of
moderate instability with MLCAPE as high as 1500-2000 J/kg in parts
of northern ND.
Widely scattered thunderstorms are expected by mid afternoon in the
vicinity of the front in southwest MT with additional storms
expected by late afternoon or early evening along the boundary in
western into north-central ND. The MT storms are expected to be high
based atop a well-mixed boundary layer with severe wind gusts being
the predominant hazard. Stronger instability and vertical shear are
forecast in ND, leading to the potential for a few supercells
capable of large to very large hail.
...Southern Plains into Gulf Coast States and Tennessee Valley...
One or multiple outflow boundaries remnant from overnight convection
are expected to focus diurnally enhanced thunderstorms from portions
of the TN and lower MS Valleys into the Red River Valley Sunday
afternoon and early evening. In addition, the models indicate an MCV
originating from a large MCS ongoing as of late evening from
southwest MO into southeast OK and northeast TX will move into the
lower MS Valley by afternoon, potentially aiding in the thunderstorm
development there. The steepest lapse rates are forecast across the
southern High Plains with increasing boundary-layer moisture content
into the lower MS and TN Valleys, both of which will contribute to a
moderately unstable environment by afternoon across the pre-frontal
warm sector.
Vertical shear is expected to remain relatively weak across the warm
sector, which should limit the potential for storm organization. A
possible exception is if the outflow boundary stalls or retreats
into southern OK in closer proximity to stronger northwest flow
aloft. In that scenario, a corridor of higher supercell potential
could materialize, requiring higher hail probabilities and a level
2/Slight Risk. Aside from that scenario, pulse and multicell storms
appear likely with a risk for sporadic large hail and severe wind
gusts in the steeper lapse rate environment in the southern Plains
with mainly damaging winds expected in the lower MS and TN Valleys.
..Mead/Moore.. 07/05/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1143 PM CDT Sat Jul 04 2026
Valid 061200Z - 071200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS MONDAY INTO
MONDAY EVENING ACROSS PARTS OF THE CENTRAL AND EASTERN DAKOTAS
THROUGH NORTHERN MINNESOTA AND ACROSS PARTS OF THE MID ATLANTIC...
...SUMMARY...
Strong thunderstorm development posing at least some risk for severe
weather is possible across parts of northern Minnesota through the
eastern and central Dakotas, as well as across parts of the Mid
Atlantic, Monday afternoon into evening.
...Discussion...
Downstream of digging large-scale mid-level troughing and an
associated surface cyclone slowly approaching the British Columbia
and Pacific Northwest coast, ridging may become increasingly
prominent across Baja California through the southern Rockies and
central Great Plains during this period. Mid-level heights may tend
to remain steady or slowly rise as far north as the eastern
Montana/North Dakota international border, in the wake of a notable
mid-level trough forecast to progress through northwestern Ontario
and Hudson Bay by late Monday night.
It appears that one vigorous impulse embedded within the troughing,
and forecast to continue accelerating east-northeastward, to the
north of the international border, may provide support for stronger
secondary surface cyclogenesis across the southern Hudson Bay
vicinity by Monday night.
To the east of the mid-level ridging, weak mid-level troughing may
continue to drift slowly east of the Mississippi Valley, toward the
Appalachians.
In association with this evolving regime, the potential for
organized severe thunderstorm activity still appears generally low
and dependent on sub-synoptic developments with rather low
predictability at this time frame. This continues to be reflected
in latest model output, including convection allowing and related
guidance, which exhibit sizable spread concerning potential
convective evolution and locations with higher probabilities for
thunderstorm development.
...Northern Great Plains...
Deeper surface troughing and mid-level height falls are forecast to
pass to the north of the international border through this period.
However, there appears at least some continuing signal in model
output that boundary-layer moisture return to the vicinity of weak
pre-frontal surface troughing, coincident with southeastward
suppression of warmer and more strongly capping elevated mixed-layer
air, could allow for scattered strong thunderstorm development by
late Monday afternoon. If this occurs, moderate to large potential
instability, in the presence of at least modest shear beneath 30-40
kt 500 mb flow, probably will be conducive to storms capable of
producing severe hail and wind, before perhaps tending to be
undercut by a southward advancing cold front trailing the developing
Canadian cyclone.
...Mid Atlantic...
The timing and/or location of highest thunderstorm probabilities
across the region differs notably between the REFS and HREF
calibrated thunderstorm guidance, and deep-layer mean flow and shear
will be rather weak. However, destabilization within broad, weak
surface troughing to the lee of the Blue Ridge might become
sufficient to focus scattered thunderstorm development with
potential to produce localized damaging surface gusts Monday
afternoon into early evening.
..Kerr.. 07/05/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0226 AM CDT Sun Jul 05 2026
Valid 071200Z - 081200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE TUESDAY
THROUGH TUESDAY NIGHT ACROSS PARTS OF CENTRAL AND EASTERN SOUTH
DAKOTA INTO SOUTHWESTERN MINNESOTA...
...SUMMARY...
An organizing cluster of thunderstorms may pose increasing potential
to produce strong to severe wind gusts by late Tuesday evening into
Tuesday night across parts of the middle Missouri Valley toward the
Upper Midwest.
...Discussion...
Models suggest that the westerlies may become a bit less progressive
across the higher latitudes of North America during this period,
with a deep remnant lower/mid-tropospheric cyclone only slowly
migrating east-northeastward across Hudson Bay toward the northern
Quebec shores. Upstream, a notable trough is forecast to only
slowly pivot inland of the British Columbia coast.
In advance of the trailing perturbation, a low-amplitude trough
within modest zonal westerlies across the northern tier of the U.S.
is forecast to progress east of the northern Rockies, and flatten
initial mid-level ridging across the middle Missouri Valley by late
Tuesday night.
Otherwise, mid-level ridging is forecast to remain prominent along
an axis from the subtropical eastern Pacific through the central and
southern Great Plains, while also developing northwestward from the
subtropical western Atlantic into parts of the southeast. A remnant
trough or shear axis will likely linger in between, near/west
through southwest of the southern Appalachians.
...Parts of the middle Missouri Valley into Upper Midwest...
Latest guidance suggests that potential for stronger convective
development may still remain largely influenced by sub-synoptic
developments with rather low predictability at this time frame.
However, there appears a consistent enough developing convective
signal among the various model output to lead to some confidence in
the evolution of an organized convective system across the mid
Missouri Valley vicinity by late Tuesday night.
It appears that stronger pre-frontal daytime heating may focus
moderate to strong destabilization in a corridor roughly across
south central South Dakota toward southwestern Minnesota by late
Tuesday afternoon. Beneath steep lapse rates, surface dew point
increases to around 70F may support mixed-layer CAPE on the order of
2000-3000+ J/kg.
As remnant warm elevated mixed-layer air is suppressed further
southward, the initiation of storms capable of producing severe
hail and wind seems probable by early Tuesday evening. It is
possible that the most substantive upscale growth, intensification
and organization awaits forcing associated with a nocturnal
strengthening low-level jet toward late evening. But, as this
occurs, the environment appears potentially conducive to the
development of a swath of damaging winds as it propagates
east-southeastward Tuesday night.
..Kerr.. 07/05/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0351 AM CDT Sun Jul 05 2026
Valid 081200Z - 131200Z
...DISCUSSION...
In the wake of a short wave trough pivoting inland of the British
Columbia coast by mid week, medium-range guidance continues to
indicate the gradual development of large-scale ridging across the
much of the Intermountain West through Great Plains and Mississippi
Valley late this week through next weekend. It appears that a
center of seasonably high mid-level heights will evolve and develop
northeastward, west through north of the Four Corners, into northern
Colorado by the end of the period. Prior to and as this occurs,
this may be preceded by the transition of a generally zonal to
broadly cyclonic regime across and east of the northern Great Plains
through northern and middle Atlantic Seaboard, but embedded short
wave developments remain rather unclear.
Regardless, it still appears that substantive potential for
organized severe thunderstorm development, if any, will largely
remain influenced by sub-synoptic developments yet to evolve, and of
particularly low predictability at this extended time frame.
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