RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1248 AM CDT Fri Jul 10 2026
Valid 101200Z - 111200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN AND CENTRAL HIGH PLAINS...AND FROM THE OZARKS INTO THE
MID MISSISSIPPI VALLEY...
...SUMMARY...
Thunderstorms with severe wind gusts and isolated large hail will be
possible this afternoon and evening across parts of the southern and
central High Plains. Severe gusts will also be possible from the
Ozarks and mid Mississippi Valley eastward into the southern and
central Appalachians, and over the western Florida Peninsula.
...Southern and Central High Plains...
At mid-levels, a shortwave ridge will be build northeastward into
the north-central U.S. today as a trough moves through the central
Plains. At the surface, a moist airmass will be in place over the
central Plains. Low-level convergence will become maximized this
afternoon from eastern Colorado southward into northeast New Mexico.
As surface heating takes place, thunderstorms will form in the
higher terrain near this convergence axis, and move eastward into
the central and southern High Plains. Moderate deep-layer shear and
steep low to mid-level lapse rates will support a threat for severe
wind gusts and isolated large hail. The threat may be greatest near
the southern edge of the moist airmass from far southeast Colorado
and southwest Kansas into the northern Texas Panhandle, where strong
moisture convergence is forecast during the early to mid evening.
...Ozarks/Mid Mississippi Valley...
A very moist airmass will be in place today across the central U.S.,
where surface dewpoints will be mostly 70s F. As surface
temperatures warm, moderate to strong instability will develop near
a moist axis extending west-to-east from the Ozarks into the mid
Mississippi Valley. Low-level convergence is expected to become
maximized this afternoon along and south of the moist axis. MLCAPE
in the 2500 to 3500 J/kg range combined with steep low-level lapse
rates will support a potential for severe wind gusts with any short
line segment that can become organized. The severe threat is
expected to be greatest during the late afternoon and early evening,
coincident with the maximum in instability.
...Southern and Central Appalachians...
A subtle mid-level shortwave trough will move eastward into the
southern and central Appalachians today. As surface temperatures
warm, moderate instability will develop over much of the region by
afternoon. Topographic forcing and subtle large-scale ascent near
the shortwave trough will support isolated to scattered convective
development. Thunderstorms will form in the higher terrain and move
eastward into the lower elevations during the afternoon. The
instability and steep low-level lapse rates will support isolated
severe gusts with the stronger multicells.
...Western Florida Peninsula...
Very moist air will be in place over the Gulf today, where surface
dewpoints will be in the 70s F. As temperatures warm, a sea breeze
boundary is expected to form near the coast of western Florida
around midday. Thunderstorms will develop along this boundary as the
it moves inland during the afternoon. Moderate instability and steep
low-level lapse rates will support a few severe gusts.
...Eastern South Dakota/Southwest Minnesota...
An axis of low-level moisture will be in place today from Iowa
north-northwestward into southwest Minnesota and eastern South
Dakota, where surface dewpoints will be in the 60s F. As surface
temperatures warm, moderate instability will develop along the moist
axis. Although low-level convergence is expected to remain weak, a
storm or two associated with a marginal hail threat could develop
and move southeastward along the instability axis in the late
afternoon and early evening.
..Broyles/Halbert.. 07/10/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1258 AM CDT Fri Jul 10 2026
Valid 111200Z - 121200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE OZARK
PLATEAU INTO THE TENNESSEE VALLEY...
...SUMMARY...
Severe storms capable of damaging winds will be possible from the
Ozark Plateau east into the Tennessee Valley. Surrounding this area,
strong to severe storms capable of sporadic occurrences of damaging
wind will be possible from the southern High Plains east toward to
the Mid-Atlantic and Carolinas Saturday afternoon and evening.
Isolated severe storms are also possible in southern Arizona.
... Synopsis ...
A strong midlevel ridge is expected to continue to build northward
across the West on Saturday. Downstream of this ridge, a
convectively augmented vorticity maximum is expected to be moving
east-southeast across the Mid-Mississippi Valley and into the
Tennessee Valley. Farther east, a mid-level short-wave trough will
be moving across New England and out over the Atlantic Ocean.
At the surface, a weakening cold front will stretch from far
southern New England west into the central US at the start of the
period. This front will slowly move south during the day, across the
Mid Atlantic and into the Tennessee Valley and Southern Plains. As
the aforementioned convectively augmented vorticity maximum across
the central US interacts with the residual surface front, weak
cyclogenesis may occur across the Mid-Mississippi Valley.
... Ozark Plateau into the Tennessee Valley ...
By afternoon, temperatures are expected to warm into the mid-90Fs
with dewpoints ranging from the mid 60Fs into the low 70Fs. This
should yield an unstable environment, with MUCAPE values between
1500-3000 J/kg. Thunderstorms are expected to develop along the
surface boundary during the afternoon. Deep layer shear is generally
expected to be on the order of 20-25 knots across the area, which
should support multicell clusters growing upscale into southward
moving bowing segments capable of producing damaging winds. Given
precipitable water values around 2 inches and mean sub-cloud layer
relative humidity around 40-50 percent, there is some potential for
a couple of significant wind gusts associated with strong cold pool
generation.
... Central and Southern Plains ...
Similar to areas farther east, temperatures will warm into the
mid-to-upper 90Fs with dewpoints in the mid-60Fs to low-70Fs
yielding MUCAPE values in the 1500-3000 J/kg range. Thunderstorms
should develop during the late afternoon along the surface boundary.
High precipitable water values (generally around 1.75 to 2 inches),
DCAPE values between 1000-1500 J/kg, and sub-cloud layer mean
relative humidity between 30-40 percent will support the potential
for strong, damaging outflow winds -- some potentially significant.
A few occurrences of large hail will also be possible given the
degree of instability and modest mid-level lapse rates.
Confidence in the location of where the surface boundary will
initiate is lower than areas farther east, which yields lower
confidence in adding higher wind probabilities. A Level 2/Slight
Risk may be needed in later outlooks if confidence in the number and
location of storms increases.
... Mid-Atlantic into northern Florida ...
Convergence along the southward moving front and the preceding lee
trough should allow for scattered thunderstorm development during
the afternoon. Although vertical shear is expected to remain
generally less than 25 knots, a moderately unstable environment
coupled with high precipitable water values (around 2 inches) should
support strong to potentially damaging downbursts.
... Southern Arizona ...
East/northeast mid-level flow is forecast to strengthen slightly on
Saturday to the south of the upper high, resulting in a belt of
deep-layer shear on the order of 30 knots. A moist and unstable
airmass across southern Arizona will support scattered thunderstorm
development. As these storms move west, the strengthening flow/shear
will support a few strong to briefly severe storms capable of
locally damaging wind gusts.
..Marsh.. 07/10/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0229 AM CDT Fri Jul 10 2026
Valid 121200Z - 131200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF
THE SOUTHEAST AND PORTIONS OF ARIZONA...
...SUMMARY...
Scattered strong-to-severe thunderstorms capable of producing wind
damage will be possible across much of the Southeast on Sunday.
Additional strong-to-severe thunderstorms will be possible across
portions of Arizona late Sunday into Sunday night.
... Synopsis ...
The western ridge will continue to build northward on Sunday, with
the highest 500-mb heights (nearing 600 dam) becoming centered over
the Dakotas. To the south and east of this substantial ridge,
ensemble guidance has a highly-positively tilted trough, with
perhaps an embedded closed low, across the Tennessee and Lower
Mississippi Valleys.
At the surface, a weak boundary will stretch from west-to-east from
the Southern Plains into the Southeast. The exact location of this
boundary will be highly influenced by repeated rounds of convection
the prior two days.
... Southeast ...
A very moist airmass will remain in place across the region with
surface dewpoint temperatures in the 60Fs and 70Fs and precipitable
water values around 2 inches likely to the south of the surface
boundary. As diurnal heating occurs, scattered thunderstorms should
once again develop along the residual surface boundary. Despite the
proximity of a closed low/positively tilted trough, vertical wind
shear will be generally less than 20 knots. The result will be
scattered single cell and clusters of multicell thunderstorms
capable of producing strong to perhaps damaging downbursts.
... Arizona ...
Modest easterly mid-level flow will persist across Arizona on Sunday
as the region remains south of the closed mid-level high over the
northern US. At the surface, southerly to westerly winds will
combine with this mid-level flow to support around 30 knots of
deep-layer shear. Model guidance shows a seasonably moist airmass in
place across much of southern and western Arizona, with surface
dewpoints rising into the upper-50Fs to mid-60Fs. The warm, moist
environment in place will support afternoon thunderstorm development
across the favored higher terrain of the Mogollon Rim. The
deep-layer flow should support at least a few of these storms moving
west, off the terrain. Steep low-level lapse rates will support
strong downward momentum transport capable of producing damaging
wind gusts with any thunderstorm.
..Marsh.. 07/10/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0359 AM CDT Fri Jul 10 2026
Valid 131200Z - 181200Z
...DISCUSSION...
Ensemble guidance continues to indicate that the western US
mid-level ridge will build into the north-central US during the
first part of the forecast period. Toward the middle and end of the
week, this ridge should retrograde westward as a series of mid-level
troughs move across the apex of the ridge in central Canada. One
particularly strong trough will impact New England on Tuesday into
Wednesday.
... Tuesday/Day 5 ...
GEFS and EPS ensemble guidance is in remarkably good agreement that
a strong short-wave trough will approach New England during the day
on Tuesday and move across the region Tuesday night. Ahead of this
trough, both ensemble systems have mean surface temperatures in the
70Fs and 80Fs with surface dewpoints in the mid-to-upper-60Fs across
much of the area. The result will be MUCAPE values in the 1000-2000
J/kg range amidst seasonably strong vertical shear. Supporting this
are ensemble probabilities greater than 50 percent for the supercell
composite index to be greater than 1.
As the trough approaches New England, the expectation is for one or
more clusters of storms to develop during the afternoon across
portions of Quebec and move into and then across New England during
the late afternoon into evening/overnight hours. Although there is
some spread within the ensemble regarding the timing of the wave
moving across the area, with solutions ranging from afternoon to
overnight, the overall environment should remain favorable for
damaging thunderstorm winds to occur, even into the early overnight
hours.
... Friday/Day 8 ...
Ensemble guidance is beginning to suggest some severe potential
across portions of the Ohio Valley into the Mid-Atlantic region.
This area is forecast to be on the eastern periphery of the strong
western US ridge and near the basal region of a long-wave trough
across eastern Canada and New England. Surface temperatures are
expected to range from the upper-80Fs to mid-90Fs with surface
dewpoint temperatures in the 60Fs. Parcel trajectories around the
western ridge do not favor much in the way of an elevated mixed
layer, so scattered thunderstorm development is likely. The
magnitude of the severe potential will likely rest on the strength
of the deep-layer shear and the number of storms.
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