RSS Mesoscale Discussions from Storm Prediction Center
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1130 AM CDT Sat Jul 11 2026
Valid 111630Z - 121200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM OKLAHOMA INTO
THE LOWER MISSISSIPPI VALLEY/TENNESSEE VALLEY AND SOUTHEAST...AND
ACROSS SOUTHERN ARIZONA...
...SUMMARY...
Thunderstorms capable of producing scattered severe/damaging winds
will be possible this afternoon and evening from parts of the
southern Plains eastward into the lower Mississippi Valley and
Southeast. Scattered severe wind gusts are possible over southern
Arizona late this afternoon through the evening.
...Southern Plains/Ozarks into the Tennessee Valley/Southeast and
Mid-Atlantic...
Weak mid-level troughing with multiple embedded and convectively
enhanced vorticity maxima (i.e., several MCVs evident in radar
mosaic/satellite imagery) will advance slowly eastward across the
mid MS Valley into the lower OH Valley/Midwest and TN Valley and
southern Appalachians. A developing thunderstorm cluster over the
Upstate of SC will likely move east towards the Carolina coast later
today. Ahead of this cluster, strong heating with temperatures
warming into the 90s with lower to mid 70s F dewpoints will result
in a moderately unstable airmass. Westerly low-level flow will
imply the wind risk will likely overspread the coast.
Isolated damaging winds may also occur farther north along/near a
weak synoptic front, but less instability is forecast with northward
extent into the OH Valley and Mid-Atlantic.
Farther west, several clusters may evolve across the Mid South with
damaging gusts the primary severe hazard. Visible-satellite imagery
shows an MCV over northwest OK moving east. The airmass south of a
stalled frontal zone will undergo strong heating via clear skies
through mid afternoon. Short-term model guidance (HREF, HRRR-RRFS
time-lagged ensemble) show scattered storms developing across
north-central OK by 21-23 UTC. A well-mixed boundary layer will
support strong evaporatively cooled downdrafts capable of severe
gusts with the more intense single and multicells. Have expanded
the Slight Risk to account for this increased confidence in a severe
threat across central OK.
...Southern Arizona...
With a mid-level anticyclone centered over the Four Corners, a weak
easterly mid-level flow regime is present today across the Sonoran
Desert. Very strong heating will result in a deeply mixed boundary
layer and this was depicted on the 12 UTC Phoenix raob, with an
accompanying 11.6 g/kg lowest 100-mb mean mixing ratio. Forecast
soundings show 20-kt easterly flow in the mid levels atop weak
westerly surface flow. Very steep low- to mid-level lapse rates and
inverted-V thermodynamic profiles will strongly favor evaporatively
cooled downdrafts with the more intense cores. Severe gusts 60-80
mph appear likely with the stronger microbursts. This activity will
likely transition from a few cells into an outflow-dominant cluster
during the evening and coincide with a greater prevalence of severe
gusts. Isolated hail may also occur with the stronger cores.
..Smith/Chalmers.. 07/11/2026
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
1235 PM CDT Sat Jul 11 2026
Valid 121200Z - 131200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF EASTERN
GEORGIA INTO THE CAROLINAS...PARTS OF CENTRAL ARIZONA...
CORRECTED FOR WORD USAGE
...SUMMARY...
Scattered strong-to-severe thunderstorms capable of producing wind
damage will be possible across much of the Southeast on Sunday, with
the greatest potential across South Carolina. Additional
strong-to-severe thunderstorms will be possible across portions of
Arizona late Sunday afternoon into Sunday night.
...Portions of Carolinas into eastern Georgia...
An upper-level trough will continue to slide eastward north of these
regions. A belt of stronger mid-level flow will be present across
portions of the Carolinas, though winds will weaken with
southwestward extent. A modest surface low is expected to develop
along a stationary surface boundary. Scattered convection is
possible during the afternoon within the very moist airmass south of
the boundary. The most organized storms may exist along the boundary
within North Carolina where shear will be stronger. However, surface
heating may be more muted in this area. Stronger heating is more
probable farther southwest, though shear will be weaker. Where the
most favorable parameters overlap, scattered storms along with a few
clusters will be capable of wind damage.
...Arizona...
Model guidance continues to suggest that around 30 kt of mid-level
easterly winds will persist into Sunday across the Mogollon Rim.
Strong heating of the lower deserts along with greater moisture
moving farther northwest will support widely scattered to scattered
convection. Severe wind gusts will be possible with this activity
during the late afternoon and early evening.
...Upper Great Lakes...
Mid to upper 60s F dewpoints and steep mid-level lapse rates will
support 2500-3000 J/kg MLCAPE by the afternoon. A passing shortwave
trough to the northeast will promote moderate effective shear of
35-45 kt. With the upper ridge building in from the west, mid-level
heights will be steadily rising through the period. This leads to
uncertainty as to how many storms can form. The lake breeze
boundaries present would likely be the focus for development. The
environment would support large hail, damaging winds, and perhaps a
tornado with a sustained supercell. Storm coverage precludes any
upgrade in risk category, though storms could be intense if they
form.
...Southern Plains into Southeast...
Marginally severe storms are possible along and south of a stalled
surface boundary. Afternoon buoyancy will be moderate to strong, but
mid-level lapse rates and shear will generally be weak. Any greater
threat for damaging winds will be tied to where organized clusters
can form.
..Wendt.. 07/11/2026
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0232 PM CDT Sat Jul 11 2026
Valid 131200Z - 141200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF
SOUTH CAROLINA INTO CENTRAL GEORGIA AND FAR NORTH FLORIDA...
...SUMMARY...
A few strong-to-severe storms will be possible from South Carolina
into central Georgia and far North Florida on Monday.
...Southeast...
A weak, cut-off upper low will likely be present in the vicinity of
the Tennessee Valley/southern Appalachians. This may help to
organize storms along a stalled surface boundary within GA/SC. A
moist airmass will promote a few stronger storms capable of wind
damage. The overall threat does appear marginal as lapse rates will
be less steep than previous days.
...Arizona...
With at least 50s F dewpoints remaining within parts of Arizona,
thunderstorm activity can again be expected during the afternoon.
With mid-level flow being slightly more out of the southwest and
weakening with time, it is not certain how strong storms will become
and how many will move into the lower deserts. Even so, strong gusts
will be possible given the inverted-v thermodynamic profiles.
...Southwest Montana...
Models show a convective signal during the late afternoon within the
higher terrain of southwest Montana. Due to cloud cover, buoyancy
will not likely be very strong. Stronger flow aloft would allow for
isolated, organized storms should heating be greater than forecast.
..Wendt.. 07/11/2026
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