RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Wed Jul 29 12:50:02 UTC 2026.
No Mesoscale Discussions are in effect as of Wed Jul 29 12:50:02 UTC 2026.
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0746 AM CDT Wed Jul 29 2026
Valid 291300Z - 301200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTHEAST AND NORTHERN HIGH PLAINS...
...SUMMARY...
Thunderstorms with severe wind gusts and hail will be possible this
afternoon and evening in the northern Plains. Severe wind gusts will
also be possible today across southern Georgia and northern Florida,
as well as the Great Basin/northern Intermountain West.
...Southeast States...
Near the base of the extensive eastern CONUS trough, a cold front
will slowly spread southward/stall regionally, with a moist and
unstable air mass to its south. Surface dewpoints in the 70s F will
contribute to an axis of strong instability by afternoon, with
MLCAPE likely reaching 3000+ J/kg with steep low-level lapse rates.
Damaging winds will be possible with the stronger storms, which
could include the development of some semi-organized clusters into
late afternoon/early evening.
...Northern Plains/Upper Midwest...
An approaching disturbance and weak height falls will develop into
the region later today, interfacing with an east-southeastward
moving front and somewhat sharpening the regional lee trough ahead
of it. Surface dewpoints in the mid to upper 50s F will contribute
to moderate instability as surface temperatures diurnally warm.
Low-level convergence along the front/lee trough will aid convective
initiation, with scattered thunderstorms moving eastward
across the western Dakotas during the late afternoon and early
evening. Large hail can be expected, and the high-based storms will
be capable of severe-caliber wind gusts, especially if storms
aggregate and cluster into the evening.
Farther east, a more conditional-type threat will exist diurnally
into northern Minnesota within a very unstable environment, but it
is a bit more probable that widely scattered storms develop into the
region tonight. If so, a few severe storms capable of wind/hail
could occur.
...Great Basin/northern Intermountain West...
A northeastward-transitioning shortwave trough and speed max, along
with diurnal heating, will influence thunderstorm development across
the region, including portions of southern/eastern Idaho and nearby
portions of northeast Nevada, northern Utah and southwest Montana.
Modestly enhanced mid-level winds and sufficient buoyancy/steep
lapse rates will support the potential for a few severe storms
capable of severe-caliber wind gusts and possibly some hail.
...Coastal southern New England...
Bands of semi-organized convection will move toward the coast
through the afternoon, preceding the offshore surface low/triple
point. Some stronger storms could materialize toward the coast with
gusts given the strengthening low-level winds, but current thinking
is the primary warm sector should remain offshore and limit the
severe potential.
..Guyer/Wendt.. 07/29/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0339 AM CDT Wed Jul 29 2026
Valid 011200Z - 061200Z
...DISCUSSION...
...Day 4/Saturday...
A short-wave trough will progress from the mid MS into lower OH
Valleys with modest height falls forecast across the Gulf Coast
states. At the surface, an area of low pressure will follow the same
track as the upper-air system, while a trailing cold front advances
through the lower MS and TN Valleys. While weaker than on Friday, a
modest enhancement of 850-mb winds is forecast during the afternoon
ahead of the surface low over the OH and TN Valleys.
Morning storms appear possible from the lower OH into lower MS
Valleys within a zone of warm advection associated with a nocturnal
low-level jet. The longevity and extent of early-day storms remain
uncertain, but where stronger heating can occur, the presence of
boundary-layer dewpoints in the 70s will contribute to pockets of
moderate instability. Additional storms are anticipated during the
afternoon, focused along the cold front and any residual outflow
boundaries from previous storms. Deep-layer shear is expected to
remain generally less than 30 kt, which will tend to limit the
potential for organized storm modes. A possible exception is across
parts of KY and TN where slightly stronger low-level shear could
contribute to updraft rotation and some tornado risk. Otherwise,
locally damaging wind gusts appear to be the primary hazard.
Isolated severe storms capable of mainly damaging winds and hail
appear possible over the southern High Plains Saturday afternoon and
evening within a moist and unstable upslope regime.
...Days 5 and 6/Sunday and Monday...
The models remain in relatively good agreement in depicting a strong
short-wave trough and attending belt of mid-level flow progressing
along the international border from the northern Rockies into the
northern Plains. Low-level ridging from the Great Lakes into
southern Plains may disrupt the return of robust boundary-layer
moisture ahead of a cold front moving through the northern Plains
into the upper MS Valley. Nonetheless, the presence of steep lapse
rates and strengthening vertical shear along the frontal zone will
support some severe weather risk over the northern Plains on Sunday
and the northern Plains into the upper MS Valley on Monday.
An isolated severe storm threat may also develop along the East
Coast on Sunday, ahead of a positively tilted trough moving through
the Great Lakes and OH and TN Valley.
...Days 7 and 8/Tuesday and Wednesday...
The 00Z ensemble means indicate a belt of modestly enhanced
mid-level flow from the northern Rockies into the Great Lakes,
between a trough over Hudson Bay and a flattened ridge across the
Southwest. Some severe weather threat may materialize over the
central High Plains along and to the north of a stalled front, and
perhaps in AZ if stronger easterly flow can develop on the south
side of the upper high.
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