RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1246 AM CDT Sat Mar 28 2026
Valid 281200Z - 291200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Isolated thunderstorms will be possible this afternoon across the
southern Florida Peninsula and Florida Keys, but no severe threat is
forecast.
...DISCUSSION...
Northwest mid-level flow will continue across much of the central
and eastern U.S. today, as a cold front advances southward across
Florida. Isolated thunderstorms will be possible south of the front
within a moist airmass across parts of south Florida and the Florida
Keys this afternoon. No severe threat is forecast, and no
thunderstorms are expected over the remainder of the continental
U.S.
..Broyles/Chalmers.. 03/28/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1245 AM CDT Sat Mar 28 2026
Valid 291200Z - 301200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Isolated thunderstorms are possible across the southern Florida
Peninsula and portions of southern Arizona/southwest New Mexico
Sunday afternoon and evening. Severe thunderstorms are not expected.
...Synopsis...
Surface high pressure is gradually building across the central CONUS
in the wake of a recent cold frontal passage. Aloft, broad-scale
ridging will gradually shift east from the Southwest towards the
lower MS Valley over the next 24 hours. The combination of dry
conditions behind the front and broad subsidence/height rises will
preclude thunderstorms for most regions. Exceptions to this will
likely be the southern Florida peninsula and portions of Arizona and
New Mexico. 00z soundings from south FL sampled sufficient low-level
moisture for surface-based buoyancy, and further moistening is
anticipated over the next 48 hours. While poor lapse rates and weak
deep-layer shear will modulate thunderstorm intensity, a few
thunderstorms appear possible given negligible capping and localized
ascent within a residual frontal zone. Across southern AZ/NM, an
influx of mid-level Pacific moisture coupled with strong
heating/deep mixing will likely support around 250 J/kg SBCAPE by
late afternoon. Weak ascent ahead of a mid-level disturbance and/or
localized orographic ascent may support a few thunderstorms. Deep
inverted-V profiles may support strong downburst winds, but
thunderstorm coverage will likely be too sparse to warrant
highlights.
..Moore.. 03/28/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0219 AM CDT Sat Mar 28 2026
Valid 301200Z - 311200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE
UPPER MISSISSIPPI RIVER VALLEY AND LAKE MICHIGAN VICINITY...
...SUMMARY...
Isolated strong to severe thunderstorms are possible across portions
of the upper Mississippi River Valley and Lake Michigan vicinity
late Monday night into early Tuesday morning.
...Synopsis...
Zonal flow over the central to northern Rockies is forecast to
increase over the next 48-72 hours as an upper ridge shifts towards
the Southeast and a low-amplitude upper wave begins to translate
along the U.S./Canadian border. Lee cyclone development is
anticipated across the northern High Plains by early Monday with
steady intensification expected as it migrates east ahead of the
upper wave. The deepening surface low will promote northward
moisture return through the MS Valley and into the upper Great Lakes
region while eastward advection of 7-8 C/km mid-level lapse rates
takes place aloft. Thunderstorm development appears probable
overnight across the upper MS Valley and upper Great Lakes region as
isentropic ascent increases along the tightening warm frontal zone
of the cyclone.
Elsewhere, more isolated thunderstorms are possible along the
western FL Gulf coast where sea-breeze ascent within a moist and
weakly capped environment should support a few thunderstorms.
Similarly, isolated convection is possible across parts of the lower
MS Valley within a plume of rich low-level moisture. Another day of
isolated, high-based thunderstorms is expected across portions of
the Southwest. Weak deep-layer wind shear across these regions will
limit severe thunderstorm potential.
....Upper MS Valley/Lake Michigan...
The combination of low-level moistening and steepening lapse rates
aloft will support steady destabilization through Monday and into
Monday night. Model consensus is that 1500-2000 J/kg MUCAPE should
be in place by Monday evening across the southern WI region.
Initially dry and capped low-level profiles will likely preclude
thunderstorm development during the day, though increasing ascent
within the 925-850 mb warm frontal zone should increase thunderstorm
chances during the 00-06 UTC period. While elevated convection
appears likely, hodograph elongation through the CAPE-bearing layer
should support storm organization, including the potential for a
supercell or two. Although storm motions along the frontal zone hint
that some degree of clustering is probable, at least a localized
hail threat should materialize given the favorable buoyancy/shear
environment.
..Moore.. 03/28/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0356 AM CDT Sat Mar 28 2026
Valid 311200Z - 051200Z
...DISCUSSION...
A return to a more seasonal upper-level regime will promote
strong/severe thunderstorm chances beginning D4/Tuesday and
potentially persisting into the upcoming weekend. A well-anticipated
upper-level regime shift remains likely late this weekend and into
early next week as an upper ridge over the south-central CONUS
de-amplifies and shifts east. The return to mean troughing over the
West will promote persistent lee troughing and southerly return flow
into the Plains and lower MS Valley. Long-range guidance depicts
several upper disturbances propagating across the northern and
central U.S. through late week, which may each support some risk of
strong/severe thunderstorms.
...D4/Tuesday...
A low-amplitude upper wave is forecast to traverse the U.S./Canadian
border and into the Great Lakes region Monday into Tuesday.
Northeastward moisture return ahead of an intensifying surface
cyclone and trailing cold front will likely establish a fairly broad
warm sector from the Ozarks into the Midwest/Great Lakes region.
Thunderstorm development along the cold front is expected by late
afternoon with most deterministic and ensemble guidance showing
strong QPF signals. Any severe weather threat will likely be focused
from central IL northeastward into northern IN/southern MI where
deep-layer wind shear will be stronger in proximity to the upper jet
and shear vectors should be more orthogonal to the front. While some
solutions depict favorable MLCAPE and shear for organized convection
(e.g. the 00z GFS), ensemble consensus shows muted probabilities for
a highly favorable convective environment (e.g. recent GEFS depicts
less than 20% probability for SCP values above 3). This suggests
that even though some severe threat will likely materialize,
considerable uncertainty remains regarding the quality of the
convective environment.
...D5/Wednesday and D6/Thursday...
Tuesday's cold front is expected to stall roughly along or south of
the OH River by the afternoon of D5/Wednesday. This will maintain a
moist warm sector across the southern Plains eastward to the TN
Valley. Strong to severe thunderstorm potential may emerge on
D5/Wednesday and D6/Thursday as an upper disturbance propagates
across the southern Plains and into the OH Valley and supports
ascent along and north of the stalled frontal zone. Given the
relatively focused nature of the wave and attendant mid-level jet,
widespread severe convection seems improbable, though a favorable
buoyancy/shear environment is possible in the vicinity of the
stalled front each afternoon.
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