RSS Mesoscale Discussions from Storm Prediction Center
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1129 AM CDT Sun May 03 2026
Valid 031630Z - 041200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
MIDDLE MISSISSIPPI VALLEY...
...SUMMARY...
Isolated severe storms capable of hail and gusty winds are possible
mainly this evening across northern/eastern Missouri into
south-central Illinois.
...Northern/eastern Missouri into south-central Illinois...
Airmass modification and modest-caliber moist advection will occur
north-northeastward into the region along and south of a
decelerating southeastward-moving front. The limited low-level
moisture, coupled with strong heating and mixing, should keep the
airmass across the region capped through the afternoon. However,
toward/after sunset, sufficient moistening atop the decoupling
boundary layer should support increasing thunderstorm development
this evening. Convection will tend to be rooted around 750-850 mb,
and while elevated buoyancy will not be robust, the steep lapse
rates could yield some severe hail (and possibly gusty winds) in the
presence of 40+ kt shear through the cloud-bearing layer.
...Far South Florida...
While a couple of strong storms could occur through the afternoon,
cloud cover and an increasingly prevalent post-frontal regime, along
with weak lapse rates in the cloud-bearing layer, should tend to
limit storm intensity inland.
...Northern California/southwest Oregon...
Thunderstorms are expected along the northern periphery of the upper
low off the central California coast. Increasing mid-level moisture
and cold mid-level temperatures will support modest buoyancy amid
moderate easterly flow aloft, supporting the potential for small
hail and gusty winds with these westward progressing storms during
the late afternoon and early evening. However, organized severe
storm potential is expected to remain low.
..Guyer/Chalmers.. 05/03/2026
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1224 PM CDT Sun May 03 2026
Valid 041200Z - 051200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE MIDWEST...
...SUMMARY...
Strong to severe thunderstorms are possible across portions of the
Midwest late Monday afternoon into Monday night.
...Synopsis...
A split upper-level flow pattern is expected on Monday. A broad
trough across the northern Plains/Upper Midwest will eventually sag
southward late in the period. Another trough will move into the
lower Colorado Valley. A stronger cold front will move into the
Great Lakes/Midwest/southern Plains late afternoon into the
overnight. A surface low and attendant dryline is forecast within
the central/southern Plains.
...Eastern Kansas into Mid-Mississippi Valley...
Forcing for ascent will remain weak/nebulous across the region until
after 00Z. A stalled weak boundary within central Missouri may serve
as a potential area for storm initiation during the afternoon.
Low-level convergence would be weak and development remains
uncertain. Afternoon develop could pose a greater hail risk with
steep mid-level lapse rates and 35-40 kt of effective shear.
Development along the front is not expected to occur until 00Z or
later as mid-level height falls and the low-level jet increases.
Storms would be initially capable of large hail, but increasing
coverage and interaction should eventually yield upscale growth.
Damaging winds should become the primary threat with time. A locally
greater severe risk could develop should a small MCS develop during
the evening. There is significant spread in guidance on where this
could occur and the late timing of this suggests nocturnal
stabilization could also limit the potential for strong/damaging
surface gusts.
...Lower Great Lakes Vicinity...
Moisture will be more limited with northeastward extent. Daytime
heating may be enough to initiate a few storms along the surface
boundary during the afternoon. However, a more probable scenario is
that greater storm development will occur as large-scale forcing
increases during the evening. Modest shear and buoyancy will limit
the overall severe threat, but damaging winds and isolated large
hail are possible.
...Oklahoma into south-central Kansas...
There is a general agreement within current guidance that a surface
low will deepen in western Kansas/Oklahoma. A triple point is
expected to be located in central Kansas. Despite greater surface
moisture than areas farther northeast, lack of large-scale forcing
will keep capping in place near the surface low and southward along
the dryline in Oklahoma. That said, there will be a strong dryline
circulation with temperatures in the upper 80s/low 90s F to the
west. Models indicate attempts at convection along the dryline, but
confidence in sustained activity remains quite low. A risk for
severe weather would exist if storms can develop and persist.
..Wendt.. 05/03/2026
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