SPC Forecast Products
SPC Apr 11, 2026 1300 UTC Day 1 Convective Outlook
Published: Sat, 11 Apr 2026 at 07:45:02 AM CDT
SPC 1300Z Day 1 Outlook
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0742 AM CDT Sat Apr 11 2026

Valid 111300Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTHERN HIGH PLAINS...

...SUMMARY...
Scattered thunderstorms producing hail and strong wind gusts are
possible across portions of the southern High Plains this afternoon
and evening. More isolated strong to severe thunderstorms are
expected across parts of the central Rockies, central Plains, upper
Mississippi Valley, and portions of the California coast.

...Southern High Plains...
Thunderstorm development is likely by mid/late-afternoon across
southwest Texas and eastern New Mexico as increase forcing for
ascent overspreads modest but increasing low-level moisture.
Initially discrete cells are likely and will pose a threat for large
hail given adequate deep-layer wind shear /generally 30-40 kt/.
However, weak capping and strong ascent should promote upscale
growth by early evening into several linear clusters. As this
transition occurs, strong to severe wind gust potential will
increase and become the predominant hazard, though an embedded
circulation or two may occur with a tornado possible.

...Central Plains to the Upper Mississippi Valley...
Low-level warm air advection will likely become increasingly focused
through the day and into the overnight hours from the central Plains
into the upper Mississippi Valley. 850 mb winds are forecast to
steadily strengthen to 40-60 kt by this evening and will support
moistening in the lowest 1-2 km under a plume of 7-7.5 C/km
mid-level lapse rates. Forecast soundings suggest that this
environment will be weakly capped and should support isolated to
widely scattered thunderstorms during the afternoon hours across the
central Plains before spreading/re-developing northeastward into the
upper Mississippi Valley late tonight. While deep-layer wind shear
will not be overly strong (around 30 kt), it should be sufficient
for a few organized cells capable of severe hail.

A more conditional supercell potential may materialize by mid/late
afternoon through early evening across portions of the middle/lower
Missouri Valley near/just south of the northward-shifting surface
warm front, which may augmented by residual cloud cover/weakening
storms across northeast Kansas/far southeast Nebraska in the
pre-dawn hours. Forecast soundings from this region suggest a weakly
capped, but moderately buoyant airmass, with notably strong
low-level/deep-layer wind profiles that would conditionally support
supercells including some tornado risk.

...Central/northern Rockies...
A northeast-ejecting shortwave trough, along with steep mid-level
lapse rates and modest mid-level moisture, will likely support
additional thunderstorms across the central to northern Rockies this
afternoon as diurnal heating occurs. A combination of modest
deep-layer wind shear and well-mixed boundary layers will support
potential for strong to severe downburst winds.

...Northern/central California Coast...
A progressive upper wave will continue eastward and reach the
northern California coast tonight. As this occurs, ascent within
the left-exit region of an attendant upper jet, coupled with cool
mid-level temperatures near the center of the upper low, will
support isolated thunderstorms across northern/central California.
Winds within the lowest 1-2 km AGL should increase to around 40 kt
as the wave moves onshore, which will contribute to the potential
for convective downdrafts to produce a few locally damaging wind
gusts.

..Guyer/Broyles.. 04/11/2026

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SPC - No watches are valid as of Sat Apr 11 12:45:02 UTC 2026
Published: Sat, 11 Apr 2026 at 07:44:05 AM CDT
No watches are valid as of Sat Apr 11 12:45:02 UTC 2026.

SPC - No MDs are in effect as of Sat Apr 11 12:45:02 UTC 2026
Published: Sat, 11 Apr 2026 at 07:44:04 AM CDT
No Mesoscale Discussions are in effect as of Sat Apr 11 12:45:02 UTC 2026.

SPC Apr 11, 2026 Day 4-8 Severe Weather Outlook
Published: Sat, 11 Apr 2026 at 03:46:57 AM CDT
Day 4-8 Outlook
Day 4-8 Outlook Image
Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0344 AM CDT Sat Apr 11 2026

Valid 141200Z - 191200Z

...DISCUSSION...
...Day 4/Tue -- Southern Plains to Great Lakes...

A shortwave upper trough embedded within the larger-scale western
U.S. trough will eject across portions of the Plains to the Upper
Midwest on Day 4/Tue. As this occurs, a surface low will deep over
the central Plains and lift northeast across the Upper Midwest/Great
Lakes. Some uncertainty remains regarding the exact evolution of
this system, mainly due to differences in medium range guidance with
respect to surface low placement and timing of the upper shortwave
trough. Nevertheless, a moist and unstable airmass is expected ahead
of the low and to the east of a Plains dryline and south of a Great
Lakes warm front. Thunderstorm development should be more widespread
along these boundaries compared to prior days given stronger
large-scale ascent will overspread the central U.S., and height
falls will result in a more robust low-level jet response. As a
result, an all-hazards severe event is expected from the southern
Plains into portions of the Upper Midwest/Great Lakes vicinity on
Tuesday/Tuesday night.

...Day 5/Wed -- Southern Plains to the Midwest...

Medium range guidance varies heading into Wednesday with the
operational GFS much more progressive and lower amplitude than the
operational ECMWF. The AIGFS is much more in-line with the
ECMWF/AIFS, so this period is weighted more toward those solutions.
It appears the upper trough over the southern Rockies will eject
across the Plains to the Mid-MS Valley during this time. A moist and
unstable airmass will reside across the region ahead of dryline
across western OK into central TX and a sagging cold front across
the Lower MO/Mid-MS Valley. Areas of precipitation could be ongoing
at the beginning of the period and does result in some uncertainty
regarding where stronger destabilization will occur. Nevertheless,
an overall favorable thermodynamic/kinematic parameter space will
overlap this corridor and isolated to scattered severe storms appear
likely.

...Days 6-8/Thu-Sat...

Medium range guidance depicts another trough developing across the
West on Day 6/Thu and quickly progressing east through the end of
the period. This could support a continued severe risk across parts
of the southern Plains into the Midwest in the Thursday or Friday
time frame. However, run to run consistency toward the end of the
forecast period has not been very good. Additionally, multiple
rounds of storms across the same areas earlier in the period may
impact later severe potential. Trends will be monitored and
probabilities may be needed in later outlooks.

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