RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Sat Apr 11 08:47:02 UTC 2026.
No Mesoscale Discussions are in effect as of Sat Apr 11 08:47:02 UTC 2026.
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1242 AM CDT Sat Apr 11 2026
Valid 111200Z - 121200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE SOUTHERN HIGH PLAINS...
...SUMMARY...
Scattered thunderstorms producing hail and strong wind gusts will be
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.
...Synopsis...
An upper trough is evident in early-morning water-vapor imagery off
the California Coast. This wave will gradually de-amplify over the
next 24 hours as it progresses northeastward into the northern
Rockies. Further south, a lower-amplitude upper disturbance is noted
off the coast of Baja CA, and will migrate northeast into southwest
TX through this evening. Ahead of these features, modest lee
troughing along the High Plains and the southeastward shift of
surface high from the Midwest into the upper OH Valley will yield an
extended fetch of southerly low-level flow from the TX coast into
the upper MS Valley, resulting in northward moisture return as well
as a broad zone of isentropic ascent from the Plains into the upper
MS Valley.
...Southern High Plains...
Thunderstorm development appears likely by mid-afternoon across
southwest TX as ascent associated with the upper disturbance off the
coast of Baja CA migrates out of northern Mexico and overspreads
returning moisture. Initially discrete cells are likely and will
pose a threat for large hail given adequate deep-layer wind shear.
However, weak capping and strong ascent should promote upscale
growth by early evening into one or more convective lines. As this
transition occurs, strong to severe wind gusts will become the
predominant hazard, though an embedded circulation or two may be
possible. Based on latest guidance, the wind/tornado threat may be
maximized along and south of the I-20 corridor where the signal for
clustering/banding is greatest in latest CAM and ensemble guidance.
...Central Plains to the Upper MS 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 MS Valley. 850 mb winds are forecast to strengthen to
40-50 knots by this evening and will support steady 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 scattered thunderstorms during
the afternoon hours across the central Plains before
spreading/re-developing northeastward into the upper MS Valley late
tonight. While deep-layer wind shear will not be overly strong
(around 30 knots), it should be sufficient for a few transient
organized cells capable of large hail.
A more conditional supercell threat may materialize across portions
of the lower MO valley where some CAM guidance depicts convection
developing late afternoon along the surface warm front. Forecast
soundings from this region suggest a weakly capped, but moderately
buoyant and strongly sheared environment may be in place that could
support a well-organized supercell. However, poor ensemble consensus
limits confidence in this scenario.
...Central to northern Rockies...
00z RAOBs from the Great Basin/Four Corners region sampled steep
mid-level lapse rates with modest mid-level moisture. While fairly
dry, this environment was sufficient for convection yesterday and
will likely support additional thunderstorms across the central to
northern Rockies this afternoon as diurnal heating erodes inhibition
and maximizes surface-based buoyancy. Ascent ahead of the decaying
upper wave will likely support isolated to scattered thunderstorms,
and a combination of modest deep-layer wind shear and deep,
well-mixed boundary layers will promote strong to severe downburst
winds. A fairly strong wind signal in latest HREF guidance
co-located with transient UH streaks lent enough confidence to
expand 5% wind probabilities northwestward to address this concern.
...CA Coast...
A progressive upper wave will move into northern CA late this
afternoon into the overnight hours. 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, should
support isolated thunderstorms across northern CA. Winds within the
lowest 1-2 km should increase to around 40 knots as the wave moves
onshore, which may be augmented by convective downdrafts to yield a
few damaging gusts along the coast.
..Moore/Halbert.. 04/11/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1237 AM CDT Sat Apr 11 2026
Valid 121200Z - 131200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE CENTRAL AND SOUTHERN PLAINS...
...SUMMARY...
Isolated severe thunderstorms are possible from the southern and
central Plains into the Upper Midwest on Sunday.
...Synopsis...
An upper trough will slowly pivot east over the western U.S. on
Sunday while upper riding envelopes the East. A couple of shortwave
impulses will migrate northeast from the Plains to the Upper
Midwest/MS Valley vicinity. Persistent midlevel southwesterly flow
across the central portions will maintain lee troughing over the
Plains. Meanwhile, southerly low-level flow will transport 60s F
dewpoints northward from TX to WI ahead of a surface trough/dryline
oriented across eastern NE into central KS, arcing south/southwest
into northwest OK and western TX. A surface low is forecast to move
across the Upper Midwest, where a boundary will be draped across
southern MN into WI.
...Central/Southern Plains...
Numerous showers and thunderstorms are likely to be ongoing Sunday
morning across OK/TX, with more isolated activity possible northward
into the Mid-MO Valley. This convection will have implications on
airmass recovery and thunderstorm development along the dryline
during the afternoon/evening. Some isolated wind/hail risk could
accompany this early activity as clusters and/or line segments move
across OK/TX during the morning.
In the wake of this morning activity, persistent southwesterly
mid/upper flow will maintain a plume of steep midlevel lapse rates
and mixing near the dryline should erode cloud cover over portions
of KS/OK/western TX. Large-scale ascent will remain nebulous, with a
lack of height falls precluding large-scale support for thunderstorm
development. Nevertheless, modest confluence along the dryline is
forecast. Mid 60s F dewpoints beneath steep lapse rates will support
up to 2500 J/kg MLCAPE. Furthermore, supercell wind profiles are
apparent in forecast soundings. This environment will conditionally
support supercells along the dryline by late afternoon into the
evening. However, given a lack of forcing, storm coverage is
uncertain. If storms can develop along the dryline, at least a
narrow corridor of large to very large hail potential will exist in
addition to damaging winds and a tornado or two.
Some guidance suggests morning convection could intensify or
redevelop across portions of north/central TX toward the ArkLaTex,
but this scenario remains very uncertain.
...South Texas/Rio Grande vicinity...
A conditional severe risk is apparent during the evening/nighttime
hours. A moderately unstable airmass will be in place, though
deep-layer flow will be somewhat weaker compared to further north.
Nevertheless, some guidance suggests supercells will develop across
Mexico and could approach/cross the Rio Grande during the evening.
If this occurs, an initial risk for large hail and damaging gusts
will exist. With time, some potential for clustering could occur and
bring a continued risk for strong winds across portions of
south-central/southern TX during the nighttime hours.
...Upper Midwest...
Thunderstorm development during peak heating is uncertain. If the
upper shortwave trough moves across the area too early, convective
development may be limited in the wake of that feature.
Nevertheless, a corridor of modest destabilization is expected ahead
of the surface low as cool temperatures aloft support steepened
midlevel lapse rates amid a moistening boundary layer. If storms
develop, isolated severe hail and wind are possible with stronger
storms.
..Leitman.. 04/11/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0225 AM CDT Sat Apr 11 2026
Valid 131200Z - 141200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE UPPER MISSISSIPPI VALLEY...AND ACROSS PARTS OF THE SOUTHERN
PLAINS...
...SUMMARY...
Severe thunderstorms are possible across the Upper Mississippi
Valley and Great Lakes region, and across portions of the southern
Plains on Monday.
...Synopsis...
An upper trough from the northern Rockies to southern CA will pivot
east on Monday, overspreading the Four Corners vicinity by early
Tuesday. Meanwhile, a shortwave upper trough will migrate east
across the northern Plains to the Upper Midwest. At the surface, a
low over the Mid-MO Valley will shift east along a frontal wave
across MN/WI. Persistent southwesterly deep-layer flow over the
Rockies into the Plains will maintain surface lee troughing across
the Plains. Meanwhile, south/southwesterly low-level flow will
maintain 60s F dewpoints from the southern Plains toward Lake
Michigan.
...Upper Midwest...
Some spread among various medium-range guidance in the
placement/track of the surface low leads to some uncertainty
regarding the northward extent of severe potential on Monday.
Nevertheless, a moist airmass will reside ahead of the low in the
vicinity of a surface warm front. Storm coverage is uncertain,
partly due to possibly capping. However, persistent moderate
southwesterly flow atop the front as the low begins to shift east
should provide focus for thunderstorm development during the
afternoon and evening. Steep midlevel lapse rates and elongated
hodographs suggest large hail will be possible both within the warm
sector and with any elevated storms on the cool side of the
boundary. Some guidance suggests storms could consolidate into a bow
or linear segment, which would increase damaging wind potential.
However, this scenario is uncertain. Some severe risk will persist
eastward along the warm front into MI overnight. These elevated
storms will mainly pose a hail risk.
...Central/Southern Plains...
Capping is likely to suppress convection along a dryline extending
across eastern KS into western OK/TX. The exception may be across
portions of western TX into southwest OK where modest height falls
could occur toward evening as the western upper trough beings to
slowly shift east toward the southern Rockies. Mid 60s F dewpoints
and steep midlevel lapse rates will support moderate to strong
destabilization. Strong heating along and west of the dryline will
support mixing and an increasing southerly low-level jet by 00z
could be sufficient for isolated storm development. Supercell wind
profiles will support mainly a risk of large hail, though locally
damaging gusts and a tornado or two will be possible if storms
develop.
..Leitman.. 04/11/2026
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Day 4-8 Outlook
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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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0137 AM CDT Sat Apr 11 2026
Valid 111200Z - 121200Z
...Synopsis...
Broad mid-level toughing over the Western U.S. with an embedded
shortwave will be responsible for both isolated dry thunderstorms
and dry/breezy conditions across portions of eastern Wyoming into
the Central High Plains.
...Eastern Wyoming into the Central High Plains...
Broad southwesterly flow and a weak embedded jet streak associated
with a mid-level shortwave trough will overspread the Rockies,
resulting in lee troughing and a developing/deepening surface low
over eastern Montana. Dry and breezy boundary layer conditions will
overspread receptive fuels across eastern Wyoming into far western
South Dakota/Nebraska and portions of far northern Colorado, with
surface winds of 15-20 MPH and relative humidity of 15-20%. Dry
thunderstorm potential will overlap these Elevated fire-weather
concerns owing to deep, dry, and well-mixed boundary layer profiles
resulting in limited precipitation efficiency amidst an otherwise
convectively unstable regime.
..Halbert.. 04/11/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0139 AM CDT Sat Apr 11 2026
Valid 121200Z - 131200Z
...Synopsis...
A mid-level closed low is forecast to progress from the northern
California coast into the Intermountain West, with broad
west-southwesterly flow overspreading the Four Corners into the
Great Plains on Sunday. Widespread dry and breezy conditions are
expected, resulting in several areas of Elevated fire-weather
highlights.
...Four Corners/Central High Plains...
While represented by separate Elevated highlights, much of the area
from southern Arizona/New Mexico into eastern Colorado/Wyoming and
portions of western/central Nebraska and southern South Dakota will
experience widespread dry and breezy conditions. Though fuels across
portions of Arizona and New Mexico are more marginally receptive to
ignition and spread, winds of 15-20 MPH and relative humidity as low
as 10% will support at least Elevated wildfire concerns. Further
east into the Central High Plains, fuels are largely at or exceeding
the 98th annual ERC percentiles with winds forecast at 15-20 MPH and
relative humidity at 10-15%. Locally Critical conditions may occur
across areas just east of the Front Range of the Rockies, where
topography results in an enhancement of the surface winds, or
perhaps where a stronger downslope component of the winds develop.
However, uncertainty in the duration and magnitude of Critical winds
precludes highlights at this time. While meteorological conditions
will reach Elevated status in the gap between these areas, recent
wetting rainfall and less than receptive fuels will lessen the
overall fire-weather concerns between the highlights.
...Ohio River Valley...
While forecast relative humidity values are more variable, ranging
from 25-35%, much of the lower Ohio River Valley is experiencing
widespread moderate to severe drought. Fuels at or exceeding the
98th annual percentile for ERCs and southerly surface winds around
15 MPH will support Elevated fire-weather concerns amidst deeply
mixed and dry boundary layer profiles. While instances of light to
moderate precipitation may occur the prior afternoon/evening, this
will do little to alleviate the overall fire-weather concerns.
..Halbert.. 04/11/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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