RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Sat Apr 11 17:08:01 UTC 2026.
No Mesoscale Discussions are in effect as of Sat Apr 11 17:08:01 UTC 2026.
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1128 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.
...Synopsis...
Recent satellite imagery reveals two shortwave troughs, one moving
through the Great Basin and the other moving into central Mexico,
progressing through the southwesterly flow aloft between the
subtropical ridging that extends through the Southeast states and a
deep upper low off the central West Coast. Steep mid-level lapse
rates precede the northern shortwave (i.e. from the northern/central
Rockies northeastward) and low-level moisture continues to advect
northward across the southern and central Plains. Both of these
factors will increase buoyancy ahead of these two shortwaves, which
are expected to become increasingly phased as they progress
northeastward throughout the day. This evolution will support a
large area of thunderstorms from the northern Rockies through the
southern Plains this afternoon/evening. Environmental conditions
support strong to isolated severe thunderstorms across these areas,
with a relatively higher chance of severe from the southern High
Plains into central TX and along the eastern NE/KS border vicinity.
Additionally, the West Coast upper low is forecast to progress
east-southeastward into southern OR and northern/central CA this
evening and overnight, supporting the potential for thunderstorms, a
few of which could be strong.
...Southern High Plains into Central Texas...
Scattered to numerous thunderstorms are expected to develop this
afternoon across the southern High Plains as a shortwave trough
lifts out of central Mexico and interacts with the moist and
modestly buoyant airmass in places over the region. A few initially
discrete storms are possible, and adequate deep-layer wind shear
around 35 kt could result in a few instances of severe hail.
However, weak capping and strong ascent should promote increasing
thunderstorm coverage, resulting in a transition to a more clustered
storm mode. Eventual evolution into one or more line segments is
possible, particularly over southwest TX as low-level flow
nocturnally strengthens and low-level moisture increases. As this
transition occurs, damaging gust potential will become the
predominant hazard. The strengthening low-level flow will also
lengthen low-level hodograph, supporting the potential for an
embedded circulation or two, particularly along the southern extent
of whatever line develops.
...Central Plains into the Upper Mississippi Valley...
Recent surface analysis places a warm front across central KS. This
warm front is forecast to progress northward throughout the day amid
persistent southerly flow and resulting moderate/strong low-level
moisture advection. Given the ongoing cloud cover across the region,
as well as the showers and thunderstorms over northwest MO, there is
some uncertainty to how this surface boundary will evolve. General
expectation is for this front to extend from the central NE vicinity
into north-central MO by this evening.
Large, looping low-level hodographs are anticipated in the vicinity
of this warm front. These profiles, along with dewpoints in the
low/mid 60s and modestly steep mid-level lapse rates, result in an
environment that is conditionally favorable for supercells. However,
some capping will likely linger across the region and large-scale
forcing will be negligible, casting doubt to whether convective
initiation will be realized. This uncertainty is matched by the CAM
guidance, none of which establishes meaningful convection during the
afternoon and evening. All that to say, if an updraft does mature in
this environment, all severe hazards are possible, including a
tornado.
More certain (but less intense) thunderstorm potential is
anticipated as low-level warm air advection becomes increasingly
focused from the central Plains into the upper Mississippi Valley
this evening and overnight. Moderate elevated buoyancy and
deep-layer shear support the potential for a few stronger updrafts
capable of hail as thunderstorms expand northeastward from IA into
the Upper Midwest.
...Northern/Central Rockies...
Scattered thunderstorm development is anticipated across the
northern and central Rockies, ahead of a shortwave trough
progressing northeastward into the region. Deep boundary-layer
mixing ahead of this system coupled with steep mid-level lapse rates
and moderate deep-layer vertical shear will result in an environment
that supports the potential for strong to severe gusts across much
of the region.
...Northern/Central California Coast...
A frontal band, associated with an upper low moving over the
northern California coast tonight, is expected to progress
southeastward through the central CA coastal vicinity this evening.
Thermodynamic profiles appear marginally supportive of isolated
convection deep enough to produce lightning. 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.
..Mosier/Squitieri.. 04/11/2026
Read more
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1205 PM CDT Sat Apr 11 2026
Valid 111630Z - 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.
...Synopsis...
Recent satellite imagery reveals two shortwave troughs, one moving
through the Great Basin and the other moving into central Mexico,
progressing through the southwesterly flow aloft between the
subtropical ridging that extends through the Southeast states and a
deep upper low off the central West Coast. Steep mid-level lapse
rates precede the northern shortwave (i.e. from the northern/central
Rockies northeastward) and low-level moisture continues to advect
northward across the southern and central Plains. Both of these
factors will increase buoyancy ahead of these two shortwaves, which
are expected to become increasingly phased as they progress
northeastward throughout the day. This evolution will support a
large area of thunderstorms from the northern Rockies through the
southern Plains this afternoon/evening. Environmental conditions
support strong to isolated severe thunderstorms across these areas,
with a relatively higher chance of severe from the southern High
Plains into central TX and along the eastern NE/KS border vicinity.
Additionally, the West Coast upper low is forecast to progress
east-southeastward into southern OR and northern/central CA this
evening and overnight, supporting the potential for thunderstorms, a
few of which could be strong.
...Southern High Plains into Central Texas...
Scattered to numerous thunderstorms are expected to develop this
afternoon across the southern High Plains as a shortwave trough
lifts out of central Mexico and interacts with the moist and
modestly buoyant airmass in places over the region. A few initially
discrete storms are possible, and adequate deep-layer wind shear
around 35 kt could result in a few instances of severe hail.
However, weak capping and strong ascent should promote increasing
thunderstorm coverage, resulting in a transition to a more clustered
storm mode. Eventual evolution into one or more line segments is
possible, particularly over southwest TX as low-level flow
nocturnally strengthens and low-level moisture increases. As this
transition occurs, damaging gust potential will become the
predominant hazard. The strengthening low-level flow will also
lengthen low-level hodograph, supporting the potential for an
embedded circulation or two, particularly along the southern extent
of whatever line develops.
...Central Plains into the Upper Mississippi Valley...
Recent surface analysis places a warm front across central KS. This
warm front is forecast to progress northward throughout the day amid
persistent southerly flow and resulting moderate/strong low-level
moisture advection. Given the ongoing cloud cover across the region,
as well as the showers and thunderstorms over northwest MO, there is
some uncertainty to how this surface boundary will evolve. General
expectation is for this front to extend from the central NE vicinity
into north-central MO by this evening.
Large, looping low-level hodographs are anticipated in the vicinity
of this warm front. These profiles, along with dewpoints in the
low/mid 60s and modestly steep mid-level lapse rates, result in an
environment that is conditionally favorable for supercells. However,
some capping will likely linger across the region and large-scale
forcing will be negligible, casting doubt to whether convective
initiation will be realized. This uncertainty is matched by the CAM
guidance, none of which establishes meaningful convection during the
afternoon and evening. All that to say, if an updraft does mature in
this environment, all severe hazards are possible, including a
tornado.
More certain (but less intense) thunderstorm potential is
anticipated as low-level warm air advection becomes increasingly
focused from the central Plains into the upper Mississippi Valley
this evening and overnight. Moderate elevated buoyancy and
deep-layer shear support the potential for a few stronger updrafts
capable of hail as thunderstorms expand northeastward from IA into
the Upper Midwest.
...Northern/Central Rockies...
Scattered thunderstorm development is anticipated across the
northern and central Rockies, ahead of a shortwave trough
progressing northeastward into the region. Deep boundary-layer
mixing ahead of this system coupled with steep mid-level lapse rates
and moderate deep-layer vertical shear will result in an environment
that supports the potential for strong to severe gusts across much
of the region.
...Northern/Central California Coast...
A frontal band, associated with an upper low moving over the
northern California coast tonight, is expected to progress
southeastward through the central CA coastal vicinity this evening.
Thermodynamic profiles appear marginally supportive of isolated
convection deep enough to produce lightning. 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.
..Mosier/Squitieri.. 04/11/2026
Read more
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1131 AM CDT Sat Apr 11 2026
Valid 111700Z - 121200Z
...Eastern Wyoming into the Central High Plains...
An approaching mid-level short wave and associated increasing shear
and instability aloft in conjunction with a dry and well mixed
sub-cloud layer, will support quick moving isolated showers and dry
thunderstorms with minimal precipitation this afternoon across
southeastern WY and portions of the central High Plains today. An
evolving lee surface trough will also promote dry and breezy
conditions across much of eastern WY, southwestern SD and
northwestern NE as southwest winds of 15-20 mph and relative
humidity in the 15-20% range align over receptive fuels. Elevated
highlights were extended westward to include downslope favored areas
in the lee of the Bighorn Mountains in north-central WY based on
current surface observations and short term model guidance.
...Southern Great Basin...
Dry and breezy conditions are expected under passing mid-level short
wave and associated enhanced southwest flow aloft.
Southwest winds of around 15 to 20 mph and relative afternoon
humidity of 10-15% within a deep, well-mixed boundary layer will
support elevated fire weather conditions for portions of the
southern NV, UT and northern AZ today. However, marginal fuel
receptiveness should limit wildfire spread potential which precluded
introduction of Elevated highlights.
...Southeast...
A very dry air mass coupled with exceptionally dry fuels will
persist across much of the Southeast today under an upper-level
ridge. Relative humidity falling to 20-30% by mid-afternoon (locally
15% in the Piedmont regions of northern GA and western SC) will be
common across the region. However, a diffuse surface pressure
gradient in place will support light surface and boundary layer
winds through the afternoon, limiting a more significant fire
weather threat.
..Williams.. 04/11/2026
.PREV DISCUSSION... /ISSUED 0137 AM CDT Sat Apr 11 2026/
...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.
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
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