RSS Mesoscale Discussions from Storm Prediction Center
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0258 PM CDT Sun May 10 2026
Valid 102000Z - 111200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
WESTERN/CENTRAL TEXAS...
...SUMMARY...
Scattered large hail (some 2+ inches) and numerous severe/damaging
wind gusts (isolated 75+ mph) are expected this afternoon/evening
across parts of west-central to central Texas. A couple of tornadoes
also appear possible across parts of west-central Texas along/near a
front.
...20z Update...
The previous forecast remains largely on track with only minor
adjustments required based on recent observed trends. The
convectively reinforced cold front across northwest TX continues to
surge south faster than anticipated by morning guidance.
Nonetheless, elevated supercell development is ongoing immediately
north of the boundary where MUCAPE was recently analyzed near 2000
J/kg. Consequently, severe hail probabilities (and the ENH
categorical bounds) have largely been left in place with only a
southward reduction in the wind and tornado probabilities based on
the expected 20 UTC frontal position.
Across central to southern TX, recent HRRR/RRFS time-lagged
ensembles depict the potential for 75+ mph winds across the
Austin/San Antonio region and southward into south TX late tonight.
This signal appears reasonable given the expected evolution of the
eventual MCS and downstream environment (both sampled by recent
ACARS soundings and forecast by short-range guidance). The 15% wind
and Intensity Level 1 contours have been expanded south to address
this potential.
Across northeast TX, the remnants of an early-morning MCS have
transitioned into a single organized supercell that has begun
weakening over the past 20-30 minutes. However, attempts at new
convective development are noted along the outflow boundary to the
south of the decaying supercell. With temperatures in the mid 80s
along/south of the boundary, lingering inhibition should be
minimized and may allow for additional strong/severe thunderstorms
through early evening with an attendant threat for severe hail/wind.
Elsewhere, the forecast remains on track. See the previous
discussion below and MCDs 693, 694, and 695 for additional
short-term details.
..Moore.. 05/10/2026
.PREV DISCUSSION... /ISSUED 1138 AM CDT Sun May 10 2026/
...Texas into the ArkLaTex/Lower Mississippi Valley...
Severe potential today will be complicated by ongoing thunderstorms
along/near the Red River and a convectively reinforced outflow
boundary across the ArkLaTex/lower MS Valley. In general, a
favorable setup for scattered to numerous severe/damaging winds
remains apparent this afternoon/evening across parts of west-central
into north TX to the south of current convective activity, along
with the potential for large to very large hail and perhaps a couple
of tornadoes with initial supercells that may develop.
Recent surface analysis shows a low over northwest TX, with a
dryline extending southward to the Big Bend region. A cold front
arcing northeastward from the low across western north TX into
southern OK and western/northern AR will likely serve as a focus for
additional robust thunderstorm development this afternoon. The
observed 12Z FWD sounding sampled the pre-convective airmass well,
with steep mid-level lapse rates atop a rather moist low-level
airmass aiding MUCAPE around 2500 J/kg.
There is some uncertainty regarding airmass recovery with eastward
extent towards the ArkLaTex given a notable outflow boundary from
earlier convection noted on latest visible satellite imagery
extending from north-central to east-central TX. Still, this
boundary seems to have stalled recently, with mostly clear skies to
its north across northeast TX ahead of ongoing thunderstorms in
north-central TX. Current expectations are for moderate to strong
instability to develop this afternoon as diurnal heating occurs
across west-central to north TX, with the greatest instability
focused south of the cold front/outflow and east of the dryline.
Stronger west-northwesterly mid-level flow associated with a
southeastward-moving shortwave trough may tend to remain displaced
along and slightly to the north of the cold front through the day.
Still, sufficient overlap of modestly enhanced mid-level winds and
related deep-layer shear is forecast across the northern portions of
the warm sector in TX. This shear should support some supercells
with initial development, particularly across parts of west-central
into north-central TX. Large to isolated very large hail (2+ inches)
may occur with these supercells, before convection quickly grows
upscale into an intense bowing cluster. A narrow zone of tornado
potential is also apparent with the supercells across parts of
west-central TX near the sagging front, where low-level shear will
be locally enhanced by east-northeasterly near-surface winds.
Scattered to numerous severe/damaging winds are expected across much
of central TX after this mode transition occurs. With ample
instability and a highly organized cold pool expected, some of these
gusts could exceed 75 mph on a localized basis. The severe/damaging
wind threat should continue through the evening as the bowing
cluster spreads south-southeastward across much of TX. Eventual
weakening is forecast late tonight into early Monday morning,
although at least an isolated damaging wind threat may persist into
south/coastal TX through the end of the period.
Lower confidence in organized severe potential exists with eastward
extent into the ArkLaTex and lower MS Valley, as ongoing cloud cover
and outflow from earlier convection may inhibit diurnal heating and
the development of any more than weak instability this afternoon.
Still, some chance for redevelopment remains apparent along/east of
the cold front, so severe hail/wind probabilities have been
maintained with adjustments based on current observations and latest
short-term guidance.
...Central New Mexico into Far West Texas...
Low-level orographic ascent with the surging cold front should
support isolated to widely scattered thunderstorms developing across
central NM into parts of far west TX this afternoon and evening.
Cool temperatures aloft will aid in the development of weak
instability, even with limited low-level moisture. Around 30-35 kt
of effective bulk shear should foster organized updrafts, with the
strongest cores capable of producing isolated hail and occasional
severe/damaging winds.
...Florida...
Isolated to widely scattered thunderstorms should develop along the
stalled front this afternoon across the northern FL Peninsula, and
southward along the Atlantic Coast sea breeze. Diurnal heating of a
moist low-level airmass, with MLCAPE up to 1500-2000 J/kg, should
support water-loaded downdrafts capable of producing locally
damaging winds. Sufficient deep-layer shear may also foster
sufficient updraft organization for isolated hail with the more
robust cores.
...Mid-Atlantic...
Strong to locally damaging winds may occur with high-based
convection that forms on the Appalachians/Blue Ridge this afternoon
and subsequently spreads east-northeastward along/ahead of a cold
front. While instability will remain weak, a deeply mixed boundary
layer should encourage gusty downdraft winds to reach the surface in
a narrow corridor where a Marginal Risk has been introduced.
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1220 PM CDT Sun May 10 2026
Valid 111200Z - 121200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE SOUTHEAST...
...SUMMARY...
Isolated severe storms with locally damaging wind gusts and hail are
possible Monday afternoon across parts of the Southeast.
... Overview ...
As a western midlevel ridge amplifies, a midlevel shortwave trough
will slowly progress southeast across eastern Texas into Louisiana
on Monday. At the same time, a surface cold front will slowly sag
south across the Southeast. Deep-layer ascent associated with the
midlevel vorticity maximum will interact with the trailing portion
of a surface front allowing the development of a surface trough/low
that will move east along the front.
... Southeast US ...
Along and ahead of the surface front, temperatures will warm into
the upper-70Fs to low-80Fs with dewpoint temperatures rising into
the upper-60Fs to low-70Fs. Convergence along the front will result
in scattered thunderstorm development, perhaps by late morning.
Strong cloud-layer shear, tall, skinny buoyancy profiles, and
precipitable water values around 1.75 inches will support a
marginally severe wind threat. Depending on the degree of heating of
the airmass ahead of the front, a marginal hail risk may also
develop. The most likely area for a concentration of wind and hail
occurrence will be where the surface front intersects any inland
moving sea breeze across southern South Carolina, Georgia, and
northern Florida.
Farther west across southeast Louisiana, convective coverage is less
certain. Although scattered thunderstorms will be possible along the
sagging front, additional thunderstorms may develop in response to
the deep-layer ascent with the midlevel vorticity maximum and
inverted trough/surface low. However, there is significant
disagreement within the 20260510/12Z HREF guidance as to the
coverage of any convection. Given the presence of a midlevel
vorticity maximum and a surface boundary, will lean toward the
wetter solutions. A similar kinematic and thermodynamic environment
will exist here as farther east, supporting primarily a marginal
wind threat.
..Marsh.. 05/10/2026
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0230 PM CDT Sun May 10 2026
Valid 121200Z - 131200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST
KANSAS NORTHEAST INTO SOUTHERN WISCONSIN...
...SUMMARY...
Isolated severe storms with strong wind gusts and hail will be
possible on Tuesday from parts of southeast Kansas northeast into
southern Wisconsin.
... Overview ...
The midlevel pattern will amplify further on Tuesday as a midlevel
low and associated trough move southeast over the Upper Great Lakes
in response to a building ridge upstream. As the midlevel flow
amplifies, a jet streak will redevelop on the upshear side of the
trough, resulting in strong vertical shear across the Central US.
At the surface, a low will quickly drop southeast out of Canada,
across Wisconsin, into Lower Michigan. To the west/southwest of this
low, a cold front will quickly push south and east.
... Southeast Kansas northeast into Southern Wisconsin ...
Ahead of the aforementioned surface cold front, southerly winds on
the west side of a surface anticyclone will support northward
moisture transport across the central US. The 20260510/12Z guidance
suite shows considerable variance in the depth and quality of the
moisture return and in turn, convective coverage.
Low level convergence along the front will be greatest the closest
to the surface low. Despite surface dewpoints in the upper-40Fs to
perhaps low-50Fs, a couple of thunderstorms are likely to develop
across southern Wisconsin. Convergence along the front should
decrease with southwest extent with an increasing EML/cap in the
same direction. Thus, despite better low level moisture, and in turn
buoyancy, across the Central Plains, confidence in thunderstorm
development is low. That said, the 20260510/12Z Hi-Res NAM shows
thunderstorm development all along the front from southeast Kansas
into Wisconsin. The overall kinematic environment will be favorable
for at least a few severe wind reports where ever thunderstorms
develop, and thus the Level 1/Marginal Risk has been expanded to
incorporate this potential.
... Central and South Florida ...
A post frontal airmass should be in place across the area on
Tuesday, with northerly surface winds advecting in a slightly drier
airmass. Despite that, a myriad of potential surface boundaries
(including both Gulf and Atlantic sea breezes) will be around during
the afternoon to serve as potential thunderstorm initiation
mechanisms. Although effective layer shear will be around 30 to
perhaps 40 knots, the degree of instability may limit the overall
wind threat.
... Interior Pacific Northwest ...
A few thunderstorms may develop during the late afternoon and
overnight across portions of Oregon and Washington within a belt of
strong southerly flow ahead of an approaching midlevel trough to the
west and the building ridge to the east. Although low level moisture
should remain scant, sufficient midlevel moisture should combine
with large-scale ascent and steep lapse rates to support a few
thunderstorms. Fast storm motions and steep low-to-midlevel lapse
rates may support a few severe thunderstorm wind gusts. However, the
nature of this threat is still too low to warrant unconditional
severe probabilities.
..Marsh.. 05/10/2026
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