ACUS01 KWNS 130536
SWODY1
SPC AC 130534

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1234 AM CDT Mon Apr 13 2026

Valid 131200Z - 141200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE UPPER MISSISSIPPI RIVER VALLEY...

...SUMMARY...
Severe thunderstorms are likely across the Upper Mississippi Valley
and Great Lakes region with potential for large to very large hail,
damaging wind, and tornadoes. A more conditional and isolated risk
for severe storms is possible across portions of the southern Plains
late this afternoon and evening.

...Synopsis...
Early-morning water-vapor imagery depicts an upper trough with
multiple embedded vorticity maxima over the Great Basin. While the
primary upper wave will remain over the West for today, a leading
impulse is forecast to eject towards the northern Plains and into
the Great Lakes through tonight. At the surface, a weak lee cyclone
over the central High Plains will migrate northeastward in tandem
with the upper impulse, likely reaching the southern MN vicinity by
early evening. As this occurs, a plume of mid-60s dewpoints will
spread north into the upper MS Valley along and south of a warm
front. Scattered thunderstorm development along and north of the
warm front is anticipated by late afternoon as forcing for ascent
gradually increases. Elsewhere, more isolated strong to severe
thunderstorms are possible across portions of TX and OK where deep
mixing along a dryline may result in sustained deep convection.

...Upper MS Valley...

A combination of shortwave ridging and capping at the base of an EML
will limit thunderstorm development through much of the day across
southern MN into central WI. This will allow for continued moisture
return as a warm front lifts into the region with MLCAPE values
forecast to reach 2000-2500 J/kg by around 21 UTC. Thunderstorm
development will become increasingly probable through the 21-00 UTC
period as isentropic ascent strengthens ahead of the approaching
upper disturbance. Lingering inhibition coupled with 45-50 knot
effective bulk shear should promote initially discrete supercells
along or just north of the surface boundary. Hodograph elongation
appears favorable for a large hail threat, possibly as large as 2-3
inches with the more robust cells. Additionally, enhanced low-level
SRH along the frontal zone may result in a corridor of relatively
higher tornado potential if convection can remain rooted along the boundary.

While the overall environment appears very favorable for intense
convection, east/northeasterly storm motions along or just north of
the warm front will likely promote storm advection towards the cool
side of the boundary and clustering/upscale growth through the
evening. This, combined with capping over the remainder of the warm
sector, limits confidence in a more widespread tornado threat, and
could modulate the potential for significant (2+ inch) hail within a
few hours after convective initiation. Nonetheless, a corridor of
higher hail potential remains evident in latest guidance along and
just north of the warm front where discrete supercells are most
probable. 30% hail probabilities have been shifted to reflect a
southward trend in frontal placement noted in most recent guidance.

...Southern Plains...

A moist and very unstable air mass will remain in place across TX
and OK today with MLCAPE values expected to increase to around 2500
J/kg by late afternoon. Ample diurnal heating/mixing on the western
periphery of the moisture plume will likely result in weak,
high-based convection by mid to late afternoon. Easterly storm
motions may promote downstream intensification as convection
migrates towards richer low-level moisture, but this will be
conditional on convection remaining sustained long enough to realize
the favorable thermodynamic environment. If this can occur,
deep-layer shear values on the order of 40 knots should promote
organized convection - likely in the form of supercells - with an
attendant threat for all hazards, including very large hail. While
both global and CAM ensemble guidance hint at this potential, the
lack of appreciable lifting mechanisms (aside from the dryline circulation/boundary-layer mixing) casts considerable uncertainty on
overall storm coverage.

..Moore/Wendt.. 04/13/2026

$$
--- MultiMail/DOS
* Origin: Project Scorpio TEST (618:250/6)

ACUS01 KWNS 171240
SWODY1
SPC AC 171239

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0739 AM CDT Fri Apr 17 2026

Valid 171300Z - 181200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE UPPER AND MID MISSISSIPPI VALLEY SOUTHWESTWARD INTO KANSAS AND OKLAHOMA...

...SUMMARY...
Numerous severe thunderstorms are likely this afternoon into tonight
across parts of the Upper Midwest southward across the lower
Missouri Valley into central Great Plains. Initially this may be
accompanied by a risk for large to giant hail and a few strong
tornadoes, before severe wind gusts 60 to 90 mph become the
most prominent hazard by this evening.

...Synopsis...
Surface analysis this morning depicts a front bisecting MN north to
south to a low near the NE-IA-SD border, with the front extending
southwestward into the central High Plains. Water-vapor imagery
shows a prominent upper trough near the MT-ND border
south-southwestward into eastern UT. A belt of increasingly strong southwesterly 500-mb flow will overspread a destabilizing warm
sector today as the upper trough eventually reaches the Upper
Midwest and central Great Plains late tonight. Concurrently, the aforementioned cyclone will develop northeast to Lake Superior as a
warm front over IA advances northward into the western Great Lakes.
Meanwhile, the cold front will sweep southeast reaching the central
Great Lakes southwestward into the southern Great Plains by early Saturday.

...Upper and Mid Mississippi Valley...

A northward expanding warm/moist sector on the nose of a 50+ kt
southerly LLJ will continue to destabilize as large-scale ascent
approaches from the west. A large-hail threat may develop this
morning with developing convection across southern MN (see
forthcoming MCD #472 for short-term details). Heating and advection
of 60s deg F surface dewpoints beneath steep mid-level lapse rates
will support the development of a moderately to very unstable
airmass from IA-IL northward into the upper MS Valley to the east of
the front and southeast of the low. Upwards of 1500-3000 J/kg
MLCAPE is forecast immediately ahead of the front with strengthening
flow aloft, strongly favoring organized storms, including
supercells. Recent model guidance continues to show the development
of discrete supercells later this afternoon ahead of the front over
parts of central/northern WI near the low, and farther south in the
vicinity of eastern IA into adjacent portions of WI/northwest IL.
All hazards will be possible with this potential activity, including
the possibility for an intense tornado. Large to giant hail will be
possible with supercells. Other storms likely to evolve quickly
into a band of severe thunderstorms will develop farther west and
push east coincident with the front. Damaging wind gusts will tend
to become more prevalent during the evening with linear storm modes.
Some tornado risk may continue into the evening as maturing bands of
storms yield a threat for bowing segments and embedded mesovortices,
before this activity gradually diminishes late as it moves east into
IN/Lower MI late.

...KS-OK eastward into the lower MO Valley...

Continued moistening and heating of an airmass to the east of a
dryline/cold front and associated triple point will lead to a very
unstable airmass from OK into KS by early to mid afternoon. A
capping inversion will likely inhibit storm development until mid
afternoon near the front. Initial storm development will likely be supercellular near the triple point before a more extensive band of
cellular storms develops along the boundary. Both a supercell and
QLCS tornado risk is apparent given the appreciably large
CAPE/shear. A coalescing of cold pools and intensification of a
squall line with embedded surges and bowing segments may result in
focused swaths of more intense severe gusts (i.e., locally 75-90
mph) from south-central and eastern KS into west-central MO.
Farther south, a more conditional setup south of the triple point
along the dryline is expected. Large to giant hail could accompany
any mature/sustained supercell along with a tornado risk.
Eventually the front will sweep southeastward with a convective line
yielding a risk for wind/hail.

..Smith/Dean.. 04/17/2026

$$
--- MultiMail/DOS
* Origin: Project Scorpio TEST (618:250/6)

ACUS01 KWNS 231251
SWODY1
SPC AC 231250

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0750 AM CDT Thu Apr 23 2026

Valid 231300Z - 241200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATER THIS AFTERNOON/EVENING FOR EASTERN KANSAS INTO EXTREME NORTHERN OKLAHOMA...

...SUMMARY...
Severe thunderstorms are expected to develop this afternoon and
evening from the southern and central Plains into the lower to mid
Missouri Valley, and upper Mississippi Valley. Tornadoes, large hail
and severe wind gusts will be possible.

...MN/IA to KS/northern OK this afternoon into tonight...

The interaction of a southeastward moving midlevel trough over
southern BC/AB and a northeastward moving trough over the western
Dakotas will lead to the formation of a deep closed low over
southern SK. An associated, occluding surface cyclone will weaken
across southern MB by this evening, as a trailing cold front moves
across MN/IA/KS/MO and northern OK. Low-level moisture will spread
northward across IA/MN in advance of the cold front, beneath the
northeast edge of an elevated mixed layer. Surface heating and the
degree of buoyancy may be limited by extensive clouds from IA into
MN, and forecast wind profiles show complex/messy hodographs
structures (stronger low-level shear lingering across IA). Mixed
convective modes are expected along and ahead of the front this
afternoon, which could produce occasional wind damage, large hail
and perhaps a couple of tornadoes.

The more substantial severe threat is expected late this afternoon
through late evening from eastern KS into far northern OK, near and
just northeast of a cold front/dryline triple point and weak
secondary cyclone. A midlevel speed max near the Four Corners will
progress eastward to the TX Panhandle by this evening, with ascent
in the left exit region of the jet coincident with the triple point
near or just north of the KS/OK border. An influx of mid 60s
boundary-layer dewpoints beneath steep midlevel lapse rates will
contribute to MLCAPE of 2000-3000 J/kg, with weakening convective
inhibition across KS by mid afternoon.

Storm development is expected along the cold front in KS by mid
afternoon, with storms expected to develop southward to near the
triple point. The large buoyancy, steep midlevel lapse rates and
deep-layer shear sufficient for supercells will favor very large
hail (2-3 inches in diameter) with the initial/more discrete storms.
The tornado threat will peak this evening as low-level
shear/hodograph curvature increase near the KS/OK border - there
will be strong tornado potential with the anchor/southern supercells
near the triple point. Upscale storm growth and cold pool
development will favor a more linear convective mode with occasional
wind damage as the outflow/effective cold front spreads
southeastward into northeast OK and southwest MO overnight.

...OK dryline this evening...

Storm development along the dryline in OK is uncertain late this afternoon/evening. Forecast soundings suggest that the degree of
surface heating/mixing along the dryline and residence time in the
dryline circulation will be close to supporting deep convection. If
storms do form, the environment will conditionally favor very large
hail initially, and the possibility of an evening tornado threat
with any sustained storm.

..Thompson/Bentley.. 04/23/2026

$$
--- MultiMail/DOS
* Origin: Project Scorpio TEST (618:250/6)

ACUS01 KWNS 241232
SWODY1
SPC AC 241230

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0730 AM CDT Fri Apr 24 2026

Valid 241300Z - 251200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
SOUTHEAST OKLAHOMA AND THE ARKLATEX...

...SUMMARY...
Scattered severe thunderstorms are expected today from parts of the
southern Plains into the ArkLaTex and lower Mississippi Valley.
Large hail, damaging winds, and a few tornadoes will be possible.
The greatest threat for supercells with very large hail (2+ inches)
should focus across parts of southeast Oklahoma into the ArkLaTex.

...Southern Plains into the ArkLaTex/Lower Mississippi Valley...

A band of mainly sub-severe thunderstorms ongoing this morning from
eastern OK into AR and southern MO is being aided by southwesterly
warm/moist advection at low levels. With time, this forcing should
weaken, and a decrease in convective intensity should continue
through late morning. Outflow from this convection is forecast to
extend from south-central/southeast OK into AR this afternoon, and
should serve as a focus for additional robust thunderstorms later
today. Daytime heating of a moist airmass already present across
much of the southern Plains into the ArkLaTex and lower MS Valley
will aid in the development of moderate to strong instability by mid
afternoon along/south of the residual outflow and east of a surface
dryline extending from northeast to south-central TX. The greatest
instability should exist across southeast OK/northeast TX, where
steep mid-level lapse rates will likely still exist. A weak surface
low should also be in place across northeast TX by mid to late afternoon.

Large-scale forcing aloft will remain fairly nebulous/weak across
the southern Plains this afternoon, as a prominent/closed
upper-level low remains centered over south-central Canada. Still,
multiple robust thunderstorms should develop by 19-22Z across
southeast OK along/near the residual outflow boundary as MLCIN
becomes minimal with robust diurnal heating, and as westerly
mid/upper-level flow modestly strengthens across the ArkLaTex
through early evening. This convection will become organized and
likely supercellular given the presence of around 30-40 kt of
deep-layer shear. Large to very large hail (potentially up to
1.5-2.5 inches in diameter) should be the main threat with these
cells initially. Lower confidence in convective initiation exists
with southwestward extent along the dryline in TX, but at least a conditional/low threat for severe hail remains apparent.

With time, some clustering may occur with an increased damaging wind
threat as convection spreads east-southeastward across the ArkLaTex
through the evening. One or more clusters may also redevelop along
the outflow from ongoing convection across the lower MS Valley this
afternoon, with a threat for mainly scattered damaging winds.
Low-level flow is not forecast to be overly strong (15-25 kt at 850
mb), but ample instability and the presence of locally backed
near-surface winds near the outflow boundary may support enough 0-1
km SRH for a few tornadoes, especially across southeast OK into the
ArkLaTex with any persistent supercells. An Enhanced Risk has been
introduced across this region given increased confidence in multiple
supercells with significant severe hail potential developing through
the afternoon/evening.

...Great Lakes/Ohio Valley...

A weak mid-level shortwave trough will move northeastward across the
Midwest and Upper Great Lakes today. Convection ahead of a cold
front has generally weakened this morning across the mid MS Valley.
Modest low-level moisture is forecast to continue advancing
northward through the day ahead of the front, supporting weak
instability with filtered daytime heating. Loosely organized
clusters/cells that develop this afternoon may pose an isolated
threat for damaging winds as they move northeastward this
afternoon/evening.

..Gleason/Thompson.. 04/24/2026

$$
--- MultiMail/DOS
* Origin: Project Scorpio TEST (618:250/6)

ACUS01 KWNS 281202
SWODY1
SPC AC 281200

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0700 AM CDT Tue Apr 28 2026

Valid 281300Z - 291200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN PLAINS INTO THE LOWER MISSISSIPPI VALLEY AND MID-SOUTH...

...SUMMARY...
Multiple rounds of severe thunderstorms will occur across parts of
the southern Plains into the lower Mississippi/Tennessee Valleys and
Southeast through this evening. Very large to giant hail (2-4+
inches), swaths of severe/damaging winds, and a few tornadoes are
all possible.

...Southern Plains into the Lower Mississippi Valley/Southeast...

With large-scale upper troughing anchored over the Plains and
central Canada, an embedded mid-level shortwave trough will eject
eastward across the southern/central Plains to the lower/mid MS
Valleys by this evening. Rich low-level moisture continues to spread
northward from TX into southern OK this morning in tandem with a
low-level jet, and this trend should continue downstream into the
lower MS Valley through the day as a warm front lifts northward to a
weak surface low across the Ozarks. Another surface low will remain
over northwest TX, with a dryline extending southwestward to the Big
Bend region.

A strongly unstable airmass exists across the southern Plains to the
ArkLaTex, along and near a slowly retreating/northward-returning
warm front. Elevated supercells are ongoing across western north TX.
This activity is being aided by lift and strong deep-layer shear
associated with the ejecting mid-level shortwave trough, and
low-level warm/moist advection. Current expectations are for these
supercells to continue posing a threat for mainly large to very
large hail through the rest of the morning as they spread
east-northeastward across north TX/southern OK. But, eventual
clustering and a greater damaging wind threat may materialize into
the afternoon as this convection crosses the front and accesses
greater instability across AR and the Ozarks.

Additional surface-based convective development is forecast near the
triple point in north-central TX towards the ArkLaTex this
afternoon, where extreme instability (4000+ J/kg MLCAPE) and very
strong deep-layer shear (50-60+ kt) will support the potential for
multiple intense supercells. Very large to giant hail (2-4+ inches)
may occur with the strongest supercells given the overall very
favorable environment and presence of steep mid-level lapse rates.
Some tornado threat may also exist with these supercells, even
though low-level shear is not forecast to be overly strong.

Numerous to widespread convection across the Mid-South to southern
Appalachians has generally diminished in intensity this morning. In
its wake, airmass recovery is anticipated today across the lower MS
Valley and Mid-South. A convectively reinforced front/outflow
boundary from the morning thunderstorms should attempt to lift
northward some through the day, with the greater instability
forecast across the lower MS Valley where steep mid-level lapse
rates are in place. Convective evolution across these areas through
the evening remains unclear, but multiple rounds of supercells and
multicell clusters capable of producing large hail, scattered to
numerous damaging winds, and perhaps a few tornadoes appear likely.
Less instability is forecast to the north of the ongoing convection
across the TN Valley, but some airmass recovery and severe threat
still appears possible by late afternoon/early evening.

..Gleason/Jewell.. 04/28/2026

$$
--- MultiMail/DOS
* Origin: Project Scorpio TEST (618:250/6)

ACUS01 KWNS 061243
SWODY1
SPC AC 061242

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0742 AM CDT Wed May 06 2026

Valid 061300Z - 071200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF NORTHERN LOUISIANA...CENTRAL MISSISSIPPI...AND CENTRAL ALABAMA...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE WESTERN
TEXAS HILL COUNTRY...

...SUMMARY...
Scattered severe thunderstorms are expected this afternoon and
evening from eastern Texas into the lower Mississippi and Tennessee Valleys/southern Appalachians. Supercells capable of all hazards
will be possible across portions of central Mississippi and Alabama
before a shift to a more of a damaging wind risk into the late evening/overnight.

...Synopsis...
Early-morning satellite imagery shows a pair of phased shortwave
troughs, one in the northern stream moving southward into UT/CO and
the other in southern stream off the southern CA/northern Baja
coast. Strong, confluent flow aloft exists downstream of these
shortwaves, with an extensive fetch of moderate to strong
southwesterly flow extending from northern Mexico into the
Northeast. A general deepening of the upper troughing is anticipated
throughout the day as the northern-stream shortwave continues
southeastward while the southern-stream shortwave moves gradually
eastward. This evolution will result in strengthening mid to upper
level flow from the southern Plain into New England, particularly
from the Lower MO Valley through the OH Valley where 500 mb flow
could exceed 100 kt. This evolution will also push a cold front,
which currently extends from the TX Hill Country into western PA,
farther south.

There will be some displacement between the strongest flow aloft and
the more warm and moist conditions south of the front. However,
even with this displacement, moderate to strong upper/mid flow is
still expected across much of the southern Plains and Southeast.
Strong to severe thunderstorms are still expected along and ahead of
this cold front from the TX Hill Country through the Southeast and
into the Carolinas. Highest coverage of severe thunderstorms will be
from central MS into central AL, where supercells capable of all
hazards will be possible.

...East TX/Lower MS Valley into the Southeast...

Recent surface analysis placed the cold front from near JCT in the
TX Hill Country northeastward through the Arklatex, northern MS, and
western TN. A weak low exists along this boundary over the western
AR/LA vicinity. 70s dewpoints extend from south TX across LA into
far western MS and southern AR, with upper 60s dewpoints through
much of MS. Low-level moisture advection is expected to continue
throughout the day, with mid 70s dewpoints possible from central LA
into central MS by the afternoon. This increasing moisture amid
filtered daytime heating will result in strong buoyancy ahead of the
front (i.e. 2500 J/kg of MLCAPE), despite poor mid-level lapse
rates. Also, as mentioned in the synopsis, strong deep-layer shear
will be in place, resulting in an overall airmass that supports supercells.

However, whether discrete supercells can develop and mature remains
uncertain. A combination of neutral height tendencies, widespread
cloud cover, and warm-air advection initiated storms will likely
lead to complex convective evolution and related storm interactions.
Majority of the convection-allowing guidance develops
thunderstorms within the warm sector from northern LA into central
MS by 18Z. Thunderstorm development is possible along the front from
northern AL into northern LA around this time as well. Large to very
large hail will be the primary risk with these storms, although
there is also a risk for tornadoes if a storm can remain discrete.
The tornado risk is expected to increase from the late afternoon
through the evening from central MS into central AL as low-level
hodographs lengthen in response to strengthening low-level flow.
Environmental conditions support the potential for a strong tornado
during this timeframe. Whether or not storms can realize this
increasing low-level shear will largely be a function of storm mode.
Storms should eventually begin to cluster and to grow upscale, with
an increasing damaging wind threat continuing downstream into
portions of southern Alabama and central/southern Georgia.

The front will continue slowly southward, and the very moist
environment could support additional warm sector storms throughout
much of the evening and overnight, supporting a continued risk for
all severe hazards. Several rounds of elevated storms are possible
as well, with hail as the primary risk with these storms.

...TX Hill Country into southeast TX...

A pair of supercells capable of large hail are currently ongoing
across southwest TX (Crockett and Sutton Counties). Environmental
conditions are favorable for storm maintenance for at least an hour
or two before northward displacement from the better buoyancy leads
to weakening. Additional isolated development is possible farther
east into central and southeast TX during the afternoon and evening.
Any storms that mature would likely be supercellular and capable of
producing severe hail and damaging wind gusts.

..Mosier/Dean.. 05/06/2026

$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

ACUS01 KWNS 102000
SWODY1
SPC AC 101958

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.

$$
--- MultiMail/DOS
* Origin: Project Scorpio TEST (618:250/6)

ACUS01 KWNS 151250
SWODY1
SPC AC 151248

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0748 AM CDT Fri May 15 2026

Valid 151300Z - 161200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF IOWA...

...SUMMARY...
Severe thunderstorms capable of producing severe/damaging winds and
large to very large hail are likely late this afternoon and evening
across much of Iowa and vicinity. Isolated to scattered severe hail
and damaging winds are possible over a broader area from parts of
the southern High Plains to the Upper Midwest.

...Central Plains into the Upper Midwest...

Generally zonal/westerly mid-level flow will persist over the
northern tier of the U.S. today, with an upper trough/low moving
slowly eastward over central Canada. At the surface, the primary low
will remain in northern Ontario, with a trailing cold front
extending southward into the Upper Midwest and northern/central
Plains. A secondary surface low will likely exist over southwest
KS/northwest OK by peak afternoon heating. A dryline will extend
southward from this low across much of the southern High Plains.

Current expectations are for robust thunderstorm development along
the cold front/surface trough from eastern NE into IA to be delayed
until late afternoon or early evening (around 22-00Z), as
large-scale ascent will remain weak until a low-amplitude shortwave
trough embedded within the westerly mid-level flow eventually
overspreads the surface warm sector. Continued low-level warm/moist
advection through the day and diurnal heating will contribute to the development of moderate to locally strong instability across this
region by early evening. While low-level winds are forecast to
remain fairly modest, enhanced mid/upper-level flow will support
sufficient deep-layer shear for updraft organization.

Initial supercells should pose a threat for large to isolated very
large hail (2+ inches in diameter), before likely quick upscale
growth this evening across IA supports a risk for mainly scattered severe/damaging winds. Some of these gusts could exceed 75 mph on a
localized basis given the expectation for an organized cluster and
ample instability. A tornado or two could also occur this evening as
low-level shear gradually increases with a strengthening low-level
jet. Some adjustments have been made to the Slight and Enhanced Risk
areas based on latest observational trends and short-term guidance.
Namely, the Slight Risk has been extended northward into parts of
southeast MN/southwest WI, where some risk for hail-producing
supercells should exist along/ahead of the front. The Enhanced Risk
has also been expanded to include more of western IA, as multiple
supercells may form and eventually congeal into one or more bowing
clusters through the evening.

...Southern High Plains...

Robust daytime heating will yield a very well-mixed/deep boundary
layer near/south of the secondary surface low over southwest KS and
vicinity. Mid-level temperatures will remain cool enough to support
at least weak instability, even with modest low-level
moisture/surface dewpoints. A weak mid-level shortwave trough moving
from the southern Rockies into the southern High Plains will enhance large-scale ascent late in the day. This should support the
development of high-based thunderstorms, with occasional strong to
severe wind gusts expected. Isolated gusts of 75+ mph may occur
given the very deeply mixed boundary layer extending up to around
500 mb. Cells that develop in west/southwest TX may contain marginal
hail, with elongated hodographs in mid/upper levels.

..Gleason/Bentley.. 05/15/2026

$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

ACUS01 KWNS 161249
SWODY1
SPC AC 161248

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0748 AM CDT Sat May 16 2026

Valid 161300Z - 171200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL HIGH PLAINS...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE OHIO VALLEY...

...SUMMARY...
Severe thunderstorms capable of producing large to very large hail, severe/damaging winds (some 75+ mph), and a few tornadoes should
occur this afternoon and evening across parts of the central Plains into Iowa.

...Synopsis...
Large-scale upper troughing will gradually amplify over the western
CONUS today, while modestly enhanced west-southwesterly mid-level
flow persists over the southern/central Plains. A separate
mid/upper-level trough with strong westerly mid-level jet will move
eastward across the Great Lakes and Ontario/Quebec through the day,
while remaining generally displaced to the north of the surface warm
sector. At the surface, a weak low over the southern High Plains
this morning should reform over the central High Plains of eastern
CO by late afternoon, as large-scale ascent preceding the western
CONUS upper trough gradually overspreads this region. Greater
low-level moisture will remain confined along/south of a
convectively reinforced front from NE/IA into the southern Great
Lakes region. A dryline will extend southward from this boundary
across the southern/central High Plains.

...Central High Plains to Iowa...

High-based thunderstorms that initially develop across the higher
terrain of central CO this afternoon will eventually encounter a
more unstable airmass in eastern CO/western KS, as low-level
moisture gradually increases in the bent back region to the
north/northwest of the surface low. An increase in convective
coverage and intensity is anticipated as this activity spreads
eastward across the central High Plains late this afternoon and
evening, aided by at least moderate instability and deep-layer
shear. While some supercell potential will exist, along with a
threat for large to isolated very large hail, most guidance
continues to suggest that an intense bowing cluster will develop and
spread eastward along/near the surface boundary across southern
NE/northern KS through the evening. A greater threat for severe
winds, some of which could be significant (75+ mph), remains
apparent, as steep low/mid-level lapse rates aid in efficient
downward momentum transfer within the convective cluster. A modest
expansion has been made to the Enhanced Risk to account for the
potential of a slightly larger cluster.

A separate area of robust convective development should also occur
farther east this afternoon/evening across parts of IA and vicinity
along/near the surface front. This activity will likely be aided by strengthening low-level warm advection this evening, and it may
persist through much of the night. The presence of steep mid-level
lapse rates, increasing low-level moisture, and daytime heating all
suggest that moderate to locally strong instability will likely be
in place by late afternoon along/south of the front. While westerly
mid-level flow should only be modestly enhanced, sufficient
deep-layer shear is forecast to support supercells initially. Large
to very large hail (isolated 2+ inches) appears possible within the
first couple hours of initiation, before thunderstorm
mergers/interactions occur and the overall mode becomes messy. Some
increase in the severe/damaging wind threat may develop if a more
organized cluster can emerge and spread east-southeastward through
the evening and early overnight hours. A few tornadoes also appear
possible through the evening with any sustained supercells. This
potential should remain focused along/near the front where backed
low-level easterly winds may locally enhance 0-1 km SRH.

...Southern High Plains...

Isolated thunderstorms may initiate this afternoon along the surface
dryline from southwest KS into the eastern OK/TX Panhandles and
western OK. While deep-layer shear will be weaker with southward
extent across the southern High Plains, a narrow zone of minimal
MLCIN along/east of the dryline may support isolated convection
capable of producing both locally severe hail and wind gusts.

...Mid Mississippi Valley into the Midwest/Ohio Valley...

Scattered to numerous thunderstorms are ongoing this morning from
central MO into the Midwest/OH Valley. This convection is likely
being aided by warm/moist advection associated with a
west-southwesterly low-level jet. While instability remains fairly
limited at the moment, some potential for occasional gusty winds and
marginally severe hail should continue through the late morning with
this activity. Greater destabilization is forecast along/south of
this ongoing convection across the lower OH Valley this afternoon.
One or more convectively enhanced MCVs may aid robust thunderstorm
development across parts of western/central KY, with a threat for
scattered damaging winds and isolated severe hail. A brief tornado
or two also appears possible. A Slight Risk has been introduced
across this area where a more focused risk for damaging winds has
become apparent in short-term guidance.

..Gleason/Bentley.. 05/16/2026

$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

ACUS01 KWNS 171252
SWODY1
SPC AC 171250

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0750 AM CDT Sun May 17 2026

Valid 171300Z - 181200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS AND MID MISSOURI VALLEY...

...SUMMARY...
Severe thunderstorms are expected this afternoon into tonight across
parts of the southern/central Plains to the Upper Midwest.
Supercells with very large hail and strong tornadoes are possible
initially this afternoon, before one or more bowing clusters leads
to a greater threat for severe/damaging winds this evening.

...Synopsis...
Large-scale upper troughing over the western CONUS should further
amplify today as an embedded mid-level jet and associated shortwave
trough move from the West Coast to the Four Corners region through
the period. A broad zone of around 40-50 kt southwesterly mid-level
flow will persist today from the southern/central High Plains to the
Upper Midwest, with multiple small-scale perturbations forecast to
advance northeastward across these regions. At the surface, a low
over western KS this morning is expected to gradually develop
northeastward towards the KS/NE border vicinity this evening. A
dryline trailing from this low will mix eastward through late
afternoon peak heating across the southern/central High Plains. A
warm front will attempt to lift northward today across NE/IA into
southeast SD and parts of southern MN, while a cold front is
forecast to gradually advance southeastward across the
northern/central Plains through the period.

...Southern/Central Plains into the Upper Midwest...

Initial thunderstorm development appears likely across eastern CO
this afternoon in a low-level upslope flow regime. This activity
will likely become supercellular and capable of producing large to
very large hail given the presence of steep mid-level lapse rates,
strong deep-layer shear, and moderate instability. By 20-22Z,
additional robust convection is expected to develop along/near the
cold front across north-central NE/south-central SD in a rapidly
destabilizing airmass. There is still some uncertainty with how far
north the warm front and related rich low-level moisture will reach
across the northern Plains/Upper Midwest, especially given ongoing
convection and related outflow this morning across NE/IA.

Still, an increasing large hail threat remains evident with any
convection that develops along/near the cold front this afternoon,
as ample MUCAPE and strong deep-layer shear will support organized
updrafts, including supercells initially. A strong tornado threat
will exist with any of these supercells that can become/remain
surface based, as low-level shear strengthens through the late
afternoon/early evening. A greater threat for severe/damaging winds
should develop as convection quickly grows upscale into bowing
clusters this evening. The northeastward extent of this severe wind
threat remains a bit uncertain, especially into southern/central MN
where the warm front is forecast to reach. A risk for embedded QLCS
tornadoes may continue with the surface-based portion of the cluster.

Thunderstorm initiation farther south along the length of the
dryline appears somewhat conditional given modest large-scale
ascent. But, most guidance continues to show at least isolated
high-based convection developing by late afternoon across parts of north-central KS southward into the eastern TX Panhandle/western OK.
Any thunderstorms which can be sustained will pose a threat for
large to very large hail and tornadoes, especially across KS where a
40-50 kt southerly low-level jet will enhance 0-1 km shear. A strong
tornado appears possible this evening with any supercell that can
persist, although there should be a tendency for upscale growth into
a severe wind producing cluster with time as the cold front
overtakes the dryline.

...Great Lakes/Lower Michigan...

Recent radar and visible satellite imagery show an MCV associated
with earlier convection across the central Plains is present over IA
this morning. This feature is forecast to track east-northeastward
today, and should approach eastern WI and Lower MI by late
afternoon/early evening. Modest enhancement to the low/mid-level
wind field should exist in close proximity to this MCV, and the
surface warm front is expected to gradually develop northward across
these regions through the day. Some intensification of convection is
possible this afternoon/evening along and near the warm front, with
sufficient instability and shear to support a mix of supercells and
multicell clusters capable of producing damaging winds, hail, and
perhaps a tornado. A Slight Risk has been added for parts of Lower
MI given increased confidence in this scenario occurring.

...Southeast...

On the western periphery of a surface high centered over the western
Atlantic, diurnally maximized thunderstorm development should focus
from the southern Appalachians across GA and the interior/western FL
Peninsula. Even though deep-layer shear will remain weak, a
favorable thermodynamic environment with steepened low-level lapse
rates should support strong to pulse-severe type convection capable
of producing isolated wind damage/downbursts and perhaps marginally
severe hail.

...Central and North Texas/ArkLaTex/Lower Mississippi Valley...

A fairly robust cap is expected to remain across the southern extent
of the warm sector today, with minimal/nebulous large-scale ascent
over the southern Plains. Still, some guidance suggests elevated
thunderstorms may develop through peak afternoon heating across
parts of northeast TX into the ArkLaTex/lower MS Valley in a
persistent low-level warm advection regime. If this occurs, then
isolated severe hail and damaging winds would be possible given the
strong MUCAPE forecast.

...Mid-Atlantic...

Mid-level ridging should build over the Mid-Atlantic through the
afternoon, which should tend to suppress most convection. However, a
weak mid-level perturbation noted in water vapor imagery this
morning over OH may support isolated convective development this
afternoon across parts of MD/PA and vicinity. The overall
environment does not appear overly favorable for organized severe thunderstorms, but gusty winds could occur with any of the stronger
cores that may develop.

..Gleason/Marsh.. 05/17/2026

$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)