ACUS01 KWNS 261257
SWODY1
SPC AC 261256

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0756 AM CDT Sun Apr 26 2026

Valid 261300Z - 271200Z

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

...SUMMARY...
Scattered severe thunderstorms with large to very hail, damaging
winds and tornadoes are expected this afternoon through tonight
across parts of the southern/central Plains. A couple of strong
tornadoes and hailstones up to 2-3 inches in diameter are possible.

...Southern/Central Plains to the Mid Mississippi Valley...

Fairly substantial changes have been made to the outlook based on
latest observational and guidance trends. Namely, the Enhanced Risk
has been expanded into northern OK to account for the potential of
both surface-based supercells this afternoon, and elevated
supercells this evening/tonight. The Slight Risk has been expanded
southward into north-central TX for a somewhat more
conditional/uncertain supercell threat. The eastern extent of severe probabilities have also been expanded in MO to account for a
potential cluster producing severe/damaging winds occurring late
tonight into early Monday morning.

A weak lead mid-level vorticity maximum over the central High Plains
this morning should continue to aid elevated thunderstorm
development across KS through the afternoon. Increasing MUCAPE with
persistent low-level warm/moist advection and steepening mid-level
lapse rates combined with strong deep-layer shear will support
organized updrafts, including the potential for supercells. This
convection will probably tend to remain elevated to the north of a
front as it spreads east-northeastward over the central Plains, but
scattered large hail may occur given the overall favorable
environment. Isolated 2+ inch diameter hail also appears possible
with the strongest cores. Eventually, this activity may pose a
greater threat for damaging winds across eastern KS into western MO
by late afternoon/early evening, if it can become truly surface based.

A more notable mid-level shortwave trough is expected to eject
northeastward across the Southwest and southern/central High Plans
today, accompanied by a 50-60 kt southwesterly mid-level jet. Weak
lee cyclogenesis is forecast to occur across the southeast
CO/northeast NM vicinity in response, with the surface low
developing into the OK Panhandle and southwest KS by this evening.
Strong to locally extreme instability is once again forecast to
develop to the east of a sharpening dryline across western/central
OK as daytime heating of a moist airmass occurs. There is still a
fair amount of uncertainty with the placement of an effective warm
front by late afternoon/early evening, but current expectations are
for this boundary to be draped somewhere near north-central OK by
peak afternoon heating. The surface triple point may serve as a
focus for convective initiation today, although better large-scale
ascent associated with the mid-level shortwave trough overspreading
the warm sector will be delayed until this evening and past peak
diurnal heating.

Greater than average uncertainty exists regarding the potential for surface-based convective initiation today in OK/north TX. Still, it
appears possible that multiple supercells may develop with gradual
erosion of lingering MLCIN and weak ascent preceding the ejecting
shortwave trough. Any supercells that can root and ingest the ample
low-level moisture will be capable of producing very large hail
(2-3+ inches in diameter) given a overall rather favorable
environment. The tornado potential is less clear through the day,
but a southerly low-level jet will quickly strengthen this evening
and aid curved/elongated hodographs with strong effective SRH. A
somewhat conditional/uncertain threat for a couple of strong
tornadoes remains apparent, especially if any supercells that can
form this afternoon persist into the evening.

Additional, somewhat elevated supercells may form this evening into
tonight along/north of the warm front from northwest OK near the
triple point into KS. This activity will also pose a threat for
large to very large hail. Some guidance suggests a cluster
eventually evolves from this convection across eastern KS into MO
late tonight/early Monday morning. If this occurs, then a greater
threat for severe/damaging winds would exist.

Farther south into TX, the forcing for ascent will remain
weak/nebulous along the dryline. Still, some potential for a few
supercells is apparent across north-central TX where the greatest
heating and minimal MLCIN is forecast to exist. Large to very large
hail should be the main threat with any splitting supercells that
can develop this afternoon along/east of the dryline and be sustained.

...ArkLaTex/Lower Mississippi Valley/Central Gulf Coast...

A small cluster will continue tracking southeastward this morning
from southern MS to the central Gulf Coast. With sufficient
low-level moisture and instability in place ahead of this
convection, isolated damaging winds may occur. A pair of supercells
across northeast TX have fluctuated in intensity over the past
couple of hours. The potential for additional thunderstorms to form
on the western flank/outflow of this morning convection remains
unclear given weak large-scale forcing and the low-level jet
forecast to weaken further through the morning. If any additional
convection can form, it would pose an isolated severe hail and
damaging wind threat.

..Gleason/Thompson.. 04/26/2026

$$

--- ScorpioBBS/QWK v0.32a (Linux/x86_64)
* Origin: Project Scorpio TEST (618:250/6)

ACUS01 KWNS 301236
SWODY1
SPC AC 301234

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0734 AM CDT Tue Jun 30 2026

Valid 301300Z - 011200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR WESTERN KANSAS...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
ENHANCED RISK AND OVER THE UPPER GREAT LAKES AND PARTS OF THE NORTHEAST...

...SUMMARY...
Scattered severe thunderstorms are probable over parts of the
central High Plains, with severe wind gusts (60 to 85 mph) being the
primary hazard during the late afternoon and evening.

...Synopsis...
Water-vapor imagery this morning shows a mid- to upper-level low
near the ND/Canadian border and a weak disturbance cresting a
mid-level ridge over southeastern ON and moving towards NY.
Downstream of a mid-level trough over the Southwest, a couple of
weak mid-level vorticity maxima over the southern and central High
Plains will slowly migrate northeast around the periphery of a
mid-level anticyclone centered over TN. A front will push east
across parts of the Upper Midwest and extend southwestward into the
central High Plains near a weak low. A weak lee trough/dryline will
focus storm development from western KS southward into the southern
High Plains.

...Southern/Central High Plains...
Perhaps associated with a weak disturbance, scattered thunderstorms
are forecast later this afternoon over the High Plains on the
western rim of richer low-level moisture and strong insolation.
Model guidance shows considerable erosion of the capping layer by
mid afternoon with MLCAPE ranging from 1500 J/kg over the TX South
Plains to 3500 J/kg over western KS. Initially higher-based
convection will gradually move east into richer moisture and promote
larger thunderstorm cores and increased potential for storm clusters
to develop. Large hail will be possible with any supercell activity
(i.e., most probable from the northern TX Panhandle into KS; 25-40
kt effective shear). However, very steep surface to 300-mb lapse
rates will favor strong evaporative cooling with the more intense
cores. Ample deep-layer shear for organized storms but
veering/backing of flow with height will aid in storm outflow
aggregating as linear clusters become the primary storm mode with
time. These organized but linear clusters will likely be efficient
in promoting severe wind gusts (60-85 mph) during the early evening,
coincident with a strengthening LLJ and WAA before this threat wanes
by late evening. Weaker deep-layer shear farther south in the
southern High Plains will likely limit both storm organization and
overall coverage of the wind risk.

...Upper Midwest/Great Lakes...
An ongoing area of showers and isolated thunderstorms over the upper
MS Valley will likely translate east-northeast today in conjunction
with a convectively augmented mid-level disturbance over southern MN
this morning. Ahead of this activity, a fetch of very rich moisture
will be maintained within south-southwesterly low-level flow. As
the boundary layer destabilizes ahead of this disturbance,
additional storms are forecast to develop later today within a very
to extremely unstable airmass. Ample tropospheric flow will support
organized storms, including supercells capable primarily of a
hail/wind risk and perhaps a tornado. By late evening,
strengthening WAA across NE and the mid MO Valley implies widely
scattered storms developing during the mid-late evening, with this
activity shifting northeast during the overnight. Isolated
hail/wind are the main threats with the stronger storms.

...Northeast...
A belt of 30-40 kt 500-mb northwesterly flow will reside across the
Northeast today. There is uncertainty regarding boundary layer
destabilization over portions of this region. Nonetheless, weak to
moderate destabilization is progged by model guidance with isolated
to scattered storms developing by early afternoon. A couple of
short-lived supercells are possible before one or more
clusters/bowing segments develop and spread south and eastward with
damaging wind potential.

...Southeastern US...
Located to the south of an upper high centered over the OH/TN
Valley, a very moist air mass will be present across much of the
region. Strong heating will yield moderate buoyancy by early
afternoon. Forecast soundings depict around 20-kt effective shear
which will aid in minor multicellular organization. Localized 50-60
mph gusts capable of isolated wind damage will probably accompany
the stronger storms.

..Smith/Dean.. 06/30/2026

$$

--- Scorpio BBS
* Origin: (618:250/10)