Mesoscale Discussion 2309
NWS Storm Prediction Center Norman OK
0234 PM CDT Sat Sep 19 2026

Areas affected...northwest Oklahoma into much of central to
northeast Kansas

Concerning...Severe potential...Watch possible 

Valid 191934Z - 192130Z

Probability of Watch Issuance...60 percent

SUMMARY...Storms will develop into northwest Oklahoma, and from
central into northeast Kansas later this afternoon. Scattered severe
wind gusts and sporadic marginal hail will be possible.

DISCUSSION...A cold front extends from the OK/northern TX Panhandles
into central KS, and from northern KS into southeast NE. Strong
heating and a plume of steep low-level lapse rates exists ahead of
this cold front, with temperatures near 100 F from TX into southern
KS. Despite boundary layer mixing, dewpoints remain near 60 F over
the eastern TX Panhandle, with mid 60s F from western OK toward
Wichita.

The 18Z AMA soundings shows moderate instability, though shear is
weak. Still, mean southwest flow through a deep layer will support
east/northeast storm motions, with a bit stronger flow overall into
KS.

Visible imagery and radar already show agitated CU fields and
initial deeper convection developing west of KGAG in OK, and this is
where initial storms are expected in the near term. Additional
storms will form along the cold front later this afternoon into KS.

Despite weak shear, thermodynamics appear to support multicell storm
mode with damaging wind gust potential with moderate instability,
steep low-level lapse rates and high DCAPE. A few of the stronger
storms may briefly produce hail over 1.00" diameter.

..Jewell.. 09/19/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...TOP...ICT...OUN...GID...DDC...AMA...

LAT...LON   36659823 35389993 35310030 35500042 35920040 36620006
            37309956 38109917 38919877 39239819 39459744 39689676
            39629600 39249588 38669623 36659823 

MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1129 AM CDT Sat Sep 19 2026

Valid 191630Z - 201200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS AND CENTRAL HIGH PLAINS...

...SUMMARY...
Thunderstorms with scattered severe wind gusts and large hail are
possible this afternoon and evening across parts of the central
Plains.

...Ohio Valley...
Recent surface analysis places a weak low over northern IN, along
the northern end of an outflow boundary that is pushing
southward/south-southeastward across central IL and central IN.
Airmass south of this boundary is very moist, with dewpoints
generally in the upper 60s to low 70s. Filtered heating is
anticipated across this region today, with the resulting warm and
moist conditions supporting moderate buoyancy. The strongest
buoyancy is expected from southern IN into southwest OH and adjacent
far northern KY. The surging character of the outflow combined with
limited deep-layer vertical shear results in uncertainty regarding
how thunderstorms will evolve this afternoon, with at least some
potential for a predominance of undercut, poorly organized updrafts.
That being said, potential also exists for just enough
buoyancy/shear balance for a few stronger, more persistent bowing
clusters. Steep low-level lapse rates will promote strong to severe
gusts with any more persistent line segments that develop. 

...Southern Appalachians/Southeast...
Warm and moist conditions will support airmass destabilization and
the potential of afternoon/evening thunderstorms across the region.
The region is largely void of coherent surface features, so any
convective initiation would likely be tied to mesoscale areas of
low-level confluence. Widely scattered to scattered storms are
forecast during the afternoon, and a few stronger water-loaded
downdrafts capable of 50 to 60 mph gusts are possible.

...Central and Southern Plains/Lower Missouri Valley...
Recent surface analysis places a low over southwest IA, with a cold
front extending back southwestward through southwest KS and the
central OK Panhandle into the northwest TX Panhandle. This front is
expected to slowly push south while larger-scale mid-level troughing
over the Great Basin and central Rockies gradually shifts eastward.
A seasonably moist airmass is in place ahead of the cold front, and
moderate buoyancy is expected as this airmass heats and destabilizes
this afternoon. 

Low-level convergence along the cold front, augmented by modest
large-scale forcing for ascent, will support scattered storm
development during the late afternoon and early evening as
convective inhibition is locally eroded. Given adequate speed and
directional shear, a few short-lived supercells are possible early
in the convective cycle, particularly across KS. Large hail will be
possible with the stronger updrafts. Thereafter, high-based storm
character coupled with steep low-level lapse rates will support
strong to severe gusts, including the potential for a few gusts of
60 to 75 mph.

...Central High Plains...
Low-level easterly flow across the central High Plains will help
maintain at least upper 50s/low 60s dewpoints across the region this
afternoon/evening. The low-amplitude shortwave trough currently
moving through northern NV/UT is forecast to continue eastward,
interacting with this moist and unstable airmass to support
scattered thunderstorm development. With time, strengthening
mid-level flow will help support upscale growth from a loosely
organized band of a storms (including some supercells) to a more
organized linear cluster. Some hail is possible early with the more
cellular development, with wind gusts becoming more likely with
time. There is some indication this activity may continue into
western KS during the late evening and early overnight.

..Mosier/Chalmers.. 09/19/2026

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1158 AM CDT Sat Sep 19 2026

Valid 201200Z - 211200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL
HIGH PLAINS AND PORTIONS OF OKLAHOMA...

...SUMMARY...
A few severe wind and hail producing thunderstorms are possible over
eastern Colorado on Sunday, with severe gusts also possible with
storms over portions of Oklahoma. Isolated severe thunderstorms are
also possible from the Ozarks to the central Appalachians.

...Central/Southern Plains...

A weak upper shortwave trough will move across the central Rockies
and adjacent High Plains on Sunday. This will bring modestly
enhanced mid/upper westerly flow to the region. At the surface,
easterly upslope flow is expected across eastern CO into the OK/TX
Panhandles. Vertically veering wind profiles will foster 25-35 kt
effective shear magnitudes. Steepening midlevel lapse rates and
modest MLCAPE (500-1500 J/kg) amid favorable vertical shear profiles
will foster potential for organized updrafts capable of isolated
large hail. Surface temperatures will be somewhat cool, but strong
heating will result in steepening low-level lapse rates as well, and
isolated gusty outflow winds also will be possible. 

Further south into the OK/TX Panhandle vicinity, somewhat better
boundary layer moisture will be in place in the vicinity of a cold
front. Isolated thunderstorms are expected to develop during the
afternoon and may pose a risk for isolated marginal hail and gusty
winds. Further east across OK, a surface low is forecast across
western portions of the state, with a cold front extending southwest
to northeast across north-central/northeast OK. Rich boundary layer
moisture is forecast near and east of the front, supporting moderate
instability (1500-2500 J/kg MLCAPE) where stronger heating occurs.
Early day showers and cloud cover introduces some uncertainty
regarding location of better severe risk during the
afternoon/evening, but isolated to scattered thunderstorm clusters
will pose a risk of wind damage and perhaps isolate hail across
parts of OK into north TX. 

...Ozark to Ohio Valley...

A surface cold front will extend west to east from central MO to
central OH by midday. A seasonally moist airmass and strong heating
ahead of the boundary will support widely scattered thunderstorm
develop as the front develops south through the afternoon/evening.
Weak vertical shear will limit longevity/organization of stronger
storm updrafts. Nevertheless, moderate instability (1500-2500 J/kg
MLCAPE) and steepened low-level lapse rates will support some risk
for isolated damaging gusts. Cool temperatures aloft may also
support marginal hail in the stronger updraft pulses. 

...Central Appalachians...

Thunderstorms are expected to develop near higher terrain along a
surface trough Sunday afternoon across parts WV/VA. Vertical shear
and midlevel lapse rates are expected to remain weak. However, a
moist airmass will support modest instability and steepening
low-level lapse rates will aid in isolated strong outflow gusts,
perhaps resulting in sporadic wind damage.

..Leitman.. 09/19/2026

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0211 PM CDT Sat Sep 19 2026

Valid 211200Z - 221200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
THE SOUTHERN/CENTRAL APPALACHIANS...

...SUMMARY...
Isolated severe gusts may accompany the stronger storms over parts
of the southern and central Appalachians on Monday.

...Central/Southern Appalachians...

Mainly zonal flow will overspread the eastern CONUS on Monday. While
weak westerly flow aloft is forecast, a surface cold front will
continue to develop southward across the Midwest, TN Valley and
central Appalachians/Mid-Atlantic regions. A moist airmass ahead of
the front, characterized by 60s to low 70s F dewpoints, will support
a corridor of moderate instability (1500-2500 J/kg MLCAPE) from the
eastern TN Valley toward the southern/central Appalachians. Where
stronger heating occurs, steepened low-level lapse rates are
forecast. Sufficient instability coupled with steep low-level lapse
rates and PW values around 1.75 inches may support sporadic strong
gusts from wet microbursts across parts of the TN Valley into
southern VA and western/central NC.

..Leitman.. 09/19/2026