LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0722 AM CDT Tue Sep 22 2026
Valid 221300Z - 231200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR MUCH OF UTAH
INTO ADJACENT PARTS OF WYOMING AND COLORADO...AND ACROSS A PORTION
OF THE SOUTHEAST...
...SUMMARY...
An isolated threat for severe wind gusts is expected today in Utah
into southwest Wyoming and western Colorado. Thunderstorms capable
of strong to locally severe damaging gusts are also possible across
parts of the Southeast.
...Utah into southwest Wyoming and western Colorado...
Water-vapor imagery this morning shows a potent mid-level trough
over the western Great Basin. This upper feature and an
accompanying speed max ---beginning to be sampled by the Cedar City,
UT WSR-88D VAD (KICX)--- are forecast to move northeast across UT
through early evening. In the wake of early day showers and a few
thunderstorms associated with an initial lobe of ascent, some
heating will yield steepened 0-2 km lapse rates and the development
of marginal buoyancy. As storms develop and intensify, elongated
hodographs will support a few stronger cells to be capable of
marginally severe hail. However, 60 to 75 mph gusts on an isolated
basis will likely be the primary severe hazard. This activity will
eventually move into western CO and southwest WY towards the late
afternoon/early evening with severe gusts potentially in proximity
to stronger cores and outflow.
...Southeast...
A slow-moving cold front will aid in focusing thunderstorms across
portions of the Deep South into the southern Appalachians. Heating
of a moist airmass featuring upper 60s to lower 70s deg F surface
dewpoints will likely result in 1500-2500 J/kg MLCAPE by early to
mid afternoon. Weak low to mid tropospheric flow will limit overall
storm vigor, but some of the stronger water-loaded downdrafts will
probably be capable of strong to locally severe gusts and pockets of
wind damage into the early evening.
..Smith/Mead.. 09/22/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVbRBl
Windy.com Temps | Gusts | WU KORD KPWK |
CLICK for this month's BIG night sky ... | RADAR FULL MAP SCREEN |
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MOBILE DEVICE? Turn sideways. Weather conditions directly above are near Lakefront. Top tabs refer to O'Hare (official).
Archives for the SPC Convective Outlook are updated daily (approximately) with a live map at the beginning of each article. Follow the link at the end of the article to check for current updates on the NOAA/NWS Storm Prediction Center website. Also, see Archives for Chicago's hourly weather data on CARDINAL NEWS Magazine.
CONVECTIVE | TORNADO | WIND | HAIL
O'Hare International Airport KORD
(Arlington Heights South)
Chicago Executive Airport KPWK
(Arlington Heights North)
Tuesday, September 22, 2026
SPC Sep 22, 2026 1300 UTC Day 1 Convective Outlook
SPC Sep 22, 2026 0600 UTC Day 1 Convective Outlook
LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1250 AM CDT Tue Sep 22 2026
Valid 221200Z - 231200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHEAST...AND IN THE VICINITY OF NORTH-CENTRAL AND
NORTHEASTERN UTAH....
...SUMMARY...
Thunderstorms with isolated severe wind gusts are possible today
across parts of the Southeast, and in the vicinity of north-central
and northeastern Utah.
...Southeast...
At the surface, a cold front will advance southward into the
Southeast today. The position of the front by afternoon will be from
the northern Gulf Coast States into southern Appalachians. Warming
surface temperatures and increasing low-level convergence near and
ahead of the boundary will result in scattered thunderstorm
development this afternoon. Surface dewpoints across the moist
airmass will mostly range from the mid 60s to mid 70s F. This will
aid destabilization, with MLCAPE expected to peak in the 1500 to
2500 J/kg in most areas ahead of the front. Although deep-layer
shear will be limited, the thermodynamic environment will be able to
support isolated severe wind gusts with convection that develops
within the strongest localized instability.
...North-central and Northeastern Utah/Far Southwest Wyoming...
A mid-level trough and low pressure center will move northeastward
across the Intermountain West today. Ahead of the system, a surface
low will deepen across western Utah. To the east and northeast of
the low, surface dewpoints will range from the mid 40s to mid 50s F.
This will be enough for the development of weak instability by
afternoon. MLCAPE is forecast to increase to around 1000 J/kg over
much of north-central and northeast Utah, as a cold pocket
associated with the approaching upper-level low begins to affect the
area. The Salt Lake City RAP forecast sounding at 21Z has 0-6 km
shear near 40 knots with steep low to mid-level lapse rates in the 7
to 8 C/km range. This should support an isolated potential for
supercells. Hail and isolated severe gusts would be the primary
threats.
..Broyles/Thornton.. 09/22/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVb9J3
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1250 AM CDT Tue Sep 22 2026
Valid 221200Z - 231200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHEAST...AND IN THE VICINITY OF NORTH-CENTRAL AND
NORTHEASTERN UTAH....
...SUMMARY...
Thunderstorms with isolated severe wind gusts are possible today
across parts of the Southeast, and in the vicinity of north-central
and northeastern Utah.
...Southeast...
At the surface, a cold front will advance southward into the
Southeast today. The position of the front by afternoon will be from
the northern Gulf Coast States into southern Appalachians. Warming
surface temperatures and increasing low-level convergence near and
ahead of the boundary will result in scattered thunderstorm
development this afternoon. Surface dewpoints across the moist
airmass will mostly range from the mid 60s to mid 70s F. This will
aid destabilization, with MLCAPE expected to peak in the 1500 to
2500 J/kg in most areas ahead of the front. Although deep-layer
shear will be limited, the thermodynamic environment will be able to
support isolated severe wind gusts with convection that develops
within the strongest localized instability.
...North-central and Northeastern Utah/Far Southwest Wyoming...
A mid-level trough and low pressure center will move northeastward
across the Intermountain West today. Ahead of the system, a surface
low will deepen across western Utah. To the east and northeast of
the low, surface dewpoints will range from the mid 40s to mid 50s F.
This will be enough for the development of weak instability by
afternoon. MLCAPE is forecast to increase to around 1000 J/kg over
much of north-central and northeast Utah, as a cold pocket
associated with the approaching upper-level low begins to affect the
area. The Salt Lake City RAP forecast sounding at 21Z has 0-6 km
shear near 40 knots with steep low to mid-level lapse rates in the 7
to 8 C/km range. This should support an isolated potential for
supercells. Hail and isolated severe gusts would be the primary
threats.
..Broyles/Thornton.. 09/22/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVb9J3
Monday, September 21, 2026
SPC Sep 21, 2026 2000 UTC Day 1 Convective Outlook
LIVE MAP (ABOVE) ... SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0256 PM CDT Mon Sep 21 2026
Valid 212000Z - 221200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE SOUTHEAST INTO CENTRAL APPALACHIANS AND OVER THE TEXAS SOUTH
PLAINS...
...SUMMARY...
Isolated damaging wind gusts remain possible this afternoon from
parts of the Southeast into the southern and central Appalachians.
An isolated risk for large hail and severe gusts is also forecast
over parts of the Texas South Plains later today.
...20z Update...
No changes were made to the existing outlook with this update cycle
as the forecast remains on track. See MCD #2323 and the discussion
below for additional information.
..Chalmers/Wendt.. 09/21/2026
.PREV DISCUSSION... /ISSUED 1125 AM CDT Mon Sep 21 2026/
...Southeast/Southern and Central Appalachians...
Recent radar and satellite imagery reveals a trio of MCVs over the
OH Valley, with perhaps another MCV farther southwest in the
Mid-South vicinity. These vorticity maxima are north/west of an
arcing cold front that extends from southern VA west-northwest into
northern KY and then back southwestward through northern AR and
central OK into the TX South Plains. A moist airmass persists south
of this boundary, with dewpoints in the low 70s across much of
Southeast, TN Valley, and Carolinas. The front is forecast to slowly
shift southward today, interacting with the moist, diurnally
destabilized, and moderately buoyant airmass to support scattered
thunderstorms. Vertical shear will be weak, and largely
multicellular, outflow-dominant storm mode is anticipated. Even so,
ample moisture is in place (i.e. PW values over 2" sampled on the
12Z BMX sounding), and sporadic stronger downdrafts may yield a
strong to locally severe gusts (50 to 60 mph). Highest thunderstorm
coverage is expected from southeast TN and northwest GA through
northern AL into central/southern MS and eastern LA.
...TX South Plains into north-central/northeast TX...
Western periphery of the front described in the previous section
intersects a weak low over far southeast NM. A moist airmass exists
along and south of this boundary, with dewpoints ranging from the
low 60s over the TX South Plains to the low 70s across much of
central and eastern TX. Easterly flow will help maintain this
moisture amid strong heating over the TX South Plain vicinity,
contributing to airmass destabilization and moderate buoyancy by
this afternoon. Low-level convergence along the front (and/or
residual outflow) and near the surface low will likely result in
scattered thunderstorm development. Vertical shear will be modest,
but any stronger, more persistent thunderstorms may yield an
isolated risk for large hail/severe gusts before dissipating during
the evening.
A secondary area of higher thunderstorm coverage appears likely over
northeast TX this afternoon/evening. Here, differential heating
and/or outflow from ongoing thunderstorms could result in an area of
increased low-level convergence within a warm, moist, and moderately
unstable airmass this afternoon. Isolated water-loaded downbursts
capable of producing damaging wind gusts are possible. Anticipated
limited severe coverage precludes introducing low wind probabilities
in this area.
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVb2XV
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0256 PM CDT Mon Sep 21 2026
Valid 212000Z - 221200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE SOUTHEAST INTO CENTRAL APPALACHIANS AND OVER THE TEXAS SOUTH
PLAINS...
...SUMMARY...
Isolated damaging wind gusts remain possible this afternoon from
parts of the Southeast into the southern and central Appalachians.
An isolated risk for large hail and severe gusts is also forecast
over parts of the Texas South Plains later today.
...20z Update...
No changes were made to the existing outlook with this update cycle
as the forecast remains on track. See MCD #2323 and the discussion
below for additional information.
..Chalmers/Wendt.. 09/21/2026
.PREV DISCUSSION... /ISSUED 1125 AM CDT Mon Sep 21 2026/
...Southeast/Southern and Central Appalachians...
Recent radar and satellite imagery reveals a trio of MCVs over the
OH Valley, with perhaps another MCV farther southwest in the
Mid-South vicinity. These vorticity maxima are north/west of an
arcing cold front that extends from southern VA west-northwest into
northern KY and then back southwestward through northern AR and
central OK into the TX South Plains. A moist airmass persists south
of this boundary, with dewpoints in the low 70s across much of
Southeast, TN Valley, and Carolinas. The front is forecast to slowly
shift southward today, interacting with the moist, diurnally
destabilized, and moderately buoyant airmass to support scattered
thunderstorms. Vertical shear will be weak, and largely
multicellular, outflow-dominant storm mode is anticipated. Even so,
ample moisture is in place (i.e. PW values over 2" sampled on the
12Z BMX sounding), and sporadic stronger downdrafts may yield a
strong to locally severe gusts (50 to 60 mph). Highest thunderstorm
coverage is expected from southeast TN and northwest GA through
northern AL into central/southern MS and eastern LA.
...TX South Plains into north-central/northeast TX...
Western periphery of the front described in the previous section
intersects a weak low over far southeast NM. A moist airmass exists
along and south of this boundary, with dewpoints ranging from the
low 60s over the TX South Plains to the low 70s across much of
central and eastern TX. Easterly flow will help maintain this
moisture amid strong heating over the TX South Plain vicinity,
contributing to airmass destabilization and moderate buoyancy by
this afternoon. Low-level convergence along the front (and/or
residual outflow) and near the surface low will likely result in
scattered thunderstorm development. Vertical shear will be modest,
but any stronger, more persistent thunderstorms may yield an
isolated risk for large hail/severe gusts before dissipating during
the evening.
A secondary area of higher thunderstorm coverage appears likely over
northeast TX this afternoon/evening. Here, differential heating
and/or outflow from ongoing thunderstorms could result in an area of
increased low-level convergence within a warm, moist, and moderately
unstable airmass this afternoon. Isolated water-loaded downbursts
capable of producing damaging wind gusts are possible. Anticipated
limited severe coverage precludes introducing low wind probabilities
in this area.
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVb2XV
SPC Sep 21, 2026 1630 UTC Day 1 Convective Outlook
LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1125 AM CDT Mon Sep 21 2026
Valid 211630Z - 221200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE SOUTHEAST INTO CENTRAL APPALACHIANS...AND OVER THE TEXAS SOUTH
PLAINS...
...SUMMARY...
Isolated damaging wind gusts are possible this afternoon from parts
of the Southeast into the southern and central Appalachians. An
isolated risk for large hail and severe gusts is forecast over parts
of the Texas South Plains later today.
...Southeast/Southern and Central Appalachians...
Recent radar and satellite imagery reveals a trio of MCVs over the
OH Valley, with perhaps another MCV farther southwest in the
Mid-South vicinity. These vorticity maxima are north/west of an
arcing cold front that extends from southern VA west-northwest into
northern KY and then back southwestward through northern AR and
central OK into the TX South Plains. A moist airmass persists south
of this boundary, with dewpoints in the low 70s across much of
Southeast, TN Valley, and Carolinas. The front is forecast to slowly
shift southward today, interacting with the moist, diurnally
destabilized, and moderately buoyant airmass to support scattered
thunderstorms. Vertical shear will be weak, and largely
multicellular, outflow-dominant storm mode is anticipated. Even so,
ample moisture is in place (i.e. PW values over 2" sampled on the
12Z BMX sounding), and sporadic stronger downdrafts may yield a
strong to locally severe gusts (50 to 60 mph). Highest thunderstorm
coverage is expected from southeast TN and northwest GA through
northern AL into central/southern MS and eastern LA.
...TX South Plains into north-central/northeast TX...
Western periphery of the front described in the previous section
intersects a weak low over far southeast NM. A moist airmass exists
along and south of this boundary, with dewpoints ranging from the
low 60s over the TX South Plains to the low 70s across much of
central and eastern TX. Easterly flow will help maintain this
moisture amid strong heating over the TX South Plain vicinity,
contributing to airmass destabilization and moderate buoyancy by
this afternoon. Low-level convergence along the front (and/or
residual outflow) and near the surface low will likely result in
scattered thunderstorm development. Vertical shear will be modest,
but any stronger, more persistent thunderstorms may yield an
isolated risk for large hail/severe gusts before dissipating during
the evening.
A secondary area of higher thunderstorm coverage appears likely over
northeast TX this afternoon/evening. Here, differential heating
and/or outflow from ongoing thunderstorms could result in an area of
increased low-level convergence within a warm, moist, and moderately
unstable airmass this afternoon. Isolated water-loaded downbursts
capable of producing damaging wind gusts are possible. Anticipated
limited severe coverage precludes introducing low wind probabilities
in this area.
..Mosier/Chalmers.. 09/21/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVZtZk
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1125 AM CDT Mon Sep 21 2026
Valid 211630Z - 221200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE SOUTHEAST INTO CENTRAL APPALACHIANS...AND OVER THE TEXAS SOUTH
PLAINS...
...SUMMARY...
Isolated damaging wind gusts are possible this afternoon from parts
of the Southeast into the southern and central Appalachians. An
isolated risk for large hail and severe gusts is forecast over parts
of the Texas South Plains later today.
...Southeast/Southern and Central Appalachians...
Recent radar and satellite imagery reveals a trio of MCVs over the
OH Valley, with perhaps another MCV farther southwest in the
Mid-South vicinity. These vorticity maxima are north/west of an
arcing cold front that extends from southern VA west-northwest into
northern KY and then back southwestward through northern AR and
central OK into the TX South Plains. A moist airmass persists south
of this boundary, with dewpoints in the low 70s across much of
Southeast, TN Valley, and Carolinas. The front is forecast to slowly
shift southward today, interacting with the moist, diurnally
destabilized, and moderately buoyant airmass to support scattered
thunderstorms. Vertical shear will be weak, and largely
multicellular, outflow-dominant storm mode is anticipated. Even so,
ample moisture is in place (i.e. PW values over 2" sampled on the
12Z BMX sounding), and sporadic stronger downdrafts may yield a
strong to locally severe gusts (50 to 60 mph). Highest thunderstorm
coverage is expected from southeast TN and northwest GA through
northern AL into central/southern MS and eastern LA.
...TX South Plains into north-central/northeast TX...
Western periphery of the front described in the previous section
intersects a weak low over far southeast NM. A moist airmass exists
along and south of this boundary, with dewpoints ranging from the
low 60s over the TX South Plains to the low 70s across much of
central and eastern TX. Easterly flow will help maintain this
moisture amid strong heating over the TX South Plain vicinity,
contributing to airmass destabilization and moderate buoyancy by
this afternoon. Low-level convergence along the front (and/or
residual outflow) and near the surface low will likely result in
scattered thunderstorm development. Vertical shear will be modest,
but any stronger, more persistent thunderstorms may yield an
isolated risk for large hail/severe gusts before dissipating during
the evening.
A secondary area of higher thunderstorm coverage appears likely over
northeast TX this afternoon/evening. Here, differential heating
and/or outflow from ongoing thunderstorms could result in an area of
increased low-level convergence within a warm, moist, and moderately
unstable airmass this afternoon. Isolated water-loaded downbursts
capable of producing damaging wind gusts are possible. Anticipated
limited severe coverage precludes introducing low wind probabilities
in this area.
..Mosier/Chalmers.. 09/21/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVZtZk
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