SPC Convective Outlook Day 1

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790
ACUS01 KWNS 091940
SWODY1
SPC AC 091939

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0239 PM CDT Mon Mar 09 2026

Valid 092000Z - 101200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
ARKANSAS EAST-SOUTHEASTWARD INTO WESTERN AND CENTRAL ALABAMA...

...SUMMARY...
Large hail, damaging winds and a couple of tornadoes are possible
this afternoon/evening from the Mid-South into northwest Georgia.

...20Z Update...
Two changes have been made to the outlook for this issuance. The
first change is to trim southeast Oklahoma mostly out of thunder,
and completely out of the hail and wind probabilities. The second
change is to add thunder across parts of South Carolina and Georgia.

..Broyles.. 03/09/2026

.PREV DISCUSSION... /ISSUED 1130 AM CDT Mon Mar 09 2026/

...AR to north GA this afternoon/evening...
A weak mid-upper speed max is cresting the larger-scale ridge and
will move from AR to the TN Valley this afternoon/evening.
Associated/ongoing convection across AR will likely persist through
the afternoon with some tendency for upscale growth, while spreading
eastward along the northern gradient of boundary-layer dewpoints in
the low-mid 60s. Surface heating in cloud breaks, beneath the
eastern extent of 7-8 C/km midlevel lapse rates, will contribute to
moderate buoyancy (MLCAPE of 1000-1500 J/kg) along this corridor
with minimal convective inhibition.

Deep-layer vertical shear will be sufficient for a somewhat
organized/bowing storm cluster to evolve from the ongoing AR storms
as they spread across the TN Valley this afternoon, potentially
reaching northwest GA by late evening. The initial storms in the
cluster will pose a threat for large hail (1-2"diameter), with some
increase in the threat for wind damage from northern MS across
northern AL/northwest GA. More discrete storms will be possible
immediately south of the MCS path this afternoon/evening as a
maritime tropical air mass (68-72 F dewpoints) spreads inland. Wind
profiles will support supercells capable of producing large hail
(some could exceed 2 inches in diameter). A modest increase in
low-level shear this afternoon, combined with rich low-level
moisture and the possibility of lingering convective outflow from
the ongoing storms in AR will also support the potential for a
couple of tornadoes.

Isolated thunderstorm development may also occur farther southwest
along the marine warm front into southeast TX, where there is a
conditional threat for large hail.

...Southern AZ this afternoon/evening...
High-based, low-topped convection is expected in the band of ascent
immediately north-northeast of the closed low near northern Baja.
Low-level moisture will be somewhat limited, but steep low-midlevel
lapse rates and substantial south-southeasterly deep-layer shear
will support a few storms/clusters capable of marginally severe hail
and gusts approaching 60 mph.

$$

The "Convective Outlooks" issued by SPC can be thought of as a detailed discussion of the Severe Thunderstorm threat and it's associated risks nationwide. Risk levels range from Marginal to Slight, Enhanced, Moderate, and High and are issued based on the likelihood of 3 major severe weather threats; the risk of tornadoes, damaging winds, and hail. These discussions are often heavily laced meteorological terminology that may be difficult to understand without a background in the field. However understanding these discussions shouldn't be thought of as necessary. Instead, should DuPage county fall under one of these threat levels for severe weather, the response should be to have a heightened level of awareness about the deveoloping weather. Keep an eye on the "Watch County Notification" for any active severe weather watches issued for DuPage county; the "Hazardous Weather Outlook" and "Severe Weather Statement" can also be helpful in explaining the developing risk; additionally, watch for "Active Weather Warnings" and keep an eye on our "Regional Satellite and Radar" products which can be viewed with active watches/warnings or lightning activity.

Hazardous Weather Outlook

See Product Description

811
FLUS43 KLOT 092039
HWOLOT

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
339 PM CDT Mon Mar 9 2026

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-102045-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-
La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-
Northern Cook-Central Cook-Southern Cook-Northern Will-
Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-Benton-
339 PM CDT Mon Mar 9 2026 /439 PM EDT Mon Mar 9 2026/

This Hazardous Weather Outlook is for portions of north central
Illinois...northeast Illinois and northwest Indiana.

.DAY ONE...Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Tuesday...
Elevated Flooding Risk.
Elevated Thunderstorm Risk...with an associated:
Level 3 of 5 Severe Thunderstorm Risk.
Wednesday Morning...
Limited Thunderstorm Risk south of I-80.

DISCUSSION...

Severe thunderstorms will be possible late Tuesday afternoon
into Tuesday evening. A front is expected to set up along or
just south of the Interstate 80 corridor, with large hail,
damaging winds, and tornadoes possible south of this front.
North of this front, large hail will be possible.

Locally heavy rainfall may occur late Tuesday afternoon into
early Wednesday morning and may lead to localized flash
flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be necessary through tonight.

$$

LMZ740>745-102045-
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
339 PM CDT Mon Mar 9 2026

This Hazardous Weather Outlook is for portions of the Illinois
nearshore waters of Lake Michigan and the Indiana nearshore
waters of Lake Michigan.

.DAY ONE...Tonight.

Limited Fog Risk late overnight.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Tuesday...
Hazardous conditions for small craft are likely.
Elevated Thunderstorm Risk...with an associated:
Level 3 of 5 Severe Thunderstorm Risk.
Limited Fog Risk.
Wednesday through Sunday...
Hazardous conditions for small craft are likely at times.

$$

Ogorek

Visit us at www.weather.gov/chicago

The "Hazardous Weather Outlook" contains information regarding any and all weather expected to occur within the region that could be hazardous to travel, life or property. This is one of our most highly recommended products to check on a daily basis, and it some cases multiple times per day should significant weather be expected to affect DuPage county.

SPC Convective Outlook Day 2

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217
ACUS02 KWNS 091729
SWODY2
SPC AC 091727

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1227 PM CDT Mon Mar 09 2026

Valid 101200Z - 111200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL
ILLINOIS INTO NORTHWEST INDIANA AND ACROSS THE EDWARDS PLATEAU INTO
CENTRAL TEXAS...

...SUMMARY...
Scattered severe thunderstorms are forecast on Tuesday from the
southern Plains into the southern Great Lakes vicinity. All severe
hazards are possible.

...Synopsis...
A bi-modal severe weather event is expected Tuesday afternoon and
evening across the Mid-West and portions of central Texas.
Mid-morning surface observations/analyses reveal a surface low
migrating eastward across the upper Great Lakes with a trailing cold
front draped southwestward into the central Plains. Weakening winds
behind the front suggest that this boundary will begin to stall
later today across the Midwest/central Plains. Meanwhile, returning
moisture is forecast to spread north over the next 24 hours as
surface pressure falls and southerly winds increase across the
Plains with the approach of the upper trough currently meandering
over Baja California and a slight amplification of the upper wave
over the north-central CONUS. This will help establish an expansive
warm sector from southern Texas northward into the central Plains
and Great Lakes region, bounded to the north by the stalled frontal
boundary and to the west by a weak dryline/Pacific front. Strong to
severe thunderstorms are expected within this warm sector as ascent
along the Midwest frontal zone and across the southern Plains
increases with the ejection of the upper trough late Tuesday
afternoon into Tuesday night.

...Midwest...
The greatest regional severe threat will likely be focused along the
frontal boundary Tuesday afternoon and evening. Most guidance
suggests the stalled cold front will advance northward as a warm
front as low-level southerly flow increases within the warm conveyor
belt of a developing cyclone over IA/northern MO, but the exact
placement and orientation of the boundary, and any potential
influence by cool lake-breezes off lower Lake Michigan, remain
uncertain given spread between 12z CAM and global guidance.

Regardless, strong isentropic ascent over the frontal zone coupled
with ample low-level moistening and steepening mid-level lapse rates
will support a convective environment favorable for well-organized
convection along both the warm front and southwestward along the
cold front across northern MO and KS. Effective SRH on the order of
200-300 m2/s2 coupled with MLCAPE of 1500-2000 J/kg along/just south
of the boundary will support the potential for tornadoes - including
strong tornadoes - with any discrete supercell that can become
established. Convection developing north of the surface fronts will
still reside in a very favorable environment for elevated supercells
capable producing large/very large hail (possibly in excess of 2
inches). Upscale growth/clustering is expected through the evening
hours, which should support an increase in severe winds. It remains
somewhat unclear how quickly upscale growth will occur given
along-boundary flow through a deep layer, and this may curtail the
supercellular tornado threat if clustering occurs too quickly.
However, based on latest forecast soundings and CAM guidance, the
tornado potential will likely be greatest along the warm front
across central IL between 21-02 UTC where low-level SRH and surface
pressure falls/ascent will be maximized.

...Southern Plains...
12 UTC soundings across the southern Plains sampled steep mid-level
lapse rates already in place across the region. The onset of deep
moisture return is noted along the TX Coastal Plain, which should
spread north across central TX into OK by Tuesday morning.
Isentropic ascent within the warm sector may support isolated
thunderstorm development by late morning across north TX into the
Texarkana region where capping should be weaker. By late
afternoon/early evening, more widespread thunderstorm development is
expected across central TX as strong height falls associated with
the ejecting upper wave overspread the region. Initially discrete
supercells will be capable of all hazards, through very large (2+
inch) hail appears to be the most probable threat. Strong forcing
for ascent will promote upscale growth through the evening with one
or more bowing segments possible. Enlarging low-level hodographs
associated with an increasing nocturnal jet may support embedded
circulations within the developing squall line. 30% hail/wind
probabilities were introduced to highlight the corridor of higher
hail/wind threat from the Edwards Plateau into central TX.

..Moore.. 03/09/2026

$$

The "Convective Outlooks" issued by SPC can be thought of as a detailed discussion of the Severe Thunderstorm threat and it's associated risks nationwide. Risk levels range from Marginal to Slight, Enhanced, Moderate, and High and are issued based on the likelihood of 3 major severe weather threats; the risk of tornadoes, damaging winds, and hail. These discussions are often heavily laced meteorological terminology that may be difficult to understand without a background in the field. However understanding these discussions shouldn't be thought of as necessary. Instead, should DuPage county fall under one of these threat levels for severe weather, the response should be to have a heightened level of awareness about the deveoloping weather. Keep an eye on the "Watch County Notification" for any active severe weather watches issued for DuPage county; the "Hazardous Weather Outlook" and "Severe Weather Statement" can also be helpful in explaining the developing risk; additionally, watch for "Active Weather Warnings" and keep an eye on our "Regional Satellite and Radar" products which can be viewed with active watches/warnings or lightning activity.

SPC Convective Outlook Day 3

See Product Description

558
ACUS03 KWNS 091926
SWODY3
SPC AC 091925

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0225 PM CDT Mon Mar 09 2026

Valid 111200Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST TEXAS
AND THE LOWER MISSISSIPPI RIVER VALLEY INTO THE OHIO RIVER VALLEY...

...SUMMARY...
Isolated to scattered severe thunderstorms are expected on Wednesday
from the ArkLaTex and Lower Mississippi Valley northeastward through
the Ohio Valley vicinity.

...Synopsis...
Strong to severe thunderstorms are probable across an expansive warm
sector stretching from the Gulf Coast northward into the upper Ohio
Valley region. The amplification of an upper wave over the northern
CONUS will support steady intensification of a surface cyclone as it
migrates from the Great Lakes region into southeast Quebec by 12 UTC
Thursday. An attendant cold front will push across the MS Valley
into the upper OH Valley and Southeast states during the forecast
period, and will act as the primary foci for thunderstorm
development.

...East Texas into the Lower MS Valley...
Thunderstorm clusters and/or convective bands will likely be
ongoing, albeit weakening, across the eastern TX/OK at the start of
the forecast period. A combination of daytime heating, ascent ahead
of a southern-stream upper trough, and forcing along the approaching
cold front should promote an uptick in convective intensity and
coverage by late morning/early afternoon across LA and MS.
Storm-motion vectors largely along the front will maintain a linear
storm mode and support primarily a severe wind threat. The severe
threat may be maximized during the late morning/early afternoon
hours as buoyancy increases but before low to mid-level flow
decreases as the synoptic low accelerates away to the northeast.

...OH Valley...
Low-level moisture and a remnant EML will continue to spread
north/northeast in tandem with the translation of the surface low.
This should support adequate buoyancy within a narrow, but
migratory, warm sector for surface-based convection. Strong flow in
proximity to the surface low/upper jet will promote organized
convection along the front, most likely organized clusters and lines
capable of severe gusts and perhaps embedded circulations. Recent
extended-range RRFS solutions hint at the development of pre-frontal
supercells within a diffuse plume of low-level theta-e advection
across the upper OH Valley. Forecast soundings from this region
suggest that tornadic supercells are possible. Other guidance also
depicts this plume of theta-e advection, which lends some credence
to this scenario. However, the RRFS is typically overly aggressive
with convective intensity, and recent MPAS solutions are less
bullish on deep convection ahead of the front where mostly cloudy
skies should limit diurnal insolation to some degree. This
uncertainty precludes the introduction of higher risk probabilities,
but trends will be monitored for a more robust severe threat within
this regime.

..Moore.. 03/09/2026

$$

The "Convective Outlooks" issued by SPC can be thought of as a detailed discussion of the Severe Thunderstorm threat and it's associated risks nationwide. Risk levels range from Marginal to Slight, Enhanced, Moderate, and High and are issued based on the likelihood of 3 major severe weather threats; the risk of tornadoes, damaging winds, and hail. These discussions are often heavily laced meteorological terminology that may be difficult to understand without a background in the field. However understanding these discussions shouldn't be thought of as necessary. Instead, should DuPage county fall under one of these threat levels for severe weather, the response should be to have a heightened level of awareness about the deveoloping weather. Keep an eye on the "Watch County Notification" for any active severe weather watches issued for DuPage county; the "Hazardous Weather Outlook" and "Severe Weather Statement" can also be helpful in explaining the developing risk; additionally, watch for "Active Weather Warnings" and keep an eye on our "Regional Satellite and Radar" products which can be viewed with active watches/warnings or lightning activity.

Special Weather Statement

See Product Description

No active Special Weather Statement for DuPage County.

The "Special Weather Statement" details notable weather either occuring or expected to occur, but does not necessarily have to be considered severe or hazardous. This is a supplementary product issued by the National Weather Service to help describe noteworthy weather. It's terminology should be reasonably easy to understand by the general public.

Watch County Notification

See Product Description

No active Watch County Notification for DuPage County.

The "Watch County Notification" will contain updates regarding active severe weather watches that pertain to DuPage county. This may be for a newly issued watch, or the cancelation of an existing watch. Severe weather watches come in two forms; Severe Thunderstorm and Tornado, and it should be noted that a Severe Thunderstorm Watch does NOT rule out the possibility of tornadoes occuring. It generally means that the tornado threat is minimal while damaging winds and hail are still likely. See our "Watch, Warning, and Advisory Criteria" for more detailed information on the differences and critera for watches, warnings and advisory for all forms of weather.

Winter Weather Statement

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No active Winter Weather Statement for DuPage County.

The "Winter Weather Statement" is a product aimed at the general public that will discuss impacts caused by winter weather. This may include information about watches, warnings and advisories as well as details about impactful winter weather that may not warrant the issuance of a watch, warning or advisory.

Severe Weather Statement

See Product Description

No active Severe Weather Statement for DuPage County.

The "Severe Weather Statement" is a product aimed at the general public that will discuss impacts caused by severe thunderstorms. This may include information about watches and warnings as well as details about impactful "sub-severe" weather that may not warrant the issuance of a watch or warning which sometimes may come when a watch or warning has been canceled.

Non-Precip Statement

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No active Non-Precip Statement for DuPage County.

The "Non-Precip Statement" is aimed at the general public and will detail notable weather that is either occuring or expected to occur, but does not relate to any form of precipitation. These would include but are not limited to high winds, reduced visibility or extreme temperatures.

Active Weather Warnings

Tornado Warnings

No active Tornado Warnings.

Severe Thunderstorm Warnings

No active Severe Thunderstorm Warnings.

Flood Warnings

No active Flood Warnings.

General Tornado/Severe Weather Safety

1. A Tornado or Severe Thunderstorm Warning is issued when it has been reported, or when it has been detected via National Weather Service radar. It is to be interpreted that this event is occuring and is expected to affect all warned areas. Those within the warning need to take action immediately.
2. If under a warning remain calm and if it is necessary to seek shelter. Students and Employees should head to their nearest designated shelter area. The route to these shelter areas are posted in all rooms on campus and signs are placed in the hallways to direct you to the nearest shelter area. Review these instructions and be familiar with where your nearest shelter is. Stay indoors, away from windows and large unsupported ceilings. Faculty should account for their students and Supervisors should account for their areas employees.
3. If outside, take shelter in the nearest building.
4. After the storm has passed, dial Police at 911 to report any injuries or damage to buildings.
5. If the building is severely damaged, evacuate the building as soon as possible after the storm has passed.