SPC Convective Outlook Day 1

See Product Description

248
ACUS01 KWNS 111603
SWODY1
SPC AC 111601

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1001 AM CST Tue Nov 11 2025

Valid 111630Z - 121200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are not forecast across the contiguous United States
through tonight.

...Synopsis...
A large-scale mid-level trough over the East will be maintained as a
series of additional upstream disturbances over western Ontario and
the Upper Midwest act to reinforce troughing over the eastern U.S.
An arctic surface high centered over the northeast Gulf Coast will
result in seasonably cool/stable conditions east of the Rockies.
Farther west, a mid-level ridge will lead to tranquil conditions
across the Rockies to the Pacific coast.

..Smith/Wendt.. 11/11/2025

$$

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

473
FLUS43 KLOT 110905
HWOLOT

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
305 AM CST Tue Nov 11 2025

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-120600-
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-
305 AM CST Tue Nov 11 2025 /405 AM EST Tue Nov 11 2025/

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

.DAY ONE...Today and Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be necessary through tonight.

$$

LMZ740>745-120600-
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-
305 AM CST Tue Nov 11 2025

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...Today and Tonight.

Weather hazards expected...

Hazardous conditions for small craft.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Wednesday...
Hazardous conditions for small craft are likely.
Saturday through Monday...
Hazardous conditions for small craft are likely.

$$

DK

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

See Product Description

356
ACUS02 KWNS 111711
SWODY2
SPC AC 111710

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1110 AM CST Tue Nov 11 2025

Valid 121200Z - 131200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
The risk for thunderstorms appears negligible across much of the
U.S. Wednesday through Wednesday night.

...Discussion...
As an increasingly prominent blocking high evolves near the southern
Greenland Atlantic coast, it appears that broad mid/upper troughing
will generally be maintained across the Atlantic Seaboard into
Labrador Sea/Baffin Bay vicinity through this period, though
large-scale ridging inland of the Pacific coast may slowly expand
east of the Great Plains through Mississippi Valley. Upstream,
particularly across the western into central mid-latitude Pacific,
models indicate that flow will remain more progressive, with
building ridging on the leading edge of this regime shifting across
the central toward eastern Pacific. As this occurs, it appears that
an initially digging downstream trough across the eastern Pacific
will split while approaching the North American Pacific coast.

There appears increasing consensus within/among the model output
that forcing for ascent, associated with the most vigorous short
wave perturbation within the southern portion of the splitting
trough, will support significant lower/mid-tropospheric cyclogenesis
late Wednesday through Wednesday night. The deepening,
northeastward migrating surface cyclone center may approach the
southern Oregon/northern California coast by 12Z Thursday, while the
mid-level cold core remains farther offshore--and generally slower
to approach the coast than suggested by prior guidance.

...Northern California...
Latest high resolution, convection allowing ensemble output, and
related guidance, suggests that the deepening surface cyclone might
include an evolving warm sector corridor becoming sufficiently
unstable to support a period of increasing pre-frontal thunderstorm
development Wednesday evening, initially 100-200+ miles offshore of
the northern California coast. Based on this same guidance, and
forecast soundings from the NAM and Rapid Refresh, it remains
unclear the extent to which thermodynamic profiles will remain
conducive to convection capable of produce lightning, as the
occluding cyclone/front approach coastal areas north of San
Francisco Bay overnight through 12Z Thursday. Activity will be
embedded within rather strong ambient wind fields, perhaps including
50-70 kt within the lowest kilometer or two above ground level.
However, weak CAPE and stable near-surface lapse rates across and
inland of coastal areas seem likely to limit the potential for
convectively augmented surface gusts.

..Kerr.. 11/11/2025

$$

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

849
ACUS03 KWNS 110728
SWODY3
SPC AC 110727

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0127 AM CST Tue Nov 11 2025

Valid 131200Z - 141200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not expected on Thursday or Thursday night.

...Discussion...
Isolated thunderstorms are possible, mainly on Thursday morning to
afternoon, from central CA to western OR. Embedded within a broader
upper trough initially off the West Coast, a leading shortwave
impulse should eject northeast and move inland by Thursday night.
The attendant low-level warm conveyor will be most pronounced
Thursday morning before diminishing as it separates southward in CA.
While a few lightning flashes are possible amid flimsy instability
within this regime, mid-level lapse rates will steepen in its wake
with approach of the cold core. This should focus isolated,
low-topped thunderstorms from northern CA through western OR on
Thursday afternoon. Small hail may accompany a storm in the northern
Sacramento Valley but scant buoyancy should limit severe potential.

..Grams.. 11/11/2025

$$

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

See Product Description

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

See Product Description

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.

Winter Weather Warnings

No active Winter Weather 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.