SPC Convective Outlook Day 1

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153
ACUS01 KWNS 300521
SWODY1
SPC AC 300520

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1220 AM CDT Thu Oct 30 2025

Valid 301200Z - 311200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE MIDDLE ATLANTIC...

...SUMMARY...
Thunderstorms with an isolated damaging wind/tornado threat may
occur from coastal North Carolina into parts of the Mid Atlantic.

...Middle Atlantic...

Seasonally strong upper low over eastern TN is beginning to eject
northeast, partly in response to an upstream speed max digging
southeast across the northern High Plains. This lead low will
advance into WV by 18z before moving into upstate NY by the end of
the period. Favorable high-level diffluence/large-scale ascent will
encourage a surface low to be drawn north-northwest across the
Middle Atlantic to a position near the MD/PA border by mid day. This
track will permit higher theta-e air mass to overspread eastern
VA/Delmarva into southeast PA such that buoyancy will become
supportive of deep convection.

Early-day shear will prove strongest across the Middle Atlantic as
LLJ will be focused across eastern MD into central PA. LLJ will
shift quickly north into NY by 18z along with more focused low-level
warm advection. Prior to this, forecast soundings exhibit strongly
sheared environment with adequate instability for thunderstorms.
While the maximum SBCAPE should peak near 500-600 J/kg, a few robust
updrafts are possible given the strength of the wind fields.
Isolated strong/severe thunderstorms, possibly supercells, may
generate damaging winds and perhaps a tornado or two. Greatest risk
is between sunrise and 21z.

..Darrow/Wendt.. 10/30/2025

$$

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

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070
FLUS43 KLOT 291923
HWOLOT

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
223 PM CDT Wed Oct 29 2025

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-301930-
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-
223 PM CDT Wed Oct 29 2025 /323 PM EDT Wed Oct 29 2025/

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...Thursday through Tuesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be necessary through tonight.

$$

LMZ740>745-301930-
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-
223 PM CDT Wed Oct 29 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...Tonight.

Weather hazards expected...

Hazardous conditions for small craft.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Thursday and Friday...
Hazardous conditions for small craft are likely.
Monday and Tuesday...
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

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859
ACUS02 KWNS 300544
SWODY2
SPC AC 300542

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1242 AM CDT Thu Oct 30 2025

Valid 311200Z - 011200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorm potential appears low on Friday.

...Synopsis...
A strong mid/upper-level shortwave trough and embedded midlevel
cyclone will move northeastward across New England on Friday, in
conjunction with a deep surface low. Stable conditions in the wake
of this system and its attendant cold front will limit thunderstorm
potential through the period. Weak elevated convection may accompany
the midlevel cyclone across northern New England early in the day,
but buoyancy appears too weak/shallow for more than very
isolated/sporadic lightning flashes.

Farther west, a mid/upper-level trough will dig southeastward across
the Great Plains and upper MS Valley. Cold temperatures aloft
associated with this trough could support weak convection across
parts of the Upper Midwest and Great Lakes, but this convection is
generally expected to remain too shallow for thunderstorm
development. Weak low-level moisture return may commence near the TX
Gulf Coast by early Saturday morning, but forecast buoyancy is very
weak to negligible through the end of the period.

..Dean.. 10/30/2025

$$

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

715
ACUS03 KWNS 291914
SWODY3
SPC AC 291913

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0213 PM CDT Wed Oct 29 2025

Valid 311200Z - 011200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorm potential appears low on Friday.

...Discussion...
A large scale upper-trough will exist across the eastern two-thirds
of the CONUS on Friday. Meanwhile, a strong cold front will have
pushed well offshore into the Atlantic and Gulf on Day 2/Thu. As a
result, an expansive dry/stable airmass will be present across the
CONUS. Some shallow convection is possible across the Upper
Midwest/Great Lakes, but it is expected to be too shallow for
lightning generation. Therefore, thunderstorm potential is low
across the CONUS on Friday.

..Bentley.. 10/29/2025

$$

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

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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

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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

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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.

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.