SPC Convective Outlook Day 1

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816
ACUS01 KWNS 270602
SWODY1
SPC AC 270600

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Sat Jul 27 2024

Valid 271200Z - 281200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR
CENTRAL/EASTERN ND INTO NORTHWEST MN...

...SUMMARY...
Scattered severe thunderstorms are possible across portions of the
northern Plains vicinity, mainly this afternoon and evening.

...Synopsis...
An occluded deep-layer cyclone will move eastward across parts of
northern SK/AB today, as a larger scale upper-level trough will
remain in place across much of the western CONUS into the northern
Plains. Multiple embedded shortwaves within this trough will move
across parts of the Great Basin and northern Rockies/Plains through
the period. A surface trough will extend southward from the occluded
low into the northern High Plains, with secondary low development
possible across western SD.

...Dakotas into northern MN...
Elevated convection will likely linger into this morning across
parts of northern MN, and also potentially across parts of the
Dakotas. A convectively enhanced shortwave trough related to the
Dakotas convection will move northeastward through the day. Some CAM
guidance depicts robust storm redevelopment across northern MN by
early/mid afternoon with a moist and increasingly unstable
environment, as this shortwave interacts with modifying outflow.
Should this development occur, deep-layer shear will be sufficient
for organized convection. While this scenario remains uncertain, a
couple of supercells and/or stronger clusters could develop, with a
threat of hail, damaging gusts, and perhaps a tornado. The Slight
Risk has been expanded eastward to cover this possible scenario, and
additional eastward expansion is possible if confidence increases.

Farther west, there will be some potential for storm development
near the surface trough/weak cold front across west-central ND and
potentially into western SD during the late afternoon and evening,
though guidance continues to vary regarding storm coverage within
this regime. Steep low/midlevel lapse rates, moderate to strong
buoyancy, and sufficient deep-layer shear will support a threat of
hail and strong to severe gusts, which could spread into parts of
the eastern Dakotas during the evening.

...Northern Great Basin into the central Rockies/High Plains
vicinity...
Scattered thunderstorms are expected this afternoon and evening from
the northern Great Basin into the central Rockies/High Plains, as
one embedded shortwave trough moves across WY into the
central/northern High Plains, and another shortwave moves from CA
into northern NV and southern ID. Multiple outflow-driven clusters
could evolve with time, posing a threat of at least isolated severe
gusts. Somewhat stronger instability across parts of northeast
CO/southeast WY into western NE could also support some hail
potential with the strongest storms.

..Dean/Halbert/Weinman.. 07/27/2024

$$

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

786
FLUS43 KLOT 270904
HWOLOT

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
404 AM CDT Sat Jul 27 2024

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-280915-
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-
404 AM CDT Sat Jul 27 2024 /504 AM EDT Sat Jul 27 2024/

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...Sunday through Friday.

Sunday...
Limited Flooding Risk.
Limited Thunderstorm Risk.
Monday...
Limited Thunderstorm Risk...with an associated:
Level 1 of 5 Severe Thunderstorm Risk.
Tuesday through Friday...
Limited Flooding Risk at times.
Limited Thunderstorm Risk at times.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be necessary through tonight.

$$

LMZ740>745-280915-
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-
404 AM CDT Sat Jul 27 2024

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.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Sunday...
Limited Thunderstorm Risk.
Monday...
Limited Thunderstorm Risk...with an associated:
Level 1 of 5 Severe Thunderstorm Risk.
Tuesday through Friday...
Limited Thunderstorm Risk.

$$

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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

396
ACUS02 KWNS 270601
SWODY2
SPC AC 270559

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1259 AM CDT Sat Jul 27 2024

Valid 281200Z - 291200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL
SOUTH DAKOTA...

...SUMMARY...
Scattered severe thunderstorms are expected across portions of the
central/northern Plains on Sunday.

...Synopsis...
An upper-level low across Arkansas/eastern Oklahoma will start to
fill and accelerate northeast as an open wave on Sunday. A low
amplitude mid-level trough will remain centered across the western
CONUS with several embedded mid-level impulses within moderate
southwesterly flow from the Great Basin to the northern Plains.
Farther east, a mid-level trough will become a cutoff low over the
Gulf Stream and start to retrograde toward the New England coast
late in the forecast period.

Persistent southwesterly mid-level flow will result in lee troughing
across the Plains and strengthening southerly surface flow. This
will bring renewed Gulf moisture northward into the Upper Midwest
and northern Plains.

...Central/Northern Plains...
A surface low will likely be located somewhere across western South
Dakota on Sunday and will only drift slightly east through the day.
East of this surface low, southerly winds will increase low-level
moisture with dewpoints increasing to the upper 60s/near 70 by 00Z.
By late afternoon, a warm front is forecast to become better defined
across north-central South Dakota which, in addition to the cold
front/dryline, should be a source for thunderstorm development as a
mid-level shortwave trough approaches the region during the
afternoon/evening. Moderate flow associated with this mid-level
shortwave trough should result in 35 to 40 knots of effective shear
by late afternoon which would be sufficient for supercells. Moderate
instability and moderate shear will support a large hail threat,
while inverted-v thermodynamic profiles will also support a severe
wind threat. The low-level jet axis is mostly southeast of the
greatest upper-level support and thus, upscale growth into an MCS
remains uncertain. However, storm coverage may be great enough for
upscale growth into one or more MCSs which could maintain some
severe weather threat into the overnight hours across southern
Minnesota and western Iowa where the low-level jet is forecast to
strengthen to 35 to 45 knots Sunday night.

A Slight Risk has been introduced across South Dakota, in proximity
to the mid-level shortwave trough, where greater storm coverage
appears likely. Elsewhere, northeast to the Canadian border and
farther south across Nebraska and northern Kansas, storm coverage
remains more questionable, which precludes higher probabilities at
this time.

..Bentley.. 07/27/2024

$$

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

322
ACUS03 KWNS 270720
SWODY3
SPC AC 270719

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0219 AM CDT Sat Jul 27 2024

Valid 291200Z - 301200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ALONG THE
MISSISSIPPI RIVER FROM SOUTHEAST MINNESOTA AND WESTERN WISCONSIN TO
THE MISSOURI BOOTHEEL...

...SUMMARY...
Scattered strong to severe storms are possible in portions of the
Midwest on Monday.

...Synopsis...
On Monday, a broad, low-amplitude ridge will be centered across the
High Plains with a trough axis near the Pacific Coast and a trough
across the Ohio Valley and the East Coast. As the East Coast
upper-level low continues to retrograde during the day, these
features will phase into one larger trough across the eastern CONUS.
Several embedded mid-level shortwave troughs will traverse the
northern CONUS and Canadian Prairies into the northwest flow across
the Midwest.

...Midwest...
Rich Gulf moisture will become well established across the Midwest
by Monday with dewpoints in the mid 70s. This will result in a very
unstable environment with MLCAPE 3000+ J/kg across portions of the
Upper Mississippi River Basin. This strongly unstable environment
will develop beneath 25 to 40 knots of mid-level flow which will
provide ample shear for storm organization. However, despite a
favorable severe weather parameter space that is expected within a
broad zone across the Midwest, the details remain highly uncertain.
Thunderstorms will be likely Monday morning given the strong
low-level jet across Missouri and Iowa Sunday night. It is unclear
whether this convection may simply stabilize portions of the risk
area and lessen the severe weather threat, or if upscale growth can
occur and persist into the late morning and if a severe MCS can
develop from this activity and move southward along the Mississippi
River vicinity. However, if this does not occur and substantial
destabilization is able to occur farther north, the greatest severe
weather threat may be focused near southeast Minnesota, southwest
Wisconsin, eastern Iowa and northwest Illinois. The GFS favors this
scenario with suppression of southern convection and a mid-level
shortwave trough moving through southern Minnesota Monday afternoon.
However, the ECMWF has a stronger southern-stream trough Monday
morning which aids in greater storm maintenance across Missouri and
southern Illinois. These inconsistencies are likely tied to
Day2/Sunday convection across the Plains and therefore, it may not
be clear where the greatest threat is until closer to the Day 1
period. A broad marginal risk across the region with the most
favorable environment seems like the most appropriate outlook until
mesoscale details become more clear.

..Bentley.. 07/27/2024

$$

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.