SPC Convective Outlook Day 1

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172
ACUS01 KWNS 230042
SWODY1
SPC AC 230040

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0740 PM CDT Wed Mar 22 2023

Valid 230100Z - 231200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM
CENTRAL/NORTHERN MISSOURI AND SOUTHEAST IOWA INTO NORTHERN/CENTRAL
INDIANA...

...SUMMARY...
Isolated strong to severe thunderstorms -- capable of large hail --
are possible from central/northern Missouri and southern Iowa
eastward to northern Indiana.

...Synopsis...
Weak convection has started to develop across portions of northern
Missouri, southern Iowa and western Illinois this evening. This
convection will expand in coverage and intensity over the next 1 to
2 hours. See Mesoscale Discussion 308 for additional details about
this evolving threat.

..Bentley.. 03/23/2023

$$

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

729
FLUS43 KLOT 222357
HWOLOT

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
657 PM CDT Wed Mar 22 2023

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-240000-
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-
657 PM CDT Wed Mar 22 2023 /757 PM EDT Wed Mar 22 2023/

This Hazardous Weather Outlook is for portions of North Central
Illinois...Northeast Illinois and Northwest Indiana.

.DAY ONE...Tonight.

Weather hazards expected...

Elevated Thunderstorm Risk...with an associated:
Limited hail risk...up to the size of quarters.
Elevated Fog Risk.

DISCUSSION...

Areas of dense fog with visibilities locally less than one
quarter mile are expected, mainly this evening.

Scattered thunderstorms are expected to re-develop later this
evening and continue into the overnight hours. In addition to
cloud to ground lightning and heavy downpours, the strongest
storms may produce hail up to 1 inch in diameter, which is large
enough to dent cars and siding. The greatest damaging hail threat
should remain along and south of the I-80 corridor.

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

Thursday...
Limited Severe Thunderstorm Risk in the morning.
Friday Night...
Limited Snow Risk.
Saturday...
Limited Non-Thunderstorm Wind Risk.
Limited Snow Risk.

DISCUSSION:

Scattered thunderstorms are expected Thursday morning. Slushy wet
snow accumulations may occur in portions of northern Illinois late
Friday night into Saturday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be necessary through tonight.

GENERAL STORM MOTION OF THE DAY:

Moving toward the east at 45-55 mph.

$$

LMZ740>745-240000-
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-
657 PM CDT Wed Mar 22 2023

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.
Limited Thunderstorm Risk.
Elevated Fog Risk.

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

Thursday...
Hazardous conditions for small craft are likely.
Limited Thunderstorm Risk.
Friday and Saturday...
Hazardous conditions for small craft are likely.

$$

- Izzi

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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

839
ACUS02 KWNS 221736
SWODY2
SPC AC 221734

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1234 PM CDT Wed Mar 22 2023

Valid 231200Z - 241200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
EASTERN AND SOUTHERN OKLAHOMA INTO PARTS OF CENTRAL TEXAS...

...SUMMARY...
Thunderstorms capable of hail, some very large, are possible
Thursday afternoon through Friday morning across parts of the
southern Great Plains.

...Southern Great Plains into the mid MS Valley...
Models show a strong upper jet centered over the Great Lakes and
moving to the Northeast during the period. A frontal zone will sag
southward across parts of the lower MO Valley and OK during the day
before stalling during the late afternoon. Southerly low-level flow
will maintain a persistent fetch of a seasonably moisture-rich air
across the southern Great Plains, featuring mid 60s dewpoints across
north TX and into southern/central OK south of the boundary.
Large-scale troughing located over the Desert Southwest will
gradually move east and approach the southern High Plains by early
Friday morning. Low-level warm-air advection and the front will
likely aid in storm development of an initially capped airmass.
Models indicate moderate buoyancy developing by mid-late afternoon
with MLCAPE ranging from 1000-2000 J/kg from the western part of the
Ozark Plateau west-southwestward parts of western north TX. The
lack of appreciable cyclogenesis over the Red River Valley will
likely play a role in limiting both low-level flow (i.e., low-level
shear) and an overall supercell tornado risk. However, strong
deep-layer shear will promote updraft organization with the more
intense storms and favor a mix mode of supercells and multicellular
clusters with time. Large to very large hail is possible with the
stronger storms. Additional storms are possible farther south along
a dryline over parts of the Edwards Plateau during the evening.
Upscale growth into one or more convective bands with some lingering
severe risk will be possible into the overnight hours as the
activity moves east/southeast to near the north TX I-35 corridor.

Farther northeast over MO/IL, weaker buoyancy is progged by model
guidance. Scattered thunderstorms are forecast to develop near and
north of the front during the evening. A couple of stronger storms
could yield an isolated risk for large hail before convective
overturning occurs.

...Southern Great Lakes...
Elevated thunderstorms will likely be ongoing near a weak surface
low across northern IL/northern IN early Thursday morning. Weak
buoyancy on the northeast periphery of steeper mid-level lapse rates
may result in a stronger storm or two during the morning. However,
the coverage/magnitude of a hail threat precludes low-severe
probabilities.

..Smith.. 03/22/2023

$$

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

743
ACUS03 KWNS 220735
SWODY3
SPC AC 220734

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0234 AM CDT Wed Mar 22 2023

Valid 241200Z - 251200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN
LOUISIANA...SOUTHWEST ARKANSAS...AND WESTERN MISSISSIPPI...

...SUMMARY...
Supercell thunderstorms capable of all severe hazards, including
strong tornadoes, are possible across the Lower Mississippi Valley
on Friday.

...Synopsis...
The upper pattern early Friday morning will likely be characterized
by broad troughing across the western CONUS and subtropical ridging
centered over the Straits of Florida. Enhanced mid-level flow will
extend throughout western and southern periphery of the upper trough
and then throughout the northwestern periphery of the subtropical
ridge. A low-amplitude shortwave trough is forecast to move from the
base of the upper trough quickly eastward across the southern Plains
throughout the day, and then more northeastward across the Mid-South
overnight. Strong mid-level flow (i.e. 100 kt at 500-mb) will
accompany this shortwave, spreading across TX into the Mid-South.

The surface pattern preceding this shortwave trough is expected to
feature a low over north TX early Friday, with a cold front
extending southward from this low into the TX Hill Country and a
stationary front extending northeastward into the Middle OH Valley.
This low is forecast to move northeastward throughout the day, while
deepening significantly.

...Lower MS Valley...
Expectation is for a broad area of upper 60s dewpoints to be in
place from east TX across the Lower MS Valley, ahead of the surface
low and associated front. Cloud cover may temper daytime heating,
but afternoon temperatures will likely still reach the 80s,
contributing to moderate buoyancy across much of the region. In
addition to this buoyancy, moderate mid-level flow atop
strengthening low-level flow (supported by the maturing cyclone
ahead of the approaching shortwave trough) will contribute to long
hodographs with substantial low-level magnitude and veering. As a
result, the environment will be very favorable for supercells.

Current expectation is for storms to develop during the afternoon
over southwest AR and western LA (perhaps as far west as east TX).
This development should occur ahead of the cold front within the
open warm sector, maturing as it moves eastward across the Lower MS
Valley. A discrete supercell mode is anticipated initially, with all
severe hazards possible, including strong tornadoes. Upscale growth
into a convective line is anticipated after this initially discrete
mode, with the line pushing eastward across MS and AL overnight.

...Mid MS Valley...
Despite less buoyancy that areas farther south, augmented forcing
for ascent close to the surface low could result in bowing line
segments capable of damaging wind gusts and embedded tornadoes
Friday afternoon through Friday evening.

..Mosier.. 03/22/2023

$$

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.