SPC Convective Outlook Day 1

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430
ACUS01 KWNS 160511
SWODY1
SPC AC 160510

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1210 AM CDT Mon Sep 16 2019

Valid 161200Z - 171200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
NORTHERN AND CENTRAL UTAH THIS AFTERNOON INTO TONIGHT...

...SUMMARY...
A few thunderstorms with locally strong wind gusts may impact
portions of northern and central Utah this afternoon into tonight.

...Utah/Great Basin Vicinity...

A shortwave trough approaching the Pacific coast early this morning
will continue to progress eastward across the Great Basin through
the forecast period. Residual midlevel moisture should be sufficient
for a few diurnally driven thunderstorms across eastern AZ/UT as
forcing increases with the approach of the upper trough. However,
effective shear will remain weak despite increasing speed shear for
much of the period. This will limit severe potential for much of the
day, though a well-mixed sub-cloud layer producing inverted-v type
thermodynamic profiles could support some locally gusty winds.
Overnight, shear profiles will improve as the trough impinges on the
area and a surface cold front sweeps southeast across ID/NV/CA and
into UT after around 06z. Instability will be limited, but guidance
continues to suggest a weak convective line associated with the
front moving across parts of northern/central UT overnight. Given
the strength of the background wind field and the dry sub-cloud
layer, some downward momentum transport could result in a couple of
severe wind gusts associated with weak convection.

..Leitman/Bentley.. 09/16/2019

$$

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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080
FLUS43 KLOT 160753
HWOLOT

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
253 AM CDT Mon Sep 16 2019

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
170930-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-Cook-
La Salle-Kendall-Grundy-Will-Kankakee-Livingston-Iroquois-Ford-
Lake IN-Porter-Newton-Jasper-Benton-
253 AM CDT Mon Sep 16 2019 /353 AM EDT Mon Sep 16 2019/

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

.DAY ONE...Today and Tonight.

Weather hazards expected...

Significant Fog Risk.

DISCUSSION...

Areas of dense fog will linger across the region through early Monday
morning, especially across portions of northern Illinois. While fog is
possible area wide, the most favored area is northwest of a line from
Peru to Sugar Grove to Waukegan. Very limited and fluctuating visibilities
will lead to potentially hazardous travel.

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

Tuesday...
Elevated Fog Risk.
Wednesday through Sunday...
Limited Thunderstorm Risk.

DISCUSSION:
Localized dense fog is again possible tonight. Thunderstorm chances
remain low for the next few days, but chances do return later in the week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be necessary through tonight.

$$

LMZ740>745-170930-
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-
253 AM CDT Mon Sep 16 2019

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...

Elevated Fog Risk.

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

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

$$

KMD

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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

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536
ACUS02 KWNS 160453
SWODY2
SPC AC 160453

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1153 PM CDT Sun Sep 15 2019

Valid 171200Z - 181200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TUESDAY THROUGH
TUESDAY NIGHT ACROSS PARTS OF THE NORTHERN ROCKIES THROUGH MUCH OF
THE NORTHERN PLAINS...

...SUMMARY...
Strong thunderstorms may impact parts of the northern Rockies
through much of the northern Plains Tuesday through Tuesday night,
accompanied by at least some potential for severe weather.

...Synopsis...
Within the westerlies, models continue to indicate substantial
mid-level trough amplification near the northern Pacific coast
during this period, in response to another strong, digging short
wave trough and embedded closed low. As this occurs, downstream
mid-level ridging is forecast to remain prominent along an axis
across the Great Lakes into Hudson Bay. Within southwesterly flow
between these two features, a couple of short wave impulses are
expected to remain progressive. The lead impulse may undergo
considerable deformation northeast of the Dakotas through northwest
Ontario and the upper Great Lakes region, as it approaches the crest
of the mid-level ridge. The much more vigorous upstream impulse
appears likely to maintain considerable strength while accelerating
northeastward out of the Great Basin through the Dakotas by 12Z
Wednesday.

Beneath this regime, modestly deep surface troughing, to the lee of
the northern Rockies at the outset of the period, appears likely to
develop eastward across the northern and central Plains, while an
embedded cyclone migrates from eastern Montana into Manitoba. A
trailing cold front probably will begin to overtake the surface
troughing across the northern Plains by late Tuesday night.

Between the surface troughing (and developing cyclone) and
low/mid-level ridging to the east, it appears that confluent
low-level flow, near the nose of a persistent 30-50 kt
south-southwesterly 850 mb jet, will maintain seasonably moist air
supportive of moderate CAPE across eastern portions of the northern
Plains. While much drier boundary layer conditions are forecast to
prevail across the higher Plains into the northern Rockies, daytime
heating is expected to contribute to steep lapse rates and deep
boundary mixing.

...Wyoming through the northern High Plains...
The steepening low-level lapse rates, coupled with strong mid-level
forcing for ascent and cooling in the exit region of 50-70 kt
southwesterly 500 mb jet, are expected to support sufficient
destabilization to initiate thunderstorm activity by midday Tuesday
across the higher terrain of western into central Wyoming.
As activity gradually intensifies and spreads northeastward toward
the western Dakotas through early evening, sub-cloud evaporative
cooling will contribute to strengthening downdrafts, aiding downward
mixing of higher momentum to the surface. At least scattered strong
to severe gusts appear possible, before the onset of diurnal cooling
across the Plains.

...Eastern Dakotas into western Minnesota...
As some combination of conglomerate convective outflow and the
surface cold front surge into the more moist environment across the
eastern Dakotas Tuesday evening, there appears potential for renewed
vigorous thunderstorm development. Given the strength of the
low-level jet, and the presence of CAPE probably in excess of 2000
J/kg, considerable upscale convective growth appears possible
beneath difluent upper flow. This may be accompanied by at least
some severe hail and wind risk, and spread into western Minnesota
before weakening overnight.

...MAXIMUM RISK BY HAZARD...
Tornado: 2% - Marginal
Wind: 5% - Marginal
Hail: 5% - Marginal

..Kerr.. 09/16/2019

$$

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

947
ACUS03 KWNS 160714
SWODY3
SPC AC 160713

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0213 AM CDT Mon Sep 16 2019

Valid 181200Z - 191200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
A few strong thunderstorms are possible across parts of the Upper
Midwest Wednesday afternoon and evening, but the risk for severe
weather currently appears negligible.

...Discussion...
Within the westerlies, models indicate that amplified mid-level
troughing, near the northern Pacific coast at the start of the
period, will gradually dig inland through the northern and central
Intermountain West and Sierra Nevada Mountains vicinity Wednesday
through Wednesday night. As this occurs, large-scale downstream
ridging is forecast to build east-northeast of the northern Rockies,
toward northwest Ontario and the Upper Great Lakes region. At the
same time, ridging appears likely to remain strong along an axis
from the lower Ohio Valley through the lower Great Lakes region,
with the increasingly deformed remnants of a vigorous short wave
impulse migrating around its western/northern periphery, across
northwestern Ontario by late Wednesday night.

At 12Z Wednesday, it appears that the vigorous impulse will probably
be approaching the North Dakota/Manitoba border area, with stronger
associated forcing for ascent and deep-layer wind fields generally
shifting north of the international border early in the day. Models
indicate that this may contribute to substantive deepening of a
surface cyclone migrating across Manitoba into Hudson Bay, but the
trailing cold front may stall and weaken across portions of the
Upper Midwest.

Seasonably moist boundary layer air may linger along this front and
contribute to moderately large CAPE (2000+ J/kg) with daytime
heating, along a corridor through central Iowa, southeastern
Minnesota and western Wisconsin by late Wednesday afternoon. While
this could support the development of scattered vigorous
thunderstorm activity, questions remain concerning mid-level
inhibition and weak to negligible large-scale forcing for ascent.
Given generally weak and/or weakening vertical shear expected across
this region, the potential for severe thunderstorms still appears
negligible at the present time.

Elsewhere, in lower latitudes, some model guidance indicates
strengthening of southerly low-level wind fields to the east of an
inland migrating tropical cyclone, across the upper Texas coastal
plain during this period. This could be accompanied by enlarging
hodographs sufficient to support a risk for tornadoes, in the
presence of tropical boundary layer moisture. At this point,
however, this potential appears too low to introduce severe
probabilities.

..Kerr.. 09/16/2019

$$

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.