SPC Convective Outlook Day 1

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857
ACUS01 KWNS 250054
SWODY1
SPC AC 250052

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0752 PM CDT Fri May 24 2019

Valid 250100Z - 251200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS
PARTS OF THE LOWER MISSOURI VALLEY INTO THE UPPER MIDWEST...AND THIS
EVENING ACROSS PARTS OF SOUTHWESTERN THROUGH CENTRAL OKLAHOMA...

...SUMMARY...
Evolving clusters of thunderstorms may pose a risk for severe wind
gusts and perhaps a couple of tornadoes tonight across parts of the
south central Plains and lower Missouri Valley into the upper
Midwest.

...01Z Outlook Update...
The northwestern periphery of prominent mid/upper subtropical
ridging centered near the eastern Gulf coast has become the focus
for the most significant convective development, with considerable
vigorous thunderstorms ongoing across parts of the southern and
central Plains into the Upper Midwest. This is where a continuing
return flow of seasonably high boundary-layer moisture content is
contributing to moderately large mixed-layer CAPE (2000-3000 J/kg),
in the presence of lingering modestly steep lower/mid tropospheric
lapse rates.

Activity appears generally focused along a remnant surface boundary
generated largely by convective outflow from preceding days. This
is well to the south of the surface cold front associated with a
lower/mid tropospheric cyclone within the westerlies, now migrating
east-northeastward across North Dakota, toward areas near/north of
the Upper Great Lakes region overnight. However, seasonably strong
southwesterly mid-level flow (including 40-50 kt at 500 mb) is
present as far south and east as the corridor of ongoing
thunderstorm development, and associated shear will continue to
contribute to organizing convective systems with potential to
produce severe wind gusts and perhaps a couple of tornadoes through
this evening into the overnight hours.

...Oklahoma/Kansas into Missouri Ozarks...
One such system has recently evolved across southwest Oklahoma, and
seems likely to maintain strength at least another couple of hours
across parts of central Oklahoma. Similar development is possible
across northeast Oklahoma and southeastern Kansas into west central
Missouri, but more uncertainty exists due to relatively modest
nature of southerly 850 mb flow (30-35+ kt) and waning boundary
layer instability.

...Lower Missouri Valley into Upper Midwest...
Across northeastern Missouri into the vicinity of a warm frontal
zone across parts of eastern Iowa and northern Illinois, it appears
that an area of enhanced forcing (associated with a convectively
generated or enhanced mid-level cyclonic vorticity center now
developing northeast of the Kansas City area) may still support an
upscale growing convective system later this evening into the
overnight hours. This may be accompanied by another swath of strong
to severe wind gusts.

...Northern Plains...
Finally, weak instability in the warm sector of the cyclone
progressing across North Dakota is expected to remain a limiting
factor to severe weather potential. But the environment has been at
least marginally sufficient to support isolated organized severe
thunderstorm development, and may remain so into mid/late evening
while spreading into/across parts of northwest Minnesota.

..Kerr.. 05/25/2019

$$

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

See Product Description

549
FLUS43 KLOT 242100
HWOLOT

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
400 PM CDT Fri May 24 2019

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
252100-
Winnebago-Boone-McHenry-Lake-Ogle-Lee-De Kalb-Kane-DuPage-Cook-
La Salle-Kendall-Grundy-Will-Kankakee-Livingston-Iroquois-Ford-
Porter-Newton-Jasper-Benton-
400 PM CDT Fri May 24 2019 /500 PM EDT Fri May 24 2019/

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 Tornado risk.
Elevated hail risk...up to golf ball size.
Elevated damaging wind risk...up to 70 mph.
Significant Flooding Risk.

DISCUSSION...

The threat of strong to severe storms will likely increase across
much of northern Illinois and northwest Indiana this evening into
the overnight hours. Large hail and damaging winds are the main
hazards, however, a few tornadoes will remain possible especially
across north central IL. Additionally, any storm will be capable
of producing torrential rainfall, which could result in localized
flash flooding tonight. The threat of severe storms will lower
after midnight, though a flash flood threat will remain.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Saturday...
Limited Severe Thunderstorm Risk.
Elevated Flooding Risk.
Sunday...
Limited Severe Thunderstorm Risk.
Limited Flooding Risk.
Monday and Tuesday...
Elevated Thunderstorm Risk.
Wednesday...
Limited Thunderstorm Risk.
Limited Non Thunderstorm Wind Risk.

DISCUSSION:

While there will be many dry hours, there will also be periodic
bouts of showers and thunderstorms. Some potential does exist for
both severe thunderstorms and heavy rainfall resulting in
flooding.

.SPOTTER INFORMATION STATEMENT...

Spotters may be needed tonight.

GENERAL STORM MOTION OF THE DAY:

Moving toward the northeast at 35 to 45 mph.

$$

LMZ740>745-252100-
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-
400 PM CDT Fri May 24 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...Tonight.

Weather hazards expected...

Elevated Thunderstorm Risk...with an associated:
Limited Waterspout Risk.
Elevated hail risk...up to golf ball size.
Elevated thunderstorm wind gust risk...up to 60 knots.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Saturday...
Limited Severe Thunderstorm Risk.
Sunday...
Limited Thunderstorm Risk.
Monday and Tuesday...
Elevated Thunderstorm Risk.
Wednesday...
Hazardous conditions for small craft are likely.
Limited Thunderstorm Risk.

$$

Rodriguez

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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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594
ACUS02 KWNS 241911
SWODY2
SPC AC 241910

Day 2 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0210 PM CDT Fri May 24 2019

Valid 251200Z - 261200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN AND CENTRAL PLAINS...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OH
VALLEY AND LOWER GREAT LAKES...

CORRECTED FOR OUTLOOK LINE

...SUMMARY...
Organized severe, some potentially significant, is expected to
develop across the central and southern High Plains. Very large
hail, along with tornadoes are expected. Isolated severe is also
expected across the Ohio Valley into the lower Great Lakes region.

...Central/Southern Plains...

Latest model guidance suggests a potentially significant mid-level
speed max will develop across northern Mexico later tonight then
translate north-northeast into the central High Plains Saturday
afternoon. While this feature is subtle, and will likely not
suppress height fields appreciably, latest thinking is severe
convection will likely develop from west TX, north into KS by
mid-late afternoon.

HIgh-PW air mass will easily be drawn northwest across the High
Plains ahead of the speed max as lee trough/dry line establishes
itself by afternoon near the NM/TX border. Strong heating near this
boundary should remove CINH such that convection develops along the
dryline by 20-21z. Northward-lifting warm front should retreat to
near the I-70 corridor and this boundary is expected to play a role
in potential severe development/evolution as well. Latest NAM
suggests mixing ratios near 15 g/kg across the High Plains and this
moisture surge will result in impressive thermodynamic profiles
within a strongly sheared environment. Forecast soundings favor
supercells and very large hail can be expected with storms that
evolve across this region. Additionally, tornadoes can be expected
as low LCL heights will exist along with favorable low-level shear.
Latest CAMs support scattered supercell development across the
western edge of the ENH Risk by 21-23z and this activity should
spread downstream toward central KS during the evening hours. The
lack of a more identifiable short-wave trough will prevent an
upgrade to MDT Risk at this time; however, an upgrade may be
required if confidence increases.

...OH Valley/Lower Great Lakes...

Significant mid-level height falls will spread across ON/QC during
the day ahead of a strong mid-level short-wave trough that should
translate into eastern ON by 26/00z. This feature will flatten the
ridge over the OH Valley/Great Lakes region early while forcing a
pronounced surface front to a position from ON-central WI-northern
IA by late afternoon. Early in the period, low-level warm advection
is expected to drive convection across the lower Great Lakes and
favorable deep-layer westerly flow should allow for destabilization
in the wake of this early-day convection ahead of the front. It
appears isolated thunderstorms will evolve within the
moistening/warming warm sector as low-level lapse rates steepen. It
appears deep convection may regenerate by 18-20z across the OH
Valley then spread east within strong westerly flow regime. Damaging
winds, along with some hail should be the primary threats.

...MAXIMUM RISK BY HAZARD...
Tornado: 10% - Enhanced
Wind: 30% - Enhanced
Hail: 30% SIG - Enhanced

..Darrow.. 05/24/2019

$$

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

987
ACUS03 KWNS 240722
SWODY3
SPC AC 240721

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0221 AM CDT Fri May 24 2019

Valid 261200Z - 271200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS
NORTHWARD TO CENTRAL NEBRASKA...

...SUMMARY...
Severe thunderstorms are possible across a broad area of the Plains.
More isolated severe storms are possible along the Ohio Valley.

...Much of the Great Plains...
Western troughing/eastern ridging will keep the Plains active with
respect to severe weather potential on D3/Sunday. A vigorous system
will migrate southeastward across California and Nevada during the
forecast period as a lower-amplitude wave lifts from Baja California
through New Mexico and toward Nebraska late. Specific timing of
this wave is in question, however. Meanwhile, a broad area of 60s
and low 70s F dewpoints will extend from a dryline (located from
northeastern Colorado southward to the Transpecos) eastward through
much of the Plains, Mid-Missouri Valley, and Midwest. Lesser
moisture will extend northward into the Dakotas, with an airmass
characterized by 50s F dewpoints. A surface low will deepen in
northeastern Colorado while moving slowly east.

Models develop widespread precipitation along and east of the
dryline during the afternoon within an airmass that will likely be
strongly sheared and moderately to strongly unstable. The magnitude
of lift associated with the mid-level wave and resultant widespread
nature of the convection suggests that a mix of linear and cellular
modes will exist, with all modes of severe possible. Mesoscale
details will likely drive any localized/focused corridors of
heightened severe potential, and subsequent model guidance should
offer those details with time. However, latest indications that
storms should migrate northeastward through a reservoir of strong
instability over Kansas and southern Nebraska during the evening,
perhaps evolving into one or two convective complexes with time.

Convection should also develop northward into portions of eastern
Wyoming and the Dakotas. This area will be north of the Colorado
surface low, with backed low-level flow promoting upslope
(especially in eastern Wyoming) and supercellular wind profiles
areawide. Destabilization and convective coverage are a bit less
certain in these areas compared to farther south, and lower severe
probabilities exist for what will likely be a lesser severe threat
in this area.

...Ohio Valley...
A southward moving cold front across the region will interact with a
weakly to moderately buoyant airmass with weak inhibition to foster
scattered thunderstorm development during the afternoon. Low-level
wind fields are relatively weak, though 40-50 kt deep shear will
support some organization of storms in this region into linear
segments that will migrate southeastward during the afternoon. A
wind-damage threat will exist with this activity.

..Cook.. 05/24/2019

$$

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

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

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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.