SPC Convective Outlook Day 1

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165
ACUS01 KWNS 261956
SWODY1
SPC AC 261955

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0155 PM CST Tue Jan 26 2021

Valid 262000Z - 271200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE THIS
AFTERNOON INTO TONIGHT ACROSS PARTS OF THE FLORIDA
PANHANDLE...SOUTHERN GEORGIA...SOUTHERN SOUTH CAROLINA...

...SUMMARY...
A couple of strong thunderstorms could still impact a narrow
corridor across the Florida Panhandle and parts of southern Georgia
into southern South Carolina late this afternoon into tonight,
accompanied by some risk for severe weather.

...20Z Outlook Update...

...Southeast...
Thunderstorms through this afternoon have been mostly confined to
the vicinity of a narrow plume of higher precipitable water
returning around the northern periphery of the subtropical ridge.
Pre-frontal destabilization over land, aided by daytime heating, has
been generally weak, but in the presence of strong deep-layer shear.
While low severe weather probabilities are being maintained along
this corridor into early evening, the Rapid Refresh, supported by
area VWP data, suggests that low-level flow is in the process of
weakening. An appreciable increase in severe weather potential
seems unlikely, and strongest thunderstorms may tend to remain
focused near the coastal waters south/west of Panama City through
Pensacola, aided by inflow (albeit perhaps slightly elevated above a
stable near surface layer) of higher moisture content/potential
instability. Otherwise, in advance of the significant short wave
trough accelerating northeast of the southern Rockies tonight,
strengthening lower/mid tropospheric warm advection may support
increasing thunderstorm activity, mostly to the cool side of the
stalling surface frontal zone, across parts of southern Mississippi
through north central Georgia.

...Southeast Arizona into southern Rockies...
While convection capable of producing a flash or two of lightning
might still be possible across southeastern Arizona through 20-22Z,
the relatively compact mid-level cold core appears in the process of
the shifting northeastward into southwestern New Mexico, with
mid-level warming underway in its wake. As the larger-scale
mid-level thermal trough continues overspreading the higher terrain
of New Mexico this afternoon, forecast soundings suggest that
thermodynamic profiles might become conducive for some convection
capable of producing lightning. However, eastward into the high
plains, this potential appears likely to become increasingly
negligible.

...Northern California coast...
Some lightning is evident in convection along the occluding surface
front offshore, which might spread into northern California coastal
areas by early evening. Otherwise, post-frontal cooling aloft may
contribute to isolated thunderstorm activity approaching coastal
areas toward 12Z Wednesday.

..Kerr.. 01/26/2021

.PREV DISCUSSION... /ISSUED 1025 AM CST Tue Jan 26 2021/

...FL/AL/GA/SC...
Deep southwesterly tropospheric flow is present today over much of
the eastern CONUS, with the primary mid level jet extending from TX
into the upper OH Valley. A surface boundary extends from southern
SC southwestward into parts of southern GA, southeast AL, and the FL
panhandle. A moist and marginally unstable air mass remains along
and south of the boundary, with a few breaks in the clouds possible
this afternoon. This will provide sufficient CAPE and forcing for
scattered afternoon thunderstorms across the MRGL risk area. Flow
fields are strong but veered. This would suggest that locally
gusty/damaging winds are the main concern, although an isolated
tornado is possible.

Mid level heights will rise slightly this evening in between
systems, before the next upper trough begins to approach AL/FL
panhandle late tonight. Low level winds will strengthen before dawn
in this area, with the potential for redevelopment of a few
thunderstorms - with some risk of gusty/damaging wind or an isolated
tornado.

$$

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

456
FLUS43 KLOT 262141
HWOLOT

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
341 PM CST Tue Jan 26 2021

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-272145-
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-
341 PM CST Tue Jan 26 2021 /441 PM EST Tue Jan 26 2021/

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

.DAY ONE...Tonight.

Weather hazards expected...

Limited Excessive Cold Risk.
Limited Snow Risk Near Lake Michigan.

DISCUSSION...

Light to briefly moderate lake effect snow showers will
continue tonight, focusing primarily into Cook County and
Lake County Indiana.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Wednesday...
Limited Excessive Cold Risk.
Limited Snow Risk Near Lake Michigan.
Thursday...
Limited Morning Excessive Cold Risk.
Saturday...
Elevated Snow Risk.

DISCUSSION:

Light to briefly moderate lake effect snow showers are expected
along Lake Michigan on Wednesday, focusing primarily into Cook
County and Lake County Indiana.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be necessary through tonight.

$$

LMZ740>745-272145-
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-
341 PM CST Tue Jan 26 2021

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 Freezing Spray Risk.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Wednesday...
Hazardous conditions for small craft are likely.
Limited Freezing Spray Risk.
Thursday...
Hazardous conditions for small craft are likely.
Saturday through Monday...
Hazardous conditions for small craft are likely.

$$

KJB

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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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746
ACUS02 KWNS 261717
SWODY2
SPC AC 261716

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1116 AM CST Tue Jan 26 2021

Valid 271200Z - 281200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WEDNESDAY ACROSS
PARTS OF SOUTHERN GEORGIA...

...SUMMARY...
A couple of strong thunderstorms may impact parts of southern
Georgia Wednesday, accompanied by at least some risk for severe
weather.

...Synopsis...
One belt of westerlies emanating from the mid-latitude Pacific
appears likely to maintain a prominent influence across the U.S.
through this period. Across much of the eastern Pacific, models
indicate that embedded mid/upper ridging will remain amplified, with
downstream troughing undergoing further amplification/sharpening
just west of the Pacific coast, while ridging builds across the
Rockies and Great Plains. As this occurs, broadly confluent flow
eastward through the Atlantic Seaboard (between the blocked regime
across eastern Canada and the prominent subtropical ridge over the
Caribbean), appears likely to transition from westerly to
west-northwesterly. Embedded within this regime, after turning
eastward across the middle Mississippi Valley during the day
Wednesday, a significant remnant impulse emerging from the Southwest
is forecast to dig into southern Mid Atlantic coastal areas by 12Z
Thursday.

In lower levels, models indicate that an initially stalled surface
frontal zone, across the western Atlantic and Southeast into
northwestern Gulf of Mexico, will provide the focus for significant
cyclogenesis with the approach of the digging short wave impulse.
While it appears that surface wave development may commence across
the southeastern Alabama/western Florida Panhandle/southwestern
Georgia vicinity by early Wednesday, guidance suggests that this
will remain fairly weak until Wednesday evening, generally well east
of the Carolina coast. As stronger surface cyclogenesis proceeds, a
cold front will surge through much of Florida and the eastern Gulf
of Mexico by late Wednesday night, accompanied by considerable
lower/mid tropospheric drying.

...Southeast...
Along the northern periphery of the subtropical ridging, lower/mid
tropospheric lapse rates will be generally weak, at least initially.
But, conditions along the surface front will still be moist, with a
narrow plume of higher precipitable water content (emanating from
southwestern Gulf of Mexico) initially arcing northeastward along
and north of the frontal zone, before being shunted southward.

Within the warm sector of the developing frontal wave, it appears
that surface dew points in the mid 60s may contribute to weak
boundary-layer CAPE up to 500 + J/kg, across southern Georgia by
Wednesday afternoon. On the southern fringe of the stronger
mid-level height falls, which may glance areas as far south as the
Georgia/Florida border vicinity, this may become supportive of
scattered vigorous thunderstorm development. Coinciding with
strengthening of west-southwesterly flow to 40-50 kt around the 850
mb level, enlarging low-level hodographs could become supportive of
supercell structures posing a risk for damaging wind gusts and/or an
isolated tornado or two.

..Kerr.. 01/26/2021

$$

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

287
ACUS03 KWNS 260749
SWODY3
SPC AC 260748

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0148 AM CST Tue Jan 26 2021

Valid 281200Z - 291200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe weather is not expected across the U.S. Thursday.

...Discussion...
The upper pattern over the U.S. will continue to feature troughs
near both the East and West Coasts, and a broad area of anticyclonic
flow covering central portions of the country. Some evolution with
respect to the eastern trough is expected, as one shorter-wavelength
feature shifts into the western Atlantic, and is replaced by a low
advancing southeastward out of Canada and into the Northeast.
Meanwhile, the more steady-state western trough will make very slow
eastward progress toward the West Coast.

At the surface, high pressure will prevail east of the Rockies, with
ridging/continental air spreading southward across nearly the entire
Gulf of Mexico. In the West, a weak Pacific front will move
gradually onshore, in advance of the aforementioned upper system.

Showers are expected over the West Coast area through much of the
period, as the trough aloft slowly advances. Although an
occasional/isolated lightning flash may occur inland within the
broader area of weak/low-topped convection, coverage is currently
expected to remain too sparse to warrant inclusion of a 10% thunder
area.

..Goss.. 01/26/2021

$$

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

386
WWUS43 KLOT 262113
WSWLOT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Chicago IL
313 PM CST Tue Jan 26 2021


ILZ006-013-103-104-262215-
/O.CAN.KLOT.WS.W.0001.000000T0000Z-210126T2300Z/
Lake IL-DuPage-Northern Cook-Central Cook-
Including the cities of Waukegan, Buffalo Grove, Mundelein,
Gurnee, Naperville, Wheaton, Downers Grove, Lombard,
Carol Stream, Evanston, Des Plaines, Schaumburg, Palatine,
Northbrook, Chicago, Cicero, Oak Lawn, Oak Park, and La Grange
313 PM CST Tue Jan 26 2021

...WINTER STORM WARNING IS CANCELLED...

Lake effect snow showers will continue across the area into
tonight, but the threat for widespread accumulations has come to
an end.

$$

ILZ105>108-INZ001-002-262215-
/O.CAN.KLOT.WW.Y.0001.000000T0000Z-210126T2300Z/
Southern Cook-Northern Will-Southern Will-Eastern Will-Lake IN-
Porter-
Including the cities of Calumet City, Oak Forest, Lemont,
Orland Park, Park Forest, Joliet, Bolingbrook, Plainfield,
Mokena, Channahon, Manhattan, Wilmington, Crete, Peotone,
Beecher, Gary, Hammond, Merrillville, Portage, Valparaiso,
and Chesterton
313 PM CST Tue Jan 26 2021

...WINTER WEATHER ADVISORY IS CANCELLED...

Lake effect snow showers will continue across the area into
tonight, but the threat for widespread accumulations has come to
an end.

$$

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.

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.