Wind Chill Advisory 1, NWS Chicago, IL

Boone County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Ford County, IL, Grundy County, IL, Iroquois County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, McHenry County, IL, Ogle County, IL, Will County, IL, Winnebago County, IL, Benton County, IN, Jasper County, IN, Lake County, IN, Newton County, IN, Porter County, IN

232 
WWUS43 KLOT 061539
WSWLOT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Chicago IL
939 AM CST Sat Feb 6 2021

ILZ008-010>013-019>021-023-032-033-039-103>108-INZ001-002-010-011-
019-062345-
/O.CON.KLOT.WW.Y.0005.210206T1800Z-210207T0600Z/
/O.CON.KLOT.WC.Y.0001.210207T0600Z-210207T1800Z/
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-
Including the cities of Rochelle, Oregon, Byron, Dixon, DeKalb, 
Sycamore, Aurora, Elgin, Naperville, Wheaton, Downers Grove, 
Lombard, Carol Stream, Ottawa, Streator, La Salle, Mendota, 
Marseilles, Oswego, Yorkville, Plano, Morris, Coal City, Minooka,
Kankakee, Bourbonnais, Bradley, Pontiac, Dwight, Fairbury, 
Watseka, Gilman, Paxton, Gibson City, Evanston, Des Plaines, 
Schaumburg, Palatine, Northbrook, Chicago, Cicero, Oak Lawn, 
Oak Park, La Grange, Calumet City, Oak Forest, Lemont, 
Orland Park, Park Forest, Joliet, Bolingbrook, Plainfield, 
Mokena, Channahon, Manhattan, Wilmington, Crete, Peotone, 
Beecher, Gary, Hammond, Merrillville, Portage, Valparaiso, 
Chesterton, Roselawn, Kentland, Morocco, Rensselaer, DeMotte, 
Fowler, and Oxford
939 AM CST Sat Feb 6 2021 /1039 AM EST Sat Feb 6 2021/

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL MIDNIGHT CST
/1 AM EST/ TONIGHT...
...WIND CHILL ADVISORY REMAINS IN EFFECT FROM MIDNIGHT CST /1 AM
EST/ TONIGHT TO NOON CST /1 PM EST/ SUNDAY...

* WHAT...For the Winter Weather Advisory, snow expected. Total
  snow accumulations of 2 to 4 inches. For the Wind Chill 
  Advisory, very cold wind chills expected. Wind chills as low as 
  30 below zero.

* WHERE...Portions of northwest Indiana and north central and 
  northeast Illinois.

* WHEN...For the Winter Weather Advisory, from noon CST /1 PM 
  EST/ today to midnight CST /1 AM EST/ tonight. For the Wind 
  Chill Advisory, from midnight CST /1 AM EST/ tonight to noon 
  CST /1 PM EST/ Sunday.

* IMPACTS...Plan on slippery road conditions. The dangerously cold
  wind chills could cause frostbite on exposed skin in as little
  as 10 minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling.

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves.

In Illinois, the latest road conditions for Illinois can be
obtained on the internet at www.gettingaroundillinois.com. In
Indiana, the latest road conditions for Indiana are available by
calling 1-800-261-7623.

&&

$$

ILZ003>006-062345-
/O.CON.KLOT.WC.Y.0001.210207T0600Z-210207T1800Z/
Winnebago-Boone-McHenry-Lake IL-
Including the cities of Rockford, Belvidere, Crystal Lake, 
Algonquin, McHenry, Woodstock, Waukegan, Buffalo Grove, 
Mundelein, and Gurnee
939 AM CST Sat Feb 6 2021

...WIND CHILL ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO
NOON CST SUNDAY...

* WHAT...Very cold wind chills expected. Wind chills as low as 
  30 below zero.

* WHERE...Winnebago, Boone, McHenry and Lake IL Counties.

* WHEN...From midnight tonight to noon CST Sunday.

* IMPACTS...The dangerously cold wind chills could cause frostbite
  on exposed skin in as little as 10 minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves.

&&

$$

309 
WWUS43 KLOT 061934
WSWLOT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Chicago IL
134 PM CST Sat Feb 6 2021

ILZ008-010>013-019>021-023-032-033-039-103>108-INZ001-002-010-011-
019-070600-
/O.CON.KLOT.WW.Y.0005.000000T0000Z-210207T0600Z/
/O.CON.KLOT.WC.Y.0001.210207T0600Z-210207T1800Z/
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-
Including the cities of Rochelle, Oregon, Byron, Dixon, DeKalb, 
Sycamore, Aurora, Elgin, Naperville, Wheaton, Downers Grove, 
Lombard, Carol Stream, Ottawa, Streator, La Salle, Mendota, 
Marseilles, Oswego, Yorkville, Plano, Morris, Coal City, Minooka,
Kankakee, Bourbonnais, Bradley, Pontiac, Dwight, Fairbury, 
Watseka, Gilman, Paxton, Gibson City, Evanston, Des Plaines, 
Schaumburg, Palatine, Northbrook, Chicago, Cicero, Oak Lawn, 
Oak Park, La Grange, Calumet City, Oak Forest, Lemont, 
Orland Park, Park Forest, Joliet, Bolingbrook, Plainfield, 
Mokena, Channahon, Manhattan, Wilmington, Crete, Peotone, 
Beecher, Gary, Hammond, Merrillville, Portage, Valparaiso, 
Chesterton, Roselawn, Kentland, Morocco, Rensselaer, DeMotte, 
Fowler, and Oxford
134 PM CST Sat Feb 6 2021 /234 PM EST Sat Feb 6 2021/

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL MIDNIGHT CST
/1 AM EST/ TONIGHT...
...WIND CHILL ADVISORY REMAINS IN EFFECT FROM MIDNIGHT CST /1 AM
EST/ TONIGHT TO NOON CST /1 PM EST/ SUNDAY...

* WHAT...For the Winter Weather Advisory, snow expected. Total
  snow accumulations of 2 to 4 inches. Localized blowing and
  drifting snow this evening for rural locations. For the Wind
  Chill Advisory, very cold wind chills expected. Wind chills 20
  to 30 below zero.

* WHERE...Portions of northwest Indiana and north central and
  northeast Illinois, mainly along and south of Interstate 90.

* WHEN...For the Winter Weather Advisory, to midnight CST /1 AM 
  EST/ tonight. For the Wind Chill Advisory, from midnight CST /1 
  AM EST/ tonight to noon CST /1 PM EST/ Sunday.

* IMPACTS...Plan on quickly snow covered roads at snow onset and  
  slippery road conditions. The dangerously cold wind chills could
  cause frostbite on exposed skin in as little as 10 minutes.

* ADDITIONAL DETAILS...Winds will increase tonight with some 
  gusts to 25 mph that will result in localized blowing and 
  drifting of the newly fallen dry snow. Caution is urged when 
  traveling on open roadways. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling.

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves.

In Illinois, the latest road conditions for Illinois can be
obtained on the internet at www.gettingaroundillinois.com. In
Indiana, the latest road conditions for Indiana are available by
calling 1-800-261-7623.

&&

$$

ILZ003>006-070600-
/O.CON.KLOT.WC.Y.0001.210207T0600Z-210207T1800Z/
Winnebago-Boone-McHenry-Lake IL-
Including the cities of Rockford, Belvidere, Crystal Lake, 
Algonquin, McHenry, Woodstock, Waukegan, Buffalo Grove, 
Mundelein, and Gurnee
134 PM CST Sat Feb 6 2021

...WIND CHILL ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO
NOON CST SUNDAY...

* WHAT...Very cold wind chills expected. Wind chills 20 to 30 
  below zero.

* WHERE...Winnebago, Boone, McHenry and Lake IL Counties.

* WHEN...From midnight tonight to noon CST Sunday.

* IMPACTS...The dangerously cold wind chills could cause 
  frostbite on exposed skin in as little as 10 minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves.

&&

$$

002 
WWUS43 KLOT 070219
WSWLOT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Chicago IL
819 PM CST Sat Feb 6 2021

ILZ008-010>012-019-071030-
/O.CAN.KLOT.WW.Y.0005.000000T0000Z-210207T0600Z/
/O.CON.KLOT.WC.Y.0001.210207T0600Z-210207T1800Z/
Ogle-Lee-De Kalb-Kane-La Salle-
Including the cities of Rochelle, Oregon, Byron, Dixon, DeKalb, 
Sycamore, Aurora, Elgin, Ottawa, Streator, La Salle, Mendota, 
and Marseilles
819 PM CST Sat Feb 6 2021

...WIND CHILL ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO
NOON CST SUNDAY...
...WINTER WEATHER ADVISORY IS CANCELLED...

* WHAT...Very cold wind chills expected. Wind chills 20 to 30 
  below zero.

* WHERE...Ogle, Lee, De Kalb, Kane and La Salle Counties.

* WHEN...From midnight tonight to noon CST Sunday.

* IMPACTS...The dangerously cold wind chills could cause 
  frostbite on exposed skin in as little as 10 minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves. 

&&

$$

ILZ013-020-021-023-032-033-039-103>108-INZ001-002-010-011-019-
071030-
/O.CON.KLOT.WW.Y.0005.000000T0000Z-210207T0600Z/
/O.CON.KLOT.WC.Y.0001.210207T0600Z-210207T1800Z/
DuPage-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-
Northern Cook-Central Cook-Southern Cook-Northern Will-
Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-Benton-
Including the cities of Naperville, Wheaton, Downers Grove, 
Lombard, Carol Stream, Oswego, Yorkville, Plano, Morris, 
Coal City, Minooka, Kankakee, Bourbonnais, Bradley, Pontiac, 
Dwight, Fairbury, Watseka, Gilman, Paxton, Gibson City, Evanston,
Des Plaines, Schaumburg, Palatine, Northbrook, Chicago, Cicero, 
Oak Lawn, Oak Park, La Grange, Calumet City, Oak Forest, Lemont, 
Orland Park, Park Forest, Joliet, Bolingbrook, Plainfield, 
Mokena, Channahon, Manhattan, Wilmington, Crete, Peotone, 
Beecher, Gary, Hammond, Merrillville, Portage, Valparaiso, 
Chesterton, Roselawn, Kentland, Morocco, Rensselaer, DeMotte, 
Fowler, and Oxford
819 PM CST Sat Feb 6 2021 /919 PM EST Sat Feb 6 2021/

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL MIDNIGHT CST
/1 AM EST/ TONIGHT...
...WIND CHILL ADVISORY REMAINS IN EFFECT FROM MIDNIGHT CST /1 AM
EST/ TONIGHT TO NOON CST /1 PM EST/ SUNDAY...

* WHAT...For the Winter Weather Advisory, snow expected. Total
  snow accumulations of 1 to 3 inches. Localized blowing and 
  drifting snow this evening for rural locations. For the Wind 
  Chill Advisory, very cold wind chills expected. Wind chills 20 
  to 30 below zero.

* WHERE...Portions of northwest Indiana, east central and 
  northeast Illinois.

* WHEN...For the Winter Weather Advisory, to midnight CST /1 AM 
  EST/ tonight. For the Wind Chill Advisory, from midnight CST 
  /1 AM EST/ tonight to noon CST /1 PM EST/ Sunday.

* IMPACTS...Plan on snow covered and slippery road conditions. 
  The dangerously cold wind chills could cause frostbite on 
  exposed skin in as little as 10 minutes.

* ADDITIONAL DETAILS...Winds will increase tonight with some 
  gusts to 25 mph that will result in localized blowing and 
  drifting of the newly fallen dry snow. Caution is urged when 
  traveling on open roadways.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves. 

In Illinois, the latest road conditions for Illinois can be
obtained on the internet at www.gettingaroundillinois.com. In
Indiana, the latest road conditions for Indiana are available by
calling 1-800-261-7623.

&&

$$

ILZ003>006-071030-
/O.CON.KLOT.WC.Y.0001.210207T0600Z-210207T1800Z/
Winnebago-Boone-McHenry-Lake IL-
Including the cities of Rockford, Belvidere, Crystal Lake, 
Algonquin, McHenry, Woodstock, Waukegan, Buffalo Grove, 
Mundelein, and Gurnee
819 PM CST Sat Feb 6 2021

...WIND CHILL ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO
NOON CST SUNDAY...

* WHAT...Very cold wind chills expected. Wind chills 20 to 30 
  below zero.

* WHERE...Winnebago, Lake IL, McHenry and Boone Counties.

* WHEN...From midnight tonight to noon CST Sunday.

* IMPACTS...The dangerously cold wind chills could cause 
  frostbite on exposed skin in as little as 10 minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves. 

&&

$$

893 
WWUS43 KLOT 070345
WSWLOT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Chicago IL
945 PM CST Sat Feb 6 2021

ILZ013-020-021-023-032-033-039-103>108-INZ001-002-010-011-019-
071145-
/O.CAN.KLOT.WW.Y.0005.000000T0000Z-210207T0600Z/
/O.CON.KLOT.WC.Y.0001.210207T0600Z-210207T1800Z/
DuPage-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-
Northern Cook-Central Cook-Southern Cook-Northern Will-
Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-Benton-
Including the cities of Naperville, Wheaton, Downers Grove, 
Lombard, Carol Stream, Oswego, Yorkville, Plano, Morris, 
Coal City, Minooka, Kankakee, Bourbonnais, Bradley, Pontiac, 
Dwight, Fairbury, Watseka, Gilman, Paxton, Gibson City, Evanston,
Des Plaines, Schaumburg, Palatine, Northbrook, Chicago, Cicero, 
Oak Lawn, Oak Park, La Grange, Calumet City, Oak Forest, Lemont, 
Orland Park, Park Forest, Joliet, Bolingbrook, Plainfield, 
Mokena, Channahon, Manhattan, Wilmington, Crete, Peotone, 
Beecher, Gary, Hammond, Merrillville, Portage, Valparaiso, 
Chesterton, Roselawn, Kentland, Morocco, Rensselaer, DeMotte, 
Fowler, and Oxford
945 PM CST Sat Feb 6 2021 /1045 PM EST Sat Feb 6 2021/

...WIND CHILL ADVISORY REMAINS IN EFFECT UNTIL NOON CST /1 PM
EST/ SUNDAY...
...WINTER WEATHER ADVISORY IS CANCELLED...

* WHAT...Very cold wind chills expected. Wind chills 20 to 30 
  below zero.

* WHERE...Portions of northwest Indiana and central, east 
  central and northeast Illinois.

* WHEN...From midnight tonight to noon CST Sunday.

* IMPACTS...The dangerously cold wind chills could cause 
  frostbite on exposed skin in as little as 10 minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves. 

&&

$$

ILZ003>006-008-010>012-019-071145-
/O.CON.KLOT.WC.Y.0001.210207T0600Z-210207T1800Z/
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-La Salle-
Including the cities of Rockford, Belvidere, Crystal Lake, 
Algonquin, McHenry, Woodstock, Waukegan, Buffalo Grove, 
Mundelein, Gurnee, Rochelle, Oregon, Byron, Dixon, DeKalb, 
Sycamore, Aurora, Elgin, Ottawa, Streator, La Salle, Mendota, 
and Marseilles
945 PM CST Sat Feb 6 2021

...WIND CHILL ADVISORY REMAINS IN EFFECT UNTIL NOON CST SUNDAY...

* WHAT...Very cold wind chills expected. Wind chills 20 to 30 
  below zero.

* WHERE...Portions of north central and northeast Illinois.

* WHEN...From midnight tonight to noon CST Sunday.

* IMPACTS...The dangerously cold wind chills could cause 
  frostbite on exposed skin in as little as 10 minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves. 

&&

$$

657 
WWUS43 KLOT 070900
WSWLOT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Chicago IL
300 AM CST Sun Feb 7 2021

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-071800-
/O.CON.KLOT.WC.Y.0001.000000T0000Z-210207T1800Z/
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-
Including the cities of Rockford, Belvidere, Crystal Lake, 
Algonquin, McHenry, Woodstock, Waukegan, Buffalo Grove, 
Mundelein, Gurnee, Rochelle, Oregon, Byron, Dixon, DeKalb, 
Sycamore, Aurora, Elgin, Naperville, Wheaton, Downers Grove, 
Lombard, Carol Stream, Ottawa, Streator, La Salle, Mendota, 
Marseilles, Oswego, Yorkville, Plano, Morris, Coal City, Minooka,
Kankakee, Bourbonnais, Bradley, Pontiac, Dwight, Fairbury, 
Watseka, Gilman, Paxton, Gibson City, Evanston, Des Plaines, 
Schaumburg, Palatine, Northbrook, Chicago, Cicero, Oak Lawn, 
Oak Park, La Grange, Calumet City, Oak Forest, Lemont, 
Orland Park, Park Forest, Joliet, Bolingbrook, Plainfield, 
Mokena, Channahon, Manhattan, Wilmington, Crete, Peotone, 
Beecher, Gary, Hammond, Merrillville, Portage, Valparaiso, 
Chesterton, Roselawn, Kentland, Morocco, Rensselaer, DeMotte, 
Fowler, and Oxford
300 AM CST Sun Feb 7 2021 /400 AM EST Sun Feb 7 2021/

...WIND CHILL ADVISORY REMAINS IN EFFECT UNTIL NOON CST /1 PM
EST/ TODAY...

* WHAT...Very cold wind chills expected. Wind chills 20 to 30 
  below zero.

* WHERE...Portions of northwest Indiana and central, east 
  central and northeast Illinois.

* WHEN...Through noon CST.

* IMPACTS...The dangerously cold wind chills could cause 
  frostbite on exposed skin in as little as 10 minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves.

&&

$$

Ratzer

901 
WWUS43 KLOT 071752
WSWLOT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Chicago IL
1152 AM CST Sun Feb 7 2021


ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-071900-
/O.EXP.KLOT.WC.Y.0001.000000T0000Z-210207T1800Z/
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-
Including the cities of Rockford, Belvidere, Crystal Lake, 
Algonquin, McHenry, Woodstock, Waukegan, Buffalo Grove, 
Mundelein, Gurnee, Rochelle, Oregon, Byron, Dixon, DeKalb, 
Sycamore, Aurora, Elgin, Naperville, Wheaton, Downers Grove, 
Lombard, Carol Stream, Ottawa, Streator, La Salle, Mendota, 
Marseilles, Oswego, Yorkville, Plano, Morris, Coal City, Minooka,
Kankakee, Bourbonnais, Bradley, Pontiac, Dwight, Fairbury, 
Watseka, Gilman, Paxton, Gibson City, Evanston, Des Plaines, 
Schaumburg, Palatine, Northbrook, Chicago, Cicero, Oak Lawn, 
Oak Park, La Grange, Calumet City, Oak Forest, Lemont, 
Orland Park, Park Forest, Joliet, Bolingbrook, Plainfield, 
Mokena, Channahon, Manhattan, Wilmington, Crete, Peotone, 
Beecher, Gary, Hammond, Merrillville, Portage, Valparaiso, 
Chesterton, Roselawn, Kentland, Morocco, Rensselaer, DeMotte, 
Fowler, and Oxford
1152 AM CST Sun Feb 7 2021 /1252 PM EST Sun Feb 7 2021/

...WIND CHILL ADVISORY WILL EXPIRE AT NOON CST /1 PM EST/ TODAY...

While wind chills are expected to improve some this afternoon,
expect subzero values to continue through the afternoon.

$$

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
328 AM CST Sat Feb 6 2021

.SHORT TERM...
328 AM CST

Through Sunday night...

Main focus in the near term is on the likelihood of a period of
accumulating snow this afternoon and evening in association with
an Alberta Clipper, and sub-zero temperatures and dangerously cold
wind chills later tonight into Sunday morning. Have adjusted the
Winter Weather Advisory northward through the I-88 corridor in
northern IL and into northwest IN. Will also issue a Wind Chill
Advisory for the entire area from midnight tonight through noon
Sunday for wind chills of -20 and colder.

Early morning GOES water vapor depicts a mid-level short wave
digging southeast across eastern Montana. This fast-moving
"Alberta Clipper" is forecast to continue to track southeast
toward MN and IA by midday, eventually inducing forcing for deep
ascent across the forecast area. Of particular note, is the
tightening of the low level baroclinic zone across northern MO
into central IL by late afternoon, with relatively strong
frontogenetic forcing developing across the southern parts the
cwa. RAP model cross section oriented from southeast to northwest
(normal to the thermal gradient) depicts a fairly strong region of
sloped frontogenesis south of the I-88 corridor, with the
resultant direct ageostrophic circulation rising into a region of
weak static stability (negative EPVs values, and lapse rates of
7.5-8 C/km in soundings). Nice vertical motion maxima noted in the
omega field in this region, that while centered a bit above the
dendritic growth zone, suggests the potential for some decent
banding and enhanced snowfall rates from the I-80 corridor
northward into the I-88 corridor this afternoon. This stronger
mesoscale forcing then shifts east and appears to weaken somewhat
into this evening, with snow likely ending fairly quickly from the
northwest by midnight as the mid-level short wave moves through.
Model QPF amounts generally around a tenth of an inch don't
suggest heavy snow per say, with snow/liquid ratios likely in the
20:1 range supporting around 2 inches or so of accumulation.
However, the presence of stronger mesoscale banding does indicate
that there may be some potential for locally higher amounts, of
3-4", including across areas just north of the inherited Winter
Weather Advisory. While the advisory may be somewhat marginal,
felt the need to expand it north into the I-88 corridor as well as
east into northwest Indiana. Temperatures in the single
digits/low teens will allow for quick accumulation on pavement,
with rates of a quarter to a half inch per hour likely in some
spots. This will make for some slipper travel conditions and low
visibilities for a time, lending support for the headline. As
indicated, snow will end quickly from west to east during the mid-
late evening hours.

Surface high pressure is progged to build in behind the clipper
later tonight, with a renewed push of colder arctic air. Combined
with clearing skies and some fresh snow cover, air temperatures
are expected to drop below zero across much of the forecast area
by Sunday morning, with lows as cold as -10 to -15 F across parts
of north central IL. Adding northwest winds of 10-12 mph, this is
expected to result in dangerously low wind chill values in the -20
to -25 F range. Based on this, will issue a Wind Chill Advisory
for the entire cwa from midnight tonight through noon Sunday.
Surface ridge builds into the area Sunday, with sunshine expected
during the morning. With the very cold start to the day however,
even morning sunshine won't warm temps appreciably and highs are
only expected to be in the single digits above zero, with wind
chills still sub-zero.

Clouds are expected to increase once again Sunday
midday/afternoon, as another more sheared mid-level short wave
approaches from the mid- Missouri Valley. Some light snow may
develop across parts of the area late in the afternoon or evening,
though there is some differences in the various models with the
placement. Better potential for more widespread accumulations look
to come on Monday. Despite cloud cover, sub-zero temps are likely
Sunday night, with the potential for advisory criteria bitter
wind chills again overnight.

Ratzer

&&

.LONG TERM...
328 AM CST

Monday through Friday...

The arctic airmass will remain in place through the work week
with high temperatures in the teens and lows in the single digits
to a few degrees below zero. Although not as low as what is
expected this weekend, morning wind chills will still dip into the
negative teens most nights.

We remain locked in a favorable pattern for multiple subtle
disturbances to move over the area with our next chance for light
to possibly moderate snow on Monday. Model ensembles are in fairly
good agreement that we will see accumulating snow Monday into
Monday night. There remains some uncertainty with how much snow we
ultimately end up with, however. Latest guidance has trended down
a bit with an additional 1 to 3 inches in the current forecast ,
but the previous shift's concerns of potentially higher snowfall
amounts remains valid, especially with the 500 mb vorticity max
aligned with mid-level frontogenesis could result in a quick burst
of moderate snow over the area. Regardless, with surface
temperatures well below freezing, any snow that falls Monday
afternoon and evening will stick to surfaces creating hazardous
travel conditions.

Beyond Monday, uncertainty in the details begins to decrease with
considerable variability in the amplitude of the upper jet
heading into the latter half of the week, which will have
implications on precipitation chances as well as if we get another
reinforcing shot of cold air. Have opted to carry at least slight
chances on Thursday.

Petr

&&

.AVIATION...
For the 06Z TAFs...

* West winds continue to diminish overnight
* Snow arrives Saturday midday, restricting visibilities and ceilings

Winds remain breezy from the west for the central and eastern sites,
but have dropped below 30 kt breezes. Winds will continue to slowly
decrease throughout the night, dropping down to around 10 kts by
early morning Saturday.

The next weather system approaches from the west bringing snow, with
onset of snow expected between 12Z and 13Z Saturday at KRFD,
starting more towards 13Z to 14Z at KORD. Winds will be from the
northwest at around 9 kts with no significant gusts expected. Cloud
ceilings will lower somewhat with the snow, but expect lower
visibilities as the stronger lifting mechanisms move in place in the
mid-afternoon, with VIS less than 2SM and MVFR ceilings. Under the
more intense snowfall, visibilities could go even lower, with LIFR
visibilities possible. Confidence is fairly good on the occurrence
of snow, but timing of more intense snowfall is not as confidence,
as some models indicate more intense snow a bit earlier, as well as
not as confident on how low visibilities will drop, as normally
would expect them to drop possibly below 1/2SM, but most models
presently keep us above 1/2 SM. This system will move through
relatively quickly, so expect conditions to begin improving Saturday
mid to late evening as winds shift a bit more northwesterly.
Presently snow accumulations appear to be between 1.5 near KRFD, to
2.5 inches towards the metro sites, while temperatures remain very
cold, with lows Sunday morning from -1 to -8.

BKL

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Winter Weather Advisory...ILZ008-ILZ010-ILZ011-ILZ012-ILZ013-
     ILZ019-ILZ020-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039-ILZ103-
     ILZ104-ILZ105-ILZ106-ILZ107-ILZ108...noon Saturday to
     midnight Sunday.

     Wind Chill Advisory...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
     ILZ011-ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ023-ILZ032-
     ILZ033-ILZ039-ILZ103-ILZ104-ILZ105-ILZ106-ILZ107-
     ILZ108...midnight Sunday to noon Sunday.

IN...Wind Chill Advisory...INZ001-INZ002-INZ010-INZ011-
     INZ019...midnight Sunday to noon Sunday.

     Winter Weather Advisory...INZ001-INZ002-INZ010-INZ011-
     INZ019...noon Saturday to midnight Sunday.

LM...Heavy Freezing Spray Warning...IN nearshore waters until 9 AM
     Saturday.

     Small Craft Advisory...IN nearshore waters until 9 AM Saturday.

&&

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Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
335 PM CST Fri Feb 5 2021

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-062145-
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-
335 PM CST Fri Feb 5 2021 /435 PM EST Fri Feb 5 2021/

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

.DAY ONE...Tonight.

Weather hazards expected...

  Elevated Excessive Cold Risk.
  Limited Non thunderstorm wind Risk through early evening.

DISCUSSION...

Wind chills will fall into the teens below zero late tonight.

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

Saturday...
  Significant Excessive Cold Risk at night.
  Elevated Snow Risk.
Sunday...
  Significant Excessive Cold Risk.
Monday through Wednesday...
  Elevated Excessive Cold Risk.
Thursday...
  Significant Excessive Cold Risk.

DISCUSSION:

A very cold and active weather pattern is expected to persist
across the region through next week. This will feature the
potential for additional rounds of accumulating fluffy snow for
the area Saturday afternoon and evening, and again late Sunday
through Monday night or early Tuesday. The very cold temperatures
will worsen travel impacts from the snow.

Well below zero wind chills are possible at times during the
stretch, with some locations possibly having minimum wind chills
as cold as 15 to 25 below zero late Saturday night into Sunday
morning. The very cold temperatures and wind chills will continue
through much of next week.

.SPOTTER INFORMATION STATEMENT...

  Spotter activation will not be necessary through tonight.

LMZ740>745-062145-
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-
335 PM CST Fri Feb 5 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...

  Gale force winds and or very hazardous waves.
  Significant Freezing Spray Risk.

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

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

KJB

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