Flash Flood Watch 3, NWS Chicago, IL

436 
WGUS63 KLOT 240224
FFALOT

Flood Watch
National Weather Service Chicago IL
924 PM CDT Sat Oct 23 2021

ILZ019>021-023-032-033-039-105>108-INZ001-002-010-011-019-241030-
/O.CON.KLOT.FF.A.0003.211024T2100Z-211025T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-Southern
Cook-Northern Will-Southern Will-Eastern Will-Lake IN-Porter-Newton-
Jasper-Benton-
Including the cities of Gilman, Kentland, Calumet City, Portage, 
Fowler, Gary, Marseilles, Plainfield, Roselawn, Gibson City, La 
Salle, Bourbonnais, Chesterton, Merrillville, Park Forest, Watseka, 
Pontiac, Mendota, Hammond, Manhattan, Lemont, Streator, Oxford, 
Plano, Beecher, Valparaiso, Bolingbrook, Kankakee, Wilmington, 
Minooka, Ottawa, Morocco, Morris, Rensselaer, Peotone, Joliet, 
Paxton, Dwight, Channahon, Orland Park, Mokena, Oswego, Oak Forest, 
Yorkville, Bradley, Coal City, Crete, Fairbury, and DeMotte
924 PM CDT Sat Oct 23 2021 /1024 PM EDT Sat Oct 23 2021/

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM SUNDAY AFTERNOON THROUGH 
MONDAY MORNING...

The Flash Flood Watch continues for

* Portions of Illinois and northwest Indiana, including the 
  following areas, in Illinois, Eastern Will, Ford, Grundy, 
  Iroquois, Kankakee, Kendall, La Salle, Livingston, Northern Will, 
  Southern Cook and Southern Will. In northwest Indiana, Benton, 
  Jasper, Lake IN, Newton and Porter.

* From Sunday afternoon through Monday morning.

* Moderate to heavy rain will result in widespread rainfall totals 
  of 1.5 to 4 inches, with localized amounts over 4 inches possible.

* Flash flooding on some area roads is possible. Area rivers and 
  creeks are expected to rise and these rises may be swift in places.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means rapid-onset flooding is possible, but not 
yet certain, based upon the latest forecasts. Flash flooding is a 
dangerous situation. Persons with interests along area rivers, 
creeks, and other waterways should monitor the latest forecasts and 
be prepared to take action should flooding develop.

&&

$$

Friedlein

320 
WGUS63 KLOT 240801
FFALOT

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Chicago IL
301 AM CDT Sun Oct 24 2021

ILZ013-103-104-241615-
/O.EXA.KLOT.FF.A.0003.211024T2100Z-211025T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DuPage-Northern Cook-Central Cook-
Including the cities of La Grange, Carol Stream, Lombard, Des 
Plaines, Chicago, Cicero, Wheaton, Evanston, Northbrook, Palatine, 
Oak Lawn, Schaumburg, Downers Grove, Oak Park, and Naperville
301 AM CDT Sun Oct 24 2021

...FLASH FLOOD WATCH IN EFFECT FROM THIS AFTERNOON THROUGH MONDAY 
MORNING...

The National Weather Service in Chicago has expanded the

* Flash Flood Watch to include a portion of northeast Illinois, 
  including the following areas, Central Cook, DuPage and Northern 
  Cook.

* From this afternoon through Monday morning.

* Steady rain will fall from this afternoon through Monday morning 
  leading to ponding on roadways and in low-lying areas. A narrow 
  zone of particularly heavy rain may lead to flooding of low-lying 
  areas including farm fields, ditches, and roadways. The greatest 
  threat for such flooding appears to be across Livingston, Ford, 
  Iroquois, and Benton counties.

* Rainfall totals of 2 to 4 inches are possible in the Flash Flood 
  Watch area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means rapid-onset flooding is possible, but not 
yet certain, based upon the latest forecasts. Flash flooding is a 
dangerous situation. Persons with interests along area rivers, 
creeks, and other waterways should monitor the latest forecasts and 
be prepared to take action should flooding develop.

&&

$$

ILZ019>021-023-032-033-039-105>108-INZ001-002-010-011-019-241615-
/O.CON.KLOT.FF.A.0003.211024T2100Z-211025T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-Southern
Cook-Northern Will-Southern Will-Eastern Will-Lake IN-Porter-Newton-
Jasper-Benton-
Including the cities of Gilman, Kentland, Calumet City, Portage, 
Fowler, Gary, Marseilles, Plainfield, Roselawn, Gibson City, La 
Salle, Bourbonnais, Chesterton, Merrillville, Park Forest, Watseka, 
Pontiac, Mendota, Hammond, Manhattan, Lemont, Streator, Oxford, 
Plano, Beecher, Valparaiso, Bolingbrook, Kankakee, Wilmington, 
Minooka, Ottawa, Morocco, Morris, Rensselaer, Peotone, Joliet, 
Paxton, Dwight, Channahon, Orland Park, Mokena, Oswego, Oak Forest, 
Yorkville, Bradley, Coal City, Crete, Fairbury, and DeMotte
301 AM CDT Sun Oct 24 2021 /401 AM EDT Sun Oct 24 2021/

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM THIS AFTERNOON THROUGH 
MONDAY MORNING...

The Flash Flood Watch continues for

* Portions of Illinois and northwest Indiana, including the 
  following areas, in Illinois, Eastern Will, Ford, Grundy, 
  Iroquois, Kankakee, Kendall, La Salle, Livingston, Northern Will, 
  Southern Cook and Southern Will. In northwest Indiana, Benton, 
  Jasper, Lake IN, Newton and Porter.

* From this afternoon through Monday morning.

* Steady rain will fall from this afternoon through Monday morning 
  leading to ponding on roadways and in low-lying areas. A narrow 
  zone of particularly heavy rain may lead to flooding of low-lying 
  areas including farm fields, ditches, and roadways. The greatest 
  threat for such flooding appears to be across Livingston, Ford, 
  Iroquois, and Benton counties.

* Rainfall totals of 2 to 4 inches are possible in the Flash Flood 
  Watch area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means rapid-onset flooding is possible, but not 
yet certain, based upon the latest forecasts. Flash flooding is a 
dangerous situation. Persons with interests along area rivers, 
creeks, and other waterways should monitor the latest forecasts and 
be prepared to take action should flooding develop.

&&

$$

Borchardt

783 
WGUS63 KLOT 241720
FFALOT

Flood Watch
National Weather Service Chicago IL
1220 PM CDT Sun Oct 24 2021

ILZ013-019>021-023-032-033-039-103>108-INZ001-002-010-011-019-
250130-
/O.CON.KLOT.FF.A.0003.211024T2100Z-211025T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
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 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
1220 PM CDT Sun Oct 24 2021 /120 PM EDT Sun Oct 24 2021/

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM 4 PM CDT THIS 
AFTERNOON THROUGH MONDAY MORNING...

The Flash Flood Watch continues for

* Portions of Illinois and northwest Indiana, including the 
  following areas, in Illinois, Central Cook, DuPage, Eastern 
  Will, Ford, Grundy, Iroquois, Kankakee, Kendall, La Salle, 
  Livingston, Northern Cook, Northern Will, Southern Cook, and 
  Southern Will. In northwest Indiana, Benton, Jasper, Lake IN, 
  Newton, and Porter. 

* From 4 PM CDT this afternoon through Monday morning

* Steady rain will fall from this afternoon through Monday morning 
  leading to ponding on roadways and in low-lying areas. A narrow 
  zone of particularly heavy rain may lead to flooding of low-lying 
  areas including farm fields, ditches, and roadways. The greatest 
  threat for such flooding appears to be across Livingston, Ford, 
  Iroquois, and Benton counties.

* Rainfall totals of 2 to 4 inches are possible in the Flash Flood
  Watch area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means rapid-onset flooding is possible, but
not yet certain, based upon the latest forecasts. Flash flooding
is a dangerous situation. Persons with interests along area
rivers, creeks, and other waterways should monitor the latest
forecasts and be prepared to take action should flooding develop.

&&

$$

- Izzi

135 
WGUS63 KLOT 241934
FFALOT

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Chicago IL
234 PM CDT Sun Oct 24 2021

ILZ013-019>021-023-032-033-039-103>108-INZ001-002-010-011-019-250345-
/O.EXT.KLOT.FF.A.0003.211024T2100Z-211025T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
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 La Grange, Carol Stream, Gilman, Kentland, 
Calumet City, Chicago, Portage, Fowler, Wheaton, Evanston, 
Marseilles, Palatine, Beecher, Gibson City, Schaumburg, Downers 
Grove, La Salle, Bourbonnais, Chesterton, Merrillville, Northbrook, 
Lombard, Watseka, Pontiac, Roselawn, Mendota, Hammond, Manhattan, 
Lemont, Streator, Oxford, Plano, Channahon, Cicero, Gary, 
Valparaiso, Bolingbrook, Kankakee, Wilmington, Minooka, Ottawa, 
Morocco, Morris, Oak Lawn, Rensselaer, Peotone, Joliet, Paxton, Oak 
Park, Dwight, Park Forest, Des Plaines, Orland Park, Mokena, Oswego, 
Oak Forest, Plainfield, Yorkville, Bradley, Coal City, Crete, 
Fairbury, DeMotte, and Naperville
234 PM CDT Sun Oct 24 2021 /334 PM EDT Sun Oct 24 2021/

...FLASH FLOOD WATCH NOW IN EFFECT THROUGH LATE TONIGHT...

The Flash Flood Watch is now in effect for

* Portions of Illinois and northwest Indiana, including the 
  following areas, in Illinois, Central Cook, DuPage, Eastern Will, 
  Ford, Grundy, Iroquois, Kankakee, Kendall, La Salle, Livingston, 
  Northern Cook, Northern Will, Southern Cook and Southern Will. In 
  northwest Indiana, Benton, Jasper, Lake IN, Newton and Porter.

* Through late tonight.

* Waves of rain, heavy at times, with embedded thunderstorms will 
  continue through this evening. Widespread rainfall totals of 2 to 
  4 inches are expected across the watch area, with isolated higher 
  totals possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means rapid-onset flooding is possible, but not 
yet certain, based upon the latest forecasts. Flash flooding is a 
dangerous situation. Persons with interests along area rivers, 
creeks, and other waterways should monitor the latest forecasts and 
be prepared to take action should flooding develop.

&&

$$

- Izzi

110 
WGUS63 KLOT 250228
FFALOT

Flood Watch
National Weather Service Chicago IL
928 PM CDT Sun Oct 24 2021

ILZ013-019>021-023-032-033-039-103>108-INZ001-002-010-011-019-250800-
/O.CON.KLOT.FF.A.0003.000000T0000Z-211025T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
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 La Grange, Carol Stream, Gilman, Kentland, 
Calumet City, Chicago, Portage, Fowler, Wheaton, Evanston, 
Marseilles, Palatine, Beecher, Gibson City, Schaumburg, Downers 
Grove, La Salle, Bourbonnais, Chesterton, Merrillville, Northbrook, 
Lombard, Watseka, Pontiac, Roselawn, Mendota, Hammond, Manhattan, 
Lemont, Streator, Oxford, Plano, Channahon, Cicero, Gary, 
Valparaiso, Bolingbrook, Kankakee, Wilmington, Minooka, Ottawa, 
Morocco, Morris, Oak Lawn, Rensselaer, Peotone, Joliet, Paxton, Oak 
Park, Dwight, Park Forest, Des Plaines, Orland Park, Mokena, Oswego, 
Oak Forest, Plainfield, Yorkville, Bradley, Coal City, Crete, 
Fairbury, DeMotte, and Naperville
928 PM CDT Sun Oct 24 2021 /1028 PM EDT Sun Oct 24 2021/

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 3 AM CDT/4 AM EDT/ 
MONDAY...

The Flash Flood Watch continues for

* Portions of Illinois and northwest Indiana, including the 
  following areas, in Illinois, Central Cook, DuPage, Eastern Will, 
  Ford, Grundy, Iroquois, Kankakee, Kendall, La Salle, Livingston, 
  Northern Cook, Northern Will, Southern Cook and Southern Will. In 
  northwest Indiana, Benton, Jasper, Lake IN, Newton and Porter.

* Until 3 AM CDT/4 AM EDT/ Monday.

* Waves of rain, heavy at times, with embedded thunderstorms will 
  continue through early overnight before tapering. Observed 
  rainfall totals from Sunday morning through 9 PM Sunday evening 
  have been between 1.5 and 3.5 inches across much of the area along 
  and south of I-80. Total rainfall amounts of 2 to 4.5 inches are 
  expected across the Watch area, with isolated higher totals 
  possible.

* Ponding and minor flooding on some roads and low-lying locations 
  is expected, with potential for rapid-onset flooding in some 
  locations. Expect culverts and ditches to fill and likely overflow 
  in places.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means rapid-onset flooding is possible, but not 
yet certain, based upon the latest forecasts. Flash flooding is a 
dangerous situation. Persons with interests along area rivers, 
creeks, and other waterways should monitor the latest forecasts and 
be prepared to take action should flooding develop.

&&

$$

Friedlein

346 
WGUS63 KLOT 250755
FFALOT

Flood Watch
National Weather Service Chicago IL
255 AM CDT Mon Oct 25 2021

ILZ013-019>021-023-032-033-039-103>108-INZ001-002-010-011-019-250900-
/O.EXP.KLOT.FF.A.0003.000000T0000Z-211025T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
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 La Grange, Carol Stream, Gilman, Kentland, 
Calumet City, Chicago, Portage, Fowler, Wheaton, Evanston, 
Marseilles, Palatine, Beecher, Gibson City, Schaumburg, Downers 
Grove, La Salle, Bourbonnais, Chesterton, Merrillville, Northbrook, 
Lombard, Watseka, Pontiac, Roselawn, Mendota, Hammond, Manhattan, 
Lemont, Streator, Oxford, Plano, Channahon, Cicero, Gary, 
Valparaiso, Bolingbrook, Kankakee, Wilmington, Minooka, Ottawa, 
Morocco, Morris, Oak Lawn, Rensselaer, Peotone, Joliet, Paxton, Oak 
Park, Dwight, Park Forest, Des Plaines, Orland Park, Mokena, Oswego, 
Oak Forest, Plainfield, Yorkville, Bradley, Coal City, Crete, 
Fairbury, DeMotte, and Naperville
255 AM CDT Mon Oct 25 2021 /355 AM EDT Mon Oct 25 2021/

...FLASH FLOOD WATCH WILL EXPIRE AT 3 AM CDT/4 AM EDT/ EARLY THIS 
MORNING...

The Flash Flood Watch for portions of Illinois and northwest 
Indiana, including the following areas, in Illinois, Central Cook, 
DuPage, Eastern Will, Ford, Grundy, Iroquois, Kankakee, Kendall, La 
Salle, Livingston, Northern Cook, Northern Will, Southern Cook and 
Southern Will. In northwest Indiana, Benton, Jasper, Lake IN, Newton 
and Porter will expire at 3 AM CDT/4 AM EDT/ early this morning.

While scattered rain showers will continue this morning, flash 
flooding is no longer a threat. Accordingly, the Flash Flood Watch 
will be allowed to expire.

$$

Borchardt

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
654 AM CDT Sat Oct 23 2021

.SHORT TERM...
329 AM CDT

Through tonight...

The tail end of a plume of scattered and broken clouds is pushing
east through the area and should mostly clear out by daybreak.
Areas of frost are still anticipated through the early morning
hours with the potential for a few spots dropping to freezing
conditions, particularly in the far west and northwest suburbs. A
climb in surface pressure as well as some drier air being fed in
from the NW will keep skies mostly sunny through the day today.
Seasonable highs in the middle and upper 50's are expected. As
heights begin to drop and more moisture starts to move in from the
southwest, cloud cover will gradually build across the area from
the southwest through tonight in anticipation of our next storm
system which is forecast to arrive early Sunday.

Doom

&&

.LONG TERM...
329 AM CDT

Sunday through Monday Night...

The main forecast concerns remain around a period of steady, soaking
rain and blustery winds from Sunday afternoon through Monday morning
across much if not most of our area.

As an elongated 180-200kt jet streak currently stretching from the
Kamchatka Peninsula of Russia to the northern California coast
propagates eastward over the Rocky Mountains this afternoon, a low
pressure system will develop in southern Colorado and rapidly deepen
overnight thanks to favorably "coupled" diffluent upper-level flow.
Ensemble model guidance is in fair agreement the low will track from
near Wichita, Kansas to Kansas City, Missouri by midday Sunday, and
pass through central Illinois overnight Sunday into Monday.

Increasing warm-air advection early Sunday morning will lead to the
burgeoning of showers and thunderstorms along an axis from northern
Missouri to southern Illinois along a developing 850mb warm front.
As the surface low approaches Sunday afternoon, the 850mb front will
tighten and frontogenetical forcing will increase leading to the
development of waves of steady rain across our area (e.g. the
morning hours may end up mostly dry). Sunday evening, the surface
low will track through central Illinois potentially lifting the
surface warm front as far north as Livingston, Ford, and Iroquois
counties. Should the front indeed make it so far north, at least
some threat for surface-based severe storms cannot be ruled out with
an associated threat for all severe hazards. However, it currently
appears more likely that the surface front will remain south,
and the approach of the surface low will "merely" allow the zone
of active thunderstorms (with effective inflow above the boundary
layer) to lift northward into our area but south of I-80. Behind
the center of the low, steady rain will continue overnight into
Monday thanks to a healthy TROWAL and impressive low-level
moisture convergence aided by an easterly 40-50kt 950mb low-level
jet. Rain should taper from west to east through morning on
Monday, with all areas expected to be dry by afternoon.

Pinpointing where and how much rain will fall can sometimes be
tricky whenever warm-season moisture (PWATs of 1.25 to 1.5")
overlaps with cool-season synoptic-scale forcing, especially when
convection is involved. However, it appears most of our area has a
good shot at seeing at least 1" of rain by Monday morning (EPS
probabilities are 80-100% chance areawide), with the heaviest totals
exceeding 2" increasingly likely as one heads downstate (especially
south of I-80). Depending on whether the zone of active convection
works as far north as our area (again, looking at Livingston, Ford,
and Iroquois counties) rainfall totals may easily get out of hand
leading to a narrow, localized west to east zone where flooding of
roads, farm fields, and low-lying areas would become likely. Our
feeling at this point is that the zone of most active convection
should remain just to our south, but trends will need to be
monitored closely. Regardless of how much rain falls, confidence is
high that Sunday afternoon through Monday morning will be wet and
that river and stream levels will increase toward bankfull.

Increasing easterly low-level flow north of the center of the low
will lead to blustery winds particularly Sunday night through at
least daybreak Monday but possibly as late as Monday afternoon.
EPS mean ensemble wind gusts peak between 35-40 mph north of I-88
during the overnight hours, which is right on the cusp of strong
enough to blow around twigs, lawn furniture, and even down a few
small tree branches. The strongest wind gusts are likely along the
immediate Illinois shoreline of Lake Michigan, where EPS mean
ensemble peak wind gusts approach 50 mph. With such strong winds
over the lake, waves heights are likely to build greater than 8
feet (highest toward daybreak Monday) which will splash up on
lakeshore trails, parks, and low-lying spots. Meanwhile, winds
south of I-80 may end up rather light as the low tracks overhead.

In all, Sunday afternoon through Monday morning will be raw,
blustery, and wet, especially considering temperatures will be
somewhat stagnant near 50 degrees. The Monday morning commute in
particular may be gnarly with steady rain and blustery winds. The
best way to get through these fall storms is with a comfy sweater
and a good book (or sturdy rain gear if heading outdoors is
inevitable).

Borchardt

Tuesday through Saturday...

Tranquil weather conditions make a very brief return to the region
on Tuesday in the wake of the Sunday/Monday soaker. As high
pressure noses into the region, lingering north winds will trend
northeasterly off the lake through the afternoon yielding fairly
seasonable temperatures with highs in the upper 50s. With
relatively light winds expected to prevail through most of the
overnight hours, temperatures look set to drop back into the mid
and upper 30s across most of the forecast area away from the
immediate lakeshore, and pockets of near-freezing temperatures
seem to be in play based on the latest statistical guidance.

As has been the case the past few nights, noting quite a bit of
model disparity and run-to-run continuity issues as we head
towards the end of the week as our next potent PV-anomaly
translates across the Great Basin and out across the Continental
Divide. Latest EPS shows tremendous spread in surface low centers
with this next system from as far north as about Wisconsin to the
northern Gulf, and this amount of spread is seen across the rest
of the ensemble model suite. The main change for this forecast
package was to trend PoPs downwards and a bit slower heading into
Wednesday, but no significant alterations to the blended offering
were made Wednesday night and beyond given the aforementioned
guidance spread.

Carlaw

&&

.HYDROLOGY...
329 AM CDT

A long duration, soaking rainfall is expected Sunday afternoon
through Monday morning, with the heaviest rain rates and totals
expected to fall south of Interstate 80. Rises in river and stream
levels appear probable especially along the Kankakee, Iroquois, and
Illinois rivers where "best estimate" experimental ensemble river
forecasts depict river levels rising toward bankfull early next
week. Additionally, flooding along the sides of roadways may occur
in urban areas where leafs and other clutter clog storm sewer
drains. A narrow zone of particularly heavy rain totals may
materialize in the vicinity of Livingston, Ford, and Iroquois
counties Sunday evening which may lead to flooding of farm fields,
roadways, and low-lying areas. However, the narrow zone may
develop further to the south in central Illinois. Stay up to date
on the forecast, especially if you live along a river or stream
south of Interstate 80.

Borchardt

&&

.AVIATION...
For the 12Z TAFs...

Mostly clear skies are in store for the majority of today. Light
NW winds this morning will pick up to 7 or 8 kts by the afternoon
as they shift to NE sometime around 21Z over the Chicago
terminals. Overnight tonight, BKN and OVC ceilings will start to
push in from the SW and dramatically lower through Sunday morning.
MVFR conditions can be expected as early as 15Z. However, low
MVFR, or even IFR, cigs are possible even earlier, though
confidence in such conditions is rather low at this time and
therefore was excluded from the TAF. Easterly flow will continue
at around 10 kts through the end of the TAF period. Looking ahead
of the TAF period, rain is likely for much of Sunday afternoon and
evening with likely IFR cigs and the potential for a couple of
thunderstorms.

Doom

&&

.MARINE...
329 AM CDT

A Gale Watch remains in effect for the Illinois and Indiana
nearshore zones from Sunday evening through Monday morning for
strong easterly winds associated with a passing low pressure system
south of Lake Michigan. Confidence is growing that gale force winds
will start first along the Illinois shoreline Sunday evening, and
spread southward to the Indiana shoreline toward daybreak Monday.
Peak wind gusts exceeding 40 kt may occur, particularly on Monday
morning.

Borchardt

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Frost Advisory...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
     ILZ011-ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ103-ILZ106-
     ILZ107 until 8 AM Saturday.

IN...None.
LM...Gale Watch...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...6 PM
     Sunday to 4 PM Monday.

&&

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Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
417 AM CDT Sat Oct 23 2021

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-240930-
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-
417 AM CDT Sat Oct 23 2021 /517 AM EDT Sat Oct 23 2021/

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

.DAY ONE...Today and Tonight.

Weather hazards expected...

  Elevated Frost and Freeze Risk this morning.
  Limited Frost Risk for interior NW Illinois tonight.

DISCUSSION...

The threat for frost and near-freezing temperatures will continue
near and northwest of the I-55 corridor outside of Chicago this
morning. Elsewhere, patchy frost is possible away from the
lakefront.

Additional patchy frost development is possible late tonight.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Sunday...
  Limited Flooding Risk.
  Limited Non Thunderstorm Wind Risk.
  Elevated Lakeshore Flood Risk.
Monday...
  Limited Thunderstorm Risk.
  Limited Non Thunderstorm Wind Risk.
  Elevated Lakeshore Flood Risk.
Tuesday morning...
  Limited Frost and or Freeze Risk.

DISCUSSION:

Widespread, soaking rain and strong easterly winds are becoming
increasingly likely Sunday and Monday. Winds could gust as high as
40-45 mph near the immediate lakeshore Sunday evening into Monday.
Rises in river and stream levels, some possibly significant,
will occur. Flooding may occur on roadways near leaf-clogged
sewer drains. Additionally, flooding of parks and trails
immediately along the Lake Michigan shore may occur, particularly
in Illinois, including the Chicago bike path. Finally, a few
strong thunderstorms may occur south of US-24 Sunday evening.

.SPOTTER INFORMATION STATEMENT...

  Spotter activation will not be necessary through tonight.

LMZ740>745-240930-
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-
417 AM CDT Sat Oct 23 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...Today and Tonight.

  No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Sunday and Monday...
  Gale force winds and very hazardous waves are likely.
  Limited Thunderstorm Risk.
Tuesday...
  Hazardous conditions for small craft are likely.

Doom

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