Alert archive / Illinois / Tornado Warnings in 2020

Tornado Warning 1, NWS Chicago, IL

March 28, 2020Lee County, Ogle County, Illinois

NWS Chicago, IL issued this tornado warning at Mar 28, 2020, 8:53 PM CDT for Lee County, Ogle County, Illinois. It was in force for 37 min. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Mar 28, 2020, 8:53 PM CDT (01:53 UTC)
Expired: Mar 28, 2020, 9:30 PM CDT
In force: 37 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Lee County, IL, Ogle County, IL

The radar

The Quad Cities radar (KDVN), 103 km from the middle of the area, began a volume at 01:53 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Mar 28, 9:13 PM CDT	TORNADO	2 E Oregon, IL	AN EF-1 TORNADO BEGAN JUST EAST OF OREGON AND TRACKED 7 MILES TO THE NORTHEAST, DISSIPATING JUST PRIOR TO REACHING STILLMAN VALLEY. PRIMARILY TREE AND POWER LINE DAMAGE ALONG THE PATH WITH SOME STRUCTURAL DAMAGE, MAINLY TO SOME OUTBUILDINGS AND BARN.
Mar 28, 9:13 PM CDT	TORNADO	2 Nne Oregon, IL	LAW ENFORCEMENT REPORT OF A TORNADO, EM HAS CONFIRMED POWERLINES DOWN NORTH OF OREGON.
Mar 28, 9:18 PM CDT	TORNADO	4 Sw Stillman Valley, IL	EXTENSIVE DAMAGE PATH, SEVERAL HOMES DAMAGED WITH AT LEAST ONE WITH ROOF TOTALLY LOST. NUMEROUS TREES UPROOTED ON THAT PROPERTY, WIDESPREAD TREE DAMAGE, POWERLINES DOWN, SOME AREAS RESPONDERS ARE HAVING TO GET TO BY FOOT DUE TO ROADS BLOCKED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 3 storm reports to this tornado warning; the first came 20 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Mar 28, 2:45 PM CDT	Tornado Watch PDS	SPC	6 hr
Mar 28, 8:41 PM CDT	Tornado Watch	SPC	3 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.9 hours before the alert went out and 96 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 504 J/kg
Mixed-layer CIN: -27 J/kg
Mixed-layer LCL: 963 m above ground
0-6 km bulk shear: 88 kt
0-1 km storm-relative helicity: 480 m²/s²
0-3 km storm-relative helicity: 520 m²/s²
Significant tornado parameter: 1.7
Supercell composite: 9.3

Open this sounding in Storm Lab

The text

As transmitted.

813 
WFUS53 KLOT 290153
TORLOT
ILC103-141-290230-
/O.NEW.KLOT.TO.W.0001.200329T0153Z-200329T0230Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Chicago/Romeoville
853 PM CDT Sat Mar 28 2020

The National Weather Service in Chicago has issued a

* Tornado Warning for...
  Northwestern Lee County in north central Illinois...
  Eastern Ogle County in north central Illinois...

* Until 930 PM CDT.
    
* At 853 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Dixon, moving northeast at 45 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Oregon around 915 PM CDT.
  Byron around 925 PM CDT.

This includes...  Castle Rock State Park, Lowden State Park, and Ogle
County Fairgrounds.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4181 8957 4186 8961 4216 8925 4197 8905
TIME...MOT...LOC 0153Z 232DEG 37KT 4186 8955 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

Borchardt

2 follow-up statements

575 
WWUS53 KLOT 290203
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville
903 PM CDT Sat Mar 28 2020

ILC103-290213-
/O.CAN.KLOT.TO.W.0001.000000T0000Z-200329T0230Z/
Lee IL-
903 PM CDT Sat Mar 28 2020

...THE TORNADO WARNING FOR NORTHWESTERN LEE COUNTY IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 200 AM CDT for north central
Illinois.

LAT...LON 4192 8945 4195 8949 4216 8925 4201 8910
TIME...MOT...LOC 0203Z 221DEG 58KT 4197 8941 

$$

ILC141-290230-
/O.CON.KLOT.TO.W.0001.000000T0000Z-200329T0230Z/
Ogle IL-
903 PM CDT Sat Mar 28 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 930 PM CDT FOR CENTRAL
OGLE COUNTY...
    
At 903 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Oregon, moving northeast at 65 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Byron around 915 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4192 8945 4195 8949 4216 8925 4201 8910
TIME...MOT...LOC 0203Z 221DEG 58KT 4197 8941 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

Borchardt

621 
WWUS53 KLOT 290212
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville
912 PM CDT Sat Mar 28 2020

ILC141-290230-
/O.CON.KLOT.TO.W.0001.000000T0000Z-200329T0230Z/
Ogle IL-
912 PM CDT Sat Mar 28 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 930 PM CDT FOR CENTRAL
OGLE COUNTY...
    
At 911 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Oregon, moving northeast at 40 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation. The strongest rotation is right 
         over the town of Oregon. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Byron around 925 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4198 8935 4199 8938 4201 8939 4216 8925
      4203 8912
TIME...MOT...LOC 0211Z 229DEG 35KT 4202 8933 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

Borchardt

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Chicago, IL wrote its last area forecast discussion before this tornado warning went out at Mar 28, 7:56 PM CDT, 57 minutes earlier.

Area forecast discussion, Mar 28, 7:56 PM CDT, 57 minutes before

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
756 PM CDT Sat Mar 28 2020

.MESOSCALE DISCUSSION...
756 PM CDT

Cloudiness and earlier storms have continued to slow the northward
progression of the warm front, slowing the destabilization over
our CWA and ultimately likely resulting in weaker instability than
earlier projections.

The 00z sounding from ILX is very telling and a quick comparison
between ILX's 21z and 00z sounding shows a text book example of
synoptic ascent lifting through a cap. While there is still a
capping inversion, it is far less pronounced and now up above
850mb. Continued ascent will likely lift through the remaining
inversion, leaving the atmosphere uncapped, but only weakly
unstable this evening in the northward advancing warm sector.
While all indications are instability will remain weak (less than
1000 j/kg MLCAPE) this evening, weakening cap and strengthening
ascent in the narrow eastward advancing warm sector appears to be
a favorable high shear/low cape for at least mini-supercells with
an attendant tornado potential. Some hail threat could develop as
well if updrafts and cells can grow and become a bit more mature.

The 00z DVN sounding just popped in and confirms thinking above
with about 750 j/kg MLCAPE with only about 20 j/kg of MLCIN
remaining. The 0-1km SRH sampled on the 00z sounding was >400
m2/s2 and with 1km winds expected to increase further across
northern IL this evening there are enough concerning pieces of
evidence to certainly suggest a tornado threat spreading into the
counties in the current tornado watch and perhaps even somewhat
farther east as well.

- Izzi

&&

.SHORT TERM...
359 AM CDT

Sunday...

Low pressure associated with the current storm system will begin
its occlusion into Sunday and it will track toward Lake Superior
through the day. Pressure rises are on the order of 4-6mb/6 hr is
is not off the charts, but respectable. We will likely have a
cloud shield that will limit mixing, but well aligned low level
flow along with 40 kt of wind not too far off the surface will
promote a period of gusty winds through most of the day. Winds
look to ramp up quickly pre-dawn Sunday, with gusts in the 40-50
mph range for much of the day before gradually diminishing late in
the day/evening. Winds begin more southwesterly before shifting
more toward westerly through the day.

KMD

&&

.LONG TERM...
330 PM CDT

Monday through Friday...

315 AM...Powerful storm system will quickly exit late Sunday night
into Monday morning. High pressure will push in making for dry
but seasonably cool temperatures.

Medium range guidance does continue to suggest that a fast moving
system will likely miss most of the local area as it is progged to
track through the Ohio valley. We will get a reinforcing shot of
cooler air with northeast winds on the northern fringes of this
system, thus highs will remain in the 40s area wide, coolest
lakeside. Some moderation will occur midweek as we await a
western trough for the latter half of the week which will bring
better precipitation chances and continued cooler weather.

KMD

&&

.AVIATION...
For the 00Z TAFs...

With surface warm front hung up over terminals this evening, E to NE
flow off of Lake Michigan is keeping ORD and MDW socked in with IFR
vis and cig. Some periods of LIFR vis/cig not out of the question
next 2 hours at those two sites before wind shift so have included
TEMPO groups for that possibility. Elsewhere marine layer
shouldn't be a problem.

Regardless of marine layer conditions, developing TS arcing WSW
through northern IL will impact all of the terminals this evening,
earliest at RFD and latest at GYY, all in the next 4 hours. At the
same time, strong low level jet will create LLWS concerns at all the
terminals, most significantly at ORD and MWD. After that, cold front
moves through SW to NE. Cigs clear out and winds veer SW quickly
behind the front.

Early Sunday morning strong gusts pick up. Given 12+ hours out, have
capped gusts at 40 kts (less at RFD) but a few 45-50 kt gusts from
the WSW can't be ruled out, especially Sunday afternoon.

RJC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Wind Advisory...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
     ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
     ILZ032-ILZ033-ILZ039-ILZ103-ILZ104-ILZ105-ILZ106-ILZ107-
     ILZ108...4 AM Sunday to 7 PM Sunday.

IN...Wind Advisory...INZ001-INZ002-INZ010-INZ011-INZ019...4 AM Sunday
     to 7 PM Sunday.

LM...Gale Warning...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...4 AM
     Sunday to 10 PM Sunday.

     Small Craft Advisory...nearshore waters
     until 4 AM Sunday.

&&

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Hazardous weather outlook, Mar 28, 2:56 PM CDT, 5 hours 57 minutes before

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
256 PM CDT Sat Mar 28 2020

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-292000-
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-
256 PM CDT Sat Mar 28 2020 /356 PM EDT Sat Mar 28 2020/

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

.DAY ONE...Tonight.

Weather hazards expected...

  Significant Thunderstorm Risk...with an associated:
     Significant Tornado risk.
     Significant hail risk...up to tennis ball size.
     Elevated damaging wind risk...up to 60 mph.
  Limited Flooding Risk.

DISCUSSION...

An outbreak of severe thunderstorms remains possible this afternoon
and evening, with the potential for very large hail and tornadoes,
including some threat of significant tornadoes. While the threat
of severe weather will exist across the entire outlook area, the
greatest threat for tornadoes will be around and southwest of a
line from Dixon to Dwight to Watseka. Thunderstorm movement will
be rapidly to the northeast.

Late tonight, strong southwest to west winds will develop, with
gusts to 45 mph expected by morning.

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

Sunday...
  Elevated Non Thunderstorm Wind Risk.

DISCUSSION:

Strong west to southwest winds gusting up to 45 mph are expected
Sunday.

.SPOTTER INFORMATION STATEMENT...

Any reports of severe weather will be greatly appreciated this
afternoon and evening.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the northeast at 50 to 60 mph.

LMZ740>745-292000-
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-
256 PM CDT Sat Mar 28 2020

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 Thunderstorm Risk...with an associated:
     Significant hail risk...up to half dollar size.
     Elevated thunderstorm wind gust risk...up to 60 mph.
  Elevated Fog Risk.

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

Sunday...
  Gale force winds and or very hazardous waves are likely.
Friday...
  Hazardous conditions for small craft are likely.

Kluber

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In the hours before

Special weather statement, Mar 28, 4:29 PM CDT, 4 hours 24 minutes before

SPECIAL WEATHER STATEMENT
National Weather Service Chicago/Romeoville IL
429 PM CDT Sat Mar 28 2020

ILZ006-103-104-290030-
Lake IL-Northern Cook-Central Cook-
Including the cities of Waukegan, Buffalo Grove, North Chicago,
Highland Park, Mundelein, Gurnee, Round Lake Beach, Evanston,
Des Plaines, Schaumburg, Palatine, Northbrook, Chicago, Cicero,
Oak Lawn, Oak Park, and La Grange
429 PM CDT Sat Mar 28 2020

...Dense Fog near the lake...

Dense fog with visiblity to one quarter mile or less is possible
at times through mid evening. Fog will occasionally lift with
periods of showers or storms, so visibility may vary frequently
and over short distances. Use caution if traveling near the
lakefront in Lake and Cook Counties.

KMD

Special weather statement, Mar 28, 6:49 PM CDT, 2 hours 4 minutes before

Special Weather Statement
National Weather Service Chicago/Romeoville
649 PM CDT Sat Mar 28 2020

ILZ003-008-290015-
Winnebago IL-Ogle IL-
649 PM CDT Sat Mar 28 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN OGLE AND
SOUTHEASTERN WINNEBAGO COUNTIES UNTIL 715 PM CDT...

At 649 PM CDT, Doppler radar was tracking a strong thunderstorm over
Oregon, moving northeast at 65 mph.

Up to nickel size hail will be possible with this storm.

Locations impacted include...
Rockford, Loves Park, Machesney Park, Oregon, Rockford Airport,
Roscoe, Byron, Cherry Valley, Stillman Valley, Davis Junction and New
Millford.

Including the following interstates...
 I-39 between mile markers 111 and 123.
 I-90 between mile markers 11 and 18.

This includes...  Lowden State Park, Rock Cut State Park, Rock Valley
College, Rockford Rivets Baseball, and Rockford Speedway.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4241 8906 4233 8894 4214 8894 4197 8926
      4198 8934 4204 8936
TIME...MOT...LOC 2349Z 222DEG 56KT 4202 8929

Borchardt

Local storm report, Mar 28, 7:18 PM CDT, 1 hour 35 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO IL
718 PM CDT SAT MAR 28 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0711 PM     HAIL             3 NNE ROCKFORD AIRPORT  42.23N 89.08W
03/28/2020  E0.70 INCH       WINNEBAGO          IL   TRAINED SPOTTER

            ALSO VERY HEAVY RAINFALL WITH 4-5 INCHES OF
            STANDING WATER COVERING PORTION OF THE ROAD.

&&

The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 28, 7:01 PM CDT	Severe Thunderstorm Warning	LOT	Boone, Ogle, Winnebago	29 min
Mar 28, 9:19 PM CDT	Tornado Warning	LOT	Ogle, Winnebago	26 min
Mar 28, 11:37 PM CDT	Special Marine Warning	LOT		53 min
Mar 28, 11:41 PM CDT	Special Weather Statement	LOT	Cook	19 min
Mar 29, 12:36 AM CDT	River Flood Warning	LOT	Bureau, LaSalle, Putnam	5 days
Mar 29, 4:58 AM CDT	River Flood Warning	LOT	Lake	30 hr
Mar 29, 4:58 AM CDT	River Flood Warning	LOT	Cook	30 hr
Mar 29, 8:25 AM CDT	River Flood Advisory	LOT	LaSalle	47 hr
Mar 29, 10:17 AM CDT	River Flood Advisory	LOT	Winnebago	6 days

Nearby

Tornado Warnings in Illinois, 2020 Every tornado warning in 2020 Tornadoes in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.