Alert archive / Illinois / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 36, NWS Lincoln, IL

April 28, 20204 counties in Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at Apr 28, 2020, 7:07 PM CDT for 4 counties in Illinois. It was in force for 53 min. 1 report 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: Apr 28, 2020, 7:07 PM CDT (00:07 UTC)
Expired: Apr 28, 2020, 8:00 PM CDT
In force: 53 min
Issued by: NWS Lincoln, IL
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Christian County, IL, Macon County, IL, Sangamon County, IL, Shelby County, IL

The radar

The Lincoln radar (KILX), 49 km from the middle of the area, began a volume at 00:11 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
Apr 28, 7:48 PM CDT	HAIL 0.88	1 Ssw Niantic, IL

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

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

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
Apr 28, 3:51 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 0.1 hours before the alert went out and 78 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: 549 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 1190 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 132 m²/s²
0-3 km storm-relative helicity: 196 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 4.6

Open this sounding in Storm Lab

The text

As transmitted.

746 
WUUS53 KILX 290007
SVRILX
ILC021-115-167-173-290100-
/O.NEW.KILX.SV.W.0036.200429T0007Z-200429T0100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Lincoln IL
707 PM CDT Tue Apr 28 2020

The National Weather Service in Lincoln has issued a

* Severe Thunderstorm Warning for...
  Northern Christian County in central Illinois...
  Northeastern Sangamon County in central Illinois...
  Northwestern Shelby County in central Illinois...
  Southwestern Macon County in central Illinois...

* Until 800 PM CDT.

* At 707 PM CDT, a severe thunderstorm was located over
  Mechanicsburg, or 14 miles east of Springfield, moving east at 35
  mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Decatur, Taylorville, Moweaqua, Kincaid, Harristown, Blue Mound,
  Macon, Edinburg, Stonington, Illiopolis, Niantic, Mechanicsburg,
  Mount Auburn, Bulpitt, Jeisyville, Tovey, Dawson, Buffalo,
  Sangchris Lake State Park and Willeys.

This includes Interstate 72 between mile markers 112 and 136.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3958 8953 3978 8942 3988 8948 3987 8895
      3955 8897
TIME...MOT...LOC 0007Z 275DEG 30KT 3979 8938 

HAIL...<.75IN
WIND...60MPH
 
$$

Auten

2 follow-up statements

231 
WWUS53 KILX 290041
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
741 PM CDT Tue Apr 28 2020

ILC167-290050-
/O.CAN.KILX.SV.W.0036.000000T0000Z-200429T0100Z/
Sangamon-
741 PM CDT Tue Apr 28 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN SANGAMON COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for
central Illinois.

LAT...LON 3957 8933 3974 8920 3987 8927 3987 8895
      3955 8897
TIME...MOT...LOC 0040Z 275DEG 30KT 3976 8902 

$$

ILC021-115-173-290100-
/O.CON.KILX.SV.W.0036.000000T0000Z-200429T0100Z/
Christian-Shelby-Macon-
741 PM CDT Tue Apr 28 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM CDT
FOR NORTHEASTERN CHRISTIAN...NORTHWESTERN SHELBY AND SOUTHWESTERN
MACON COUNTIES...

At 740 PM CDT, a severe thunderstorm was located near Macon, or 7
miles southwest of Decatur, moving east at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Decatur, Taylorville, Moweaqua, Harristown, Blue Mound, Macon,
Stonington, Illiopolis, Niantic, Boody, Willeys and Elwin.

This includes Interstate 72 between mile markers 123 and 135.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3957 8933 3974 8920 3987 8927 3987 8895
      3955 8897
TIME...MOT...LOC 0040Z 275DEG 30KT 3976 8902 

HAIL...<.75IN
WIND...60MPH
 
$$

Auten

796 
WWUS53 KILX 290105
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
805 PM CDT Tue Apr 28 2020

ILC021-115-173-290115-
/O.EXP.KILX.SV.W.0036.000000T0000Z-200429T0100Z/
Christian-Shelby-Macon-
805 PM CDT Tue Apr 28 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CHRISTIAN...
NORTHWESTERN SHELBY AND SOUTHWESTERN MACON COUNTIES HAS EXPIRED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been allowed to expire.

A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for
central Illinois.

LAT...LON 3957 8933 3974 8920 3987 8927 3987 8895
      3955 8897
TIME...MOT...LOC 0105Z 275DEG 30KT 3974 8878 

$$

Auten

What forecasters said that day

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

NWS Lincoln, IL wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 28, 6:52 PM CDT, 15 minutes earlier.

Area forecast discussion, Apr 28, 6:52 PM CDT, 15 minutes before

Area Forecast Discussion
National Weather Service Lincoln IL
652 PM CDT Tue Apr 28 2020

.SYNOPSIS...
Issued at 310 PM CDT Tue Apr 28 2020

A cold front will trigger thunderstorms across central Illinois
this evening...a few of which could become severe. The storms will
push into Indiana toward midnight, with just scattered showers
lingering overnight.

&&

.SHORT TERM...(This evening through Wednesday)
ISSUED AT 310 PM CDT Tue Apr 28 2020

19z/2pm surface analysis shows a 1004mb low over southeast
Minnesota with a cold front extending southwestward to near the
Kansas City metro. The airmass ahead of the front has become
moderately unstable as per SPC mesoanalysis showing MLCAPE values
of 1000-1500J/kg near the Mississippi River. CAMs have been
consistently indicating robust convective initiation west of the
I-55 corridor between 21z/4pm and 22z/5pm. Given strengthening
instability and modest 0-6km bulk shear of around 40kt, think a
low-end severe risk will accompany the storms as they track
eastward and eventually congeal into a line early this evening.
Main threats appear to be damaging wind gusts/hail: however, an
isolated tornado cannot be ruled out as the cells first get
organized. The tornado threat will be confined to the western KILX
CWA during the first couple hours of the event until the storms
form a solid line east of I-55 by around 01z/8pm. The storms will
then push steadily eastward and exit into Indiana by late
evening. Once the initial line departs, widely scattered showers
will remain possible for the remainder of the night. Low
temperatures will range from the upper 40s in the Illinois River
Valley...to the middle 50s near the Indiana border.

A short-wave trough will dig into the region and form a closed
low over Illinois on Thursday. Given cold core aloft during peak
heating, showers will become numerous from late morning through
early evening. With extensive cloud cover limiting boundary layer
heating, instability will remain meager: however, think a few
rumbles of thunder will be possible as MUCAPE values exceed
100J/kg. May also see a few small hailstones and perhaps even a
funnel cloud or two as the cold core moves overhead. High
temperatures will remain in the 50s across much of the area, with
lower 60s noted east of the I-57 corridor.

.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 310 PM CDT Tue Apr 28 2020

The upper low will be slow to depart as several 12z models suggest
scattered showers will linger across the E/SE CWA into Thursday.
have included chance PoPs east of the I-55 corridor accordingly.
Have also lowered highs by a few degrees due to cloud cover...with
readings ranging from the middle 50s east to around 60 in the
Illinois River Valley. Once the low finally exits, rising upper
heights will lead to a significant warming trend for the end of
the week. Highs will climb into the 60s on Friday, then will soar
well into the 70s by Saturday. After that, the next storm system
will come into the picture late Saturday night through Sunday
night as low pressure tracks through the region. Once that feature
passes, a return to mild/dry weather is anticipated for
Monday/Tuesday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 652 PM CDT Tue Apr 28 2020

2345z/645pm radar imagery shows a line of convection along the
I-55 corridor. Based on radar timing tools, it appears the storms
will reach KDEC shortly before 01z and KCMI by around 01z. After 1
hour of thunder and visbys as low as 1-2 miles, the storms will
pass to the east...leaving behind a 2-3 hour period of light rain
with VFR ceilings/visbys. The rain will gradually dissipate and
come to an end at all TAF sites by late evening. After that, will
be watching MVFR ceilings currently over Minnesota/northern Iowa
working their way southward overnight. Model consensus brings MVFR
into KPIA by 10z...then further southeast to KSPI/KDEC by around
13z. With an upper low progged to track overhead, MVFR ceilings
and scattered showers will prevail for the remainder of the 00z
TAF period. Winds will initially be S at 10-15kt this evening,
then will veer to W/NW late tonight into Wednesday.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SYNOPSIS...Barnes
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Barnes

Hazardous weather outlook, Apr 28, 3:23 PM CDT, 3 hours 44 minutes before

Hazardous Weather Outlook
National Weather Service Lincoln IL
323 PM CDT Tue Apr 28 2020

ILZ027>031-037-038-042>046-051>057-061>063-291100-
Champaign-Christian-Clark-Coles-Cumberland-De Witt-Douglas-Edgar-
Knox-Logan-Macon-Marshall-McLean-Moultrie-Peoria-Piatt-Sangamon-
Shelby-Stark-Tazewell-Vermilion-Woodford-
323 PM CDT Tue Apr 28 2020

This Hazardous Weather Outlook is for portions of central
Illinois, east central Illinois and west central Illinois.

.DAY ONE...TONIGHT...

Thunderstorms are likely this evening. There is a slight risk
that some of the storms could become severe, with damaging winds
and large hail. A tornado or two is also possible.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY...

Isolated storms will be possible Wednesday afternoon.

Another chance of storms will occur Sunday and Sunday evening.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed between 5 pm and 10 pm. Please
relay any information about observed severe weather to the
National Weather Service while following all local, state and CDC
guidelines.

ILZ036-040-041-047>050-291100-
Cass-Fulton-Mason-Menard-Morgan-Schuyler-Scott-
323 PM CDT Tue Apr 28 2020

This Hazardous Weather Outlook is for portions of central
Illinois and west central Illinois.

.DAY ONE...TONIGHT...

Thunderstorms are likely this evening. There is a slight risk
that some of the storms could become severe, with damaging winds
and large hail. A tornado or two is also possible.

Minor flooding is occurring on the Illinois River at Havana and
Beardstown. Minor flooding is occurring on the lower Sangamon
river at Chandlerville and Oakford.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY...

Isolated storms will be possible Wednesday afternoon.

Another chance of storms will occur Sunday and Sunday evening.

Minor flooding will continue on the Illinois River at Beardstown,
Havana, and Valley City, and the Sangamon River at Chandlerville
and Oakford through mid-week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed between 5 pm and 8 pm. Please
relay any information about observed severe weather to the
National Weather Service while following all local, state and CDC
guidelines.

ILZ066>068-071>073-291100-
Clay-Crawford-Effingham-Jasper-Lawrence-Richland-
323 PM CDT Tue Apr 28 2020

This Hazardous Weather Outlook is for portions of southeast
Illinois.

.DAY ONE...TONIGHT...

Thunderstorms are likely this evening. There is a slight risk
that some of the storms could become severe, with damaging winds
and large hail. A tornado or two is also possible.

Minor flooding is occurring on the Little Wabash river near Clay
City.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY...

Isolated storms will be possible Wednesday afternoon.

Another chance of storms will occur Sunday and Sunday evening.

The Little Wabash river at Clay City will continue to remain above
or near flood stage through much of this week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed between 8 pm and 11 pm. Please
relay any information about observed severe weather to the
National Weather Service while following all local, state and CDC
guidelines.

Auten

In the hours before

Local storm report, Apr 28, 5:28 PM CDT, 1 hour 39 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
528 PM CDT TUE APR 28 2020

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

0525 PM     FUNNEL CLOUD     3 SE LOW POINT          40.85N 89.28W
04/28/2020                   WOODFORD           IL   TRAINED SPOTTER

&&

SBAKER

Local storm report, Apr 28, 5:31 PM CDT, 1 hour 36 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
531 PM CDT TUE APR 28 2020

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

0528 PM     HAIL             WASHBURN                40.92N 89.29W
04/28/2020  E0.75 INCH       WOODFORD           IL   PUBLIC

&&

SBAKER

Local storm report, Apr 28, 5:47 PM CDT, 1 hour 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
547 PM CDT TUE APR 28 2020

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

0542 PM     HAIL             3 ESE CAZENOVIA         40.83N 89.28W
04/28/2020  E0.75 INCH       WOODFORD           IL   TRAINED SPOTTER

&&

GEELHART

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 28, 7:24 PM CDT	Flash Flood Warning	ILX	Christian, DeWitt, Logan, Macon, Sangamon	100 min
Apr 28, 7:38 PM CDT	Severe Thunderstorm Warning	ILX	Christian, Shelby	52 min
Apr 28, 7:54 PM CDT	Severe Thunderstorm Warning	ILX	Christian	36 min
Apr 28, 8:00 PM CDT	Severe Thunderstorm Warning	ILX	Macon, Moultrie, Piatt, Shelby	45 min
Apr 28, 8:41 PM CDT	Severe Thunderstorm Warning	ILX	Douglas, Moultrie, Piatt	49 min
Apr 28, 9:41 PM CDT	Special Weather Statement	ILX	Clark, Coles, Cumberland, Edgar	49 min
Apr 28, 9:45 PM CDT	Special Weather Statement	ILX	Clay, Effingham, Jasper	45 min
Apr 28, 10:23 PM CDT	Special Weather Statement	ILX	Clay, Crawford, Jasper, Lawrence, Richland	82 min
Apr 29, 7:36 AM CDT	River Flood Warning	ILX	Piatt	5 days

Nearby

Severe Thunderstorm Warnings in Illinois, 2020 Every severe thunderstorm warning 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.