Alert archive / Illinois / Flash Flood Warnings in 2023

Flash Flood Warning 9, NWS St. Louis, MO

June 18, 2023Madison County, Monroe County, Saint Clair County, Illinois; Jefferson County, Saint Louis County, City of Saint Louis, Missouri

NWS St. Louis, MO issued this flash flood warning at Jun 18, 2023, 5:37 PM CDT for Madison County, Monroe County, Saint Clair County, Illinois; Jefferson County, Saint Louis County, City of Saint Louis, Missouri. It was in force for 3 hr. 2 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
Jun 18, 2023, 5:37 PM CDT (22:37 UTC)
Expired
Jun 18, 2023, 8:30 PM CDT
In force
3 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Madison County, IL, Monroe County, IL, Saint Clair County, IL, City of Saint Louis, MO, Jefferson County, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 37 km from the middle of the area, began a volume at 22:40 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

TimeReportWhereRemark
Jun 18, 5:54 PM CDTFLASH FLOOD2 Ne Lemay, MOInterstate 55 at Loughborough is closed due to deep water over roadway.
Jun 18, 6:18 PM CDTFLASH FLOOD3 Ese Saint Louis, MOInterstate 44 westbound is closed at Interstate 64 due to water over the roadway.

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

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 10.6 hours before the alert went out and 209 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-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2023-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2023-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1441 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

345 
WGUS53 KLSX 182237
FFWLSX
ILC119-133-163-MOC099-189-510-190130-
/O.NEW.KLSX.FF.W.0009.230618T2237Z-230619T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
537 PM CDT Sun Jun 18 2023

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Southwestern Madison County in southwestern Illinois...
  Northwestern Monroe County in southwestern Illinois...
  Northwestern Saint Clair County in southwestern Illinois...
  Northeastern Jefferson County in east central Missouri...
  Eastern Saint Louis County in east central Missouri...
  Saint Louis City in east central Missouri...

* Until 830 PM CDT.

* At 537 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. The expected rainfall rate is 1 to 2 inches in 1 
  hour. Additional rainfall amounts of 1 to 2 inches are possible in 
  the warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  St. Louis, Florissant, University City, Granite City, Kirkwood, 
  Maryland Heights, East St. Louis, Hazelwood, Webster Groves, 
  Ferguson, Arnold, Creve Coeur, Overland, Clayton, Cahokia, 
  Jennings, St. Ann, Crestwood, Bridgeton and Bellefontaine 
  Neighbors.

This includes the following State Parks...
Scott Joplin Historic Site, Mastodon Historic Site and Horseshoe 
Lake State Park.

This includes the following highways...
	Interstate 44 in Missouri between exits 276 and 277.
	Interstate 55 in Missouri between exits 190 and 191.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3883 9042 3882 9037 3885 9034 3888 9034
      3889 9032 3888 9029 3885 9026 3882 9018
      3883 9015 3881 9012 3882 9011 3881 9007
      3838 9013 3837 9047

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR

$$

MRB
4 follow-up statements
587 
WGUS73 KLSX 182249
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
549 PM CDT Sun Jun 18 2023

ILC133-MOC099-182259-
/O.CAN.KLSX.FF.W.0009.000000T0000Z-230619T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monroe IL-Jefferson MO-
549 PM CDT Sun Jun 18 2023

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN MONROE COUNTY 
IN SOUTHWESTERN ILLINOIS AND NORTHEASTERN JEFFERSON COUNTY IN EAST 
CENTRAL MISSOURI...

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

LAT...LON 3882 9037 3885 9034 3888 9034 3889 9032
      3888 9029 3885 9026 3882 9018 3883 9015
      3881 9012 3882 9011 3881 9007 3845 9012
      3846 9019 3852 9026 3848 9028 3850 9041

$$

ILC119-163-MOC189-510-190130-
/O.CON.KLSX.FF.W.0009.000000T0000Z-230619T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison IL-Saint Clair IL-Saint Louis MO-Saint Louis City MO-
549 PM CDT Sun Jun 18 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM CDT THIS 
EVENING FOR SOUTHWESTERN MADISON AND NORTHWESTERN SAINT CLAIR 
COUNTIES IN SOUTHWESTERN ILLINOIS, EASTERN SAINT LOUIS COUNTY IN 
EAST CENTRAL MISSOURI AND THE SAINT LOUIS CITY IN EAST CENTRAL 
MISSOURI...

At 549 PM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1 and 3 inches of rain have 
fallen. The expected rainfall rate is 1 to 2 inches in 1 hour. 
Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  St. Louis, Florissant, University City, Granite City, Kirkwood, 
  East St. Louis, Hazelwood, Webster Groves, Ferguson, Overland, 
  Clayton, Cahokia, Jennings, St. Ann, Crestwood, Bridgeton, 
  Bellefontaine Neighbors, Columbia, Berkeley and Richmond Heights.

This includes the following State Parks...
	Scott Joplin Historic Site and Horseshoe Lake State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3882 9037 3885 9034 3888 9034 3889 9032
      3888 9029 3885 9026 3882 9018 3883 9015
      3881 9012 3882 9011 3881 9007 3845 9012
      3846 9019 3852 9026 3848 9028 3850 9041

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR

$$

MRB
360 
WGUS73 KLSX 182325
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
625 PM CDT Sun Jun 18 2023

ILC119-163-MOC189-510-190130-
/O.CON.KLSX.FF.W.0009.000000T0000Z-230619T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison IL-Saint Clair IL-Saint Louis MO-Saint Louis City MO-
625 PM CDT Sun Jun 18 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM CDT THIS 
EVENING FOR SOUTHWESTERN MADISON AND NORTHWESTERN SAINT CLAIR 
COUNTIES IN SOUTHWESTERN ILLINOIS, EASTERN SAINT LOUIS COUNTY IN 
EAST CENTRAL MISSOURI AND THE SAINT LOUIS CITY IN EAST CENTRAL 
MISSOURI...

At 625 PM CDT, emergency management reported thunderstorms producing 
heavy rain in St. Louis. Between 1 and 3 inches of rain have fallen. 
The expected rainfall rate is 1 to 2 inches in 1 hour. Additional 
rainfall amounts of 1 to 2 inches are possible in the warned area. 
Flash flooding is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Emergency management reported that Interstate 55 closed
         in south St. Louis City due to flash flooding.
         Interstate 44 is also closed at Interstate 64 in St.
         Louis City due to flash flooding.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  St. Louis, Florissant, University City, Granite City, Kirkwood, 
  East St. Louis, Hazelwood, Webster Groves, Ferguson, Overland, 
  Clayton, Cahokia, Jennings, St. Ann, Crestwood, Bridgeton, 
  Bellefontaine Neighbors, Columbia, Berkeley and Richmond Heights.

This includes the following State Parks...
	Scott Joplin Historic Site and Horseshoe Lake State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3882 9037 3885 9034 3888 9034 3889 9032
      3888 9029 3885 9026 3882 9018 3883 9015
      3881 9012 3882 9011 3881 9007 3845 9012
      3846 9019 3852 9026 3848 9028 3850 9041

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR

$$

MRB
934 
WGUS73 KLSX 190015
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
715 PM CDT Sun Jun 18 2023

ILC119-163-MOC189-510-190130-
/O.CON.KLSX.FF.W.0009.000000T0000Z-230619T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison IL-Saint Clair IL-Saint Louis MO-Saint Louis City MO-
715 PM CDT Sun Jun 18 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM CDT THIS 
EVENING FOR SOUTHWESTERN MADISON AND NORTHWESTERN SAINT CLAIR 
COUNTIES IN SOUTHWESTERN ILLINOIS, EASTERN SAINT LOUIS COUNTY IN 
EAST CENTRAL MISSOURI AND THE SAINT LOUIS CITY IN EAST CENTRAL 
MISSOURI...

At 715 PM CDT, Doppler radar indicated thunderstorms producing heavy 
rain in St. Louis, Missouri and eastern St. Clair County, Illinois. 
Between 2 and 4 inches of rain have fallen. The expected rainfall 
rate is 1 to 2 inches in 1 hour. Additional rainfall amounts up to 1 
inch are possible in the warned area. Flash flooding is already 
occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  St. Louis, Florissant, University City, Granite City, Kirkwood, 
  East St. Louis, Hazelwood, Webster Groves, Ferguson, Overland, 
  Clayton, Cahokia, Jennings, St. Ann, Crestwood, Bridgeton, 
  Bellefontaine Neighbors, Columbia, Berkeley and Richmond Heights.

This includes the following State Parks...
	Scott Joplin Historic Site and Horseshoe Lake State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3882 9037 3885 9034 3888 9034 3889 9032
      3888 9029 3885 9026 3882 9018 3883 9015
      3881 9012 3882 9011 3881 9007 3845 9012
      3846 9019 3852 9026 3848 9028 3850 9041

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR

$$

MRB
417 
WGUS73 KLSX 190122
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
822 PM CDT Sun Jun 18 2023

ILC119-163-MOC189-510-190132-
/O.EXP.KLSX.FF.W.0009.000000T0000Z-230619T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison IL-Saint Clair IL-Saint Louis MO-Saint Louis City MO-
822 PM CDT Sun Jun 18 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 830 PM CDT THIS EVENING FOR 
SOUTHWESTERN MADISON AND NORTHWESTERN SAINT CLAIR COUNTIES IN 
SOUTHWESTERN ILLINOIS, EASTERN SAINT LOUIS COUNTY IN EAST CENTRAL 
MISSOURI AND THE SAINT LOUIS CITY IN EAST CENTRAL MISSOURI...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

LAT...LON 3882 9037 3885 9034 3888 9034 3889 9032
      3888 9029 3885 9026 3882 9018 3883 9015
      3881 9012 3882 9011 3881 9007 3845 9012
      3846 9019 3852 9026 3848 9028 3850 9041

$$

Elmore

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 18, 5:22 PM CDTAreal Flood AdvisoryLSXMadison, Monroe, Saint Clair15 min
Jun 18, 12:05 PM CDTAreal Flood AdvisoryLSXBoone3 hr
Jun 18, 12:37 PM CDTAreal Flood AdvisoryLSXBoone3 hr

Nearby

Flash Flood Warnings in Illinois, 2023Flash Flood Warnings in Missouri, 2023Every flash flood warning in 2023

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.