Alert archive / Illinois / Flash Flood Warnings in 2020
Flash Flood Warning 59, NWS St. Louis, MO
NWS St. Louis, MO issued this flash flood warning at Aug 12, 2020, 9:41 AM CDT for Madison County, Saint Clair County, Illinois. It was in force for 5 hr. 6 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
- Aug 12, 2020, 9:41 AM CDT (14:41 UTC)
- Expired
- Aug 12, 2020, 2:52 PM CDT
- In force
- 5 hr
- Issued by
- NWS St. Louis, MO
- Area
- Storm-based polygon
- Flood severity
- None
Counties Madison County, IL, Saint Clair County, IL
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 12, 10:06 AM CDT | HEAVY RAIN 1.62 | 2 Ese Belleville, IL | OVER ONE HOUR. |
| Aug 12, 10:30 AM CDT | FLASH FLOOD | 1 Wsw Scott Afb, IL | NUMEROUS REPORTS OF CLOSED ROADS FROM THE ST. CLAIR COUNTY SHERIFFS OFFICE, INCLUDING STATE ROUTE 4 NORTH OF 161, STATE ROUTE 161 EAST OF ROUTE 4, IN BELLEVILLE, MASCOUTAH ROAD AT EIDMANN ROAD, STATE ROUTE 50 BETWEEN LEBANON AND OFALLON. |
| Aug 12, 10:33 AM CDT | FLASH FLOOD | 1 Nne Mascoutah, IL | WATER RESCUE, PERSON ON THE ROOF OF THEIR CAR AT HWY 161 AND STATE ROUTE 4. |
| Aug 12, 11:00 AM CDT | HEAVY RAIN 4.75 | Scott Afb, IL | RAINFALL BETWEEN 9 AND 11 AM. |
| Aug 12, 11:20 AM CDT | FLASH FLOOD | Scott Afb, IL | SEVERAL ROADS IMPASSIBLE AND CLOSED AT SCOTT AFB WITH SEVERAL INCHES OF WATER ALSO REPORTED COMING INTO THE FIRST LEVEL OF A FEW BUILDINGS. |
| Aug 12, 11:25 AM CDT | FLASH FLOOD | 1 W Mascoutah, IL | FROM SOCIAL MEDIA: ILLINOIS ROUTES 177, 4, AND 161 CLOSED. |
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, 2.7 hours before the alert went out and 207 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1132 m above ground
- 0-6 km bulk shear
- 3 kt
- 0-1 km storm-relative helicity
- 14 m²/s²
- 0-3 km storm-relative helicity
- -3 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
710
WGUS53 KLSX 121441
FFWLSX
ILC119-163-122045-
/O.NEW.KLSX.FF.W.0059.200812T1441Z-200812T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
941 AM CDT Wed Aug 12 2020
The National Weather Service in St Louis has issued a
* Flash Flood Warning for...
South central Madison County in southwestern Illinois...
Northeastern St. Clair County in southwestern Illinois...
* Until 345 PM CDT Wednesday.
* At 940 AM CDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Up to two inches of rain have
already fallen between 830 AM and 930 AM CDT. Flash flooding is
ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar indicated.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
* Some locations that will experience flooding include...
Belleville, O'Fallon, Collinsville, Fairview Heights, Swansea, Glen
Carbon, Shiloh, Troy, Maryville, Mascoutah, Lebanon, Caseyville,
Scott AFB, St. Jacob and Summerfield.
Additional rainfall amounts of 1 to 2 inches are possible in the
warned area as storms are expected to continue.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.
Please report flooding to your local law enforcement agency when you
can do so safely.
&&
LAT...LON 3847 9001 3877 8998 3877 8975 3844 8974
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR
$$
TES4 follow-up statements
365
WGUS73 KLSX 121552
FFSLSX
Flash Flood Statement
National Weather Service St Louis MO
1052 AM CDT Wed Aug 12 2020
ILC119-163-122045-
/O.CON.KLSX.FF.W.0059.000000T0000Z-200812T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison IL-St. Clair IL-
1052 AM CDT Wed Aug 12 2020
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
WEDNESDAY FOR SOUTH CENTRAL MADISON AND NORTHEASTERN ST. CLAIR
COUNTIES IN SOUTHWESTERN ILLINOIS...
At 1050 AM CDT, emergency management reported thunderstorms
producing heavy rain in Mascoutah at 1050 AM. Up to two inches of
rain have already fallen. Flash flooding is ongoing or expected to
begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Emergency management reported one water rescue two miles
north of Mascoutah.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other drainage
and low lying areas.
Some locations that will experience flooding include...
Belleville, O'Fallon, Collinsville, Fairview Heights, Swansea, Glen
Carbon, Shiloh, Troy, Maryville, Mascoutah, Lebanon, Caseyville,
Scott AFB, St. Jacob and Summerfield.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.
Please report flooding to your local law enforcement agency when you
can do so safely.
&&
LAT...LON 3847 9001 3877 8998 3877 8975 3844 8974
FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR
$$
MRM766
WGUS73 KLSX 121608
FFSLSX
Flash Flood Statement
National Weather Service St Louis MO
1108 AM CDT Wed Aug 12 2020
ILC119-163-122045-
/O.CON.KLSX.FF.W.0059.000000T0000Z-200812T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison IL-St. Clair IL-
1108 AM CDT Wed Aug 12 2020
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
WEDNESDAY FOR SOUTH CENTRAL MADISON AND NORTHEASTERN ST. CLAIR
COUNTIES IN SOUTHWESTERN ILLINOIS...
At 1107 AM CDT, Doppler radar and automated gauges indicated
thunderstorms producing heavy rain across the warned area. 4.75
inches of rain have fallen in Belleville, Illinois between 0900 and
1100 AM. Flash flooding is ongoing or expected to begin shortly.
Emergency management has reported water over the road on Highway 70
at Madison.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other drainage
and low lying areas.
Some locations that will experience flooding include...
Belleville, O'Fallon, Collinsville, Fairview Heights, Swansea, Glen
Carbon, Shiloh, Troy, Maryville, Mascoutah, Lebanon, Caseyville,
Scott AFB, St. Jacob and Summerfield.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.
Please report flooding to your local law enforcement agency when you
can do so safely.
&&
LAT...LON 3847 9001 3877 8998 3877 8975 3844 8974
FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR
$$
MRM757
WGUS73 KLSX 121625
FFSLSX
Flash Flood Statement
National Weather Service St Louis MO
1125 AM CDT Wed Aug 12 2020
ILC119-163-122045-
/O.CON.KLSX.FF.W.0059.000000T0000Z-200812T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison IL-St. Clair IL-
1125 AM CDT Wed Aug 12 2020
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
WEDNESDAY FOR SOUTH CENTRAL MADISON AND NORTHEASTERN ST. CLAIR
COUNTIES IN SOUTHWESTERN ILLINOIS...
At 1123 AM CDT, trained weather spotters reported thunderstorms
producing 5.16 inches of rain at Scott Air Force Base. Flash
flooding is ongoing or expected to begin shortly. Multiple roads
flooded at Scott Air Force Base.
HAZARD...Life threatening flash flooding. Heavy rain producing flash
flooding.
SOURCE...Trained weather spotters.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flooding include...
Belleville, O'Fallon, Collinsville, Fairview Heights, Swansea, Glen
Carbon, Shiloh, Troy, Maryville, Mascoutah, Lebanon, Caseyville,
Scott AFB, St. Jacob and Summerfield.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.
Please report flooding to your local law enforcement agency when you
can do so safely.
&&
LAT...LON 3847 9001 3877 8998 3877 8975 3844 8974
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR
$$
MRM785 WGUS73 KLSX 121952 FFSLSX Flash Flood Statement National Weather Service St Louis MO 252 PM CDT Wed Aug 12 2020 ILC119-163-121959- /O.CAN.KLSX.FF.W.0059.000000T0000Z-200812T2045Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Madison IL-St. Clair IL- 252 PM CDT Wed Aug 12 2020 ...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL MADISON AND NORTHEASTERN ST. CLAIR COUNTIES IN SOUTHWESTERN ILLINOIS IS CANCELLED... The heavy rain has ended, flooding continues in portions of St. Claire County, including Mascoutah and Scott Air Force Base. An areal flood warning will be issued to address this. Please continue to heed any remaining road closures. LAT...LON 3847 9001 3877 8998 3877 8975 3844 8974 $$ MRM
The office that day
Everything else NWS St. Louis, MO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 12, 10:19 AM CDT | Flash Flood Warning | LSX | Madison, Saint Clair | 4 hr |
| Aug 12, 11:18 AM CDT | Flash Flood Warning | LSX | Monroe, Randolph, Saint Clair | 3 hr |
| Aug 12, 11:47 AM CDT | Flash Flood Warning | LSX | Clinton, Randolph, Saint Clair, Washington | 6 hr |
| Aug 12, 2:57 PM CDT | Areal Flood Warning | LSX | Saint Clair | 3 hr |
Nearby
Flash Flood Warnings in Illinois, 2020Every flash flood 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.