Alert archive / Illinois / Flash Flood Warnings in 2020

Flash Flood Warning 29, NWS St. Louis, MO

June 30, 2020Monroe County, Saint Clair County, Washington County, Illinois; Saint Louis County, Missouri

NWS St. Louis, MO issued this flash flood warning at Jun 30, 2020, 4:21 AM CDT for Monroe County, Saint Clair County, Washington County, Illinois; Saint Louis County, Missouri. It was in force for 6 hr. 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
Jun 30, 2020, 4:21 AM CDT (09:21 UTC)
Expired
Jun 30, 2020, 10:15 AM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Monroe County, IL, Saint Clair County, IL, Washington County, IL, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 77 km from the middle of the area, began a volume at 09:20 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 30, 7:00 AM CDTHEAVY RAIN 2.59Fayetteville, ILMESONET STATION FYEI2 FAYETTEVILLE.
Jun 30, 8:13 AM CDTHEAVY RAIN 2.6Columbia, IL
Jun 30, 8:30 AM CDTHEAVY RAIN 3.332 Se Freeburg, ILMESONET STATION FREI2 2.4 SE FREEBURG.

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 00:00Z, 9.4 hours before the alert went out and 227 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 00:00Z on 2020-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 436 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2020-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
436 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
1789 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
-17 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

233 
WGUS53 KLSX 300921
FFWLSX
ILC133-163-189-MOC189-301515-
/O.NEW.KLSX.FF.W.0029.200630T0921Z-200630T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
421 AM CDT Tue Jun 30 2020

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Northern Monroe County in southwestern Illinois...
  Southwestern Washington County in south central Illinois...
  Southern St. Clair County in southwestern Illinois...
  South central St. Louis County in east central Missouri...

* Until 1015 AM CDT.

* At 419 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the eastern portions of the warned area. 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, Arnold, Columbia, Freeburg, Millstadt, Oakville,
  Smithton, New Athens, Marissa, Okawville, Lively Grove, St. Libory,
  Lenzburg, Johannisburg, Fayetteville, Barr, Venedy, Floraville, New
  Hanover and Paderborn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 3822 8960 3822 8991 3833 8993 3841 9034
      3843 9035 3845 9034 3847 9036 3845 8971
      3842 8970 3843 8967 3844 8967 3844 8954

FLASH FLOOD...RADAR INDICATED

$$

Fuchs
2 follow-up statements
414 
WGUS73 KLSX 301329
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
829 AM CDT Tue Jun 30 2020

ILC133-163-189-MOC189-301515-
/O.CON.KLSX.FF.W.0029.000000T0000Z-200630T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monroe IL-Washington IL-St. Clair IL-St. Louis MO-
829 AM CDT Tue Jun 30 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 AM CDT FOR
NORTHERN MONROE...SOUTHWESTERN WASHINGTON...SOUTHERN ST. CLAIR AND
SOUTH CENTRAL ST. LOUIS COUNTIES...

At 827 AM CDT, Doppler radar indicated another round of 
thunderstorms producing heavy rain moving into the warned area. Up 
to three inches of rain fell last night and an additional 1 to 2 
inches is possible with these morning thunderstorms. 

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, Arnold, Columbia, Freeburg, Millstadt, Oakville,
Smithton, New Athens, Marissa, Okawville, Lively Grove, St. Libory,
Lenzburg, Johannisburg, Fayetteville, Barr, Venedy, Floraville, New
Hanover and Paderborn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you approach a flooded roadway, it is best to turn around, don't 
drown!

&&

LAT...LON 3822 8960 3822 8991 3833 8993 3841 9034
      3843 9035 3845 9034 3847 9036 3845 8971
      3842 8970 3843 8967 3844 8967 3844 8954

FLASH FLOOD...RADAR INDICATED

$$

CVKING
655 
WGUS73 KLSX 301506
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
1006 AM CDT Tue Jun 30 2020

ILC133-163-189-MOC189-301515-
/O.EXP.KLSX.FF.W.0029.000000T0000Z-200630T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monroe IL-Washington IL-St. Clair IL-St. Louis MO-
1006 AM CDT Tue Jun 30 2020

...THE FLASH FLOOD WARNING FOR NORTHERN MONROE...SOUTHWESTERN
WASHINGTON...SOUTHERN ST. CLAIR AND SOUTH CENTRAL ST. LOUIS COUNTIES
WILL EXPIRE AT 1015 AM CDT...

The heavy rain ended early this morning and any flooding that 
occurred has likely receeded.

LAT...LON 3822 8960 3822 8991 3833 8993 3841 9034
      3843 9035 3845 9034 3847 9036 3845 8971
      3842 8970 3843 8967 3844 8967 3844 8954

$$

CVKING

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 29, 11:14 PM CDTAreal Flood WarningLSXAdams3 hr
Jun 30, 12:21 AM CDTFlash Flood WarningLSXAdams, Pike6 hr
Jun 30, 1:34 AM CDTFlash Flood Warning Considerable damage threatLSXAdams6 hr
Jun 30, 2:33 AM CDTAreal Flood AdvisoryLSXMonroe, Saint Clair3 hr
Jun 30, 3:35 AM CDTFlash Flood WarningLSXPike6 hr
Jun 30, 4:33 AM CDTFlash Flood WarningLSXAdams6 hr
Jun 30, 5:15 AM CDTFlash Flood WarningLSXWashington5 hr
Jun 30, 6:02 AM CDTFlash Flood WarningLSXAdams6 hr
Jun 30, 6:13 AM CDTAreal Flood WarningLSXAdams, Pike6 hr
Jun 30, 10:12 AM CDTFlash Flood WarningLSXFayette6 hr
Jun 30, 11:41 AM CDTRiver Flood WarningLSXAdams53 hr
Jun 30, 11:41 AM CDTRiver Flood WarningLSXAdams48 hr
Jun 30, 11:41 AM CDTRiver Flood WarningLSXPike66 hr
Jun 30, 11:41 AM CDTRiver Flood WarningLSXJersey6 days
Jun 30, 12:59 PM CDTAreal Flood AdvisoryLSXMadison, Saint Clair3 hr
Jun 30, 4:49 PM CDTFlash Flood WarningLSXRandolph5 hr

Nearby

Flash Flood Warnings in Illinois, 2020Flash Flood Warnings in Missouri, 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; radar from the NEXRAD Level II archive.