Alert archive / Illinois / Flash Flood Warnings in 2020

Flash Flood Warning 23, NWS St. Louis, MO

June 22, 2020Calhoun County, Pike County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jun 22, 2020, 2:15 PM CDT for Calhoun County, Pike County, Illinois. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 22, 2020, 2:15 PM CDT (19:15 UTC)
Expired
Jun 22, 2020, 8:15 PM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Calhoun County, IL, Pike County, IL

The radar

The St Louis radar (KLSX), 84 km from the middle of the area, began a volume at 19:18 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.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 7.3 hours before the alert went out and 198 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 2020-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 401 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 12:00Z on 2020-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 square meters per square second.193958Sfc1 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
401 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
1137 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
30 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

526 
WGUS53 KLSX 221915
FFWLSX
ILC013-149-230115-
/O.NEW.KLSX.FF.W.0023.200622T1915Z-200623T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
215 PM CDT Mon Jun 22 2020

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Northwestern Calhoun County in southwestern Illinois...
  Southeastern Pike County in west central Illinois...

* Until 815 PM CDT Monday.

* At 213 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have 
  already fallen to the south of Nebo. 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...
  Pleasant Hill, Clarksville, Pike, Belleview, Independence, Bedford,
  Montezuma, Martinsburg, Nebo, Milton, Pearl, Florence, Time and
  Beecreek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3963 9061 3954 9057 3943 9062 3935 9062
      3932 9061 3929 9078 3935 9085 3938 9092
      3941 9095 3946 9105 3963 9062

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

$$

Britt
2 follow-up statements
890 
WGUS73 KLSX 222132
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
432 PM CDT Mon Jun 22 2020

ILC013-149-230115-
/O.CON.KLSX.FF.W.0023.000000T0000Z-200623T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Calhoun IL-Pike IL-
432 PM CDT Mon Jun 22 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR
NORTHWESTERN CALHOUN COUNTY IN SOUTHWESTERN ILLINOIS AND SOUTHEASTERN
PIKE COUNTIES IN WEST CENTRAL ILLINOIS...

At 430 PM CDT, Doppler radar indicated thunderstorms are diminishing 
across the warned area. However, additional storms are possible 
through this evening. Up to three inches of rain have already 
fallen. 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...
Pleasant Hill, Clarksville, Pike, Belleview, Independence, Bedford,
Montezuma, Martinsburg, Nebo, Milton, Pearl, Florence, Time and
Beecreek.

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, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3963 9061 3954 9057 3943 9062 3935 9062
      3932 9061 3929 9078 3935 9085 3938 9092
      3941 9095 3946 9105 3963 9062

FLASH FLOOD...RADAR INDICATED

$$

Byrd
290 
WGUS73 KLSX 230107
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
807 PM CDT Mon Jun 22 2020

ILC013-149-230117-
/O.EXP.KLSX.FF.W.0023.000000T0000Z-200623T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Calhoun IL-Pike IL-
807 PM CDT Mon Jun 22 2020

...THE FLASH FLOOD WARNING FOR NORTHWESTERN CALHOUN COUNTY IN
SOUTHWESTERN ILLINOIS AND SOUTHEASTERN PIKE COUNTIES IN WEST CENTRAL
ILLINOIS WILL EXPIRE AT 815 PM CDT...

Flood waters have receded. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 3963 9061 3954 9057 3943 9062 3935 9062
      3932 9061 3929 9078 3935 9085 3938 9092
      3941 9095 3946 9105 3963 9062

$$

Byrd

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 22, 2:04 PM CDTSevere Thunderstorm WarningLSXCalhoun, Pike26 min
Jun 22, 4:26 PM CDTFlash Flood WarningLSXMacoupin, Montgomery6 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.