Alert archive / Missouri / Flash Flood Warnings in 2020

Flash Flood Warning 22, NWS St. Louis, MO

June 21, 2020Lewis County, Marion County, Missouri; Adams County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jun 21, 2020, 3:24 PM CDT for Lewis County, Marion County, Missouri; Adams County, Illinois. It was in force for 6 hr. 4 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 21, 2020, 3:24 PM CDT (20:24 UTC)
Expired
Jun 21, 2020, 9:30 PM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Adams County, IL, Lewis County, MO, Marion County, MO

The radar

The St Louis radar (KLSX), 149 km from the middle of the area, began a volume at 20:25 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 21, 3:34 PM CDTHEAVY RAIN 2.651 Sw Quincy, ILWITHIN LAST 2 HOURS.
Jun 21, 3:38 PM CDTFLASH FLOOD1 Nw Quincy, ILTWO CARS STUCK IN FLOOD WATER AT 8TH AND CHESTNUT STREET. DEPTH OF WATER IS UNKNOWN.
Jun 21, 4:25 PM CDTFLASH FLOOD1 Nw Quincy, ILINTERSECTION OF 7TH AND CHERRY IN QUINCY IS FLOODED WITH FLOWING WATER. INTERSECTION OF 19TH AND VERMONT HAS WATER UP TO THE TOP OF SMALLER CAR TIRES.
Jun 21, 5:20 PM CDTHEAVY RAIN 4.51 W Quincy, ILAT WGEM-TV DOWNTOWN.

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

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.4 hours before the alert went out and 202 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, Davenport, at 12:00Z on 2020-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 807 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, Davenport, at 12:00Z on 2020-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 square meters per square second.19395878Sfc1 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
807 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
896 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
51 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.9

Open this sounding in Storm Lab

The text

As transmitted.

332 
WGUS53 KLSX 212024
FFWLSX
ILC001-MOC111-127-220230-
/O.NEW.KLSX.FF.W.0022.200621T2024Z-200622T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
324 PM CDT Sun Jun 21 2020

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Southwestern Adams County in west central Illinois...
  Northeastern Marion County in northeastern Missouri...
  Southeastern Lewis County in northeastern Missouri...

* Until 930 PM CDT Sunday.

* At 323 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. 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...
  Quincy, Payson, Fall Creek, Adams, Burton, Plainville, Taylor and
  Marblehead.

This also includes Wakonda State Park.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4005 9134 3976 9111 3976 9147 4000 9160

FLASH FLOOD...RADAR INDICATED

$$

Britt
2 follow-up statements
530 
WGUS73 KLSX 212144
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
444 PM CDT Sun Jun 21 2020

ILC001-MOC111-127-220230-
/O.CON.KLSX.FF.W.0022.000000T0000Z-200622T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Adams IL-Marion MO-Lewis MO-
444 PM CDT Sun Jun 21 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 PM CDT SUNDAY
FOR SOUTHWESTERN ADAMS...NORTHEASTERN MARION AND SOUTHEASTERN LEWIS
COUNTIES...

At 437 PM CDT, Doppler radar indicated heavy rain has moved has 
moved out of the warned area, but estimates that 2 to 4 inches of 
rain has fallen in areas around Quincy, Taylor, and Marblehead. 
Several intersections have been reported flooded in Quincy.

HAZARD...Flash flooding caused by heavy rain.

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...
Quincy, Payson, Fall Creek, Adams, Burton, Plainville, Taylor and
Marblehead.

This also includes Wakonda State Park.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4005 9134 3976 9111 3976 9147 4000 9160

FLASH FLOOD...RADAR INDICATED

$$

Britt
351 
WGUS73 KLSX 220225
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
925 PM CDT Sun Jun 21 2020

ILC001-MOC111-127-220234-
/O.EXP.KLSX.FF.W.0022.000000T0000Z-200622T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Adams IL-Marion MO-Lewis MO-
925 PM CDT Sun Jun 21 2020

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN ADAMS...NORTHEASTERN
MARION AND SOUTHEASTERN LEWIS COUNTIES WILL EXPIRE AT 930 PM CDT
SUNDAY...

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

LAT...LON 4005 9134 3976 9111 3976 9147 4000 9160

$$

Britt

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 3:26 AM CDTAreal Flood AdvisoryLSXSaint Charles, Saint Louis, City of Saint Louis3 hr
Jun 21, 4:40 AM CDTFlash Flood WarningLSXSaint Louis, City of Saint Louis5 hr
Jun 21, 5:28 AM CDTFlash Flood WarningLSXJefferson4 hr
Jun 21, 3:08 PM CDTSevere Thunderstorm WarningLSXMarion52 min
Jun 21, 1:40 AM CDTAreal Flood AdvisoryLSXSaint Clair4 hr
Jun 21, 1:51 PM CDTSevere Thunderstorm WarningLSXMacoupin39 min

Nearby

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