Alert archive / Missouri / Flash Flood Warnings in 2021

Flash Flood Warning 21, NWS St. Louis, MO

June 30, 2021Marion County, Missouri; Adams County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jun 30, 2021, 5:20 PM CDT for Marion County, Missouri; Adams County, Illinois. It was in force for 2 hr. 1 report 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, 2021, 5:20 PM CDT (22:20 UTC)
Expired
Jun 30, 2021, 7:45 PM CDT
In force
2 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Adams County, IL, Marion County, MO

The radar

The St Louis radar (KLSX), 139 km from the middle of the area, began a volume at 22:19 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, 5:30 PM CDTFLASH FLOOD4 Ne Marblehead, ILSEVERAL FACEBOOK POSTS IN A LOCAL COMMUNITY PAGE SHOW PICTURES OF MOVING WATER COVERING THE INTERSECTION OF HWY 96 AND ST. ANTHONY RD. FROM VIDEO, WATER IS MOVING RAPIDLY ACROSS ROADS AND INTO TWO CREEKS NEAR THE INTERSECTION. THE CREEKS DID NOT APPEAR TO BE O

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, 10.3 hours before the alert went out and 203 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 2021-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 377 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 2021-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
377 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
738 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.3

Open this sounding in Storm Lab

The text

As transmitted.

681 
WGUS53 KLSX 302220
FFWLSX
ILC001-MOC127-010045-
/O.NEW.KLSX.FF.W.0021.210630T2220Z-210701T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
520 PM CDT Wed Jun 30 2021

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Southern Adams County in west central Illinois...
  East Central Marion County in northeastern Missouri...

* Until 745 PM CDT.

* At 520 PM CDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  1.5 and 2.5 inches of rain have fallen. The expected rainfall rate 
  is 0.5 to 1 inch 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 and automated gauges.

  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...
  Quincy, Quincy Regional Airport, Payson, Fall Creek, Beverly, 
  Adams, Kingston, Burton, Liberty, Richfield, Plainville, Columbus, 
  Marblehead and Kellerville.

This includes the following State Parks...
	Siloam Springs State Park.

This includes the following highways...
	Interstate 172 between exits 2 and 15.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3984 9143 3998 9130 3999 9108 3998 9092
      3976 9092 3976 9153

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...0.5-1 INCH IN 1 HOUR

$$

MRB
2 follow-up statements
217 
WGUS73 KLSX 302328
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
628 PM CDT Wed Jun 30 2021

ILC001-MOC127-010045-
/O.CON.KLSX.FF.W.0021.000000T0000Z-210701T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Adams IL-Marion MO-
628 PM CDT Wed Jun 30 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM CDT THIS 
EVENING FOR SOUTHERN ADAMS COUNTY IN WEST CENTRAL ILLINOIS AND EAST 
CENTRAL MARION COUNTY IN NORTHEASTERN MISSOURI...

At 628 PM CDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 
1.5 and 2.5 inches of rain have fallen. The expected rainfall rate 
is 0.5 to 1 inch in 1 hour. Additional rainfall amounts of 0.5 to 1 
inch are possible in the warned area. Flash flooding is ongoing or 
expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and automated gauges.

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...
  Quincy, Quincy Regional Airport, Payson, Fall Creek, Beverly, 
  Adams, Kingston, Burton, Liberty, Richfield, Plainville, Columbus, 
  Marblehead and Kellerville.

This includes the following State Parks...
	Siloam Springs State Park.

This includes the following highways...
	Interstate 172 between exits 2 and 15.

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.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3984 9143 3998 9130 3999 9108 3998 9092
      3976 9092 3976 9153

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...0.5-1 INCH IN 1 HOUR

$$

MRB
979 
WGUS73 KLSX 010038
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
738 PM CDT Wed Jun 30 2021

ILC001-MOC127-010048-
/O.EXP.KLSX.FF.W.0021.000000T0000Z-210701T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Adams IL-Marion MO-
738 PM CDT Wed Jun 30 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 745 PM CDT THIS EVENING FOR 
SOUTHERN ADAMS COUNTY IN WEST CENTRAL ILLINOIS AND EAST CENTRAL 
MARION COUNTY IN NORTHEASTERN MISSOURI...

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

LAT...LON 3984 9143 3998 9130 3999 9108 3998 9092
      3976 9092 3976 9153

$$

MRB

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 29, 8:41 PM CDTRiver Flood WarningLSXLewis30 hr
Jun 30, 3:30 AM CDTFlash Flood WatchLSXAudrain, Boone, Callaway, Cole, Crawford, Franklin and 8 more33 hr
Jun 30, 5:15 AM CDTAreal Flood AdvisoryLSXBoone, Moniteau3 hr
Jun 30, 5:44 AM CDTRiver Flood WarningLSXLincoln49 hr
Jun 30, 5:59 AM CDTAreal Flood AdvisoryLSXBoone, Callaway3 hr
Jun 30, 7:01 AM CDTAreal Flood AdvisoryLSXMontgomery3 hr
Jun 30, 7:49 AM CDTAreal Flood AdvisoryLSXLincoln, Montgomery, Warren3 hr
Jun 30, 4:03 PM CDTAreal Flood AdvisoryLSXLewis, Marion3 hr
Jun 30, 4:34 PM CDTAreal Flood AdvisoryLSXMarion46 min
Jun 30, 6:00 PM CDTRiver Flood WarningLSXMarion22 hr
Jun 30, 6:00 PM CDTRiver Flood WarningLSXMarion19 hr

Nearby

Flash Flood Warnings in Missouri, 2021Flash Flood Warnings in Illinois, 2021Every flash flood warning in 2021

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.