Alert archive / Missouri / Flash Flood Warnings in 2021

Flash Flood Warning 1, NWS St. Louis, MO

April 29, 2021Crawford County, Jefferson County, Washington County, Missouri

NWS St. Louis, MO issued this flash flood warning at Apr 29, 2021, 1:49 AM CDT for Crawford County, Jefferson County, Washington County, Missouri. It was in force for 4 hr. 8 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
Apr 29, 2021, 1:49 AM CDT (06:49 UTC)
Expired
Apr 29, 2021, 6:00 AM CDT
In force
4 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Crawford County, MO, Jefferson County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 67 km from the middle of the area, began a volume at 06:51 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
Apr 29, 2:15 AM CDTFLASH FLOODCuba, MOVIADUCT NEAR THE RAILROAD TRACKS IS FLOODED, PORTIONS OF HIGHWAY 19 AND ROUTE PP ARE FLOODED BUT DEPTH OF WATER IS UNKNOWN.
Apr 29, 2:28 AM CDTFLASH FLOOD2 Se Bourbon, MOFLOODING ON HIGHWAY N, IMPASSABLE.
Apr 29, 2:30 AM CDTFLASH FLOOD1 Wsw Richwoods, MODELAYED REPORTS FROM SOCIAL MEDIA. MANY SMALL CREEKS FLOODING. LOW WATER CROSSINGS AND ROADS FLOODED UP TO SEVERAL FEET DEEP.
Apr 29, 2:30 AM CDTFLASH FLOODLeasburg, MODELAYED REPORTS FROM SOCIAL MEDIA. LOW WATER CROSSINGS AND ROADS FLOODED UP TO SEVERAL FEET DEEP.
Apr 29, 2:45 AM CDTFLASH FLOODFletcher, MODELAYED REPORTS FROM SOCIAL MEDIA. CALICO CREEK FLOODING. LOW WATER CROSSINGS AND ROADS FLOODED UP TO SEVERAL FEET DEEP INCLUDING OLD HIGHWAY H, NICKELSON ROAD, AND CALICO CREEK ROAD.
Apr 29, 3:00 AM CDTFLASH FLOOD2 Nne De Soto, MODELAYED REPORTS FROM SOCIAL MEDIA. SOME ROADS FLOODED UP TO SEVERAL FEET DEEP.
Apr 29, 4:11 AM CDTHEAVY RAIN 2.542 W Cuba, MOAPRSWXNET/CWOP.
Apr 29, 4:19 AM CDTHEAVY RAIN 2.34De Soto, MOAPRSWXNET/CWOP.

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, 6.8 hours before the alert went out and 296 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 2021-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 145 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 2021-04-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 98 square meters per square second.1939587897117Sfc1 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
145 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
1042 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
98 m²/s²
0-3 km storm-relative helicity
176 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

762 
WGUS53 KLSX 290649
FFWLSX
MOC055-099-221-291100-
/O.NEW.KLSX.FF.W.0001.210429T0649Z-210429T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
149 AM CDT Thu Apr 29 2021

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Crawford County in east central Missouri...
  Southwestern Jefferson County in east central Missouri...
  Northern Washington County in east central Missouri...

* Until 600 AM CDT.

* At 149 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  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...
  Sullivan, De Soto, Cuba, Steelville, Bourbon, Anthonies Mill, 
  Olympian Village, Leasburg, Richwoods, St. Cloud, Oak Hill, 
  Fletcher and Victoria.

This includes the following State Parks...
Washington State Park, Onondaga Cave State Park and Meramec State 
Park.

This includes the following highways...
	Interstate 44 in Missouri between exits 203 and 218.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3821 9050 3810 9045 3807 9061 3808 9064
      3806 9064 3788 9153 3821 9153

FLASH FLOOD...RADAR INDICATED

$$

Glass
2 follow-up statements
671 
WGUS73 KLSX 290757
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
257 AM CDT Thu Apr 29 2021

MOC055-099-221-291100-
/O.CON.KLSX.FF.W.0001.000000T0000Z-210429T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Crawford MO-Jefferson MO-Washington MO-
257 AM CDT Thu Apr 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 AM CDT EARLY THIS 
MORNING FOR CRAWFORD, SOUTHWESTERN JEFFERSON AND NORTHERN WASHINGTON 
COUNTIES IN EAST CENTRAL MISSOURI...

At 257 AM CDT, local law enforcement reported flooding in Cuba 
resulting from thunderstorms producing heavy rain across the warned 
area. Between 2 and 3 inches of rain have fallen across northern 
Crawford and northern Washington Counties. Flash flooding is already 
occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement reported.

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...
  Sullivan, De Soto, Cuba, Steelville, Bourbon, Anthonies Mill, 
  Olympian Village, Leasburg, Richwoods, St. Cloud, Oak Hill, 
  Fletcher and Victoria.

This includes the following State Parks...
Washington State Park, Onondaga Cave State Park and Meramec State 
Park.

This includes the following highways...
	Interstate 44 in Missouri between exits 203 and 218.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3821 9050 3810 9045 3807 9061 3808 9064
      3806 9064 3788 9153 3821 9153

FLASH FLOOD...OBSERVED

$$

Glass
887 
WGUS73 KLSX 291054
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
554 AM CDT Thu Apr 29 2021

MOC055-099-221-291104-
/O.EXP.KLSX.FF.W.0001.000000T0000Z-210429T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Crawford MO-Jefferson MO-Washington MO-
554 AM CDT Thu Apr 29 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 6 AM CDT EARLY THIS MORNING 
FOR CRAWFORD, SOUTHWESTERN JEFFERSON AND NORTHERN WASHINGTON 
COUNTIES IN EAST CENTRAL MISSOURI...

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

LAT...LON 3821 9050 3810 9045 3807 9061 3808 9064
      3806 9064 3788 9153 3821 9153

$$

Glass

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 29, 2:27 AM CDTFlash Flood WarningLSXJefferson4 hr
Apr 29, 2:53 AM CDTRiver Flood WarningLSXCrawford, Washington42 hr
Apr 29, 9:35 AM CDTRiver Flood WarningLSXLincoln12 hr
Apr 29, 9:44 AM CDTRiver Flood WarningLSXJefferson30 hr

Nearby

Flash Flood Warnings in Missouri, 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.