Alert archive / Missouri / Flash Flood Warnings in 2021

Flash Flood Warning 18, NWS St. Louis, MO

June 25, 20214 counties in Missouri

NWS St. Louis, MO issued this flash flood warning at Jun 25, 2021, 9:43 PM CDT for 4 counties in Missouri. It was in force for 4 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 25, 2021, 9:43 PM CDT (02:43 UTC)
Expired
Jun 26, 2021, 1:45 AM CDT
In force
4 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Lincoln County, MO, Montgomery County, MO, Saint Charles County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 46 km from the middle of the area, began a volume at 02:47 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 25, 9:45 PM CDTFLASH FLOOD2 N Warrenton, MOWATER OVER THE ROADWAY AT HIGHWAY 47 AND WILLOW ROAD.
Jun 25, 10:00 PM CDTFLASH FLOOD1 W Warrenton, MOWATER OVER THE ROADWAY AT VETERANS MEMORIAL HIGHWAY AND RURAL KING ROAD.
Jun 25, 10:42 PM CDTFLASH FLOOD6 Ssw Hawk Point, MOWATER OVER THE ROAD AND WATER RESCUE AT HIGHWAY W AND POWERLINE ROAD.

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, 2.7 hours before the alert went out and 261 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 2021-06-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1254 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2021-06-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 105 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
1254 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
910 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
105 m²/s²
0-3 km storm-relative helicity
204 m²/s²
Significant tornado parameter
0.7
Supercell composite
6.6

Open this sounding in Storm Lab

The text

As transmitted.

970 
WGUS53 KLSX 260243
FFWLSX
MOC113-139-183-219-260645-
/O.NEW.KLSX.FF.W.0018.210626T0243Z-210626T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
943 PM CDT Fri Jun 25 2021

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Southwestern Lincoln County in east central Missouri...
  East Central Montgomery County in east central Missouri...
  West Central Saint Charles County in east central Missouri...
  Warren County in east central Missouri...

* Until 145 AM CDT.

* At 943 PM CDT, local law enforcement reported thunderstorms 
  producing heavy rain across the warned area. Between 2 and 4 
  inches of rain have fallen. Additional rainfall amounts of 1 to 3 
  inches are possible in the warned area. Flash flooding is already 
  occurring.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Law enforcement reported.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Wentzville, Troy, Warrenton, Wright City, Moscow Mills, Jonesburg, 
  Truesdale, Hawk Point, Innsbrook, Fountain N' Lakes, Flint Hill 
  and Foristell.

This includes the following highways...
	Interstate 70 in Missouri between exits 183 and 203.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3900 9129 3899 9082 3870 9096 3871 9142

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Walsh

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 25, 7:15 PM CDTSevere Thunderstorm WarningLSXPike45 min
Jun 25, 7:20 PM CDTSevere Thunderstorm WarningLSXLincoln, Warren40 min
Jun 25, 7:32 PM CDTFlash Flood WarningLSXMarion, Monroe, Pike, Ralls6 hr
Jun 25, 7:50 PM CDTFlash Flood WarningLSXLincoln, Montgomery, Saint Charles, Warren6 hr
Jun 25, 8:00 PM CDTFlash Flood WarningLSXAudrain, Montgomery, Pike, Ralls6 hr
Jun 25, 8:11 PM CDTFlash Flood WarningLSXBoone, Callaway, Cole, Montgomery, Osage, Warren4 hr
Jun 25, 9:29 PM CDTFlash Flood WarningLSXLincoln, Saint Charles6 hr
Jun 25, 11:32 PM CDTRiver Flood WarningLSXMarion11 hr
Jun 26, 12:43 AM CDTFlash Flood WarningLSXAudrain, Boone, Callaway, Cole, Gasconade, Moniteau and 5 more6 hr
Jun 26, 12:55 AM CDTRiver Flood WarningLSXCole35 hr
Jun 26, 1:25 AM CDTAreal Flood WarningLSXMarion, Monroe, Pike, Ralls14 hr
Jun 26, 1:48 AM CDTFlash Flood WarningLSXFranklin, Gasconade, Lincoln, Montgomery, Saint Charles, Warren6 hr
Jun 26, 3:29 AM CDTAreal Flood WarningLSXLincoln, Saint Charles9 hr
Jun 26, 6:25 AM CDTAreal Flood WarningLSXAudrain, Boone, Callaway, Cole, Gasconade, Moniteau and 4 more11 hr
Jun 26, 7:34 AM CDTAreal Flood WarningLSXFranklin, Gasconade, Lincoln, Montgomery, Saint Charles, Warren8 hr
Jun 26, 11:42 AM CDTRiver Flood WarningLSXJefferson, Saint Louis8 days
Jun 26, 11:44 AM CDTRiver Flood WarningLSXSaint Charles7 days
Jun 26, 12:13 PM CDTRiver Flood WarningLSXPerry, Sainte Genevieve9 days
Jun 26, 1:37 PM CDTTornado WarningLSXLincoln, Pike38 min
Jun 26, 3:22 PM CDTAreal Flood WarningLSXLincoln2 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.