Alert archive / Missouri / Flash Flood Warnings in 2021

Flash Flood Warning 39, NWS St. Louis, MO

August 26, 2021Moniteau County, Missouri

NWS St. Louis, MO issued this flash flood warning at Aug 26, 2021, 7:51 PM CDT for Moniteau County, Missouri. It was in force for 103 min. 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
Aug 26, 2021, 7:51 PM CDT (00:51 UTC)
Expired
Aug 26, 2021, 9:34 PM CDT
In force
103 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

County Moniteau County, MO

The radar

The Pleasant Hill radar (KEAX), 154 km from the middle of the area, began a volume at 00:54 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
Aug 26, 8:30 PM CDTHEAVY RAIN 1.4California, MOFELL IN THE PAST HOUR.

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

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 0.9 hours before the alert went out and 236 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, Springfield, MO at 00:00Z on 2021-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 824 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, Springfield, MO at 00:00Z on 2021-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 square meters per square second.1939Sfc1 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
824 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
2066 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
0 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

601 
WGUS53 KLSX 270051
FFWLSX
MOC135-270500-
/O.NEW.KLSX.FF.W.0039.210827T0051Z-210827T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
751 PM CDT Thu Aug 26 2021

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Eastern Moniteau County in central Missouri...

* Until midnight CDT.

* At 751 PM CDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 4 inches of rain have fallen. 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...
  California, Jamestown, Clarksburg, McGirk, Easley, Lupus, Kliever 
  and Sandy Hook.

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.

&&

LAT...LON 3853 9246 3854 9256 3863 9269 3868 9266
      3868 9262 3869 9262 3875 9259 3892 9250
      3890 9247 3887 9248 3886 9246 3883 9244
      3882 9242 3882 9239 3881 9238 3880 9238
      3879 9238 3877 9241 3875 9241 3874 9240

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

19
1 follow-up statement
974 
WGUS73 KLSX 270234
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
934 PM CDT Thu Aug 26 2021

MOC135-270244-
/O.CAN.KLSX.FF.W.0039.000000T0000Z-210827T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Moniteau MO-
934 PM CDT Thu Aug 26 2021

...FLASH FLOOD WARNING FOR EASTERN MONITEAU COUNTY HAS BEEN REPLACED 
WITH A FLOOD ADVISORY...

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

LAT...LON 3853 9246 3854 9256 3863 9269 3868 9266
      3868 9262 3869 9262 3875 9259 3892 9250
      3890 9247 3887 9248 3886 9246 3883 9244
      3882 9242 3882 9239 3881 9238 3880 9238
      3879 9238 3877 9241 3875 9241 3874 9240

$$

19

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 26, 8:34 PM CDTAreal Flood AdvisoryLSXWarren3 hr
Aug 26, 9:34 PM CDTAreal Flood AdvisoryLSXMoniteau2 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.