Alert archive / Missouri / Flash Flood Warnings in 2023

Flash Flood Warning 21, NWS St. Louis, MO

August 2, 2023Osage County, Missouri

NWS St. Louis, MO issued this flash flood warning at Aug 2, 2023, 3:32 AM CDT for Osage County, Missouri. It was in force for 5 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: Aug 2, 2023, 3:32 AM CDT (08:32 UTC)
Expired: Aug 2, 2023, 8:30 AM CDT
In force: 5 hr
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Flood severity: None

County Osage County, MO

The radar

The St Louis radar (KLSX), 96 km from the middle of the area, began a volume at 08:36 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

Time	Report	Where	Remark
Aug 2, 6:26 AM CDT	FLASH FLOOD	3 E Frankenstein, MO	Numerous roads covered in water in the NE portion of the county, including Highway 100 near Frankenstein. Also reports of cars off of the road.
Aug 2, 6:30 AM CDT	RAIN 6.55	7 Sse Chamois, MO
Aug 2, 7:40 AM CDT	RAIN 7	6 Ssw Morrison, MO	At least 7 of rain measured. Also reported that Baileys Creek is well out of its banks.

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, 8.5 hours before the alert went out and 260 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2909 J/kg
Mixed-layer CIN: -95 J/kg
Mixed-layer LCL: 1243 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 148 m²/s²
0-3 km storm-relative helicity: 188 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 14.0

Open this sounding in Storm Lab

The text

As transmitted.

056 
WGUS53 KLSX 020832
FFWLSX
MOC151-021130-
/O.NEW.KLSX.FF.W.0021.230802T0832Z-230802T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
332 AM CDT Wed Aug 2 2023

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Northeastern Osage County in central Missouri...

* Until 630 AM CDT.

* At 332 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 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.

  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...
  Chamois and Frankenstein.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3846 9165 3846 9180 3861 9192 3863 9189
      3865 9188 3866 9187 3868 9182 3868 9176
      3871 9172 3870 9164

FLASH FLOOD...RADAR INDICATED

$$

Walsh

2 follow-up statements

997 
WGUS53 KLSX 021042
FFWLSX
MOC151-021330-
/O.EXT.KLSX.FF.W.0021.000000T0000Z-230802T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
542 AM CDT Wed Aug 2 2023

The National Weather Service in St Louis has extended the

* Flash Flood Warning for...
  Northeastern Osage County in central Missouri...

* Until 830 AM CDT.

* At 542 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 5 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.

  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...
  Chamois and Frankenstein.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3846 9165 3846 9180 3861 9192 3863 9189
      3865 9188 3866 9187 3868 9182 3868 9176
      3871 9172 3870 9164

FLASH FLOOD...RADAR INDICATED

$$

Walsh

024 
WGUS73 KLSX 021328
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
828 AM CDT Wed Aug 2 2023

MOC151-021338-
/O.EXP.KLSX.FF.W.0021.000000T0000Z-230802T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Osage MO-
828 AM CDT Wed Aug 2 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 830 AM CDT THIS MORNING FOR 
NORTHEASTERN OSAGE COUNTY...

Flood waters have receded. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.  The County 
Sheriff's Office reported County roads 315 and 317 to be damaged 
with flood debris on both roads.

Radar indicates thunderstorms with heavy rain moving across central 
portions of the county.

A Flood Watch remains in effect until 1000 AM CDT for portions of 
central, east central, northeast, and southeast Missouri.

LAT...LON 3846 9165 3846 9180 3861 9192 3863 9189
      3865 9188 3866 9187 3868 9182 3868 9176
      3871 9172 3870 9164

$$

Fuchs

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 2, 1:18 AM CDT	Areal Flood Advisory	LSX	Boone	5 hr
Aug 2, 2:25 AM CDT	Severe Thunderstorm Warning	LSX	Audrain, Monroe	50 min
Aug 2, 2:29 AM CDT	Areal Flood Advisory	LSX	Callaway	5 hr
Aug 2, 2:42 AM CDT	Severe Thunderstorm Warning	LSX	Audrain, Boone	48 min
Aug 2, 2:56 AM CDT	Flood Watch	LSX	Audrain, Boone, Callaway, Cole, Crawford, Franklin and 16 more	31 hr
Aug 2, 2:58 AM CDT	Areal Flood Advisory	LSX	Audrain, Monroe	5 hr
Aug 2, 3:11 AM CDT	Flash Flood Warning	LSX	Boone	7 hr
Aug 2, 3:20 AM CDT	Areal Flood Advisory	LSX	Osage	12 min
Aug 2, 4:22 AM CDT	Areal Flood Advisory	LSX	Gasconade	24 min
Aug 2, 4:42 AM CDT	Areal Flood Advisory	LSX	Franklin	30 min
Aug 2, 4:46 AM CDT	Flash Flood Warning	LSX	Gasconade	4 hr
Aug 2, 5:12 AM CDT	Flash Flood Warning	LSX	Franklin	4 hr
Aug 2, 5:27 AM CDT	Flash Flood Warning	LSX	Audrain, Monroe, Shelby	4 hr
Aug 2, 5:55 AM CDT	River Flood Warning	LSX	Boone	6 hr

Nearby

Flash Flood Warnings in Missouri, 2023 Every flash flood warning in 2023

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.