Alert archive / Missouri / Flash Flood Warnings in 2018

Flash Flood Warning 33, NWS St. Louis, MO

August 29, 2018Gasconade County, Osage County, Missouri

NWS St. Louis, MO issued this flash flood warning at Aug 29, 2018, 9:25 AM CDT for Gasconade County, Osage County, Missouri. It was in force for 6 hr. 2 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 29, 2018, 9:25 AM CDT (14:25 UTC)
Expired
Aug 29, 2018, 3:30 PM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Gasconade County, MO, Osage County, MO

The radar

The St Louis radar (KLSX), 91 km from the middle of the area, began a volume at 14:25 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 29, 11:00 AM CDTFLASH FLOOD5 Wnw Mount Sterling, MONUMEROUS CREEKS OUT OF BANKS IN THE AREA.
Aug 29, 11:30 AM CDTFLASH FLOOD7 E Rich Fountain, MORELAYED BY KRCG.

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 12:00Z, 2.4 hours before the alert went out and 249 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 12:00Z on 2018-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1738 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 12:00Z on 2018-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 242 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
1738 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
871 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
242 m²/s²
0-3 km storm-relative helicity
268 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.0

Open this sounding in Storm Lab

The text

As transmitted.

027 
WGUS53 KLSX 291425
FFWLSX
MOC073-151-292030-
/O.NEW.KLSX.FF.W.0033.180829T1425Z-180829T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
925 AM CDT WED AUG 29 2018

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Southeastern Osage County in central Missouri...
  Gasconade County in east central Missouri...

* Until 330 PM CDT Wednesday.

* At 925 AM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to three inches of rain have
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Owensville, Linn, Belle, Bland, Freeburg, Rosebud, Rich Fountain,
  Mount Sterling, Drake, Canaan and Bay.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3847 9190 3853 9137 3829 9136 3829 9137
      3821 9137 3821 9153 3815 9153 3815 9164
      3829 9165 3829 9194

$$

Tilly
2 follow-up statements
694 
WGUS73 KLSX 291700
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
1200 PM CDT WED AUG 29 2018

MOC073-151-292030-
/O.CON.KLSX.FF.W.0033.000000T0000Z-180829T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Osage MO-Gasconade MO-
1200 PM CDT WED AUG 29 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM CDT FOR
SOUTHEASTERN OSAGE AND GASCONADE COUNTIES...

At 1157 AM CDT, Doppler radar indicated thunderstorms have pushed 
south of the warned area, although some rain continues. Three to 
four inches of rain have already fallen. Flash flooding is expected 
across the warned area.

Some locations that will experience flooding include...
Owensville, Linn, Belle, Bland, Freeburg, Rosebud, Rich Fountain,
Mount Sterling, Drake, Canaan and Bay.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3847 9190 3853 9137 3829 9136 3829 9137
      3821 9137 3821 9153 3815 9153 3815 9164
      3829 9165 3829 9194

$$

Tilly
718 
WGUS73 KLSX 292028
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
328 PM CDT WED AUG 29 2018

MOC073-151-292038-
/O.EXP.KLSX.FF.W.0033.000000T0000Z-180829T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Osage MO-Gasconade MO-
328 PM CDT WED AUG 29 2018

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN OSAGE AND GASCONADE
COUNTIES WILL EXPIRE AT 330 PM CDT...

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

LAT...LON 3847 9190 3853 9137 3829 9136 3829 9137
      3821 9137 3821 9153 3815 9153 3815 9164
      3829 9165 3829 9194

$$

Gosselin

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 28, 7:58 PM CDTSpecial Weather StatementLSXMonroe, Shelby47 min
Aug 28, 8:13 PM CDTSpecial Weather StatementLSXKnox47 min
Aug 28, 8:18 PM CDTSevere Thunderstorm WarningLSXKnox, Lewis, Marion, Monroe, Shelby42 min
Aug 28, 9:47 PM CDTSpecial Weather StatementLSXKnox28 min
Aug 29, 12:17 AM CDTSevere Thunderstorm WarningLSXKnox, Lewis, Marion, Shelby43 min
Aug 29, 2:09 AM CDTAreal Flood AdvisoryLSXKnox, Lewis5 hr
Aug 29, 2:56 AM CDTSpecial Weather StatementLSXPike49 min
Aug 29, 4:23 AM CDTSpecial Weather StatementLSXSaint Charles, Saint Louis, City of Saint Louis52 min
Aug 29, 5:11 AM CDTRiver Flood WarningLSXLewis7 hr
Aug 29, 5:11 AM CDTRiver Flood WarningLSXLewis26 hr
Aug 29, 7:39 AM CDTAreal Flood AdvisoryLSXCallaway3 hr
Aug 29, 8:49 AM CDTAreal Flood AdvisoryLSXGasconade, Osage3 hr

Nearby

Flash Flood Warnings in Missouri, 2018Every flash flood warning in 2018

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.