Alert archive / Missouri / Flash Flood Warnings in 2018

Flash Flood Warning 32, NWS St. Louis, MO

August 24, 2018Knox County, Lewis County, Missouri

NWS St. Louis, MO issued this flash flood warning at Aug 24, 2018, 3:56 AM CDT for Knox County, Lewis County, Missouri. It was in force for 6 hr. 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 24, 2018, 3:56 AM CDT (08:56 UTC)
Expired: Aug 24, 2018, 10:00 AM CDT
In force: 6 hr
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Flood severity: None

Counties Knox County, MO, Lewis County, MO

The radar

The Quad Cities radar (KDVN), 191 km from the middle of the area, began a volume at 08:57 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 24, 6:00 AM CDT	HEAVY RAIN 6.36	Edina, MO	RAINFALL SINCE ABOUT 2 AM.

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

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 8.9 hours before the alert went out and 196 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1704 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 68 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

510 
WGUS53 KLSX 240856
FFWLSX
MOC103-111-241500-
/O.NEW.KLSX.FF.W.0032.180824T0856Z-180824T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
356 AM CDT FRI AUG 24 2018

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Knox County in northeastern Missouri...
  Lewis County in northeastern Missouri...

* Until 1000 AM CDT Friday.

* At 354 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...
  Canton, Edina, La Grange, La Belle, Lewistown, Ewing, Knox City,
  Greensburg, Plevna, Steffenville, Maywood, Colony, Hurdland,
  Novelty, Baring, Monticello and Newark.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

This also includes  Wakonda State Park.
 
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.

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

Please report flooding to your local law enforcement agency when you
can do so safely.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 4030 9195 4026 9195 4026 9193 4025 9150
      4018 9151 4003 9150 3995 9144 3995 9234
      4030 9235

$$

TES

2 follow-up statements

503 
WGUS73 KLSX 241044
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
544 AM CDT FRI AUG 24 2018

MOC103-111-241500-
/O.CON.KLSX.FF.W.0032.000000T0000Z-180824T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Knox MO-Lewis MO-
544 AM CDT FRI AUG 24 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1000 AM CDT FOR
KNOX AND LEWIS COUNTIES...

At 539 AM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. The heaviest rainfall has been 
concentrated in an axis from Edina to Monticello, also including the 
cities of Knox City, La Belle, and Lewistown. It is here where 1 to 
2 inches of additional rainfall have fallen since 4 am, resulting in 
rainfall totals of 3 to 5 inches. Flash flooding is either occurring 
or expected to begin shortly!

Some locations that will experience flooding include...
Canton, Edina, La Grange, La Belle, Lewistown, Ewing, Knox City,
Greensburg, Plevna, Steffenville, Maywood, Colony, Hurdland, Novelty,
Baring, Monticello and Newark.

Additional rainfall amounts of up to an inch are possible in the 
warned area.

This also includes  Wakonda State Park.
 
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.

Please report flooding to your local law enforcement agency when you
can do so safely.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 4030 9195 4026 9195 4026 9193 4025 9150
      4018 9151 4003 9150 3995 9144 3995 9234
      4030 9235

$$

TES

998 
WGUS73 KLSX 241456
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
956 AM CDT FRI AUG 24 2018

MOC103-111-241506-
/O.EXP.KLSX.FF.W.0032.000000T0000Z-180824T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Knox MO-Lewis MO-
956 AM CDT FRI AUG 24 2018

...THE FLASH FLOOD WARNING FOR KNOX AND LEWIS COUNTIES WILL EXPIRE AT
1000 AM 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 4030 9195 4026 9195 4026 9193 4025 9150
      4018 9151 4003 9150 3995 9144 3995 9234
      4030 9235

$$

Kanofsky

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 24, 5:54 AM CDT	Areal Flood Advisory	LSX	Marion, Monroe, Ralls, Shelby	4 hr
Aug 24, 7:08 AM CDT	Areal Flood Advisory	LSX	Pike	3 hr
Aug 24, 8:30 AM CDT	Areal Flood Advisory	LSX	Audrain, Lincoln, Marion, Monroe, Pike, Ralls and 1 more	4 hr
Aug 24, 9:20 AM CDT	River Flood Warning	LSX	Lewis	10 hr
Aug 24, 3:33 PM CDT	Heat Advisory	LSX	Audrain, Boone, Callaway, Cole, Franklin, Gasconade and 16 more	4 days

Nearby

Flash Flood Warnings in Missouri, 2018 Every 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.