Alert archive / Missouri / Flash Flood Warnings in 2012

Flash Flood Warning 18, NWS St. Louis, MO

April 30, 2012Callaway County, Missouri

NWS St. Louis, MO issued this flash flood warning at Apr 30, 2012, 2:40 AM CDT for Callaway County, Missouri. It was in force for 6 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: Apr 30, 2012, 2:40 AM CDT (07:40 UTC)
Expired: Apr 30, 2012, 8:30 AM CDT
In force: 6 hr
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Flood severity: None

County Callaway County, MO

The radar

The St Louis radar (KLSX), 115 km from the middle of the area, began a volume at 07:42 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
Apr 30, 2:41 AM CDT	FLASH FLOOD	Fulton, MO	ROAD CLOSED AT HWY F AND 341 DUE TO HIGH WATER.
Apr 30, 2:42 AM CDT	FLASH FLOOD	Holts Summit, MO	COUNTRY ROAD 4040 IS WASHED OUT NEAR VALLEY LANE.
Apr 30, 8:15 AM CDT	FLOOD	3 Wsw Mokane, MO	WATER OVER HIGHWAY PP NEAR MIDDLE RIVER BRIDGE...ABOUT A MILE NORTH OF HIGHWAY 94.

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, 7.7 hours before the alert went out and 259 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: 913 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 985 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 177 m²/s²
0-3 km storm-relative helicity: 159 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 4.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

638 
WGUS53 KLSX 300740
FFWLSX
MOC027-301330-
/O.NEW.KLSX.FF.W.0018.120430T0740Z-120430T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
240 AM CDT MON APR 30 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CALLAWAY COUNTY IN CENTRAL MISSOURI...

* UNTIL 830 AM CDT

* AT 235 AM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED FLASH     
  FLOODING OCCURRING ACROSS CALLAWAY COUNTY. SLOW MOVING             
  THUNDERSTORMS WILL BRING ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3     
  INCHES THROUGH SUNRISE.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  FULTON...HOLTS SUMMIT...AUXVASSE...LAKE MYKEE...NEW BLOOMFIELD...
  SHAMROCK AND WILLIAMSBURG.

HIGHWAY 163 IS CLOSED DUE TO HIGH WATER AT LOW WATER CROSSINGS.
HIGHWAY F AND 341 IS CLOSED DUE TO FLOODING IN FULTON.
COUNTRY ROAD 4040 HAS BEEN WASHED OUT NEAR VALLEY LANE IN HOLTS 
SUMMIT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 3881 9214 3883 9215 3885 9214 3890 9217
      3906 9213 3906 9163 3870 9165 3871 9173
      3868 9177 3867 9185 3859 9195 3856 9202
      3856 9210 3858 9217 3864 9222 3870 9222

$$

CVKING

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 29, 8:11 PM CDT	River Flood Warning	LSX	Cole	45 hr
Apr 29, 10:10 PM CDT	River Flood Warning	LSX	Lincoln	11 hr
Apr 29, 10:13 PM CDT	Severe Thunderstorm Warning	LSX	Knox, Lewis	47 min
Apr 29, 10:43 PM CDT	Flash Flood Warning	LSX	Audrain, Boone	8 hr
Apr 29, 10:45 PM CDT	Severe Thunderstorm Warning	LSX	Audrain, Monroe, Ralls	45 min
Apr 30, 12:02 AM CDT	Flash Flood Warning	LSX	Boone	7 hr
Apr 30, 6:29 AM CDT	Flash Flood Warning	LSX	Audrain, Boone	5 hr
Apr 30, 8:31 AM CDT	Areal Flood Warning	LSX	Callaway	6 hr
Apr 30, 10:48 AM CDT	Areal Flood Warning	LSX	Boone	6 hr
Apr 30, 4:51 PM CDT	Areal Flood Warning	LSX	Boone	6 hr
Apr 30, 5:27 PM CDT	River Flood Warning	LSX	Lincoln	17 hr

Nearby

Flash Flood Warnings in Missouri, 2012 Every flash flood warning in 2012

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.