Alert archive / Missouri / Flash Flood Warnings in 2020

Flash Flood Warning 43, NWS St. Louis, MO

July 27, 2020Lincoln County, Warren County, Missouri

NWS St. Louis, MO issued this flash flood warning at Jul 27, 2020, 8:02 AM CDT for Lincoln County, Warren County, Missouri. It was in force for 4 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
Jul 27, 2020, 8:02 AM CDT (13:02 UTC)
Expired
Jul 27, 2020, 12:00 PM CDT
In force
4 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Lincoln County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 33 km from the middle of the area, began a volume at 13:03 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
Jul 27, 8:50 AM CDTFLASH FLOOD4 S Cave, MOWATER OVER ROUTE 47 IN SPOTS WITH SOME LOCATIONS BARELY PASSABLE.

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

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 1.0 hours before the alert went out and 244 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, Lincoln, IL at 12:00Z on 2020-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 277 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, Lincoln, IL at 12:00Z on 2020-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 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
277 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
1099 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
20 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

101 
WGUS53 KLSX 271302
FFWLSX
MOC113-219-271700-
/O.NEW.KLSX.FF.W.0043.200727T1302Z-200727T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
802 AM CDT Mon Jul 27 2020

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Southwestern Lincoln County in east central Missouri...
  Northeastern Warren County in east central Missouri...

* Until noon CDT.

* At 800 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Radar estimates that in excess 
  of 3 inches of rain has fallen since 500 am. Flash flooding is 
  ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  IMPACT...Flooding of small creeks and streams, urban areas, 
           highways, streets and underpasses as well as other 
           drainage and low lying areas.

* Some locations that will experience flooding include...
  Troy, Warrenton, Wright City, Moscow Mills, Hawk Point, Fountain N'
  Lakes, Flint Hill, Foristell, Truxton and Cave.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3901 9083 3888 9083 3888 9086 3889 9087
      3888 9089 3889 9090 3889 9096 3883 9096
      3884 9126 3902 9126

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

Glass
2 follow-up statements
589 
WGUS73 KLSX 271512
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
1012 AM CDT Mon Jul 27 2020

MOC113-219-271700-
/O.CON.KLSX.FF.W.0043.000000T0000Z-200727T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lincoln MO-Warren MO-
1012 AM CDT Mon Jul 27 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL NOON CDT FOR
SOUTHWESTERN LINCOLN AND NORTHEASTERN WARREN COUNTIES...

At 1008 AM CDT, emergency management reported flooding on Highway 47 
near Linns Mill Road, around 3 miles west of Troy. Radar estimates 
as much as 4 inches of rain has fallen across parts of southwest 
Lincoln County. 

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Emergency management.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Troy, Warrenton, Wright City, Moscow Mills, Hawk Point, Fountain N'
Lakes, Flint Hill, Foristell, Truxton and Cave.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3901 9083 3888 9083 3888 9086 3889 9087
      3888 9089 3889 9090 3889 9096 3883 9096
      3884 9126 3902 9126

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...LESS THAN A HALF INCH THROUGH NOON.
$$

Glass
494 
WGUS73 KLSX 271652
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
1152 AM CDT Mon Jul 27 2020

MOC113-219-271701-
/O.EXP.KLSX.FF.W.0043.000000T0000Z-200727T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lincoln MO-Warren MO-
1152 AM CDT Mon Jul 27 2020

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN LINCOLN AND NORTHEASTERN
WARREN COUNTIES WILL EXPIRE AT NOON CDT...

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

LAT...LON 3901 9083 3888 9083 3888 9086 3889 9087
      3888 9089 3889 9090 3889 9096 3883 9096
      3884 9126 3902 9126

$$

Glass

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 6:34 AM CDTAreal Flood AdvisoryLSXFranklin, Gasconade, Lincoln, Montgomery, Osage, Saint Charles and 1 more4 hr

Nearby

Flash Flood Warnings in Missouri, 2020Every flash flood warning in 2020

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.