Alert archive / Missouri / Flash Flood Warnings in 2018

Flash Flood Warning 6, NWS St. Louis, MO

May 17, 2018Sainte Genevieve County, Saint Francois County, Missouri

NWS St. Louis, MO issued this flash flood warning at May 17, 2018, 1:21 PM CDT for Sainte Genevieve County, Saint Francois 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
May 17, 2018, 1:21 PM CDT (18:21 UTC)
Expired
May 17, 2018, 7:15 PM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Saint Francois County, MO, Sainte Genevieve County, MO

The radar

The St Louis radar (KLSX), 117 km from the middle of the area, began a volume at 18:23 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
May 17, 3:00 PM CDTFLASH FLOOD3 Se Coffman, MOSALINE CREEK AT BOYD ROAD OUT OF ITS BANKS AND FLOODING DUE TO HEAVY RAINFALL.

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, 6.4 hours before the alert went out and 301 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 2018-05-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2018-05-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -101 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1591 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
-101 m²/s²
0-3 km storm-relative helicity
-61 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

898 
WGUS53 KLSX 171821
FFWLSX
MOC186-187-180015-
/O.NEW.KLSX.FF.W.0006.180517T1821Z-180518T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
121 PM CDT THU MAY 17 2018

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Southeastern Ste. Genevieve County in southeastern Missouri...
  Southeastern St. Francois County in southeastern Missouri...

* Until 715 PM CDT.

* At 120 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to 
  begin shortly. Radar estimates over 3 inches of rain has fallen 
  since 1230 pm.

* Some locations that will experience flooding include...
  Womac, Coffman, Libertyville and Minnith. 

This includes Interstate 55 in Missouri near exit 141.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3765 9037 3786 9018 3785 8997 3781 9001
      3767 9011 3764 9015

$$

Glass
3 follow-up statements
033 
WGUS73 KLSX 171905
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
205 PM CDT THU MAY 17 2018

MOC186-187-180015-
/O.CON.KLSX.FF.W.0006.000000T0000Z-180518T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ste. Genevieve MO-St. Francois MO-
205 PM CDT THU MAY 17 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM CDT FOR
SOUTHEASTERN STE. GENEVIEVE AND SOUTHEASTERN ST. FRANCOIS COUNTIES...

At 200 PM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Radar estimates that in excess of 5 
inches of rain has fallen since 1230 pm across extreme southern Ste. 
Genevieve County. Flash flooding is likely! 

Some locations that will experience flooding include...
Womac, Coffman, Libertyville and Minnith. 

Areas most susceptible to flash floodinging are the Saline Creek, 
the south fork of the Saline Creek, Route T, and Route WW.

Additional rainfall amounts of 1 to 3 inches are possible in the 
warned area.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 3765 9037 3786 9018 3785 8997 3781 9001
      3767 9011 3764 9015

$$

Glass
756 
WGUS73 KLSX 172019
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
319 PM CDT THU MAY 17 2018

MOC186-187-180015-
/O.CON.KLSX.FF.W.0006.000000T0000Z-180518T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ste. Genevieve MO-St. Francois MO-
319 PM CDT THU MAY 17 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM CDT FOR
SOUTHEASTERN STE. GENEVIEVE AND SOUTHEASTERN ST. FRANCOIS COUNTIES...

At 314 PM CDT, Doppler radar indicated that the rainfall rates have 
temporarily diminished across the warned area. Persistent earlier 
thunderstorms have resulted in estimated rainfall in excess of 5 
inches across extreme southern Ste. Genevieve County since noon. The 
potential for flash flooding remains high.

Some locations that will experience flooding include...
Womac, Coffman, Libertyville and Minnith. 

New thunderstorms were developing upstream and these are likely to 
impact the warned area through 500 pm. Additional rainfall amounts 
of 1 to 3 inches are possible. 

Areas most susceptible to flash floodinging are the Saline Creek, 
the south fork of the Saline Creek, Route T, and Route WW.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 3765 9037 3786 9018 3785 8997 3781 9001
      3767 9011 3764 9015

$$

Glass
061 
WGUS73 KLSX 180015
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
715 PM CDT THU MAY 17 2018

MOC186-187-180023-
/O.EXP.KLSX.FF.W.0006.000000T0000Z-180518T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ste. Genevieve MO-St. Francois MO-
715 PM CDT THU MAY 17 2018

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN STE. GENEVIEVE AND
SOUTHEASTERN ST. FRANCOIS COUNTIES WILL EXPIRE AT 715 PM 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 3765 9037 3786 9018 3785 8997 3781 9001
      3767 9011 3764 9015

$$

GKS

The office that day

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

IssuedProductOfficeCountiesLasted
May 17, 12:51 PM CDTSevere Thunderstorm WarningLSXSainte Genevieve, Saint Francois39 min

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.