Alert archive / Missouri / Flash Flood Warnings in 2018

Flash Flood Warning 41, NWS St. Louis, MO

September 7, 2018Franklin County, Jefferson County, Washington County, Missouri

NWS St. Louis, MO issued this flash flood warning at Sep 7, 2018, 8:02 PM CDT for Franklin County, Jefferson County, Washington County, Missouri. It was in force for 6 hr. 5 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
Sep 7, 2018, 8:02 PM CDT (01:02 UTC)
Expired
Sep 8, 2018, 1:37 AM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

Counties Franklin County, MO, Jefferson County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 69 km from the middle of the area, began a volume at 01:04 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
Sep 7, 9:30 PM CDTHEAVY RAIN 1.5De Soto, MORAIN SINCE 600 PM. RELAYED VIA FOX 2.
Sep 7, 10:00 PM CDTFLASH FLOODCrystal City, MODELAYED REPORT. VIDEO ON SOCIAL MEDIA RELAYED BY MEDIA SHOWS WATER UP TO CAR BUMPERS OVER HIGHWAY 61/67 NEAR BAILEY RD.
Sep 7, 10:18 PM CDTHEAVY RAIN 1.14Antonia, MO
Sep 7, 10:45 PM CDTHEAVY RAIN 2.21 Ssw Antonia, MOSINCE 600 PM.
Sep 7, 11:30 PM CDTFLASH FLOOD1 Ssw Crystal City, MOGAS STATION PARKING LOT FLOODED.

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 00:00Z, 1.0 hours before the alert went out and 293 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 00:00Z on 2018-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 32 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 00:00Z on 2018-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 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
32 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
547 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
-43 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

175 
WGUS53 KLSX 080102
FFWLSX
MOC071-099-221-080700-
/O.NEW.KLSX.FF.W.0041.180908T0102Z-180908T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
802 PM CDT FRI SEP 7 2018

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Jefferson County in east central Missouri...
  Washington County in east central Missouri...
  Southeastern Franklin County in east central Missouri...

* Until 200 AM CDT.

* At 800 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to three inches of rain have 
  already fallen between Anthonies Mill and Richwoods in the past 
  two hours.  Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Arnold, Festus, Union, De Soto, Pevely, Crystal City, St. Clair,
  Herculaneum, Hillsboro, Potosi, Barnhart, Cedar Hill, Anthonies
  Mill, Antonia, Olympian Village, Parkway, Mineral Point, Cedar Hill
  Lakes, Miramiguoa Park and Old Mines.

This includes the following highways...
 Interstate 44 in Missouri between exits 230 and 242.
 Interstate 55 in Missouri between exits 170 and 187.

This also includes  Washington State Park, Mastodon Historic Site,
Sandy Creek Covered Bridge Historic Site, and Gov. Dunklin's Grave
Historic Site.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 3788 9110 3842 9111 3841 9038 3809 9034
      3805 9041 3802 9057 3805 9062 3807 9061
      3808 9064 3787 9064

$$

GKS
1 follow-up statement
784 
WGUS73 KLSX 080637
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
137 AM CDT SAT SEP 8 2018

MOC071-099-221-080647-
/O.CAN.KLSX.FF.W.0041.000000T0000Z-180908T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Jefferson MO-Washington MO-Franklin MO-
137 AM CDT SAT SEP 8 2018

...THE FLASH FLOOD WARNING FOR JEFFERSON...WASHINGTON AND
SOUTHEASTERN FRANKLIN COUNTIES IS CANCELLED...

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

LAT...LON 3788 9110 3842 9111 3841 9038 3809 9034
      3805 9041 3802 9057 3805 9062 3807 9061
      3808 9064 3787 9064

$$

Maples

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 7, 7:28 PM CDTRiver Flood WarningLSXMarion17 hr
Sep 7, 8:34 PM CDTFlash Flood WarningLSXJefferson, Sainte Genevieve5 hr
Sep 7, 9:27 PM CDTAreal Flood AdvisoryLSXSaint Charles, Saint Louis, City of Saint Louis4 hr
Sep 8, 1:31 AM CDTAreal Flood WarningLSXFranklin, Jefferson, Sainte Genevieve, Washington12 hr
Sep 8, 2:56 AM CDTFlash Flood WarningLSXCrawford6 hr
Sep 8, 8:44 AM CDTAreal Flood WarningLSXJefferson, Saint Louis, City of Saint Louis6 hr
Sep 8, 8:59 AM CDTAreal Flood WarningLSXCrawford6 hr
Sep 8, 1:28 PM CDTAreal Flood WarningLSXJefferson, Sainte Genevieve6 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.