Alert archive / Illinois / Flash Flood Warnings in 2011

Flash Flood Warning 56, NWS St. Louis, MO

June 18, 2011Clinton County, Marion County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jun 18, 2011, 5:01 AM CDT for Clinton County, Marion County, Illinois. 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: Jun 18, 2011, 5:01 AM CDT (10:01 UTC)
Expired: Jun 18, 2011, 11:00 AM CDT
In force: 6 hr
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Flood severity: None

Counties Clinton County, IL, Marion County, IL

The radar

The Evansville,IN radar (KVWX), 125 km from the middle of the area, began a volume at 10:04 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

Time	Report	Where	Remark
Jun 18, 5:30 AM CDT	FLASH FLOOD	Salem, IL	FLOODED ROADS THROUGHOUT COUNTY...SOME WITH ONE TO TWO FEET OF WATER. SEVERAL CARS HAVE BEEN STRANDED IN THE FLOOD WATERS.
Jun 18, 5:45 AM CDT	FLASH FLOOD	Carlyle, IL	STREETS WERE FLOODED IN TOWN.
Jun 18, 7:52 AM CDT	HEAVY RAIN 2.5	Centralia, IL	SINCE 3 AM. SOME FLOODING OF STREETS AND YARDS NORTHEAST OF AIRPORT. CORRECTED TO LOCATION.
Jun 18, 10:45 AM CDT	FLASH FLOOD	Carlyle, IL	WATER STILL ON ROADWAYS...BUT IMPROVING. ONLY ONE ROAD CLOSED NORTH OF CARLYLE...EAST OF ILLINOIS ROUTE 127.
Jun 18, 10:48 AM CDT	FLASH FLOOD	Salem, IL	WATER RECEEDING IN SALEM...THOUGH COUNTY ROADS STILL 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, 10.0 hours before the alert went out and 178 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: 601 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 644 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 27 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

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

236 
WGUS53 KLSX 181001
FFWLSX
ILC027-121-181600-
/O.NEW.KLSX.FF.W.0056.110618T1001Z-110618T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
501 AM CDT SAT JUN 18 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN CLINTON COUNTY IN SOUTH CENTRAL ILLINOIS...
  MARION COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 1100 AM CDT

* AT 458 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE   
  WARNED AREA. ONE TO TWO INCHES OF RAIN HAS FALLEN ACROSS PORTIONS 
  OF THE WARNED AREA WITH ANOTHER TWO INCHES POSSIBLE OVER THE NEXT 
  COUPLE OF HOURS. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CARLYLE...CENTRALIA...SALEM...BOULDER...CENTRAL CITY...FAIRMAN...
  HELM...KINMUNDY...ODIN...OMEGA...PATOKA...SANDOVAL...SHATTUC AND
  STEPHEN FORBES STATE PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO
NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

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 3847 8870 3847 8914 3850 8915 3852 8935
      3850 8937 3849 8942 3874 8943 3874 8925
      3874 8914 3882 8913 3883 8869 3848 8869

$$

TILLY

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 18, 12:30 AM CDT	Severe Thunderstorm Warning	LSX	Macoupin, Montgomery	45 min
Jun 18, 1:14 AM CDT	Flash Flood Warning	LSX	Macoupin, Montgomery	12 hr
Jun 18, 1:16 AM CDT	Severe Thunderstorm Warning	LSX	Macoupin, Montgomery	29 min
Jun 18, 2:51 AM CDT	Flash Flood Warning	LSX	Fayette, Montgomery	6 hr
Jun 18, 4:31 AM CDT	Flash Flood Warning	LSX	Bond, Fayette	6 hr
Jun 18, 5:10 AM CDT	Severe Thunderstorm Warning	LSX	Adams, Brown, Calhoun, Greene, Pike	65 min
Jun 18, 5:18 AM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Greene, Jersey, Madison, Monroe, Saint Clair	57 min
Jun 18, 5:30 AM CDT	Tornado Warning	LSX	Calhoun, Greene, Jersey, Madison, Pike	19 min
Jun 18, 6:09 AM CDT	Severe Thunderstorm Warning	LSX	Jersey, Macoupin, Madison, Montgomery	51 min
Jun 18, 6:20 AM CDT	Severe Thunderstorm Warning	LSX	Clinton, Madison, Monroe, Randolph, Saint Clair, Washington	40 min
Jun 18, 6:21 AM CDT	Tornado Warning	LSX	Clinton, Monroe, Randolph, Saint Clair, Washington	39 min
Jun 18, 6:51 AM CDT	Severe Thunderstorm Warning	LSX	Bond, Clinton, Fayette, Madison, Marion, Randolph and 2 more	54 min
Jun 18, 7:24 AM CDT	Severe Thunderstorm Warning	LSX	Clinton, Marion	30 min
Jun 18, 1:06 PM CDT	Areal Flood Warning	LSX	Macoupin, Montgomery	4 hr
Jun 18, 3:57 PM CDT	Flash Flood Watch	LSX	Bond, Calhoun, Clinton, Fayette, Greene, Jersey and 8 more	15 hr
Jun 18, 4:49 PM CDT	River Flood Warning	LSX	Fayette	5 days
Jun 18, 5:01 PM CDT	Areal Flood Warning	LSX	Macoupin, Montgomery	23 hr

Nearby

Flash Flood Warnings in Illinois, 2011 Every flash flood warning in 2011

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.