Alert archive / Illinois / Flash Flood Warnings in 2012

Flash Flood Warning 4, NWS Lincoln, IL

May 20, 2012Effingham County, Illinois

NWS Lincoln, IL issued this flash flood warning at May 20, 2012, 4:00 PM CDT for Effingham County, Illinois. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: May 20, 2012, 4:00 PM CDT (21:00 UTC)
Expired: May 20, 2012, 10:00 PM CDT
In force: 6 hr
Issued by: NWS Lincoln, IL
Area: Storm-based polygon
Flood severity: None

County Effingham County, IL

The radar

The Evansville,IN radar (KVWX), 116 km from the middle of the area, began a volume at 21:03 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.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 9.0 hours before the alert went out and 122 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: 616 J/kg
Mixed-layer CIN: -119 J/kg
Mixed-layer LCL: 1773 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: -67 m²/s²
0-3 km storm-relative helicity: -55 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

957 
WGUS53 KILX 202100
FFWILX
ILC049-210300-
/O.NEW.KILX.FF.W.0004.120520T2100Z-120521T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LINCOLN IL
400 PM CDT SUN MAY 20 2012

THE NATIONAL WEATHER SERVICE IN LINCOLN HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL EFFINGHAM COUNTY IN SOUTH CENTRAL ILLINOIS...

* UNTIL 1000 PM CDT

* AT 359 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE
  WARNED AREA. RADAR ESTIMATES AROUND 2 INCHES OF RAIN HAD FALLEN
  BETWEEN ALTAMONT AND WATSON IN THE PAST HOUR.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  WATSON.

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 3910 8855 3904 8851 3898 8868 3903 8873

$$

BAK

1 follow-up statement

546 
WGUS73 KILX 210257
FFSILX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LINCOLN IL
957 PM CDT SUN MAY 20 2012

ILC049-210312-
/O.EXP.KILX.FF.W.0004.000000T0000Z-120521T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
EFFINGHAM IL-
957 PM CDT SUN MAY 20 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR CENTRAL EFFINGHAM
COUNTY WILL BE ALLOWED TO EXPIRE AT 1000 PM CDT...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS
AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO
RECEDE...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED...
PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 3910 8855 3904 8851 3898 8868 3903 8873

$$

AUTEN

The office that day

Everything else NWS Lincoln, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 20, 4:54 PM CDT	Special Weather Statement	ILX	Sangamon	51 min
May 20, 5:04 PM CDT	Special Weather Statement	ILX	Logan	41 min
May 20, 5:36 PM CDT	Special Weather Statement	ILX	Logan	54 min
May 20, 5:38 PM CDT	Severe Thunderstorm Warning	ILX	Logan, Sangamon	37 min
May 20, 5:46 PM CDT	Severe Thunderstorm Warning	ILX	Morgan, Sangamon	44 min
May 20, 6:11 PM CDT	Severe Thunderstorm Warning	ILX	Logan, Mason, Tazewell	49 min
May 20, 6:56 PM CDT	Special Weather Statement	ILX	Champaign	64 min

Nearby

Flash Flood Warnings in Illinois, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.