Alert archive / Illinois / Flash Flood Warnings in 2017

Flash Flood Warning 18, NWS St. Louis, MO

July 27, 2017Bond County, Fayette County, Madison County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jul 27, 2017, 4:42 AM CDT for Bond County, Fayette County, Madison County, Illinois. 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: Jul 27, 2017, 4:42 AM CDT (09:42 UTC)
Expired: Jul 27, 2017, 10:45 AM CDT
In force: 6 hr
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Flood severity: None

Counties Bond County, IL, Fayette County, IL, Madison County, IL

The radar

The St Louis radar (KLSX), 113 km from the middle of the area, began a volume at 09:42 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
Jul 27, 6:45 AM CDT	HEAVY RAIN 3.93	Greenville, IL

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, 9.7 hours before the alert went out and 156 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: 2000 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 1104 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 55 m²/s²
0-3 km storm-relative helicity: 91 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 4.2

Open this sounding in Storm Lab

The text

As transmitted.

429 
WGUS53 KLSX 270942
FFWLSX
ILC005-051-119-271545-
/O.NEW.KLSX.FF.W.0018.170727T0942Z-170727T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
442 AM CDT THU JUL 27 2017

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Bond County in south central Illinois...
  Northeastern Madison County in southwestern Illinois...
  Southwestern Fayette County in south central Illinois...

* Until 1045 AM CDT Thursday.

* At 435 AM CDT, local law enforcement reported thunderstorms 
  producing heavy rain across the warned area which have led to 
  Highway 140 being closed just east of Greenville. Two to four 
  inches of rain have already fallen, much of it within a couple 
  hour timeframe. Flash flooding is ongoing or expected to begin 
  shortly.

* Some locations that will experience flooding include...
  Highland, Vandalia, Greenville, Pocahontas, Alhambra, Mulberry
  Grove, Tamalco, Sorento, Beaver Creek, Shobonier, Woburn, Reno,
  Pleasant Mound, Pierron, Pittsburg, Shafter, Keyesport, Panama,
  Grantfork and New Douglas.

This includes Interstate 70 in Illinois between exits 24 and 63.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Move to higher ground now. Act quickly to protect your life.

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

&&

LAT...LON 3882 8913 3874 8925 3874 8975 3888 8974
      3900 8975 3900 8959 3903 8959 3901 8904
      3884 8900

$$

TES

1 follow-up statement

273 
WGUS73 KLSX 271540
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
1040 AM CDT THU JUL 27 2017

ILC005-051-119-271550-
/O.EXP.KLSX.FF.W.0018.000000T0000Z-170727T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bond IL-Madison IL-Fayette IL-
1040 AM CDT THU JUL 27 2017

...THE FLASH FLOOD WARNING FOR BOND COUNTY IN SOUTH CENTRAL
ILLINOIS...NORTHEASTERN MADISON COUNTY IN SOUTHWESTERN ILLINOIS AND
SOUTHWESTERN FAYETTE COUNTIES IN SOUTH CENTRAL ILLINOIS WILL EXPIRE
AT 1045 AM CDT...

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

LAT...LON 3882 8913 3874 8925 3874 8975 3888 8974
      3900 8975 3900 8959 3903 8959 3901 8904
      3884 8900

$$

Kelly

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 26, 7:11 PM CDT	Special Weather Statement	LSX	Monroe	49 min
Jul 27, 1:19 AM CDT	Severe Thunderstorm Warning	LSX	Calhoun	41 min
Jul 27, 5:12 AM CDT	Flash Flood Warning	LSX	Clinton, Fayette, Marion	6 hr

Nearby

Flash Flood Warnings in Illinois, 2017 Every flash flood warning in 2017

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.