Alert archive / Illinois / Flash Flood Warnings in 2018

Flash Flood Warning 26, NWS St. Louis, MO

July 15, 2018Randolph County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jul 15, 2018, 3:15 PM CDT for Randolph 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 15, 2018, 3:15 PM CDT (20:15 UTC)
Expired
Jul 15, 2018, 9:15 PM CDT
In force
6 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Flood severity
None

County Randolph County, IL

The radar

The St Louis radar (KLSX), 90 km from the middle of the area, began a volume at 20:17 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
Jul 15, 3:39 PM CDTFLASH FLOODRuma, ILFOX 2 METEOROLOGIST RECEIVED A MULTIPLE REPORTS OF STREET FLOODING IN RUMA.

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, 8.3 hours before the alert went out and 263 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 2018-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 142 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 12:00Z on 2018-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 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
142 J/kg
Mixed-layer CIN
-145 J/kg
Mixed-layer LCL
657 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
41 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

330 
WGUS53 KLSX 152015
FFWLSX
ILC157-160215-
/O.NEW.KLSX.FF.W.0026.180715T2015Z-180716T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
315 PM CDT SUN JUL 15 2018

The National Weather Service in St Louis has issued a

* Flash Flood Warning for...
  Northern Randolph County in southwestern Illinois...

* Until 915 PM CDT.

* At 315 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Ste. Genevieve, Sparta, Tilden, Evansville, Baldwin, Eden, Preston,
  Prairie Du Rocher, Prairie, Ellis Grove, Ruma, Houston, Walsh,
  Kellogg, Roots and Modoc.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3797 9001 3801 9006 3801 9009 3802 9010
      3804 9013 3806 9013 3807 9016 3807 9017
      3809 9021 3813 9004 3818 9004 3822 8967
      3808 8964

$$

Kanofsky
2 follow-up statements
998 
WGUS73 KLSX 160059
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
759 PM CDT SUN JUL 15 2018

ILC157-160215-
/O.CON.KLSX.FF.W.0026.000000T0000Z-180716T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Randolph IL-
759 PM CDT SUN JUL 15 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM CDT FOR
NORTHERN RANDOLPH COUNTY...

At 754 PM CDT, Doppler radar indicated thunderstorms have ended 
across the warned area.  Radar estimates that between 1 to 3 inches 
of rain fell this afternoon on ground that received heavy rainfall 
last night.  Many creek and streams should be running near or above 
bankfull.

Some locations that will experience flooding include...
Ste. Genevieve, Sparta, Tilden, Evansville, Baldwin, Eden, Preston,
Prairie Du Rocher, Prairie, Ellis Grove, Ruma, Houston, Walsh,
Kellogg, Roots and Modoc.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3797 9001 3801 9006 3801 9009 3802 9010
      3804 9013 3806 9013 3807 9016 3807 9017
      3809 9021 3813 9004 3818 9004 3822 8967
      3808 8964

$$

Britt
309 
WGUS73 KLSX 160207
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
907 PM CDT SUN JUL 15 2018

ILC157-160217-
/O.EXP.KLSX.FF.W.0026.000000T0000Z-180716T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Randolph IL-
907 PM CDT SUN JUL 15 2018

...THE FLASH FLOOD WARNING FOR NORTHERN RANDOLPH COUNTY WILL EXPIRE
AT 915 PM 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 3797 9001 3801 9006 3801 9009 3802 9010
      3804 9013 3806 9013 3807 9016 3807 9017
      3809 9021 3813 9004 3818 9004 3822 8967
      3808 8964

$$

Britt

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 14, 7:32 PM CDTSpecial Weather StatementLSXWashington43 min
Jul 14, 10:03 PM CDTFlash Flood WarningLSXRandolph5 hr

Nearby

Flash Flood Warnings in Illinois, 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.