Alert archive / Illinois / Flash Flood Warnings in 2017

Flash Flood Warning 29, NWS Lincoln, IL

November 18, 2017DeWitt County, Logan County, McLean County, Illinois

NWS Lincoln, IL issued this flash flood warning at Nov 18, 2017, 8:20 AM CST for DeWitt County, Logan County, McLean County, Illinois. It was in force for 6 hr. 2 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
Nov 18, 2017, 8:20 AM CST (14:20 UTC)
Expired
Nov 18, 2017, 2:15 PM CST
In force
6 hr
Issued by
NWS Lincoln, IL
Area
Storm-based polygon
Flood severity
None

Counties DeWitt County, IL, Logan County, IL, McLean County, IL

The radar

The Lincoln radar (KILX), 49 km from the middle of the area, began a volume at 14:20 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
Nov 18, 9:24 AM CSTFLASH FLOODLe Roy, ILOVER ONE FOOT OF WATER ON RT. 150 IN LE ROY.
Nov 18, 11:00 AM CSTHEAVY RAIN 2.31Arrowsmith, 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 12:00Z, 2.3 hours before the alert went out and 35 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 2017-11-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2017-11-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 204 square meters per square second.1939587897117136Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
599 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
204 m²/s²
0-3 km storm-relative helicity
268 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted.

144 
WGUS53 KILX 181420
FFWILX
ILC039-107-113-182015-
/O.NEW.KILX.FF.W.0029.171118T1420Z-171118T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
820 AM CST SAT NOV 18 2017

The National Weather Service in Lincoln has issued a

* Flash Flood Warning for...
  Northeastern Logan County in central Illinois...
  Northern De Witt County in central Illinois...
  Southern McLean County in central Illinois...

* Until 215 PM CST

* At 819 AM CST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to 2.5 inches of rain have 
  already fallen in southern McLean county this morning. Flash 
  flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Bloomington, Le Roy, Heyworth, Atlanta, Downs, McLean, Waynesville,
  Arrowsmith, Ellsworth, Holder, Moraine View State Park, Shirley and
  Bloomington Airport.

This includes the following highways...
 Interstate 55 between mile markers 140 and 156.
 Interstate 74 between mile markers 134 and 156.

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, country roads, farmland, and other low lying
spots.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 4055 8864 4028 8857 4021 8922 4039 8924

$$

Auten
1 follow-up statement
382 
WGUS73 KILX 181923
FFSILX

Flash Flood Statement
National Weather Service Lincoln IL
123 PM CST SAT NOV 18 2017

ILC039-107-113-181932-
/O.CAN.KILX.FF.W.0029.000000T0000Z-171118T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Logan-De Witt-McLean-
123 PM CST SAT NOV 18 2017

...THE FLASH FLOOD WARNING FOR NORTHEASTERN LOGAN...NORTHERN DE WITT
AND SOUTHERN MCLEAN COUNTIES IS CANCELLED...

Flood waters have receded. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 4055 8864 4028 8857 4021 8922 4039 8924

$$

Shimon

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 18, 6:43 AM CSTSpecial Weather StatementILXMason, Tazewell47 min
Nov 18, 7:20 AM CSTSpecial Weather StatementILXMcLean40 min
Nov 18, 8:52 AM CSTFlash Flood WarningILXLogan, McLean, Mason, Menard, Tazewell6 hr
Nov 18, 8:59 AM CSTFlash Flood WarningILXChampaign, DeWitt, McLean, Piatt, Vermilion6 hr
Nov 18, 10:10 AM CSTSpecial Weather StatementILXColes, Douglas, Edgar, Moultrie, Shelby, Vermilion65 min
Nov 18, 11:18 AM CSTSpecial Weather StatementILXClark, Crawford, Cumberland, Effingham, Jasper57 min
Nov 18, 12:07 PM CSTSpecial Weather StatementILXClay, Crawford, Jasper, Richland53 min

Nearby

Flash Flood Warnings in Illinois, 2017Every 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.