Alert archive / Illinois / Flash Flood Warnings in 2018

Flash Flood Warning 23, NWS Lincoln, IL

August 17, 2018Christian County, Morgan County, Sangamon County, Illinois

NWS Lincoln, IL issued this flash flood warning at Aug 17, 2018, 12:10 AM CDT for Christian County, Morgan County, Sangamon County, Illinois. It was in force for 77 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 17, 2018, 12:10 AM CDT (05:10 UTC)
Expired
Aug 17, 2018, 1:27 AM CDT
In force
77 min
Issued by
NWS Lincoln, IL
Area
Storm-based polygon
Flood severity
None

Counties Christian County, IL, Morgan County, IL, Sangamon County, IL

The radar

The Lincoln radar (KILX), 81 km from the middle of the area, began a volume at 05:12 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 00:00Z, 5.2 hours before the alert went out and 134 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 00:00Z on 2018-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2444 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2018-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 74 square meters per square second.193958Sfc1 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
2444 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
939 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
74 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.1

Open this sounding in Storm Lab

The text

As transmitted.

576 
WGUS53 KILX 170510
FFWILX
ILC021-137-167-171115-
/O.NEW.KILX.FF.W.0023.180817T0510Z-180817T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
1210 AM CDT FRI AUG 17 2018

The National Weather Service in Lincoln has issued a

* Flash Flood Warning for...
  Central Christian County in central Illinois...
  Southern Sangamon County in central Illinois...
  Southeastern Morgan County in west central Illinois...

* Until 615 AM CDT Friday.

* At 1209 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to two and a half inches of 
  rain have already fallen. Flash flooding is expected to begin 
  shortly.

* Some locations that will experience flooding include...
  Springfield, Jacksonville, Taylorville, Chatham, Alexander, Auburn,
  Rochester, Pawnee, Kincaid, New Berlin, Waverly, Divernon,
  Edinburg, Stonington, Loami, Franklin, Murrayville, Woodson, Mount
  Auburn and Bulpitt.

Additional rainfall amounts of one to two inches are possible in the 
warned area.

This includes the following highways...
 Interstate 55 between mile markers 79 and 95.
 Interstate 72 between mile markers 59 and 101.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

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.

&&

LAT...LON 3976 9034 3979 8920 3956 8914 3952 9030
      3963 9030 3964 9034 3967 9035

$$

37
1 follow-up statement
380 
WGUS73 KILX 170627
FFSILX

Flash Flood Statement
National Weather Service Lincoln IL
127 AM CDT FRI AUG 17 2018

ILC021-137-167-170636-
/O.CAN.KILX.FF.W.0023.000000T0000Z-180817T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Christian-Sangamon-Morgan-
127 AM CDT FRI AUG 17 2018

...THE FLASH FLOOD WARNING FOR CENTRAL CHRISTIAN...SOUTHERN SANGAMON
AND SOUTHEASTERN MORGAN COUNTIES IS CANCELLED...

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

LAT...LON 3976 9034 3979 8920 3956 8914 3952 9030
      3963 9030 3964 9034 3967 9035

$$

37

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 8:01 PM CDTSpecial Weather StatementILXSchuyler29 min
Aug 16, 8:26 PM CDTSpecial Weather StatementILXCass34 min
Aug 16, 8:34 PM CDTSpecial Weather StatementILXMenard26 min
Aug 16, 8:42 PM CDTSpecial Weather StatementILXMenard33 min
Aug 16, 9:10 PM CDTSevere Thunderstorm WarningILXMenard, Sangamon50 min
Aug 16, 9:36 PM CDTSpecial Weather StatementILXCass39 min
Aug 16, 9:51 PM CDTSevere Thunderstorm WarningILXCass, Menard39 min
Aug 16, 9:57 PM CDTSpecial Weather StatementILXSangamon33 min
Aug 16, 10:25 PM CDTSevere Thunderstorm WarningILXMenard, Sangamon50 min
Aug 16, 11:01 PM CDTSpecial Weather StatementILXMcLean, Woodford44 min
Aug 16, 11:09 PM CDTSevere Thunderstorm WarningILXChristian, Macon, Sangamon51 min
Aug 16, 11:45 PM CDTAreal Flood AdvisoryILXSangamon3 hr
Aug 17, 12:52 AM CDTSpecial Weather StatementILXChampaign23 min
Aug 17, 12:55 AM CDTSpecial Weather StatementILXMoultrie35 min
Aug 17, 1:37 AM CDTSpecial Weather StatementILXChampaign38 min
Aug 17, 1:52 AM CDTSevere Thunderstorm WarningILXChampaign26 min
Aug 17, 2:02 AM CDTSpecial Weather StatementILXClark43 min
Aug 17, 12:30 PM CDTSpecial Weather StatementILXCass, Champaign, Christian, DeWitt, Douglas, Fulton and 19 more6 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.