Alert archive / Illinois / Flash Flood Warnings in 2018

Flash Flood Warning 27, NWS St. Louis, MO

July 29, 2018Randolph County, Illinois

NWS St. Louis, MO issued this flash flood warning at Jul 29, 2018, 5:15 PM CDT for Randolph County, Illinois. It was in force for 3 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: Jul 29, 2018, 5:15 PM CDT (22:15 UTC)
Expired: Jul 29, 2018, 8:21 PM CDT
In force: 3 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), 92 km from the middle of the area, began a volume at 22:14 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, 10.3 hours before the alert went out and 260 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 990 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: -12 m²/s²
0-3 km storm-relative helicity: 4 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

544 
WGUS53 KLSX 292215
FFWLSX
ILC157-300215-
/O.NEW.KLSX.FF.W.0027.180729T2215Z-180730T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service St Louis MO
515 PM CDT SUN JUL 29 2018

The National Weather Service in St Louis has issued a

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

* Until 915 PM CDT.

* At 514 PM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to 
  begin shortly. Radar estimates that 2 to 3 inches of rain has 
  fallen in the last 1 to 2 hours.

* Some locations that will experience flooding include...
  Ste. Genevieve, Sparta, Red Bud, Bremen, Steeleville, Percy,
  Coulterville, Tilden, Evansville, Baldwin, Eden, Preston, Blair,
  Prairie Du Rocher, Prairie, Ellis Grove, Ruma, Houston, Walsh and
  Kellogg.

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.

&&

LAT...LON 3797 9000 3800 9005 3802 9007 3805 9013
      3806 9013 3806 9014 3812 9010 3814 9004
      3821 9004 3822 9003 3822 8960 3796 8960

$$

Glass

1 follow-up statement

062 
WGUS73 KLSX 300121
FFSLSX

Flash Flood Statement
National Weather Service St Louis MO
821 PM CDT SUN JUL 29 2018

ILC157-300130-
/O.CAN.KLSX.FF.W.0027.000000T0000Z-180730T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Randolph IL-
821 PM CDT SUN JUL 29 2018

...THE FLASH FLOOD WARNING FOR RANDOLPH COUNTY IS CANCELLED...

The heavy rain that prompted the warning has ended and any flood 
waters have receded. Flooding is no longer expected to pose a 
threat. Please continue to heed any remaining road closures.

LAT...LON 3797 9000 3800 9005 3802 9007 3805 9013
      3806 9013 3806 9014 3812 9010 3814 9004
      3821 9004 3822 9003 3822 8960 3796 8960

$$

Glass

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 10:30 AM CDT	Special Weather Statement	LSX	Montgomery	60 min
Jul 29, 3:25 PM CDT	Severe Thunderstorm Warning	LSX	Monroe	50 min
Jul 29, 4:24 PM CDT	Severe Thunderstorm Warning	LSX	Randolph	51 min
Jul 29, 5:05 PM CDT	Tornado Warning	LSX	Randolph	25 min

Nearby

Flash Flood Warnings in Illinois, 2018 Every 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.