Alert archive / Illinois / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 417, NWS St. Louis, MO

June 27, 2011Greene County, Macoupin County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 27, 2011, 2:09 AM CDT for Greene County, Macoupin County, Illinois. It was in force for 36 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
Jun 27, 2011, 2:09 AM CDT (07:09 UTC)
Expired
Jun 27, 2011, 2:45 AM CDT
In force
36 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
70.0 mph

Counties Greene County, IL, Macoupin County, IL

The radar

The St Louis radar (KLSX), 92 km from the middle of the area, began a volume at 07:11 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jun 27, 1:32 AM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 7.2 hours before the alert went out and 157 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 2011-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 611 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 00:00Z on 2011-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 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
611 J/kg
Mixed-layer CIN
-178 J/kg
Mixed-layer LCL
767 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
169 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

696 
WUUS53 KLSX 270709
SVRLSX
ILC061-117-270745-
/O.NEW.KLSX.SV.W.0417.110627T0709Z-110627T0745Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
209 AM CDT MON JUN 27 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  GREENE COUNTY IN SOUTHWEST ILLINOIS...
  NORTHWESTERN MACOUPIN COUNTY IN SOUTHWEST ILLINOIS...

* UNTIL 245 AM CDT

* AT 205 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DESTRUCTIVE WINDS
  IN EXCESS OF 70 MPH.  THESE STORMS WERE LOCATED ALONG A LINE
  EXTENDING FROM 9 MILES SOUTHEAST OF PITTSFIELD TO 7 MILES NORTH OF
  HARDIN...AND MOVING EAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WHITE HALL...CARROLLTON...ROODHOUSE...GREENFIELD...ATHENSVILLE...
  PALMYRA...ELDRED...HAYPRESS...HILLVIEW...WALKERSVILLE...
  PATTERSON...BELLTOWN...BERDAN...BARROW...WRIGHTS...ROCKBRIDGE...
  SCOTTVILLE...CHESTERFIELD...HETTICK AND MODESTO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THESE STORMS HAVE EXHIBITED SOME WEAK ROTATION. TORNADOES CAN DEVELOP
QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH ONE IS NOT IMMEDIATELY
LIKELY...IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF
SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

THESE STORMS HAVE A HISTORY OF PRODUCING WIDESPREAD WIND DAMAGE 
ACROSS NORTHEAST MISSOURI. THIS IS AN EXTREMELY DANGEROUS SITUATION. 
SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM 
WINDOWS.

&&

LAT...LON 3952 8985 3925 8998 3928 9060 3953 9056
TIME...MOT...LOC 0709Z 276DEG 41KT 3953 9062 3925 9061
WIND...HAIL 70MPH <.75IN

$$

TRUETT

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 26, 8:34 PM CDTSevere Thunderstorm WarningLSXAdams41 min
Jun 26, 9:09 PM CDTRiver Flood WarningLSXAdams4 days
Jun 26, 9:09 PM CDTRiver Flood WarningLSXAdams5 days
Jun 26, 9:16 PM CDTSevere Thunderstorm WarningLSXAdams, Brown59 min
Jun 26, 9:45 PM CDTRiver Flood WarningLSXClinton9 days
Jun 26, 10:09 PM CDTSevere Thunderstorm WarningLSXBrown36 min
Jun 26, 10:11 PM CDTFlash Flood WarningLSXAdams, Brown11 hr
Jun 27, 12:26 AM CDTSevere Thunderstorm WarningLSXAdams49 min
Jun 27, 1:08 AM CDTTornado WarningLSXAdams, Calhoun, Pike37 min
Jun 27, 1:13 AM CDTSevere Thunderstorm WarningLSXAdams, Brown62 min
Jun 27, 1:27 AM CDTSevere Thunderstorm WarningLSXCalhoun63 min
Jun 27, 1:43 AM CDTTornado WarningLSXAdams, Calhoun, Greene, Pike32 min
Jun 27, 2:04 AM CDTSevere Thunderstorm WarningLSXCalhoun, Greene, Jersey, Macoupin, Madison41 min
Jun 27, 2:42 AM CDTSevere Thunderstorm WarningLSXBond, Jersey, Macoupin, Madison, Monroe, Montgomery and 1 more48 min
Jun 27, 3:01 AM CDTSevere Thunderstorm WarningLSXMonroe, Randolph29 min
Jun 27, 8:25 AM CDTRiver Flood WarningLSXAdams4 days
Jun 27, 8:57 AM CDTAreal Flood WarningLSXAdams, Brown12 hr

Nearby

Severe Thunderstorm Warnings in Illinois, 2011Every severe thunderstorm warning in 2011

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.