Alert archive / Illinois / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 21, NWS Quad Cities, IA

May 8, 2009Louisa County, Muscatine County, Iowa; Henry County, Mercer County, Rock Island County, Illinois

NWS Quad Cities, IA issued this severe thunderstorm warning at May 8, 2009, 7:40 PM CDT for Louisa County, Muscatine County, Iowa; Henry County, Mercer County, Rock Island County, Illinois. It was in force for 49 min. 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
May 8, 2009, 7:40 PM CDT (00:40 UTC)
Expired
May 8, 2009, 8:29 PM CDT
In force
49 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon

Counties Louisa County, IA, Muscatine County, IA, Henry County, IL, Mercer County, IL, Rock Island County, IL

The radar

The Quad Cities radar (KDVN), 34 km from the middle of the area, began a volume at 00:43 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
May 8, 7:48 PM CDTTSTM WND GST 704 W Illinois City, ILSPOTTER ESTIMATED AT 65 TO 70 MPH WITH PEA SIZE HAIL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

IssuedProductOfficeLasted
May 8, 6:10 PM CDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.7 hours before the alert went out and 38 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, Davenport, at 00:00Z on 2009-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 354 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, Davenport, at 00:00Z on 2009-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 65 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
354 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
1505 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
65 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KDVN 090040
SVRDVN
IAC115-139-ILC073-131-161-090145-
/O.NEW.KDVN.SV.W.0021.090509T0040Z-090509T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
740 PM CDT FRI MAY 8 2009

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MUSCATINE COUNTY IN EAST CENTRAL IOWA...
  WEST CENTRAL HENRY COUNTY IN NORTHWEST ILLINOIS...
  MERCER COUNTY IN NORTHWEST ILLINOIS...
  SOUTHWESTERN ROCK ISLAND COUNTY IN NORTHWEST ILLINOIS...
  CENTRAL LOUISA COUNTY IN SOUTHEAST IOWA...

* UNTIL 845 PM CDT.

* AT 740 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED APPROXIMATELY NEAR FRUITLAND...
  OR 7 MILES SOUTHWEST OF MUSCATINE...AND MOVING EAST AT 45 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ELIZA AROUND 750 PM CDT...
  ELIZA AROUND 755 PM CDT...
  MILLERSBURG AROUND 805 PM CDT...
  HAMLET AND REYNOLDS AROUND 810 PM CDT...
  MATHERVILLE...SHALE CITY AND WANLOCK AROUND 815 PM CDT...
  BODEN AROUND 820 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. MOVE IMMEDIATELY INDOORS AND STAY AWAY
FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT
SATURDAY MORNING FOR EASTERN IOWA AND NORTHWESTERN ILLINOIS.

&&

LAT...LON 4144 9034 4107 9048 4121 9130 4145 9118
TIME...MOT...LOC 0040Z 274DEG 40KT 4133 9115

$$

ERVIN
3 follow-up statements
000 
WWUS53 KDVN 090049
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
749 PM CDT FRI MAY 8 2009

IAC115-139-ILC073-131-161-090145-
/O.CON.KDVN.SV.W.0021.000000T0000Z-090509T0145Z/
MUSCATINE IA-LOUISA IA-ROCK ISLAND IL-MERCER IL-HENRY IL-
749 PM CDT FRI MAY 8 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR WEST CENTRAL HENRY...MERCER...SOUTHWESTERN ROCK ISLAND...CENTRAL
LOUISA AND SOUTH CENTRAL MUSCATINE COUNTIES...

AT 749 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DESTRUCTIVE WINDS
IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED APPROXIMATELY NEAR
ELIZA...OR 8 MILES SOUTHEAST OF MUSCATINE...MOVING EAST AT 50 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  BUFFALO PRAIRIE AND ILLINOIS CITY AROUND 750 PM CDT...
  MARSTON...EDGINGTON AND MILLERSBURG AROUND 800 PM CDT...
  HAMLET...GINGLE CORNERS AND ALEDO MERCER COUNTY AIRPORT AROUND 805
  PM CDT...
  REYNOLDS AND TAYLOR RIDGE AROUND 810 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT
SATURDAY MORNING FOR EASTERN IOWA AND NORTHWESTERN ILLINOIS.

&&

LAT...LON 4144 9110 4144 9034 4107 9048 4121 9130
TIME...MOT...LOC 0049Z 273DEG 42KT 4132 9098

$$

ERVIN
000 
WWUS53 KDVN 090115
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
815 PM CDT FRI MAY 8 2009

IAC115-139-090125-
/O.CAN.KDVN.SV.W.0021.000000T0000Z-090509T0145Z/
MUSCATINE IA-LOUISA IA-
815 PM CDT FRI MAY 8 2009

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL LOUISA AND SOUTH
CENTRAL MUSCATINE COUNTIES IS CANCELLED...

THE SEVERE THUNDERSTORM THAT PRODUCED DAMAGING WINDS AROUND 
MUSCATINE HAS MOVED OUT OF THE WARNED AREA. THEREFORE THE SEVERE 
THUNDERSTORM WARNING HAS BEEN CANCELLED.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT 
SATURDAY MORNING FOR EASTERN IOWA AND NORTHWESTERN ILLINOIS.

LAT...LON 4142 9067 4144 9034 4107 9048 4115 9093
TIME...MOT...LOC 0115Z 273DEG 42KT 4130 9058

$$

ILC073-131-161-090145-
/O.CON.KDVN.SV.W.0021.000000T0000Z-090509T0145Z/
ROCK ISLAND IL-MERCER IL-HENRY IL-
815 PM CDT FRI MAY 8 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR WEST CENTRAL HENRY...MERCER AND SOUTH CENTRAL ROCK ISLAND
COUNTIES...

AT 815 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH.  THIS STORM WAS LOCATED APPROXIMATELY NEAR
PREEMPTION...OR 11 MILES NORTHEAST OF ALEDO...MOVING EAST AT 40 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  CABLE...SHERRARD AND GRIFFIN AROUND 820 PM CDT...
  SWEDONA...NEW WINDSOR...SUNNY HILL AND 9 MILES SOUTH OF WARNER
  AROUND 825 PM CDT...
  ORION AROUND 830 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT
SATURDAY MORNING FOR EASTERN IOWA AND NORTHWESTERN ILLINOIS.

&&

LAT...LON 4142 9067 4144 9034 4107 9048 4115 9093
TIME...MOT...LOC 0115Z 273DEG 42KT 4130 9058

$$

ERVIN
000 
WWUS53 KDVN 090129
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
829 PM CDT FRI MAY 8 2009

ILC073-131-161-090138-
/O.CAN.KDVN.SV.W.0021.000000T0000Z-090509T0145Z/
ROCK ISLAND IL-MERCER IL-HENRY IL-
829 PM CDT FRI MAY 8 2009

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL HENRY...MERCER
AND SOUTH CENTRAL ROCK ISLAND COUNTIES IS CANCELLED...

THE SEVERE THUNDERSTORM THAT PRODUCED DAMAGING WINDS HAS WEAKENED.  
THEREFORE THE SEVERE THUNDERSTORM WARNING HAS BEEN CANCELLED.

HOWEVER...THIS STORM IS STILL CAPABLE OF PRODUCING HEAVY RAIN.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT
SATURDAY MORNING FOR EASTERN IOWA AND NORTHWESTERN ILLINOIS.

LAT...LON 4142 9067 4144 9034 4107 9048 4115 9093
TIME...MOT...LOC 0128Z 273DEG 42KT 4129 9038

$$

ERVIN

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 8, 7:07 PM CDTSevere Thunderstorm WarningDVNHenry, Louisa, Washington41 min
May 8, 7:57 PM CDTSevere Thunderstorm WarningDVNDes Moines, Louisa63 min
May 8, 8:07 PM CDTTornado WarningDVNLouisa38 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2009Severe Thunderstorm Warnings in Iowa, 2009Every severe thunderstorm warning in 2009

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.