Alert archive / Iowa / Tornado Warnings in 2007

Tornado Warning 23, NWS Quad Cities, IA

July 18, 2007Linn County, Iowa

NWS Quad Cities, IA issued this tornado warning at Jul 18, 2007, 7:06 PM CDT for Linn County, Iowa. It was in force for 39 min. 3 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
Jul 18, 2007, 7:06 PM CDT (00:06 UTC)
Expired
Jul 18, 2007, 7:45 PM CDT
In force
39 min
Issued by
NWS Quad Cities, IA
Area
Counties, with a storm outline in the text

County Linn County, IA

The radar

The Quad Cities radar (KDVN), 97 km from the middle of the area, began a volume at 00:07 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
Jul 18, 7:07 PM CDTFUNNEL CLOUDCedar Rapids, IA
Jul 18, 7:07 PM CDTTSTM WND GST 53Cedar Rapids, IA
Jul 18, 7:20 PM CDTTSTM WND GST 60Mount Vernon, IA

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
Jul 18, 5:35 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.1 hours before the alert went out and 102 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 2007-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3404 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 2007-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 69 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
3404 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
988 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
69 m²/s²
0-3 km storm-relative helicity
135 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.1

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KDVN 190005
TORDVN
IAC113-190045-
/O.NEW.KDVN.TO.W.0023.070719T0006Z-070719T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
706 PM CDT WED JUL 18 2007

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  LINN COUNTY IN EAST CENTRAL IOWA...

* UNTIL 745 PM CDT.

* AT 703 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO NEAR ROBINS...OR ABOUT 8 MILES NORTH OF CEDAR RAPIDS...
  MOVING SOUTHEAST AT 50 MPH.

* THE TORNADO WILL BE NEAR...
  SPRINGVILLE...BERTRAM AND 7 MILES SOUTHWEST OF VIOLA AROUND 715 PM
  CDT...
  MOUNT VERNON AROUND 720 PM CDT...
  LISBON AROUND 725 PM CDT...

THIS INCLUDES INTERSTATE 380 IN IOWA BETWEEN MILE MARKERS 15 AND 30.

THE SAFEST PLACE TO BE IN A TORNADO IS IN A BASEMENT OR INTERIOR ROOM
OR HALLWAY ON THE LOWEST FLOOR OF A BUILDING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 AM CDT
THURSDAY MORNING FOR EASTERN IOWA.

LAT...LON 4220 9167 4190 9181 4187 9138 4213 9138

$$

MAYES
2 follow-up statements
000 
WWUS53 KDVN 190020
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
719 PM CDT WED JUL 18 2007

IAC113-190045-
/O.CON.KDVN.TO.W.0023.000000T0000Z-070719T0045Z/
LINN IA-
719 PM CDT WED JUL 18 2007

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR LINN
COUNTY...

AT 716 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO.  THIS TORNADO WAS LOCATED APPROXIMATELY NEAR
MOUNT VERNON...OR ABOUT 11 MILES EAST OF CEDAR RAPIDS...MOVING
SOUTHEAST AT 50 MPH.

DAMAGING STRAIGHT-LINE WINDS ARE LIKELY IN ADDITION TO TORNADOES.  
THIS STORM HAS A HISTORY OF PRODUCING FUNNEL CLOUDS IN LINN COUNTY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 AM CDT
THURSDAY MORNING FOR EASTERN IOWA.

LAT...LON 4220 9167 4190 9181 4187 9138 4213 9138

$$

MAYES
000 
WWUS53 KDVN 190043
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
743 PM CDT WED JUL 18 2007

IAC113-190053-
/O.EXP.KDVN.TO.W.0023.000000T0000Z-070719T0045Z/
LINN IA-
743 PM CDT WED JUL 18 2007

...THE TORNADO WARNING FOR LINN COUNTY EXPIRES AT 745 PM CDT...

THE SEVERE THUNDERSTORM THAT WAS CAPABLE OF PRODUCING A TORNADO HAS
MOVED OUT OF THE WARNED AREA. THEREFORE THE TORNADO WARNING HAS BEEN
ALLOWED TO EXPIRE.

HOWEVER...THIS STORM IS STILL CAPABLE OF PRODUCING WIND GUSTS UP TO 
50 MPH IN EASTERN LINN COUNTY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 AM CDT
THURSDAY MORNING FOR EASTERN IOWA.

LAT...LON 4220 9167 4190 9181 4187 9138 4213 9138

$$

MAYES

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 7:12 PM CDTSevere Thunderstorm WarningDVNJohnson63 min
Jul 18, 7:15 PM CDTTornado WarningDVNJohnson45 min
Jul 18, 7:25 PM CDTSevere Thunderstorm WarningDVNCedar, Jones65 min
Jul 18, 7:35 PM CDTTornado WarningDVNJones40 min
Jul 18, 7:52 PM CDTSevere Thunderstorm WarningDVNClinton53 min
Jul 18, 8:06 PM CDTSevere Thunderstorm WarningDVNScott39 min
Jul 18, 8:12 PM CDTFlash Flood WarningDVNJackson6 hr

Nearby

Tornado Warnings in Iowa, 2007Every tornado warning in 2007Tornadoes in 2007

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.