Alert archive / Iowa / Tornado Warnings in 2007

Tornado Warning 20, NWS Quad Cities, IA

July 16, 2007Johnson County, Iowa

NWS Quad Cities, IA issued this tornado warning at Jul 16, 2007, 4:18 PM CDT for Johnson County, Iowa. It was in force for 42 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
Jul 16, 2007, 4:18 PM CDT (21:18 UTC)
Expired
Jul 16, 2007, 5:00 PM CDT
In force
42 min
Issued by
NWS Quad Cities, IA
Area
Counties, with a storm outline in the text

County Johnson County, IA

The radar

The Quad Cities radar (KDVN), 85 km from the middle of the area, began a volume at 21:21 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 16, 4:30 PM CDTHAIL 1.75Coralville, IAHAIL REPORTED AT CORALVILLE MALL

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 16, 3:38 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.3 hours before the alert went out and 92 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 12:00Z on 2007-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2007-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1487 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KDVN 162118
TORDVN
IAC103-162200-
/O.NEW.KDVN.TO.W.0020.070716T2118Z-070716T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
418 PM CDT MON JUL 16 2007

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

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

* UNTIL 500 PM CDT.

* AT 417 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO NEAR TIFFIN...OR ABOUT 8 MILES WEST OF IOWA CITY...MOVING
  SOUTHEAST AT 15 MPH.

* THE TORNADO WILL BE NEAR...
  CORALVILLE AND OAKDALE AROUND 425 PM CDT...
  UNIVERSITY HEIGHTS AROUND 435 PM CDT...
  IOWA CITY AROUND 440 PM CDT...
  HILLS AROUND 445 PM CDT...

THIS INCLUDES INTERSTATE 80 IN IOWA BETWEEN MILE MARKERS 235 AND 252.

THIS INCLUDES INTERSTATE 380 IN IOWA BETWEEN MILE MARKERS 1 AND 6.

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 TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT MONDAY EVENING
FOR EASTERN IOWA.

LAT...LON 4180 9173 4157 9175 4151 9140 4174 9141

$$

SHEETS
3 follow-up statements
000 
WWUS53 KDVN 162128
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
425 PM CDT MON JUL 16 2007

IAC103-162200-
/O.CON.KDVN.TO.W.0020.000000T0000Z-070716T2200Z/
JOHNSON IA-
425 PM CDT MON JUL 16 2007

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 500 PM CDT FOR JOHNSON
COUNTY...

AT 421 PM CDT...DOPPLER RADAR INDICATED A TORNADO APPROXAMATELY NEAR 
COSGROVE...OR ABOUT 8 MILES WEST OF IOWA CITY...MOVING SOUTH AT 15 
MPH.

THE TORNADO WILL BE NEAR...
  SHARON CENTER AROUND 430 PM CDT...

THIS INCLUDES INTERSTATE 80 IN IOWA BETWEEN MILE MARKERS 235 AND 252.

THIS INCLUDES INTERSTATE 380 BETWEEN MILE MARKERS 1 AND 6.

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 TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT MONDAY EVENING
FOR EASTERN IOWA.

IN ADDITION...A SEPARATE SEVERE STORM CAPABLE OF PRODUCING LARGE 
HAIL WAS LOCATED OVER NORTHWEST JOHNSON COUNTY...ABOUT 5 MILES 
NORTHEAST OF AMANAA. SEVERE THUNDERSTORMS OVER THE AREA WILL 
CONTINUE TO PRODUCE VERY HEAVY RAINFALL...RESULTING IN URBAN AND 
SMALL STREAM FLOODING. 

LAT...LON 4180 9173 4157 9175 4151 9140 4174 9141

$$

SHEETS
000 
WWUS53 KDVN 162138
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
435 PM CDT MON JUL 16 2007

IAC103-162200-
/O.CON.KDVN.TO.W.0020.000000T0000Z-070716T2200Z/
JOHNSON IA-
435 PM CDT MON JUL 16 2007

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 500 PM CDT FOR JOHNSON
COUNTY...

AT 435 PM CDT...DOPPLER RADAR CONTINUED TO INDICATE A POSSIBLE  
TORNADO NEAR SHARON CENTER...OR ABOUT 7 MILES SOUTHWEST OF IOWA 
CITY...MOVING SOUTHEAST AT 15 MPH. ALSO...AT 430 PM A TRAINED 
SPOTTER REPORTED GOLF BALL SIZED HAIL AT THE CORALVILLE MALL. THIS 
STORM HAS THE POTENTIAL TO PRODUCE VERY LARGE HAIL AND TORRENTIAL 
RAINFALL AS IT MOVES THROUGH THE CITIES OF IOWA CITY AND CORALVILLE 
THROUGH 5 PM.  

THE TORNADO WILL BE NEAR...
  HILLS AROUND 450 PM CDT...

THIS INCLUDES INTERSTATE 80 IN IOWA BETWEEN MILE MARKERS 235 AND 252.

THIS INCLUDES INTERSTATE 380 BETWEEN MILE MARKERS 1 AND 6.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT MONDAY EVENING
FOR EASTERN IOWA.

LAT...LON 4180 9173 4157 9175 4151 9140 4174 9141

$$

SHEETS
000 
WWUS53 KDVN 162159
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
458 PM CDT MON JUL 16 2007

IAC103-162208-
/O.EXP.KDVN.TO.W.0020.000000T0000Z-070716T2200Z/
JOHNSON IA-
458 PM CDT MON JUL 16 2007

...THE TORNADO WARNING FOR JOHNSON COUNTY EXPIRES AT 500 PM CDT...

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

HOWEVER...THIS STORM IS STILL CAPABLE OF PRODUCING TORRENTIAL 
RAINFALL AND A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM 
CDT FOR ALL OF JOHNSON COUNTY. 

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT MONDAY EVENING
FOR EASTERN IOWA.

LAT...LON 4180 9173 4157 9175 4151 9140 4174 9141

$$

SHEETS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 3:27 PM CDTSevere Thunderstorm WarningDVNLinn48 min
Jul 16, 3:39 PM CDTSevere Thunderstorm WarningDVNJohnson51 min
Jul 16, 4:44 PM CDTFlash Flood WarningDVNJohnson6 hr
Jul 16, 4:49 PM CDTSevere Thunderstorm WarningDVNWashington56 min
Jul 16, 5:08 PM CDTSevere Thunderstorm WarningDVNJohnson40 min
Jul 16, 5:36 PM CDTTornado WarningDVNWashington39 min
Jul 16, 5:40 PM CDTFlash Flood WarningDVNWashington6 hr
Jul 16, 6:04 PM CDTSevere Thunderstorm WarningDVNHenry56 min
Jul 16, 6:13 PM CDTSevere Thunderstorm WarningDVNJefferson, Keokuk62 min
Jul 16, 6:26 PM CDTTornado WarningDVNJefferson49 min
Jul 16, 6:51 PM CDTSevere Thunderstorm WarningDVNBenton, Linn54 min
Jul 16, 6:58 PM CDTFlash Flood WatchDVNBenton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more59 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.