Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 23, NWS Quad Cities, IA

August 28, 2018Clinton County, Scott County, Iowa

NWS Quad Cities, IA issued this tornado warning at Aug 28, 2018, 7:08 PM CDT for Clinton County, Scott County, Iowa. It was in force for 31 min. 2 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: Aug 28, 2018, 7:08 PM CDT (00:08 UTC)
Expired: Aug 28, 2018, 7:39 PM CDT
In force: 31 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Clinton County, IA, Scott County, IA

The radar

The Quad Cities radar (KDVN), 19 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

Time	Report	Where	Remark
Aug 28, 7:10 PM CDT	TORNADO	4 Sse Grand Mound, IA	EF0 TORNADO WITH WINDS OF 80 MPH TOUCHED DOWN ON THE CLINTON AND SCOTT COUNTY LINES. MINOR DAMAGE MAINLY TO TREE BRANCHES WAS OBSERVED. THE TORNADO THEN STRENGTHENED AND CAUSED DAMAGE TO TREES AND HOUSE. TOWARDS THE END OF ITS PATH IT CAUSED MAINLY DAMAGE TO C
Aug 28, 7:42 PM CDT	TSTM WND GST 59	1 Wnw Dewitt, IA	MEASURED AT THE DEWITT RWIS.

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.

Issued	Product	Office	Lasted
Aug 28, 5:06 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.1 hours before the alert went out and 19 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: 1340 J/kg
Mixed-layer CIN: -90 J/kg
Mixed-layer LCL: 1112 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 172 m²/s²
0-3 km storm-relative helicity: 279 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 10.4

Open this sounding in Storm Lab

The text

As transmitted.

883 
WFUS53 KDVN 290008
TORDVN
IAC045-163-290100-
/O.NEW.KDVN.TO.W.0023.180829T0008Z-180829T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
708 PM CDT TUE AUG 28 2018

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  North central Scott County in east central Iowa...
  Central Clinton County in east central Iowa...

* Until 800 PM CDT.
    
* At 708 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Donahue, or 13 miles north of Davenport, moving
  northeast at 25 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Grand Mound around 720 PM CDT.
  DeWitt around 730 PM CDT.
  Welton around 735 PM CDT.

Other locations impacted by this tornadic thunderstorm include Malone
and Clinton County Fairgrounds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4190 9035 4171 9055 4171 9057 4172 9061
      4172 9064 4173 9067 4173 9068 4174 9070
      4174 9072 4200 9058
TIME...MOT...LOC 0008Z 221DEG 23KT 4174 9067 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

McClure

5 follow-up statements

742 
WWUS53 KDVN 290012
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
712 PM CDT TUE AUG 28 2018

IAC045-163-290100-
/O.CON.KDVN.TO.W.0023.000000T0000Z-180829T0100Z/
Scott IA-Clinton IA-
712 PM CDT TUE AUG 28 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM CDT FOR NORTH
CENTRAL SCOTT AND CENTRAL CLINTON COUNTIES...
        
At 711 PM CDT, a confirmed tornado was located near Grand Mound, or
15 miles north of Davenport, moving northeast at 35 mph.

HAZARD...Damaging tornado.

SOURCE...Radar confirmed tornado.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornado will be near...
  Grand Mound around 715 PM CDT.
  DeWitt around 720 PM CDT.
  Welton around 725 PM CDT.

Other locations impacted by this tornadic thunderstorm include Malone
and Clinton County Fairgrounds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4190 9035 4171 9055 4171 9057 4172 9061
      4172 9064 4173 9067 4173 9068 4174 9070
      4174 9072 4200 9058
TIME...MOT...LOC 0011Z 210DEG 31KT 4178 9064 

TORNADO...OBSERVED
HAIL...<.75IN

$$

McClure

301 
WWUS53 KDVN 290019
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
719 PM CDT TUE AUG 28 2018

IAC163-290028-
/O.CAN.KDVN.TO.W.0023.000000T0000Z-180829T0100Z/
Scott IA-
719 PM CDT TUE AUG 28 2018

...THE TORNADO WARNING FOR NORTH CENTRAL SCOTT COUNTY IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for
east central Iowa.

LAT...LON 4190 9035 4179 9047 4179 9069 4200 9058
TIME...MOT...LOC 0018Z 223DEG 45KT 4186 9061 

$$

IAC045-290100-
/O.CON.KDVN.TO.W.0023.000000T0000Z-180829T0100Z/
Clinton IA-
719 PM CDT TUE AUG 28 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM CDT FOR CENTRAL
CLINTON COUNTY...
    
At 718 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Grand Mound, or 14 miles south of Maquoketa, moving
northeast at 50 mph. 

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornadic thunderstorm will remain over mainly rural areas of
central Clinton County, including the following locations... Malone
and Clinton County Fairgrounds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4190 9035 4179 9047 4179 9069 4200 9058
TIME...MOT...LOC 0018Z 223DEG 45KT 4186 9061 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

McClure

071 
WWUS53 KDVN 290025
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
725 PM CDT TUE AUG 28 2018

IAC045-290100-
/O.CON.KDVN.TO.W.0023.000000T0000Z-180829T0100Z/
Clinton IA-
725 PM CDT TUE AUG 28 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM CDT FOR CENTRAL
CLINTON COUNTY...
    
At 725 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Welton, or 12 miles southeast of Maquoketa, moving
northeast at 35 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
DeWitt, Grand Mound, Welton, Malone and Clinton County Fairgrounds. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4190 9035 4179 9047 4179 9069 4200 9058
TIME...MOT...LOC 0025Z 215DEG 29KT 4190 9057 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

McClure

222 
WWUS53 KDVN 290034 CCA
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
734 PM CDT TUE AUG 28 2018

IAC045-290100-
/O.COR.KDVN.TO.W.0023.000000T0000Z-180829T0100Z/
Clinton IA-
734 PM CDT TUE AUG 28 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM CDT FOR CENTRAL
CLINTON COUNTY...
    
At 733 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Charlotte, or 10 miles west of Clinton, moving east
at 50 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
DeWitt, Grand Mound, Welton, Malone and Clinton County Fairgrounds. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4190 9035 4179 9047 4179 9069 4200 9058
TIME...MOT...LOC 0025Z 249DEG 41KT 4190 9057 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

McClure

158 
WWUS53 KDVN 290039
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
739 PM CDT TUE AUG 28 2018

IAC045-290049-
/O.CAN.KDVN.TO.W.0023.000000T0000Z-180829T0100Z/
Clinton IA-
739 PM CDT TUE AUG 28 2018

...THE TORNADO WARNING FOR CENTRAL CLINTON COUNTY IS CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.

A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for
east central Iowa.

LAT...LON 4190 9035 4179 9047 4179 9069 4200 9058
TIME...MOT...LOC 0037Z 249DEG 41KT 4196 9036 

$$

McClure

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 28, 7:00 PM CDT	Severe Thunderstorm Warning	DVN	Clinton, Jackson	60 min
Aug 28, 8:20 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Lee, Van Buren	40 min
Aug 28, 8:26 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Louisa	49 min

Nearby

Tornado Warnings in Iowa, 2018 Every tornado warning in 2018 Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.