Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 4, NWS Quad Cities, IA

May 2, 2018Johnson County, Washington County, Iowa

NWS Quad Cities, IA issued this tornado warning at May 2, 2018, 7:24 PM CDT for Johnson County, Washington County, Iowa. It was in force for 51 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: May 2, 2018, 7:24 PM CDT (00:24 UTC)
Expired: May 2, 2018, 8:15 PM CDT
In force: 51 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties Johnson County, IA, Washington County, IA

The radar

The Quad Cities radar (KDVN), 99 km from the middle of the area, began a volume at 00:25 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
May 2, 7:24 PM CDT	HAIL 1	1 Nw Williamstown, IA
May 2, 8:19 PM CDT	HAIL 0.25	Sw Kalona, 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.

Issued	Product	Office	Lasted
May 2, 3:56 PM CDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.4 hours before the alert went out and 106 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: 1023 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 1402 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 69 m²/s²
0-3 km storm-relative helicity: 184 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 5.1

Open this sounding in Storm Lab

The text

As transmitted.

572 
WFUS53 KDVN 030024
TORDVN
IAC103-183-030115-
/O.NEW.KDVN.TO.W.0004.180503T0024Z-180503T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
724 PM CDT WED MAY 2 2018

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  Southwestern Johnson County in east central Iowa...
  Northeastern Washington County in southeastern Iowa...

* Until 815 PM CDT
    
* At 724 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Wellman, or 16 miles northwest of Washington,
  moving east at 15 mph.

  HAZARD...Tornado and quarter size hail. 

  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...
  Kalona around 745 PM CDT. 
  Riverside and Hills around 815 PM CDT. 

Other locations impacted by this tornadic thunderstorm include Amish,
Sharon Center and Frytown.

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.

&&

LAT...LON 4151 9183 4158 9183 4159 9182 4164 9160
      4149 9149 4147 9188 4151 9190
TIME...MOT...LOC 0024Z 260DEG 14KT 4152 9183 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

ERVIN

5 follow-up statements

773 
WWUS53 KDVN 030028
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
728 PM CDT WED MAY 2 2018

IAC103-183-030115-
/O.CON.KDVN.TO.W.0004.000000T0000Z-180503T0115Z/
Johnson IA-Washington IA-
728 PM CDT WED MAY 2 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR
SOUTHWESTERN JOHNSON AND NORTHEASTERN WASHINGTON COUNTIES...
    
At 728 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Wellman, or 16 miles north of Washington, moving
east at 15 mph.

HAZARD...Tornado and quarter size hail. 

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...
  Kalona around 745 PM CDT. 
  Riverside and Hills around 815 PM CDT. 

Other locations impacted by this tornadic thunderstorm include Amish,
Sharon Center and Frytown.

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.

&&

LAT...LON 4158 9183 4159 9182 4164 9160 4149 9149
      4148 9182 4149 9183
TIME...MOT...LOC 0028Z 260DEG 14KT 4152 9181 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

ERVIN

385 
WWUS53 KDVN 030033
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
733 PM CDT WED MAY 2 2018

IAC103-183-030115-
/O.CON.KDVN.TO.W.0004.000000T0000Z-180503T0115Z/
Johnson IA-Washington IA-
733 PM CDT WED MAY 2 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR
SOUTHWESTERN JOHNSON AND NORTHEASTERN WASHINGTON COUNTIES...
    
At 733 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Wellman, or 15 miles north of Washington, moving
east at 15 mph.

HAZARD...Tornado and quarter size hail. 

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...
  Kalona around 750 PM CDT. 
  Riverside and Hills around 815 PM CDT. 

Other locations impacted by this tornadic thunderstorm include Amish,
Sharon Center and Frytown.

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.

&&

LAT...LON 4153 9183 4155 9179 4164 9160 4149 9149
      4148 9182 4149 9183
TIME...MOT...LOC 0033Z 263DEG 13KT 4151 9180 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

ERVIN

503 
WWUS53 KDVN 030038
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
738 PM CDT WED MAY 2 2018

IAC103-183-030115-
/O.CON.KDVN.TO.W.0004.000000T0000Z-180503T0115Z/
Johnson IA-Washington IA-
738 PM CDT WED MAY 2 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR
SOUTHWESTERN JOHNSON AND NORTHEASTERN WASHINGTON COUNTIES...
    
At 737 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Kalona, or 13 miles southwest of Iowa City, moving
east at 20 mph.

HAZARD...Tornado and quarter size hail. 

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...
  Riverside around 805 PM CDT. 
  Hills around 810 PM CDT. 

Other locations impacted by this tornadic thunderstorm include Amish,
Sharon Center and Frytown.

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.

&&

LAT...LON 4153 9183 4155 9179 4164 9160 4149 9149
      4148 9182 4149 9183
TIME...MOT...LOC 0037Z 261DEG 17KT 4153 9173 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

ERVIN

361 
WWUS53 KDVN 030044
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
744 PM CDT WED MAY 2 2018

IAC183-030053-
/O.CAN.KDVN.TO.W.0004.000000T0000Z-180503T0115Z/
Washington IA-
744 PM CDT WED MAY 2 2018

...THE TORNADO WARNING FOR NORTHEASTERN WASHINGTON 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
southeastern and east central Iowa.

LAT...LON 4164 9160 4149 9149 4149 9151 4150 9151
      4150 9152 4151 9153 4151 9178 4153 9179
      4155 9179
TIME...MOT...LOC 0043Z 250DEG 17KT 4156 9170 

$$

IAC103-030115-
/O.CON.KDVN.TO.W.0004.000000T0000Z-180503T0115Z/
Johnson IA-
744 PM CDT WED MAY 2 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR
SOUTHWESTERN JOHNSON COUNTY...
    
At 743 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Kalona, or 10 miles southwest of Iowa City, moving
east at 20 mph.

HAZARD...Tornado and quarter size hail. 

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...
  Hills around 810 PM CDT. 

Other locations impacted by this tornadic thunderstorm include Amish,
Sharon Center and Frytown.

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.

&&

LAT...LON 4164 9160 4149 9149 4149 9151 4150 9151
      4150 9152 4151 9153 4151 9178 4153 9179
      4155 9179
TIME...MOT...LOC 0043Z 250DEG 17KT 4156 9170 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

ERVIN

538 
WWUS53 KDVN 030108
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
808 PM CDT WED MAY 2 2018

IAC103-030118-
/O.EXP.KDVN.TO.W.0004.000000T0000Z-180503T0115Z/
Johnson IA-
808 PM CDT WED MAY 2 2018

...THE TORNADO WARNING FOR SOUTHWESTERN JOHNSON COUNTY WILL EXPIRE AT
815 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However hail
and gusty winds are still possible with this thunderstorm.

A severe thunderstorm watch remains in effect until 1100 PM CDT for
southeastern and east central Iowa.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
the Quad Cities.

Remember, a Severe Thunderstorm Warning still remains in effect for
Johnson County.

LAT...LON 4164 9160 4149 9149 4149 9151 4150 9151
      4150 9152 4151 9153 4151 9178 4153 9179
      4155 9179
TIME...MOT...LOC 0108Z 260DEG 14KT 4158 9158 

$$

ERVIN

The office that day

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

Issued	Product	Office	Counties	Lasted
May 2, 7:18 PM CDT	Severe Thunderstorm Warning	DVN	Iowa, Johnson, Washington	57 min
May 2, 7:51 PM CDT	Severe Thunderstorm Warning	DVN	Scott	39 min
May 2, 7:51 PM CDT	Tornado Warning	DVN	Cedar, Johnson, Muscatine	20 min
May 2, 7:58 PM CDT	Severe Thunderstorm Warning	DVN	Keokuk, Washington	29 min
May 2, 8:07 PM CDT	Severe Thunderstorm Warning	DVN	Cedar, Johnson, Muscatine	53 min
May 2, 8:19 PM CDT	Severe Thunderstorm Warning	DVN	Delaware, Dubuque	36 min
May 2, 8:34 PM CDT	Severe Thunderstorm Warning	DVN	Cedar, Clinton, Scott	27 min
May 2, 9:51 PM CDT	Special Weather Statement	DVN	Scott	24 min
May 2, 10:18 PM CDT	Special Weather Statement	DVN	Scott	87 min
May 2, 11:40 PM CDT	Special Weather Statement	DVN	Lee, Van Buren	50 min
May 3, 10:39 AM CDT	River Flood Warning	DVN	Clinton, Scott	24 hr
May 3, 11:15 AM CDT	River Flood Watch	DVN	Jackson	11 hr
May 3, 11:15 AM CDT	River Flood Watch	DVN	Lee	7 days
May 3, 2:51 PM CDT	Special Weather Statement	DVN	Buchanan	39 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.