Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 44, NWS Quad Cities, IA

October 9, 2018Iowa County, Johnson County, Iowa

NWS Quad Cities, IA issued this tornado warning at Oct 9, 2018, 4:31 PM CDT for Iowa County, Johnson County, Iowa. It was in force for 44 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Oct 9, 2018, 4:31 PM CDT (21:31 UTC)
Expired: Oct 9, 2018, 5:15 PM CDT
In force: 44 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Iowa County, IA, Johnson County, IA

The radar

The Quad Cities radar (KDVN), 113 km from the middle of the area, began a volume at 21:31 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.

The watch it was issued in

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

Issued	Product	Office	Lasted
Oct 9, 1:46 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.5 hours before the alert went out and 119 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: 459 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 1071 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 116 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

425 
WFUS53 KDVN 092131
TORDVN
IAC095-103-092215-
/O.NEW.KDVN.TO.W.0044.181009T2131Z-181009T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
431 PM CDT TUE OCT 9 2018

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  Northwestern Johnson County in east central Iowa...
  Eastern Iowa County in east central Iowa...

* Until 515 PM CDT.
    
* At 431 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Parnell, or 17 miles south of Marengo, moving
  north at 20 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...
  Parnell around 440 PM CDT.
  Williamsburg around 500 PM CDT.
  Conroy around 510 PM CDT.
  Amana around 515 PM CDT.

Other locations impacted by this tornadic thunderstorm include East
Amana, Middle Amana, South Amana, Homestead, West Amana, High Amana,
Iowa County Fairgrounds, Holbrook and Upper South Amana.

This includes Interstate 80 in Iowa between mile markers 218 and 229.
 
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 4152 9192 4153 9200 4186 9210 4186 9173
TIME...MOT...LOC 2131Z 188DEG 16KT 4155 9196 

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

$$

Wolf

3 follow-up statements

930 
WWUS53 KDVN 092146
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
446 PM CDT TUE OCT 9 2018

IAC095-103-092215-
/O.CON.KDVN.TO.W.0044.000000T0000Z-181009T2215Z/
Johnson IA-Iowa IA-
446 PM CDT TUE OCT 9 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 515 PM CDT FOR
NORTHWESTERN JOHNSON AND EASTERN IOWA COUNTIES...
    
At 445 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Parnell, or 14 miles southeast of Marengo, moving
north at 20 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...
  Williamsburg around 500 PM CDT.
  Conroy around 510 PM CDT.
  Amana around 515 PM CDT.

Other locations impacted by this tornadic thunderstorm include East
Amana, Middle Amana, South Amana, Homestead, West Amana, High Amana
and Upper South Amana.

This includes Interstate 80 in Iowa between mile markers 220 and 228.
 
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 4159 9191 4159 9198 4186 9206 4186 9173
TIME...MOT...LOC 2145Z 188DEG 16KT 4162 9195 

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

$$

Wolf

963 
WWUS53 KDVN 092201
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
501 PM CDT TUE OCT 9 2018

IAC095-103-092215-
/O.CON.KDVN.TO.W.0044.000000T0000Z-181009T2215Z/
Johnson IA-Iowa IA-
501 PM CDT TUE OCT 9 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 515 PM CDT FOR
NORTHWESTERN JOHNSON AND NORTHEASTERN IOWA COUNTIES...
    
At 501 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Amana, or 9 miles southeast of Marengo, moving north
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...
  Amana around 510 PM CDT.

Other locations impacted by this tornadic thunderstorm include East
Amana, Middle Amana, Homestead and High Amana.

This includes Interstate 80 in Iowa between mile markers 224 and 227.
 
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 4167 9187 4169 9194 4186 9198 4186 9173
TIME...MOT...LOC 2201Z 191DEG 20KT 4174 9190 

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

$$

Wolf

676 
WWUS53 KDVN 092218
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
518 PM CDT TUE OCT 9 2018

IAC095-103-092225-
/O.EXP.KDVN.TO.W.0044.000000T0000Z-181009T2215Z/
Johnson IA-Iowa IA-
518 PM CDT TUE OCT 9 2018

...THE TORNADO WARNING FOR NORTHWESTERN JOHNSON AND NORTHEASTERN IOWA
COUNTIES HAS EXPIRED...
    
The tornadic thunderstorm which prompted the warning has been 
updated to include Benton and Linn counties. Therefore, the warning 
has been replaced but only includes extreme northeast Iowa and 
extreme northwest Johnson counties in addition to parts of Linn and 
Benton counties.

A Tornado Watch remains in effect until 900 PM CDT for east central
Iowa.

LAT...LON 4167 9187 4169 9194 4186 9198 4186 9173
TIME...MOT...LOC 2215Z 188DEG 16KT 4180 9189 

$$

Wolf

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 8, 7:45 PM CDT	Special Weather Statement	DVN	Benton, Buchanan, Delaware, Linn	90 min
Oct 8, 8:20 PM CDT	Tornado Warning	DVN	Keokuk	29 min
Oct 8, 9:23 PM CDT	Special Weather Statement	DVN	Buchanan, Delaware	82 min
Oct 8, 10:29 PM CDT	Severe Thunderstorm Warning	DVN	Benton, Iowa	46 min
Oct 9, 2:27 AM CDT	Special Weather Statement	DVN	Benton, Buchanan	63 min
Oct 9, 3:42 AM CDT	Flash Flood Watch	DVN	Clinton, Des Moines, Henry, Jackson, Lee, Louisa and 3 more	33 hr
Oct 9, 11:23 AM CDT	River Flood Warning	DVN	Buchanan, Linn	5 days
Oct 9, 11:26 AM CDT	River Flood Warning	DVN	Delaware, Jones	3 days
Oct 9, 12:45 PM CDT	River Flood Warning	DVN	Dubuque, Jackson	6 days
Oct 9, 1:31 PM CDT	River Flood Warning	DVN	Dubuque	16 days
Oct 9, 2:12 PM CDT	Tornado Warning	DVN	Dubuque	48 min
Oct 9, 3:06 PM CDT	Tornado Warning	DVN	Benton, Iowa	39 min
Oct 9, 3:09 PM CDT	Tornado Warning	DVN	Delaware	51 min
Oct 9, 3:38 PM CDT	Tornado Warning	DVN	Benton, Iowa	52 min
Oct 9, 4:03 PM CDT	Tornado Warning	DVN	Iowa, Keokuk, Washington	27 min
Oct 9, 5:14 PM CDT	Tornado Warning	DVN	Benton, Iowa, Johnson, Linn	46 min
Oct 9, 5:51 PM CDT	Tornado Warning	DVN	Linn	24 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.