Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 23, NWS Des Moines, IA

June 20, 2018Grundy County, Hardin County, Iowa

NWS Des Moines, IA issued this tornado warning at Jun 20, 2018, 3:18 PM CDT for Grundy County, Hardin County, Iowa. It was in force for 57 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: Jun 20, 2018, 3:18 PM CDT (20:18 UTC)
Expired: Jun 20, 2018, 4:15 PM CDT
In force: 57 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Observed
Hail: 0.75 in

Counties Grundy County, IA, Hardin County, IA

The radar

The Des Moines radar (KDMX), 90 km from the middle of the area, began a volume at 20:17 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
Jun 20, 3:33 PM CDT	FUNNEL CLOUD	Steamboat Rock, IA	ROTATING WALL CLOUD WITH FUNNEL.

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
Jun 20, 3:04 PM CDT	Tornado Watch	SPC	4 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.3 hours before the alert went out and 225 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: 235 J/kg
Mixed-layer CIN: -52 J/kg
Mixed-layer LCL: 502 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 80 m²/s²
0-3 km storm-relative helicity: 80 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

988 
WFUS53 KDMX 202018
TORDMX
IAC075-083-202115-
/O.NEW.KDMX.TO.W.0023.180620T2018Z-180620T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
318 PM CDT WED JUN 20 2018

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  East central Hardin County in central Iowa...
  West central Grundy County in central Iowa...

* Until 415 PM CDT.

* At 318 PM CDT, a confirmed tornado was located over Eldora, moving
  north at 10 mph.

  HAZARD...Damaging tornado.

  SOURCE...Law enforcement 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 tornadic thunderstorm will remain over mainly rural areas of
  east central Hardin and west central Grundy Counties, including the
  following locations... Pine Lake State Park and Steamboat Rock.

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.

&&

LAT...LON 4229 9301 4230 9311 4246 9309 4247 9297
TIME...MOT...LOC 2018Z 189DEG 8KT 4234 9305 

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

$$

REV

4 follow-up statements

780 
WWUS53 KDMX 202025 RRA
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
325 PM CDT WED JUN 20 2018

IAC075-083-202115-
/O.CON.KDMX.TO.W.0023.000000T0000Z-180620T2115Z/
Hardin IA-Grundy IA-
325 PM CDT WED JUN 20 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 PM CDT FOR EAST
CENTRAL HARDIN AND WEST CENTRAL GRUNDY COUNTIES...
    
At 325 PM CDT, a confirmed tornado was located over Eldora, moving
north at 10 mph.

HAZARD...Damaging tornado.

SOURCE...Law enforcement 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.

Locations impacted include...
Eldora, Steamboat Rock and Pine Lake State Park. 

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.

&&

LAT...LON 4231 9301 4232 9311 4246 9309 4247 9297
TIME...MOT...LOC 2025Z 189DEG 8KT 4235 9305 

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

$$

REV

311 
WWUS53 KDMX 202033
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
333 PM CDT WED JUN 20 2018

IAC075-083-202115-
/O.CON.KDMX.TO.W.0023.000000T0000Z-180620T2115Z/
Hardin IA-Grundy IA-
333 PM CDT WED JUN 20 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 PM CDT FOR EAST
CENTRAL HARDIN AND WEST CENTRAL GRUNDY COUNTIES...
    
At 333 PM CDT, a confirmed tornado was located over Eldora, moving
north at 10 mph.

HAZARD...Damaging tornado.

SOURCE...Law enforcement 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.

Locations impacted include...
Eldora, Steamboat Rock and Pine Lake State Park. 

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.

&&

LAT...LON 4231 9301 4232 9311 4246 9309 4247 9297
TIME...MOT...LOC 2033Z 189DEG 8KT 4237 9305 

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

$$

REV

048 
WWUS53 KDMX 202044
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
344 PM CDT WED JUN 20 2018

IAC075-083-202115-
/O.CON.KDMX.TO.W.0023.000000T0000Z-180620T2115Z/
Hardin IA-Grundy IA-
344 PM CDT WED JUN 20 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 PM CDT FOR EAST
CENTRAL HARDIN AND WEST CENTRAL GRUNDY COUNTIES...
    
A confirmed tornado touched down southeast of Eldora around 330 pm. 
Latest reports at 342 pm indicate that funnel clouds are still being 
reported in the area.  

HAZARD...Damaging tornado.

SOURCE...Law enforcement 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.

Locations impacted include...
Steamboat Rock and Pine Lake State Park. 

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.

&&

LAT...LON 4237 9300 4238 9310 4246 9309 4247 9297
TIME...MOT...LOC 2042Z 189DEG 8KT 4239 9305 

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

$$

REV

256 
WWUS53 KDMX 202113
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
413 PM CDT WED JUN 20 2018

IAC075-083-202122-
/O.EXP.KDMX.TO.W.0023.000000T0000Z-180620T2115Z/
Hardin IA-Grundy IA-
413 PM CDT WED JUN 20 2018

...THE TORNADO WARNING FOR EAST CENTRAL HARDIN AND WEST CENTRAL
GRUNDY COUNTIES WILL EXPIRE AT 415 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until 700 PM CDT for central Iowa.

Remember, an additional Tornado Warning still remains in effect for 
portions of far northeast Hardin County and far northwest Grundy 
County until 430 pm.

LAT...LON 4237 9300 4238 9310 4246 9309 4247 9297
TIME...MOT...LOC 2112Z 189DEG 8KT 4245 9304 

$$

REV

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 19, 8:39 PM CDT	River Flood Warning	DMX	Polk	9 days
Jun 19, 8:39 PM CDT	River Flood Warning	DMX	Polk	8 days
Jun 20, 1:19 AM CDT	Special Weather Statement	DMX	Carroll	56 min
Jun 20, 2:12 AM CDT	Flash Flood Warning	DMX	Calhoun, Webster	5 hr
Jun 20, 2:17 AM CDT	Special Weather Statement	DMX	Boone	58 min
Jun 20, 4:28 AM CDT	Flash Flood Watch	DMX	Adair, Audubon, Boone, Calhoun, Carroll, Cass and 18 more	23 hr
Jun 20, 10:38 AM CDT	River Flood Warning	DMX	Webster	19 days
Jun 20, 10:38 AM CDT	River Flood Warning	DMX	Boone, Hamilton, Webster	3 days
Jun 20, 10:43 AM CDT	River Flood Watch	DMX	Dallas, Polk	6 days
Jun 20, 10:43 AM CDT	River Flood Watch	DMX	Polk	6 days
Jun 20, 10:43 AM CDT	River Flood Watch	DMX	Black Hawk	34 hr
Jun 20, 10:43 AM CDT	River Flood Watch	DMX	Polk, Story	7 hr
Jun 20, 10:43 AM CDT	River Flood Watch	DMX	Jasper, Marion, Polk	10 hr
Jun 20, 10:43 AM CDT	River Flood Watch	DMX	Emmet	6 hr
Jun 20, 10:43 AM CDT	River Flood Watch	DMX	Humboldt	10 hr
Jun 20, 12:49 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Mahaska, Marion	41 min
Jun 20, 2:16 PM CDT	Tornado Warning	DMX	Carroll, Greene	29 min
Jun 20, 2:22 PM CDT	Tornado Warning	DMX	Boone, Dallas, Greene	25 min
Jun 20, 2:26 PM CDT	Special Weather Statement	DMX	Davis, Wapello	49 min
Jun 20, 2:43 PM CDT	Special Weather Statement	DMX	Polk, Story	62 min
Jun 20, 2:43 PM CDT	Tornado Warning	DMX	Webster	47 min
Jun 20, 2:46 PM CDT	Tornado Warning	DMX	Calhoun, Greene	17 min
Jun 20, 3:02 PM CDT	Tornado Warning Tornado observed	DMX	Hardin	11 min
Jun 20, 3:16 PM CDT	Tornado Warning Tornado observed	DMX	Hardin	29 min
Jun 20, 3:21 PM CDT	Tornado Warning	DMX	Humboldt, Kossuth	39 min
Jun 20, 3:24 PM CDT	Tornado Warning	DMX	Webster	37 min
Jun 20, 3:57 PM CDT	Tornado Warning	DMX	Grundy, Hardin	33 min
Jun 20, 4:06 PM CDT	Severe Thunderstorm Warning	DMX	Hancock, Humboldt, Kossuth, Wright	39 min
Jun 20, 4:13 PM CDT	Flash Flood Warning	DMX	Humboldt, Kossuth, Palo Alto, Pocahontas	6 hr
Jun 20, 4:25 PM CDT	Flash Flood Warning	DMX	Humboldt, Kossuth	6 hr
Jun 20, 5:06 PM CDT	River Flood Warning	DMX	Emmet	38 days
Jun 20, 5:20 PM CDT	River Flood Warning	DMX	Polk, Story	3 hr
Jun 20, 5:34 PM CDT	Tornado Warning Tornado observed	DMX	Mahaska, Monroe, Wapello	41 min
Jun 20, 6:05 PM CDT	Severe Thunderstorm Warning	DMX	Davis, Wapello	41 min
Jun 20, 6:45 PM CDT	Severe Thunderstorm Warning	DMX	Story	30 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.