Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 34, NWS Des Moines, IA

June 30, 20184 counties in Iowa

NWS Des Moines, IA issued this tornado warning at Jun 30, 2018, 4:10 PM CDT for 4 counties in Iowa. It was in force for 18 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: Jun 30, 2018, 4:10 PM CDT (21:10 UTC)
Expired: Jun 30, 2018, 4:28 PM CDT
In force: 18 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties Calhoun County, IA, Carroll County, IA, Greene County, IA, Webster County, IA

The radar

The Des Moines radar (KDMX), 90 km from the middle of the area, began a volume at 21:10 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
Jun 30, 1:39 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 9.2 hours before the alert went out and 177 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: 2420 J/kg
Mixed-layer CIN: -83 J/kg
Mixed-layer LCL: 962 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: -36 m²/s²
0-3 km storm-relative helicity: -9 m²/s²
Significant tornado parameter: -0.1
Supercell composite: -0.2

Open this sounding in Storm Lab

The text

As transmitted.

915 
WFUS53 KDMX 302110
TORDMX
IAC025-027-073-187-302145-
/O.NEW.KDMX.TO.W.0034.180630T2110Z-180630T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
410 PM CDT SAT JUN 30 2018

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Northwestern Greene County in west central Iowa...
  Southwestern Webster County in central Iowa...
  Southeastern Calhoun County in west central Iowa...
  Northeastern Carroll County in west central Iowa...

* Until 445 PM CDT.
    
* At 410 PM CDT, a severe thunderstorm capable of producing a tornado
  was located 7 miles southeast of Lake City, or 13 miles south of
  Rockwell City, moving northeast 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 tornadic thunderstorm will remain over mainly rural areas of
  northwestern Greene...southwestern Webster...southeastern Calhoun
  and northeastern Carroll Counties, including the following
  locations... Lohrville and Lanesboro.

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 4214 9464 4222 9473 4234 9458 4221 9438
TIME...MOT...LOC 2110Z 246DEG 16KT 4220 9460 

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

$$

Beerends

2 follow-up statements

120 
WWUS53 KDMX 302121
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
421 PM CDT SAT JUN 30 2018

IAC027-073-187-302131-
/O.CAN.KDMX.TO.W.0034.000000T0000Z-180630T2145Z/
Greene IA-Webster IA-Carroll IA-
421 PM CDT SAT JUN 30 2018

...THE TORNADO WARNING FOR NORTHWESTERN GREENE...SOUTHWESTERN WEBSTER
AND NORTHEASTERN CARROLL COUNTIES 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 900 PM CDT for
west central Iowa.

LAT...LON 4232 9455 4224 9443 4221 9451 4221 9457
      4225 9461
TIME...MOT...LOC 2121Z 239DEG 17KT 4224 9454 

$$

IAC025-302145-
/O.CON.KDMX.TO.W.0034.000000T0000Z-180630T2145Z/
Calhoun IA-
421 PM CDT SAT JUN 30 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM CDT FOR
SOUTHEASTERN CALHOUN COUNTY...
    
At 421 PM CDT, a severe thunderstorm capable of producing a tornado
was located 10 miles east of Lake City, or 12 miles southeast of
Rockwell City, moving northeast 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.

Locations impacted include...
Lohrville.

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 4232 9455 4224 9443 4221 9451 4221 9457
      4225 9461
TIME...MOT...LOC 2121Z 239DEG 17KT 4224 9454 

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

$$

Beerends

839 
WWUS53 KDMX 302128
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
428 PM CDT SAT JUN 30 2018

IAC025-302137-
/O.CAN.KDMX.TO.W.0034.000000T0000Z-180630T2145Z/
Calhoun IA-
428 PM CDT SAT JUN 30 2018

...THE TORNADO WARNING FOR SOUTHEASTERN CALHOUN COUNTY IS
CANCELLED...
    
The tornado threat has diminished and the Tornado Warning has been
cancelled. However, large hail and damaging winds remain likely and a
Severe Thunderstorm Warning remains in effect for the area.  However
small hail, gusty winds and heavy rain are still possible with this
thunderstorm.

A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
west central Iowa.

Remember, a Severe Thunderstorm Warning still remains in effect for
430 pm CDT. 

LAT...LON 4232 9455 4224 9443 4221 9451 4221 9457
      4225 9461
TIME...MOT...LOC 2126Z 246DEG 16KT 4225 9450 

$$

Beerends

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 30, 2:59 AM CDT	Flash Flood Watch	DMX	Adair, Adams, Audubon, Black Hawk, Boone, Calhoun and 31 more	27 hr
Jun 30, 3:12 AM CDT	Heat Advisory	DMX	Appanoose, Black Hawk, Bremer, Butler, Clarke, Dallas and 18 more	16 hr
Jun 30, 10:24 AM CDT	River Flood Watch	DMX	Polk	24 hr
Jun 30, 10:24 AM CDT	River Flood Watch	DMX	Wright	4 days
Jun 30, 10:24 AM CDT	River Flood Watch	DMX	Black Hawk	7 days
Jun 30, 10:24 AM CDT	River Flood Watch	DMX	Polk	16 hr
Jun 30, 10:24 AM CDT	River Flood Watch	DMX	Dallas, Greene	7 days
Jun 30, 12:57 PM CDT	Special Weather Statement	DMX	Palo Alto	63 min
Jun 30, 1:05 PM CDT	Severe Thunderstorm Warning	DMX	Palo Alto, Pocahontas	40 min
Jun 30, 1:38 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt, Kossuth, Palo Alto, Pocahontas	52 min
Jun 30, 1:47 PM CDT	Special Weather Statement	DMX	Hancock, Worth	58 min
Jun 30, 1:54 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Hancock, Winnebago, Worth	51 min
Jun 30, 2:23 PM CDT	Severe Thunderstorm Warning	DMX	Hancock, Humboldt, Kossuth, Wright	52 min
Jun 30, 2:45 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Worth	45 min
Jun 30, 2:55 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Franklin, Hancock, Wright	65 min
Jun 30, 3:56 PM CDT	Severe Thunderstorm Warning	DMX	Butler, Franklin	49 min
Jun 30, 4:05 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Carroll	25 min
Jun 30, 4:06 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Carroll, Greene, Webster	24 min
Jun 30, 4:09 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	38 min
Jun 30, 4:09 PM CDT	Severe Thunderstorm Warning	DMX	Pocahontas	51 min
Jun 30, 4:27 PM CDT	Tornado Warning	DMX	Crawford	18 min
Jun 30, 4:31 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Carroll, Greene	25 min
Jun 30, 4:59 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Greene, Webster	46 min
Jun 30, 5:02 PM CDT	Severe Thunderstorm Warning	DMX	Dallas, Madison, Polk	29 min
Jun 30, 5:06 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth, Winnebago	24 min
Jun 30, 5:43 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Dallas, Greene	23 min
Jun 30, 6:43 PM CDT	Severe Thunderstorm Warning	DMX	Dallas	47 min
Jun 30, 6:47 PM CDT	Severe Thunderstorm Warning	DMX	Marshall, Polk, Story	43 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.