Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 27, NWS Des Moines, IA

June 20, 2018Mahaska County, Monroe County, Wapello County, Iowa

NWS Des Moines, IA issued this tornado warning at Jun 20, 2018, 5:34 PM CDT for Mahaska County, Monroe County, Wapello County, Iowa. It was in force for 41 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 20, 2018, 5:34 PM CDT (22:34 UTC)
Expired: Jun 20, 2018, 6:15 PM CDT
In force: 41 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Observed
Hail: 0.75 in

Counties Mahaska County, IA, Monroe County, IA, Wapello County, IA

The radar

The Des Moines radar (KDMX), 119 km from the middle of the area, began a volume at 22:35 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 20, 3:04 PM CDT	Tornado Watch	SPC	4 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 10.6 hours before the alert went out and 172 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.

520 
WFUS53 KDMX 202234
TORDMX
IAC123-135-179-202315-
/O.NEW.KDMX.TO.W.0027.180620T2234Z-180620T2315Z/

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

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Northeastern Monroe County in south central Iowa...
  Northwestern Wapello County in southeastern Iowa...
  Southeastern Mahaska County in south central Iowa...

* Until 615 PM CDT.

* At 533 PM CDT, a confirmed tornado was located between Chillicothe 
  and Eddyville, or 10 miles southeast of Oskaloosa, moving 
  northeast at 20 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
  northeastern Monroe...northwestern Wapello and southeastern Mahaska
  Counties, including the following locations... Chillicothe, Rose
  Hill, Fremont, Kirkville, Oskaloosa Municipal Airport and Lake
  Keomah 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.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Des Moines .

&&

LAT...LON 4105 9253 4115 9265 4141 9243 4140 9241
      4116 9241 4116 9239
TIME...MOT...LOC 2233Z 212DEG 19KT 4117 9252 

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

$$

REV

3 follow-up statements

654 
WWUS53 KDMX 202253
SVSDMX

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

IAC135-202302-
/O.CAN.KDMX.TO.W.0027.000000T0000Z-180620T2315Z/
Monroe IA-
553 PM CDT WED JUN 20 2018

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

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

LAT...LON 4105 9253 4123 9258 4141 9243 4140 9241
      4116 9241 4116 9239
TIME...MOT...LOC 2252Z 212DEG 19KT 4126 9245 

$$

IAC123-179-202315-
/O.CON.KDMX.TO.W.0027.000000T0000Z-180620T2315Z/
Wapello IA-Mahaska IA-
553 PM CDT WED JUN 20 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR
NORTHWESTERN WAPELLO AND SOUTHEASTERN MAHASKA COUNTIES...
    
At 552 PM CDT, a tornado was located 7 miles southwest of Delta, or 
10 miles east of Oskaloosa, moving northeast at 20 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...
Ottumwa Industrial Airport, Fremont, Rose Hill, Kirkville,
Chillicothe, Oskaloosa Municipal Airport and Lake Keomah 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.

If a tornado or other severe weather is spotted, report it to the
National Weather Service or your local nearest law enforcement agency
who will send your report. This act may save lives of others in the
path of dangerous weather.

&&

LAT...LON 4105 9253 4123 9258 4141 9243 4140 9241
      4116 9241 4116 9239
TIME...MOT...LOC 2252Z 212DEG 19KT 4126 9245 

TORNADO...OBSERVED
HAIL...0.00IN

$$

REV

243 
WWUS53 KDMX 202307
SVSDMX

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

IAC123-179-202315-
/O.CON.KDMX.TO.W.0027.000000T0000Z-180620T2315Z/
Wapello IA-Mahaska IA-
607 PM CDT WED JUN 20 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR NORTH
CENTRAL WAPELLO AND SOUTHEASTERN MAHASKA COUNTIES...
    
At 607 PM CDT, a confirmed tornado was located near Delta, or 9 miles
west of Sigourney, moving northeast at 20 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...
Fremont, Kirkville and Oskaloosa Municipal Airport. 

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.

If a tornado or other severe weather is spotted, report it to the
National Weather Service or your local nearest law enforcement agency
who will send your report. This act may save lives of others in the
path of dangerous weather.

&&

LAT...LON 4113 9250 4123 9251 4133 9241 4116 9241
      4116 9239
TIME...MOT...LOC 2307Z 212DEG 19KT 4133 9239 

TORNADO...OBSERVED
HAIL...0.00IN

$$

REV

261 
WWUS53 KDMX 202312
SVSDMX

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

IAC123-179-202322-
/O.EXP.KDMX.TO.W.0027.000000T0000Z-180620T2315Z/
Wapello IA-Mahaska IA-
612 PM CDT WED JUN 20 2018

...THE TORNADO WARNING FOR NORTH CENTRAL WAPELLO AND SOUTHEASTERN
MAHASKA COUNTIES WILL EXPIRE AT 615 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.  However heavy rain
is still possible with this thunderstorm.

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

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

LAT...LON 4113 9250 4123 9251 4133 9241 4116 9241
      4116 9239
TIME...MOT...LOC 2312Z 212DEG 19KT 4135 9237 

$$

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, 3:18 PM CDT	Tornado Warning Tornado observed	DMX	Grundy, Hardin	57 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, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.