Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 8, NWS Des Moines, IA

May 3, 20184 counties in Iowa

NWS Des Moines, IA issued this tornado warning at May 3, 2018, 7:25 PM CDT for 4 counties in Iowa. It was in force for 35 min. 4 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 3, 2018, 7:25 PM CDT (00:25 UTC)
Expired: May 3, 2018, 8:00 PM CDT
In force: 35 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Jasper County, IA, Marion County, IA, Polk County, IA, Warren County, IA

The radar

The Des Moines radar (KDMX), 40 km from the middle of the area, began a volume at 00:26 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 3, 7:38 PM CDT	TORNADO	3 Ese Hartford, IA	WARREN COUNTY EMA RELAYED CONFIRMED REPORTS OF A TORNADO ON THE GROUND. LOCATION APPROXIMATE.
May 3, 7:42 PM CDT	TORNADO	4 Sw Prairie City, IA	OBSERVED BETWEEN PRAIRIE CITY AND RUNNELS. SPOTTER THOUGHT IT SHOULD MOVE SOUTH OF PRAIRIE CITY.
May 3, 7:45 PM CDT	TORNADO	4 Ne Swan, IA	TREES DOWN IN THE AREA.
May 3, 7:47 PM CDT	TORNADO	5 S Prairie City, IA	SPOTTER RELAYED CONFIRMATION OF TORNADO STILL ON THE GROUND, SUSPECTED MOVING SE.

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 3, 2:57 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.4 hours before the alert went out and 241 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: 1 J/kg
Mixed-layer CIN: -170 J/kg
Mixed-layer LCL: 824 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 101 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

489 
WFUS53 KDMX 040025
TORDMX
IAC099-125-153-181-040100-
/O.NEW.KDMX.TO.W.0008.180504T0025Z-180504T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
725 PM CDT THU MAY 3 2018

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Southeastern Polk County in central Iowa...
  Northwestern Marion County in south central Iowa...
  Southwestern Jasper County in central Iowa...
  Northeastern Warren County in south central Iowa...

* Until 800 PM CDT.

* At 725 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Carlisle, or near Pleasant Hill, moving east 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...
  Prairie City around 755 PM CDT. 

Other locations impacted by this tornadic thunderstorm include
Runnells, Swan and Hartford.

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 4140 9349 4150 9351 4162 9325 4144 9319
TIME...MOT...LOC 0025Z 251DEG 21KT 4149 9344 

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

$$

Donavon

3 follow-up statements

305 
WWUS53 KDMX 040042
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
742 PM CDT THU MAY 3 2018

IAC099-125-153-181-040100-
/O.CON.KDMX.TO.W.0008.000000T0000Z-180504T0100Z/
Polk IA-Marion IA-Jasper IA-Warren IA-
742 PM CDT THU MAY 3 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM CDT FOR
SOUTHEASTERN POLK...NORTHWESTERN MARION...SOUTHWESTERN JASPER AND
NORTHEASTERN WARREN COUNTIES...
        
At 741 PM CDT, a confirmed tornado was located east of Hartford, , 
moving east at 25 mph.

HAZARD...Damaging tornado. 

SOURCE...Trained spotter 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. 


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 4141 9340 4154 9343 4162 9325 4144 9319
TIME...MOT...LOC 0041Z 263DEG 24KT 4145 9330 

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

$$

Donavon

762 
WWUS53 KDMX 040051
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
751 PM CDT THU MAY 3 2018

IAC153-181-040100-
/O.CAN.KDMX.TO.W.0008.000000T0000Z-180504T0100Z/
Polk IA-Warren IA-
751 PM CDT THU MAY 3 2018

...THE TORNADO WARNING FOR SOUTHEASTERN POLK AND NORTHEASTERN WARREN
COUNTIES IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has weakened. 
moved out of the warned area. Therefore, the warning has been 
cancelled.

A severe thunderstorm watch remains in effect until 800 PM CDT for
central and south central Iowa.

LAT...LON 4144 9319 4142 9333 4158 9333 4162 9325
TIME...MOT...LOC 0050Z 251DEG 21KT 4147 9323 

$$

IAC099-125-040100-
/O.CON.KDMX.TO.W.0008.000000T0000Z-180504T0100Z/
Marion IA-Jasper IA-
751 PM CDT THU MAY 3 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM CDT FOR
NORTHWESTERN MARION AND SOUTHWESTERN JASPER COUNTIES...
        
At 750 PM CDT, a confirmed tornado was located east of Runnells, 
moving east at 25 mph.

HAZARD...Damaging tornado. 

SOURCE...Radar 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. 

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 4144 9319 4142 9333 4158 9333 4162 9325
TIME...MOT...LOC 0050Z 251DEG 21KT 4147 9323 

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

$$

Donavon

452 
WWUS53 KDMX 040056
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
756 PM CDT THU MAY 3 2018

IAC099-125-040105-
/O.EXP.KDMX.TO.W.0008.000000T0000Z-180504T0100Z/
Marion IA-Jasper IA-
756 PM CDT THU MAY 3 2018

...THE TORNADO WARNING FOR NORTHWESTERN MARION AND SOUTHWESTERN
JASPER COUNTIES WILL EXPIRE AT 800 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning will be allowed to expire.

A severe thunderstorm watch remains in effect until 900 PM CDT for
central and south central Iowa.

LAT...LON 4144 9319 4142 9333 4158 9333 4162 9325
TIME...MOT...LOC 0055Z 251DEG 21KT 4148 9319 

$$

Donavon

The office that day

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

Issued	Product	Office	Counties	Lasted
May 3, 7:36 PM CDT	Tornado Warning	DMX	Marion, Warren	24 min
May 3, 7:45 PM CDT	Tornado Warning Tornado observed	DMX	Jasper, Marion	30 min
May 3, 7:50 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Story	55 min
May 3, 7:54 PM CDT	Tornado Warning	DMX	Marion	36 min
May 3, 8:23 PM CDT	Severe Thunderstorm Warning	DMX	Grundy, Hardin, Marshall, Tama	52 min
May 3, 8:28 PM CDT	Tornado Warning	DMX	Marshall, Tama	22 min
May 3, 8:48 PM CDT	Severe Thunderstorm Warning	DMX	Poweshiek, Tama	42 min
May 3, 9:11 PM CDT	Special Weather Statement	DMX	Black Hawk	64 min
May 3, 9:26 PM CDT	River Flood Warning	DMX	Black Hawk	6 days
May 3, 9:30 PM CDT	River Flood Watch	DMX	Black Hawk	5 days
May 3, 9:30 PM CDT	River Flood Watch	DMX	Wright	37 hr
May 3, 9:30 PM CDT	River Flood Watch	DMX	Polk	13 hr
May 3, 9:30 PM CDT	River Flood Warning	DMX	Webster	6 days
May 4, 12:33 AM CDT	Special Weather Statement	DMX	Black Hawk, Bremer	27 min
May 4, 10:29 AM CDT	River Flood Warning	DMX	Black Hawk, Bremer, Butler	70 hr
May 4, 10:29 AM CDT	River Flood Warning	DMX	Black Hawk	72 hr
May 4, 10:29 AM CDT	River Flood Warning	DMX	Black Hawk, Bremer, Butler	66 hr

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.