Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 12, NWS Des Moines, IA

May 3, 2018Marshall County, Tama County, Iowa

NWS Des Moines, IA issued this tornado warning at May 3, 2018, 8:28 PM CDT for Marshall County, Tama County, Iowa. It was in force for 22 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
May 3, 2018, 8:28 PM CDT (01:28 UTC)
Expired
May 3, 2018, 8:50 PM CDT
In force
22 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Marshall County, IA, Tama County, IA

The radar

The Des Moines radar (KDMX), 90 km from the middle of the area, began a volume at 01:30 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.

IssuedProductOfficeLasted
May 3, 2:57 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.5 hours before the alert went out and 184 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-pSkew-T log-p diagram, Davenport, at 00:00Z on 2018-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2018-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
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.

942 
WFUS53 KDMX 040128
TORDMX
IAC127-171-040215-
/O.NEW.KDMX.TO.W.0012.180504T0128Z-180504T0215Z/

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

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Southeastern Marshall County in central Iowa...
  Southwestern Tama County in central Iowa...

* Until 915 PM CDT.

* At 828 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Marshalltown, moving northeast at 30 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...
  Meskwaki Casino around 855 PM CDT. 
  Toledo and Tama around 900 PM CDT. 

Other locations impacted by this tornadic thunderstorm include
Garwin, Gilman, Le Grand, Ferguson, Toledo Municipal Airport, Laurel,
Montour and Haverhill.

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 4188 9243 4186 9277 4186 9294 4204 9298
      4217 9249
TIME...MOT...LOC 0128Z 242DEG 27KT 4196 9292 

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

$$

Podrazik
2 follow-up statements
958 
WWUS53 KDMX 040148
SVSDMX

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

IAC127-040157-
/O.CAN.KDMX.TO.W.0012.000000T0000Z-180504T0215Z/
Marshall IA-
848 PM CDT THU MAY 3 2018

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

LAT...LON 4188 9243 4186 9277 4210 9277 4214 9263
      4217 9249
TIME...MOT...LOC 0147Z 254DEG 25KT 4201 9275 

$$

IAC171-040215-
/O.CON.KDMX.TO.W.0012.000000T0000Z-180504T0215Z/
Tama IA-
848 PM CDT THU MAY 3 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 915 PM CDT FOR
SOUTHWESTERN TAMA COUNTY...
    
At 847 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Meskwaki Casino, or 8 miles east of Marshalltown,
moving east at 30 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. 

Locations impacted include...
Toledo, Tama, Meskwaki Casino, Le Grand, Garwin, Montour and Toledo
Municipal Airport.

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 4188 9243 4186 9277 4210 9277 4214 9263
      4217 9249
TIME...MOT...LOC 0147Z 254DEG 25KT 4201 9275 

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

$$

Podrazik
238 
WWUS53 KDMX 040150
SVSDMX

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

IAC171-040200-
/O.CAN.KDMX.TO.W.0012.000000T0000Z-180504T0215Z/
Tama IA-
850 PM CDT THU MAY 3 2018

...THE TORNADO WARNING FOR SOUTHWESTERN TAMA COUNTY IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore the warning has been cancelled.  However small hail and
heavy rain are still possible with this thunderstorm.

LAT...LON 4188 9243 4186 9277 4210 9277 4214 9263
      4217 9249
TIME...MOT...LOC 0148Z 242DEG 27KT 4202 9272 

$$

Podrazik

The office that day

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

IssuedProductOfficeCountiesLasted
May 3, 7:25 PM CDTTornado WarningDMXJasper, Marion, Polk, Warren35 min
May 3, 7:36 PM CDTTornado WarningDMXMarion, Warren24 min
May 3, 7:45 PM CDTTornado Warning Tornado observedDMXJasper, Marion30 min
May 3, 7:50 PM CDTSevere Thunderstorm WarningDMXJasper, Marshall, Story55 min
May 3, 7:54 PM CDTTornado WarningDMXMarion36 min
May 3, 8:23 PM CDTSevere Thunderstorm WarningDMXGrundy, Hardin, Marshall, Tama52 min
May 3, 8:48 PM CDTSevere Thunderstorm WarningDMXPoweshiek, Tama42 min
May 3, 9:11 PM CDTSpecial Weather StatementDMXBlack Hawk64 min
May 3, 9:26 PM CDTRiver Flood WarningDMXBlack Hawk6 days
May 3, 9:30 PM CDTRiver Flood WatchDMXBlack Hawk5 days
May 3, 9:30 PM CDTRiver Flood WatchDMXWright37 hr
May 3, 9:30 PM CDTRiver Flood WatchDMXPolk13 hr
May 3, 9:30 PM CDTRiver Flood WarningDMXWebster6 days
May 4, 12:33 AM CDTSpecial Weather StatementDMXBlack Hawk, Bremer27 min
May 4, 10:29 AM CDTRiver Flood WarningDMXBlack Hawk, Bremer, Butler70 hr
May 4, 10:29 AM CDTRiver Flood WarningDMXBlack Hawk72 hr
May 4, 10:29 AM CDTRiver Flood WarningDMXBlack Hawk, Bremer, Butler66 hr

Nearby

Tornado Warnings in Iowa, 2018Every tornado warning in 2018Tornadoes 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.