Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 47, NWS Des Moines, IA

July 19, 2018Marshall County, Tama County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 19, 2018, 4:37 PM CDT for Marshall County, Tama County, Iowa. It was in force for 23 min. 3 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
Jul 19, 2018, 4:37 PM CDT (21:37 UTC)
Expired
Jul 19, 2018, 5:00 PM CDT
In force
23 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Emergency
Tornado emergency
Tornado
Observed
Damage threat
Catastrophic
Hail
1.0 in

Counties Marshall County, IA, Tama County, IA

The radar

The Des Moines radar (KDMX), 85 km from the middle of the area, began a volume at 21:41 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

TimeReportWhereRemark
Jul 19, 4:50 PM CDTTORNADOMarshalltown, IAMARSHALLTOWN COURTHOUSE LOST CLOCK TOWER. TREES DOWN ALL OVER TOWN.
Jul 19, 4:52 PM CDTTORNADOLe Grand, IA
Jul 19, 4:55 PM CDTTORNADO2 Nw Marshalltown, IAREPORTS OF CATASTROPHIC DAMAGE, INCLUDING VEHICLES MISSING, VEHICLES OVERTURNED, TOPS OF BUILDINGS GONE, TREES DOWN, POWER LINES, GAS LINES, ETC...

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.

IssuedProductOfficeLasted
Jul 19, 3:11 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.6 hours before the alert went out and 190 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 12:00Z on 2018-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2018-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1807 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
-21 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

041 
WFUS53 KDMX 192137
TORDMX
IAC127-171-192200-
/O.NEW.KDMX.TO.W.0047.180719T2137Z-180719T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
437 PM CDT THU JUL 19 2018

...TORNADO EMERGENCY FOR MARSHALLTOWN...

The National Weather Service in Des Moines  has issued a

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

* Until 500 PM CDT.

* At 437 PM CDT, a confirmed large and destructive tornado was
  observed over Marshalltown, moving east at 25 mph.

  TORNADO EMERGENCY for Marshalltown. This is a   PARTICULARLY 
DANGEROUS SITUATION. TAKE COVER NOW!

  HAZARD...Deadly tornado.

  SOURCE...Law enforcement confirmed tornado.

  IMPACT...You are in a life-threatening situation. Flying debris 
           may be deadly to those caught without shelter. Mobile 
           homes will be destroyed. Considerable damage to homes, 
           businesses, and vehicles is likely and complete 
           destruction is possible.

* The tornado will be near...
  Meskwaki Casino around 500 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Garwin, Gilman, Le Grand, Ferguson, Green Mountain, Montour,
Marshalltown Municipal Airport, Toledo Municipal Airport and Albion.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a large, extremely dangerous and potentially deadly
tornado is on the ground. To protect your life, TAKE COVER NOW! Move
to an interior room on the lowest floor of a sturdy building. Avoid
windows. If in a mobile home, a vehicle or outdoors.. Move to the
closest substantial shelter and protect yourself from flying debris.

&&

LAT...LON 4186 9261 4186 9276 4199 9305 4215 9296
      4207 9251
TIME...MOT...LOC 2137Z 291DEG 21KT 4205 9292 

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...CATASTROPHIC
HAIL...1.00IN

$$

Johnson
1 follow-up statement
700 
WWUS53 KDMX 192146 RRA
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
446 PM CDT THU JUL 19 2018

IAC127-171-192200-
/O.CON.KDMX.TO.W.0047.000000T0000Z-180719T2200Z/
Marshall IA-Tama IA-
446 PM CDT THU JUL 19 2018

...TORNADO EMERGENCY FOR MARSHALLTOWN!...

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 500 PM CDT FOR EASTERN
MARSHALL AND SOUTHWESTERN TAMA COUNTIES...
    
At 446 PM CDT, a confirmed large and destructive tornado was located
over Marshalltown, moving east at 20 mph.

TORNADO EMERGENCY for Marshalltown. This is a PARTICULARLY DANGEROUS 
SITUATION. TAKE COVER NOW!

HAZARD...Deadly tornado.

SOURCE...Law enforcement confirmed tornado.

IMPACT...You are in a life-threatening situation. Flying debris may 
         be deadly to those caught without shelter. Mobile homes 
         will be destroyed. Considerable damage to homes, 
         businesses, and vehicles is likely and complete destruction 
         is possible.

The tornado will be near...
  Meskwaki Casino around 500 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Garwin, Gilman, Le Grand, Ferguson, Green Mountain, Montour,
Marshalltown Municipal Airport, Toledo Municipal Airport and Albion.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a large, extremely dangerous, and potentially deadly
tornado is on the ground. To protect your life, TAKE COVER NOW! Move
to an interior room on the lowest floor of a sturdy building. Avoid
windows. If in a mobile home, a vehicle or outdoors, move to the
closest substantial shelter and protect yourself from flying debris.

&&

LAT...LON 4186 9261 4186 9276 4199 9305 4215 9296
      4207 9251
TIME...MOT...LOC 2146Z 291DEG 17KT 4204 9285 

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...CATASTROPHIC
HAIL...1.00IN

$$

Johnson

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 3:14 AM CDTSpecial Weather StatementDMXMahaska61 min
Jul 19, 12:17 PM CDTSpecial Weather StatementDMXEmmet, Humboldt, Kossuth58 min
Jul 19, 2:41 PM CDTSpecial Weather StatementDMXFranklin, Hamilton, Hardin, Wright64 min
Jul 19, 2:50 PM CDTTornado WarningDMXJasper, Marshall, Polk25 min
Jul 19, 3:05 PM CDTTornado WarningDMXFranklin, Hamilton, Hardin, Wright40 min
Jul 19, 3:11 PM CDTTornado WarningDMXJasper34 min
Jul 19, 3:22 PM CDTTornado WarningDMXMarshall, Story38 min
Jul 19, 3:26 PM CDTTornado WarningDMXHamilton, Hardin, Marshall, Story34 min
Jul 19, 3:37 PM CDTTornado Warning Tornado observedDMXJasper, Mahaska, Marion23 min
Jul 19, 3:40 PM CDTTornado WarningDMXFranklin, Hardin35 min
Jul 19, 3:54 PM CDTTornado WarningDMXGrundy, Hardin, Marshall, Story51 min
Jul 19, 3:54 PM CDTTornado Warning Tornado observedDMXJasper, Mahaska, Marion36 min
Jul 19, 4:14 PM CDTTornado Warning Tornado observedDMXMahaska, Marion31 min
Jul 19, 4:18 PM CDTSevere Thunderstorm WarningDMXMahaska42 min
Jul 19, 4:36 PM CDTTornado WarningDMXMahaska, Wapello24 min
Jul 19, 4:52 PM CDTTornado WarningDMXMahaska, Wapello38 min
Jul 19, 4:52 PM CDTTornado Warning Tornado observedDMXMarshall, Poweshiek, Tama38 min
Jul 19, 5:12 PM CDTTornado WarningDMXPoweshiek, Tama18 min
Jul 19, 5:13 PM CDTTornado Warning Tornado observedDMXDavis, Mahaska, Wapello47 min
Jul 19, 5:55 PM CDTSevere Thunderstorm WarningDMXDavis, Wapello20 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.