Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 36, NWS Des Moines, IA

July 19, 2018Jasper County, Marshall County, Polk County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 19, 2018, 2:50 PM CDT for Jasper County, Marshall County, Polk County, Iowa. It was in force for 25 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
Jul 19, 2018, 2:50 PM CDT (19:50 UTC)
Expired
Jul 19, 2018, 3:15 PM CDT
In force
25 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Jasper County, IA, Marshall County, IA, Polk County, IA

The radar

The Des Moines radar (KDMX), 30 km from the middle of the area, began a volume at 19:53 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, 2:58 PM CDTTORNADO3 N Bondurant, IAHIGHWAY 65 AND JUST NORTH OF BONDURANT.
Jul 19, 2:58 PM CDTTORNADO4 Nne Bondurant, IASEVERAL REPORTS OF THIS TORNADO.
Jul 19, 2:58 PM CDTTORNADO4 Nne Bondurant, IAMETEOROLOGIST REPORTS MACHINE SHED DESTROYED WITH PINE TREES/POWER LINES OVER THE ROAD NEAR THIS LOCATION. TIME ESTIMATED.
Jul 19, 3:01 PM CDTTORNADO2 Se Valeria, IAWELL DEFINED CONE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 7.8 hours before the alert went out and 238 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.

176 
WFUS53 KDMX 191950
TORDMX
IAC099-127-153-192015-
/O.NEW.KDMX.TO.W.0036.180719T1950Z-180719T2015Z/

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

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Northeastern Polk County in central Iowa...
  Southwestern Marshall County in central Iowa...
  Northwestern Jasper County in central Iowa...

* Until 315 PM CDT.

* At 250 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Bondurant, or 7 miles north of Altoona, moving
  east at 30 mph.

  HAZARD...Tornado.

  SOURCE...Weather spotters reported funnel cloud.

  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...
  Colfax around 310 PM CDT.

Other locations impacted by this tornadic thunderstorm include Mingo
and Valeria.

This includes Interstate 80 between mile markers 155 and 158.
 
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 4172 9348 4179 9350 4187 9318 4167 9317
TIME...MOT...LOC 1950Z 264DEG 26KT 4176 9343 

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

$$

Martin
2 follow-up statements
657 
WWUS53 KDMX 191957
SVSDMX

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

IAC099-127-153-192015-
/O.CON.KDMX.TO.W.0036.000000T0000Z-180719T2015Z/
Polk IA-Marshall IA-Jasper IA-
257 PM CDT THU JUL 19 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 315 PM CDT FOR
NORTHEASTERN POLK...SOUTHWESTERN MARSHALL AND NORTHWESTERN JASPER
COUNTIES...
        
At 257 PM CDT, a confirmed tornado was located north of Bondurant, 
or 10 miles northeast of Altoona, moving east at 30 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.

This tornado will be near...
  Colfax around 310 PM CDT.

Other locations impacted by this tornadic thunderstorm include Mingo
and Valeria.

This includes Interstate 80 between mile markers 155 and 158.
 
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 4172 9348 4179 9350 4187 9318 4167 9317
TIME...MOT...LOC 1957Z 264DEG 26KT 4177 9336 

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

$$

Martin
301 
WWUS53 KDMX 192001
SVSDMX

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

IAC099-127-153-192015-
/O.CON.KDMX.TO.W.0036.000000T0000Z-180719T2015Z/
Polk IA-Marshall IA-Jasper IA-
301 PM CDT THU JUL 19 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 315 PM CDT FOR
NORTHEASTERN POLK...SOUTHWESTERN MARSHALL AND NORTHWESTERN JASPER
COUNTIES...
        
At 301 PM CDT, a confirmed tornado was located 5 miles northeast of 
Mitchellville, or 12 miles northeast of Altoona, moving east at 30 
mph.

HAZARD...Damaging tornado and half dollar size hail.

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.

This tornado will be near...
  Colfax around 310 PM CDT.

Other locations impacted by this tornadic thunderstorm include Mingo
and Valeria.

This includes Interstate 80 between mile markers 155 and 158.
 
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 4171 9343 4180 9344 4187 9318 4167 9317
TIME...MOT...LOC 2001Z 264DEG 26KT 4177 9332 

TORNADO...OBSERVED
HAIL...1.25IN

$$

Martin

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, 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, 4:37 PM CDTTornado Warning EmergencyTornado observedCatastrophic damage threatDMXMarshall, Tama23 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.