Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 39, NWS Des Moines, IA

July 19, 2018Marshall County, Story County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 19, 2018, 3:22 PM CDT for Marshall County, Story County, Iowa. It was in force for 38 min. 1 report 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, 3:22 PM CDT (20:22 UTC)
Expired
Jul 19, 2018, 4:00 PM CDT
In force
38 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Marshall County, IA, Story County, IA

The radar

The Des Moines radar (KDMX), 63 km from the middle of the area, began a volume at 20:26 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

TimeReportWhereRemark
Jul 19, 3:37 PM CDTTORNADO2 E Collins, IALOCATION APPROXIMATE.

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, 8.4 hours before the alert went out and 211 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.

996 
WFUS53 KDMX 192022
TORDMX
IAC127-169-192100-
/O.NEW.KDMX.TO.W.0039.180719T2022Z-180719T2100Z/

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

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Southeastern Story County in central Iowa...
  Southern Marshall County in central Iowa...

* Until 400 PM CDT.
    
* At 322 PM CDT, a severe thunderstorm capable of producing a tornado
  was located 7 miles northwest of Baxter, or 13 miles southeast of
  Nevada, moving east at 55 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...
  State Center around 330 PM CDT.
  Marshalltown around 345 PM CDT.

Other locations impacted by this tornadic thunderstorm include Le
Grand, Collins, Rhodes, Ferguson, Laurel, Green Mountain, Haverhill
and Melbourne.

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 4186 9292 4186 9332 4198 9336 4213 9277
      4189 9277
TIME...MOT...LOC 2022Z 254DEG 47KT 4191 9324 

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

$$

Donavon
2 follow-up statements
373 
WWUS53 KDMX 192038
SVSDMX

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

IAC127-169-192100-
/O.CON.KDMX.TO.W.0039.000000T0000Z-180719T2100Z/
Story IA-Marshall IA-
338 PM CDT THU JUL 19 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 400 PM CDT FOR
SOUTHEASTERN STORY AND SOUTHERN MARSHALL COUNTIES...
    
At 338 PM CDT, a confirmed tornado was located near Baxter, or 14
miles southeast of Nevada, moving east at 30 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 tornado will be near...
  State Center around 350 PM CDT.

Other locations impacted by this tornadic thunderstorm include Le
Grand, Collins, Rhodes, Ferguson, Laurel, Green Mountain, Haverhill
and Melbourne.

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 4186 9292 4186 9332 4198 9336 4213 9277
      4189 9277
TIME...MOT...LOC 2038Z 254DEG 26KT 4190 9323 

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

$$

Johnson
099 
WWUS53 KDMX 192052
SVSDMX

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

IAC127-169-192102-
/O.EXP.KDMX.TO.W.0039.000000T0000Z-180719T2100Z/
Story IA-Marshall IA-
352 PM CDT THU JUL 19 2018

...THE TORNADO WARNING FOR SOUTHEASTERN STORY AND SOUTHERN MARSHALL
COUNTIES WILL EXPIRE AT 400 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until 1000 PM CDT for central 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 4186 9292 4186 9332 4198 9336 4213 9277
      4189 9277
TIME...MOT...LOC 2052Z 254DEG 47KT 4195 9300 

$$

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, 3:26 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.