Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 48, NWS Des Moines, IA

July 19, 2018Mahaska County, Wapello County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 19, 2018, 4:52 PM CDT for Mahaska County, Wapello County, Iowa. It was in force for 38 min. 2 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, 4:52 PM CDT (21:52 UTC)
Expired
Jul 19, 2018, 5:30 PM CDT
In force
38 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

Counties Mahaska County, IA, Wapello County, IA

The radar

The Des Moines radar (KDMX), 125 km from the middle of the area, began a volume at 21:53 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, 5:12 PM CDTTSTM WND GST 714 Se Kirkville, IA
Jul 19, 5:12 PM CDTTORNADO5 N Ottumwa, IASTATE LAW ENFORCEMENT REPORTED A TORNADO A RAIN-WRAPPED TORNADO NEAR THE OTTUMWA AIRPORT.

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, 9.9 hours before the alert went out and 167 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.

563 
WFUS53 KDMX 192152
TORDMX
IAC123-179-192230-
/O.NEW.KDMX.TO.W.0048.180719T2152Z-180719T2230Z/

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

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Northwestern Wapello County in southeastern Iowa...
  Southeastern Mahaska County in south central Iowa...

* Until 530 PM CDT.
    
* At 451 PM CDT, a severe thunderstorm capable of producing a 
  tornado was located near Oskaloosa, moving southeast at 25 mph.

  HAZARD...Tornado and quarter size hail.

  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...
  Eddyville around 455 PM CDT.
  Ottumwa Industrial Airport around 520 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Chillicothe, Fremont, Kirkville and Oskaloosa 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 4116 9221 4104 9257 4122 9267 4132 9241
      4116 9241
TIME...MOT...LOC 2151Z 313DEG 21KT 4124 9259 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Martin
2 follow-up statements
518 
WWUS53 KDMX 192206
SVSDMX

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

IAC123-179-192230-
/O.CON.KDMX.TO.W.0048.000000T0000Z-180719T2230Z/
Wapello IA-Mahaska IA-
506 PM CDT THU JUL 19 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 530 PM CDT FOR
NORTHWESTERN WAPELLO AND SOUTHEASTERN MAHASKA COUNTIES...
    
At 505 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Kirkville, moving southeast at 30 mph.

HAZARD...Tornado and quarter size hail.

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...
  Ottumwa Industrial Airport around 515 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Chillicothe, Fremont, Kirkville and Oskaloosa 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 4116 9221 4104 9257 4122 9267 4132 9241
      4116 9241
TIME...MOT...LOC 2205Z 308DEG 24KT 4118 9248 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Martin
142 
WWUS53 KDMX 192226
SVSDMX

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

IAC123-179-192235-
/O.EXP.KDMX.TO.W.0048.000000T0000Z-180719T2230Z/
Wapello IA-Mahaska IA-
526 PM CDT THU JUL 19 2018

...THE TORNADO WARNING FOR NORTHWESTERN WAPELLO AND SOUTHEASTERN
MAHASKA COUNTIES WILL EXPIRE AT 530 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

Remember, a Tornado Warning still remains in effect for central and 
eastern Wapello County until 600 PM CDT.

A Tornado Watch remains in effect until 1000 PM CDT for south central
and southeastern Iowa.

LAT...LON 4116 9221 4104 9257 4122 9267 4132 9241
      4116 9241
TIME...MOT...LOC 2225Z 313DEG 21KT 4110 9237 

$$

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