Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 41, NWS Des Moines, IA

July 19, 2018Jasper County, Mahaska County, Marion County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 19, 2018, 3:37 PM CDT for Jasper County, Mahaska County, Marion County, Iowa. It was in force for 23 min. 5 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, 3:37 PM CDT (20:37 UTC)
Expired
Jul 19, 2018, 4:00 PM CDT
In force
23 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Tornado
Observed
Hail
0.75 in

Counties Jasper County, IA, Mahaska County, IA, Marion County, IA

The radar

The Des Moines radar (KDMX), 57 km from the middle of the area, began a volume at 20:38 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, 3:39 PM CDTTORNADO3 W Reasnor, IAVIA SOCIAL MEDIA.
Jul 19, 3:51 PM CDTTORNADO3 E Monroe, IALOCATION ESTIMATED BY RADAR.
Jul 19, 3:51 PM CDTTORNADOMonroe, IANEAR HIGHWAY 163 AND MILE MARKER 25.
Jul 19, 4:03 PM CDTFUNNEL CLOUD4 Ese Monroe, IANEAR OTLEY.
Jul 19, 4:09 PM CDTFUNNEL CLOUD4 Nnw Pella, IACONE TORNADO - VIA SOCIAL MEDIA.

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, 8.6 hours before the alert went out and 214 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.

339 
WFUS53 KDMX 192037
TORDMX
IAC099-123-125-192100-
/O.NEW.KDMX.TO.W.0041.180719T2037Z-180719T2100Z/

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

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Northeastern Marion County in south central Iowa...
  Northwestern Mahaska County in south central Iowa...
  Southern Jasper County in central Iowa...

* Until 400 PM CDT.

* At 336 PM CDT, a confirmed tornado was located near Prairie City,
  or 7 miles southwest of Newton, moving southeast at 20 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.

* The tornado will be near...
  Monroe around 350 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Reasnor, Sully and Prairie City Krohn Airport.

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 4156 9325 4166 9319 4166 9277 4144 9288
TIME...MOT...LOC 2036Z 297DEG 18KT 4161 9314 

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

$$

Martin
2 follow-up statements
102 
WWUS53 KDMX 192044 RRA
SVSDMX

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

IAC099-123-125-192100-
/O.CON.KDMX.TO.W.0041.000000T0000Z-180719T2100Z/
Marion IA-Mahaska IA-Jasper IA-
344 PM CDT THU JUL 19 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 400 PM CDT FOR
NORTHEASTERN MARION...NORTHWESTERN MAHASKA AND SOUTHEASTERN JASPER
COUNTIES...
    
At 343 PM CDT, a confirmed tornado was located 3 miles west of 
Reasnor, or 9 miles south of Newton, moving southeast at 25 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 tornadic thunderstorm will remain over mainly rural areas of
northeastern Marion...northwestern Mahaska and southeastern Jasper
Counties, including the following locations... Reasnor and Sully.

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 4153 9315 4166 9308 4166 9277 4144 9288
TIME...MOT...LOC 2043Z 309DEG 24KT 4156 9308 

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

$$

Martin
538 
WWUS53 KDMX 192051
SVSDMX

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

IAC099-123-125-192100-
/O.CON.KDMX.TO.W.0041.000000T0000Z-180719T2100Z/
Marion IA-Mahaska IA-Jasper IA-
351 PM CDT THU JUL 19 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 400 PM CDT FOR
NORTHEASTERN MARION...NORTHWESTERN MAHASKA AND SOUTHEASTERN JASPER
COUNTIES...
        
At 350 PM CDT, a confirmed tornado was located 2 miles east of 
Monroe, or 9 miles northwest of Pella, moving southeast at 25 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 tornadic thunderstorm will remain over mainly rural areas of
northeastern Marion...northwestern Mahaska and southeastern Jasper
Counties.

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 4151 9309 4157 9307 4156 9282 4144 9288
TIME...MOT...LOC 2050Z 310DEG 22KT 4151 9303 

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

$$

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, 3:40 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.