Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 38, NWS Des Moines, IA

July 19, 2018Jasper County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 19, 2018, 3:11 PM CDT for Jasper County, Iowa. It was in force for 34 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, 3:11 PM CDT (20:11 UTC)
Expired
Jul 19, 2018, 3:45 PM CDT
In force
34 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.25 in

County Jasper County, IA

The radar

The Des Moines radar (KDMX), 40 km from the middle of the area, began a volume at 20:13 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, 3:31 PM CDTFUNNEL CLOUD3 N Prairie City, IAEAST OF HWY 117 AND S 60TH ST.

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, 8.2 hours before the alert went out and 228 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.

776 
WFUS53 KDMX 192011
TORDMX
IAC099-192045-
/O.NEW.KDMX.TO.W.0038.180719T2011Z-180719T2045Z/

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

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Northwestern Jasper County in central Iowa...

* Until 345 PM CDT.
    
* At 311 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Colfax, or 10 miles east of Altoona, moving east
  at 15 mph.

  HAZARD...Tornado and half dollar 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...
  Colfax around 320 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Prairie City Krohn Airport and Valeria.

This includes Interstate 80 between mile markers 150 and 163.
 
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 4161 9334 4174 9334 4179 9310 4160 9309
TIME...MOT...LOC 2011Z 278DEG 15KT 4170 9328 

TORNADO...RADAR INDICATED
HAIL...1.25IN

$$

Martin
3 follow-up statements
694 
WWUS53 KDMX 192022
SVSDMX

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

IAC099-192045-
/O.CON.KDMX.TO.W.0038.000000T0000Z-180719T2045Z/
Jasper IA-
322 PM CDT THU JUL 19 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 345 PM CDT FOR
NORTHWESTERN JASPER COUNTY...
    
At 322 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Colfax, or 9 miles west of Newton, moving east at 15
mph.

HAZARD...Tornado and half dollar 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 tornadic thunderstorm will remain over mainly rural areas of
northwestern Jasper County, including the following locations...
Prairie City Krohn Airport and Valeria.

This includes Interstate 80 between mile markers 150 and 163.
 
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 4164 9334 4174 9334 4179 9310 4160 9309
TIME...MOT...LOC 2022Z 278DEG 15KT 4169 9322 

TORNADO...RADAR INDICATED
HAIL...1.25IN

$$

Martin
000 
WWUS53 KDMX 192030
SVSDMX

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

IAC099-192045-
/O.CON.KDMX.TO.W.0038.000000T0000Z-180719T2045Z/
Jasper IA-
330 PM CDT THU JUL 19 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 345 PM CDT FOR
NORTHWESTERN JASPER COUNTY...
        
At 329 PM CDT, a confirmed tornado was located 4 miles south 
of Colfax, or 9 miles west of Newton, moving east at 20 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.

Locations impacted include...
Colfax and Prairie City Krohn Airport. 

This includes Interstate 80 between mile markers 154 and 163.
 
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 4163 9330 4173 9325 4179 9310 4160 9309
TIME...MOT...LOC 2029Z 273DEG 19KT 4165 9321 

TORNADO...OBSERVED
HAIL...1.25IN

$$

Martin
991 
WWUS53 KDMX 192042
SVSDMX

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

IAC099-192051-
/O.EXP.KDMX.TO.W.0038.000000T0000Z-180719T2045Z/
Jasper IA-
342 PM CDT THU JUL 19 2018

...THE TORNADO WARNING FOR NORTHWESTERN JASPER COUNTY WILL EXPIRE AT
345 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire. A Tornado Warning 
continues for southern Jasper County until 400 PM CDT. 

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

LAT...LON 4163 9330 4173 9325 4179 9310 4160 9309
TIME...MOT...LOC 2041Z 278DEG 15KT 4164 9315 

$$

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, 3:22 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.