Alert archive / Iowa / Tornado Warnings in 2017

Tornado Warning 3, NWS Des Moines, IA

March 6, 2017Marion County, Warren County, Iowa

NWS Des Moines, IA issued this tornado warning at Mar 6, 2017, 7:21 PM CST for Marion County, Warren County, Iowa. It was in force for 24 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: Mar 6, 2017, 7:21 PM CST (01:21 UTC)
Expired: Mar 6, 2017, 7:45 PM CST
In force: 24 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties Marion County, IA, Warren County, IA

The radar

The Des Moines radar (KDMX), 64 km from the middle of the area, began a volume at 01:24 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

Time	Report	Where	Remark
Mar 6, 7:22 PM CST	TORNADO	2 Ssw Milo, IA	POSSIBLE TORNADO. BARN DESTROYED.
Mar 6, 7:30 PM CST	TORNADO	2 W Knoxville, IA	TRAINED SPOTTER REPORTS SMALL TORNADO ON THE GROUND SEEN DURING LIGHTNING.
Mar 6, 7:37 PM CST	TSTM WND DMG	4 Nw Knoxville, IA	STRUCTURE DAMAGE REPORTED BY MARION COUNTY EMERGENCY MANAGER. REPORT LOCATION AND TIME ESTIMATED VIA RADAR.
Mar 6, 7:40 PM CST	TORNADO	2 S Lake Red Rock, IA	POSSIBLE TORNADO - FRONT PORCH BLOWN OFF. WINDOWS BLOWN OUT. PINE TREES SHEARED OFF THE TOP. DAMAGE TOWARD ILLINOIS DR. .

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.

Issued	Product	Office	Lasted
Mar 6, 1:54 PM CST	Tornado Watch	SPC	8 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.4 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 39 J/kg
Mixed-layer CIN: -343 J/kg
Mixed-layer LCL: 1016 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 407 m²/s²
0-3 km storm-relative helicity: 489 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

496 
WFUS53 KDMX 070121
TORDMX
IAC125-181-070145-
/O.NEW.KDMX.TO.W.0003.170307T0121Z-170307T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
721 PM CST MON MAR 6 2017

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Western Marion County in south central Iowa...
  Southeastern Warren County in south central Iowa...

* Until 745 PM CST.

* At 720 PM CST, a severe thunderstorm capable of producing a tornado
  was located 10 miles west of Melcher-Dallas, or 10 miles southeast
  of Indianola, moving east at 55 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...
  Melcher-Dallas around 730 PM CST. 
  Knoxville, Knoxville Raceway and Lake Red Rock around 740 PM CST. 

Other locations impacted by this tornadic thunderstorm include Elk
Rock State Park, Lacona, Milo and Knoxville 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.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4116 9348 4125 9353 4148 9310 4119 9298
TIME...MOT...LOC 0120Z 251DEG 48KT 4124 9344 

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

$$

Small

2 follow-up statements

233 
WWUS53 KDMX 070127
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
727 PM CST MON MAR 6 2017

IAC125-181-070145-
/O.CON.KDMX.TO.W.0003.000000T0000Z-170307T0145Z/
Marion IA-Warren IA-
727 PM CST MON MAR 6 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CST FOR
NORTHWESTERN MARION AND EAST CENTRAL WARREN COUNTIES...
    
At 726 PM CST, a severe thunderstorm capable of producing a tornado
was located 7 miles northwest of Melcher-Dallas, or 11 miles
southeast of Indianola, moving northeast at 60 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...
  Pleasantville around 735 PM CST. 
  Knoxville, Knoxville Raceway and Lake Red Rock around 740 PM CST. 

Other locations impacted by this tornadic thunderstorm include Elk
Rock State Park, Milo and Knoxville 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.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4123 9340 4129 9345 4148 9310 4126 9301
TIME...MOT...LOC 0126Z 243DEG 51KT 4129 9335 

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

$$

Small

274 
WWUS53 KDMX 070135
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
735 PM CST MON MAR 6 2017

IAC181-070144-
/O.CAN.KDMX.TO.W.0003.000000T0000Z-170307T0145Z/
Warren IA-
735 PM CST MON MAR 6 2017

...THE TORNADO WARNING FOR EAST CENTRAL WARREN COUNTY IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has weakened. 
moved out of the warned area. Therefore, the warning has been 
cancelled.

A tornado watch remains in effect until 1000 PM CST for south central
Iowa.

LAT...LON 4128 9326 4133 9330 4146 9309 4137 9305
      4128 9302
TIME...MOT...LOC 0134Z 251DEG 48KT 4133 9320 

$$

IAC125-070145-
/O.CON.KDMX.TO.W.0003.000000T0000Z-170307T0145Z/
Marion IA-
735 PM CST MON MAR 6 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CST FOR CENTRAL
MARION COUNTY...
    
At 734 PM CST, a confirmed tornado was located near Knoxville
Raceway, or near Knoxville, moving east at 55 mph.

HAZARD...Damaging tornado and quarter size hail. 

SOURCE...Weather spotters 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...
  Knoxville and Lake Red Rock around 740 PM CST. 

Other locations impacted by this tornadic thunderstorm include Elk
Rock State Park and Knoxville Municipal 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.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4128 9326 4133 9330 4146 9309 4137 9305
      4128 9302
TIME...MOT...LOC 0134Z 251DEG 48KT 4133 9320 

TORNADO...OBSERVED
HAIL...1.00IN

$$

Small

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 6, 6:03 PM CST	Severe Thunderstorm Warning	DMX	Adair, Boone, Cass, Dallas, Greene, Guthrie and 1 more	42 min
Mar 6, 6:09 PM CST	Severe Thunderstorm Warning	DMX	Franklin, Hamilton, Hardin, Wright	51 min
Mar 6, 6:30 PM CST	Severe Thunderstorm Warning	DMX	Adair, Boone, Dallas, Madison, Polk, Story and 1 more	45 min
Mar 6, 6:31 PM CST	Severe Thunderstorm Warning	DMX	Cerro Gordo	29 min
Mar 6, 6:39 PM CST	Severe Thunderstorm Warning	DMX	Clarke, Union	51 min
Mar 6, 7:07 PM CST	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Polk, Story	53 min
Mar 6, 7:07 PM CST	Severe Thunderstorm Warning	DMX	Butler, Franklin, Grundy, Hardin, Marshall	37 min
Mar 6, 7:12 PM CST	Severe Thunderstorm Warning	DMX	Marion, Warren	48 min
Mar 6, 7:21 PM CST	Severe Thunderstorm Warning	DMX	Clarke, Lucas, Monroe	54 min
Mar 6, 7:31 PM CST	Severe Thunderstorm Warning	DMX	Decatur, Wayne	59 min
Mar 6, 7:32 PM CST	Severe Thunderstorm Warning	DMX	Black Hawk, Bremer, Butler, Grundy	58 min
Mar 6, 7:40 PM CST	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Poweshiek, Tama	54 min
Mar 6, 7:40 PM CST	Tornado Warning Tornado observed	DMX	Jasper, Mahaska, Marion	22 min
Mar 6, 7:43 PM CST	Tornado Warning	DMX	Jasper, Poweshiek	32 min
Mar 6, 7:51 PM CST	Severe Thunderstorm Warning	DMX	Mahaska, Marion	54 min
Mar 6, 7:56 PM CST	Tornado Warning Tornado observed	DMX	Wayne	34 min
Mar 6, 8:08 PM CST	Severe Thunderstorm Warning	DMX	Appanoose, Lucas, Monroe, Wayne	35 min
Mar 6, 8:22 PM CST	Tornado Warning	DMX	Appanoose, Wayne	23 min
Mar 6, 8:38 PM CST	Severe Thunderstorm Warning	DMX	Appanoose, Davis, Monroe, Wapello	41 min
Mar 6, 8:40 PM CST	Tornado Warning	DMX	Appanoose, Davis, Monroe, Wapello	35 min
Mar 7, 4:00 AM CST	Red Flag Warning	DMX	Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 45 more	14 hr
Mar 7, 10:40 AM CST	River Flood Warning	DMX	Black Hawk	4 days

Nearby

Tornado Warnings in Iowa, 2017 Every tornado warning in 2017 Tornadoes in 2017

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.